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Micro/Immuno > Exam 1 > Flashcards

Exam 1 Flashcards

1
Q

Parasites

A

Most diverse of all living microorganisms

Some are multicellular with their own organ systems

  • Complex life cycles needing multiple vertebrate and invertebrate hosts
  • Some depend on combinations of animals, Arthropoda, or crustacean hosts for survival
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2
Q

Fungi

A

Distinct from animals and plats- - considered Eukaryotic

Exists as yeast or molds. Most are free living-ubiquitous in nature

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3
Q

Bacteria

A

Smallest independently living cell-Cytoplasmic membrane surrounded by a cell wall.

No organelles.

Divides by binary fission.

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4
Q

Viruses

A

Smallest and simplistic infectious agent:

Protein coat surrounding nucleic acid

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5
Q

Obligate intracellular paraste

A

Require a host

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6
Q

Tissue Tropism

A

Only infect certain cells

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7
Q

Symbiotic

A

Benefit host

Ex. Gut bacteria

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8
Q

Commensalism

A

Neutral relationship to the host

Oral streptococci

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9
Q

Parasitic Relationship

A

Harm to host

Ex. tape worms

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10
Q

Residents

A

Established niche at a particular body site

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11
Q

Transients

A

Acquired from the environment and establish themselves briefly

(Inhibited by resident bacteria or by host immune system)

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12
Q

Carrier State

A

Potentially pathogenic organisms becomes resident

Ex. Streptococcus mutans

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13
Q

Babies are Sterile at birth

A

First microbe are from the mothers vagina

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14
Q

Bacteria colonize the locations______

A

Best suited to their physiology

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15
Q

Factors bacteria consider when determining to colonize

A
  • Nutrients
  • pH
  • Oxidation reduction potential
  • Resistant to locals antibacterial substances
  • Adhesion mediated affinity to receptor on host cells
  • Microbial interactions (who else is already there—competition and inhibition)
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16
Q

Skin Bacteria

A

Skin is dry slightly acidic aerobic environment

Flora is resitent to bactericidal effects of skin lipids and fatty acids

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17
Q

Bacterial skin flora is highest where

A

Armpits perineum and between toes

Moist skin

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18
Q

Proprionibacteria

A

Microaerophilic or anaerobic gram positive rods can grow on sebum and break down skin lipids to fatty acids

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19
Q

Mouth and Pharynx

A

Many bacteria

Species differ at different sites

Lots of streptococci- also high number of neisseria and Moraxella

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20
Q

Orthopharynx

A

Back of throat

Mostly Neisseria and Streptococci

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21
Q

Stomach and small bowel

A

PH 1-4

Few organisms more toward lower ileum

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22
Q

Colon

A

Most abundant and diverse microbiota

Feces 25%
-90% are anaerobes

Bactericides
Fusobacterium
Eubacteria
Clostridium

Remainder are facultative organisms like E. coli, enterococci, yeasts, and others

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23
Q

Anterior Nares

A

Similar to skin flora

Primary sites of carriage for pathogens- staph aureus

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24
Q

Nasopharynx

A

Similar flora as mouth

Site for carriage of pneumococci meningococci and haeophilus species

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25
Q

Larynx and lower respiratory tract

A

Protected in health by epithelial cilia and by movement of mucocilary blanket (only transient inhaled organisms in trachea and larger bronchi)

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26
Q

Accessory sinuses

A

Normally sterile protected by epithelium and estancias tubes

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27
Q

Urinary Tract

A

Bladder and upper urinary tract are sterile in health (except for about 1 cm of distal urethra)

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28
Q

Valiant tract

A

Flora is influenced by hormonal fluctuations and is different at different ages

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29
Q

Pre puberty vag

After menopause vag

A

Mixed nonspecific and relatively scanty-mostly organisms derived from skins flora and colon

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30
Q

Childbearing years vag

A

Mostly lactobacillus and some anaerobic gram neg rods, gram pos cocci and yeats

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31
Q

Due to estrogen _____is deposited in vaginal epithelia tissue which ______ feed on

A

Glycogen

Lactobacilli

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32
Q

Opportunistic infections

A

Can occur when microbes invade normally sterile locations or reduced host defenses or immunologic response results in invasion by flora

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33
Q

Exclusionary effect

A

Competition between normal flora and potential invades

Ex antibiotics wipe out normal flora, may give pathogens a competing advantage

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34
Q

Priming the immune system

A

Presence of microbiota is important for the development of our immune system

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35
Q

What separates a pathogen from commensal

A

Ability to attach to host tissues

Ability to adapt to new environemnt

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36
Q

Persistent and invasion do not necessarily lead to disease

A

Must cause damage to host

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37
Q

Host response to organism

A

Can cause damage or symptoms

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38
Q

Organisms must cause damage to host

A

Immune response
Bacteria Toxins
Enzymes

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39
Q

Bacteria can produce toxins that act on host cells

A

Diphtheria makes a toxin that inhibits host protein synthesis

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40
Q

bacteria can secrete enzymes that degrade host tissues

A

Cuases inflammations and facilitate spread

Collagenases
Pro teases
Hydrologic enzymes

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41
Q

Pathogens have ways to evade the immune response

A

Pathogens can

Attack immune effector cells

Secrete enzymes that degrade host effector molecules

Changes surface structure to evade the immune response

hide inside host cells

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42
Q

Competition between normal flora and potential invaders is an example of

A

Exclusionary effect

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43
Q

Which locations in the body is normally sterile

A

Accessory sinuses

Upper urinary tract

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44
Q

Specimen collection is critical

A

Otherwise can be challenging to distinguish normal flora or environmental contaminates from causative agent of disease

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45
Q

Direct specimen

A

Localized in an otherwise sterile location

-deep abscess or CSF

Highest risk and quality

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46
Q

Indirect sample

A

Must pass through a site containing normal flora

Expectorated sputum and voided urine

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47
Q

Sample from site with normal flora

A

Pathogen and nonpathogenic flora are mixed (throat and stool)

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48
Q

Issues with sample collections

A

Time between sample collection and isolation is critical (3 to 4 hours)

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49
Q

Viability

A

Some organisms don’t survive long outside the body

-Gonorrhoea requires transport media

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50
Q

Bacterial growth

A

After collection can be particularly problematic for enteric gram negative rods and if found in low numbers

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51
Q

Transport Media

A

Buffered fluid or semisolid media

Designed to maintain a neutral pH and prevent sample from drying out

Contains minimal nutrients to minimize growth of bacterial contaminants

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52
Q

Primary Stains

A

Crystal Violet

Carbon fuschsin

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53
Q

Crystal violet

A

Gram stain

Stains ribonuclear proteins inside cell

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54
Q

Carbon fuchsia

A

Acid fast stain

Stains myucolic acid of acid fast bacteria

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55
Q

Counter Stains

A

Safranin

Methylene blue

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56
Q

Safranin

A

Gram stain

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57
Q

Methylene blue

A

Acid fast stain

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58
Q

Gram Stain

A

Gram positive = purple

Gram negative=pink

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59
Q

Acid fast Stain

A

Acid fast bacteria=red

Non acid fast bacteria= blue

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60
Q

Differential Media

A

Distinguish between closely related species of bacteria based on characteristics on media.

Color change or colony morphology

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61
Q

Selective Media

A

Used to select (isolate) specific groups of bacteria

-Media might contain chemical substances that inhibit the growth of one type of bacteria while permitting growth of another

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62
Q

Blood agar is an example of a _______type of media that is used to differentiate between closely related organisms based on growth characteristics

A

Differential media

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63
Q

Culture characteristics

A

Nutritional requirements pigment production etc

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64
Q

Biochemical tests

A

Ability to attack various substrates or produce metabolic by products

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65
Q

Toxin Prodcution and pathogenicity

A

Only conducted in specialized labs

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66
Q

Antigenic Structure

A

Serology-ability to interact with antibodies

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67
Q

Genomic Structure

A

DNA sequences relatedness as determined by homology or direct sequence comparison

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68
Q

Precipitation reactions

A

When antibody and antigen interact they form a precipitate

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69
Q

Hemagglutination

A

Cross linking of red blood cells

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70
Q

Hemagglutination

A

Some viruses bind to red blood cells causing cross linking

-can be neutralized by antibodies from patients blood against suspected virus

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71
Q

Mononucleosis test

A

Uses horse or sheep red blood cells which cross react to antibodies against EBV resulting in agglutination of red blood cells

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72
Q

DNA Hybridization and probes

A

Target DNA is bound to a membrane and complementary DNA probe attached to a color producing enzyme is reacted with membrane. Signal is produced only if DNA finds its target

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73
Q

Polymerase Chain Reaction

A

DNA specific primers are used to amplify a target DNA molecule. A product signifies target is present in sample

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74
Q

Cocci

A

Spheres

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75
Q

Bacilli

A

Rods

Straight or bent

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76
Q

Spirilla

A

Spirals

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77
Q

All bacteria have

A

DNA
Cytoskeleton
Plasma membrane
Cell wall

Bacteria DO NOT have organelles

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78
Q

Nucleiod

A

Region in cytoplasm where the genomic DNA is located.

Most bacteria have a single circular supercooled double stranded DNA chromosomes

Attached to cell membrane and central structures of the cell

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79
Q

Cytoplasm

A

Densely packed with ribosomes (70S)

Cytoskeleton-provides shape to cell

Inclusion bodies-granules that contain reserve materials

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80
Q

Cell Wall and its function

A

Rigid structure that surround the plasma membrane

Provides physical protection, lysis, barrier against toxic agents, determines cell shape

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81
Q

Gram Positive Bacteria

A

Many Layers of peptidoglycan

Teichoic Acid

Specific cell wall components

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82
Q

Teichoic Acid

A

is a polymer of glycerol phosphate or ribitol phosphate and various sugars, amino acids-function unknown

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83
Q

Lipoteichoic acid

A

Variation of teichoic acid that anchors cell wall to membrane through glycolipids

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84
Q

Peptidoglycan (murein) Structure

A

Peptidoglycan consists of a linear glycan chain (backbone) of two alternating sugars, N-acetyleneglucosamine and N-actelymuramic acid. A peptide side chain and a pentylglycine interbred gets form crosslinking between the glycan chains

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85
Q

Gram - bacteria peptidogluycan structure

A

Has a diaminopimelic acid instead of lysine

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86
Q

Lysozyme

A

Present in tears, saliva, and mucus (innate immune system)

-Cleaves beta 1-4 glycosidic bonds between NAG and NAM polysaccharides of peptidoglcuan

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87
Q

Penicillin

A

Antibiotic affective against Gram positive bacteria

Blocks cell wall synthesis by inihibiting cross links

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88
Q

Gram Negative Cell Wall

A

Two membranes and thing single layer of peptidoglycan in between

Impermeable outer membrane

Periplasmic space

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89
Q

Impermeable outer membrane (gram - cell wall)

A

Porins that allow diffusion of hydrophilic solute molecules and excludes harmful molecules from the environment

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90
Q

Periplasmic space (gram - cell wall)

A

Contains a gel like matrix proteins important for transport chemotactic and hydrolyctic roles

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91
Q

Lipopolysaccharide

A

Endotoxin protection against phagocytosis

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92
Q

Mycoplasma

A

NO cell-exception

Smallest known bacterial species

Membrane contain a sterile like molecule

Usually inhabit osmotically protected environments

Parasitism hsot cells-walking pneumonia

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93
Q

This portion of LPS makes up the toxin

A

Lipid A

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94
Q

TA is unique to which structures

A

Gram positive cells

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95
Q

Peptidogluycan contains

A

A glycan backbone

Glycine interbrdige
A tetrapeptide side chain

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96
Q

LPS Components

A

O antigen polysaccharide side chain

Core polysaccharide

Lipid A-toxin

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97
Q

Capsule

A

A thick hydrophilic gel that surrounds the bacterial cell. Usually polysaccharides. Some are polypeptides if discrete layer=capsule
If amorphous=slime layer

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98
Q

Purpose of capsule

A

Protects bacteria from immune system

Nutrient source-can be digested by enzymes

Presence or absence is dependent on growth conditions

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99
Q

Flagella

A

Found in gram + and -

Large and rotating helical protein

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100
Q

Fimbriae

A

Small hair like projection function in attachment

+ and -

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101
Q

Pili

A

Longer and thicker than fimbriae function in attachment and or DNA transfer.

Sex pili-transfer DNA between gram - bacteria

Composed of Pailin protein

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102
Q

Spores

A

Resistant to heat can germinate after centuries

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103
Q

Difference between prokaryotes (bacteria) and eukaryotes

A

Speed- much faster metabolism
Versatility-bacteria use a greater variety of compounds
Simplicity-no organelles
Uniqueness-some biosuntheitc process are unique to bacteria

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104
Q

Catabolism

A

Breakdown of carbon source into atp

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105
Q

Anabolism

A

Uses energy to synthesize and assemble subunits of macromolecules

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106
Q

Embedded Meyerhof glycolysis pathway

A

ATP, metabolic intermediate and pyruvate—> fermented or TCA cycle

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107
Q

Penrose phosphate Pathway

A

Generates NADPH and Penrose’s and ribose 5 phosphate

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108
Q

Kern’s Cycle

A

Generates ATP from oxidative phosphorylation

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109
Q

Facilitated diffusion

A

Based on concentration gradient using carrier protein

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110
Q

Active Transport

A

Soluble binding proteins binds the substrate

Transporte complex cleaves ATP providing energy for transport

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111
Q

Fermentation

A

Transfer of electrons and protons via NAD+ directly to an organic acceptor to make characteristic end products

Substrate-level phosphorylation

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112
Q

Respiration

A

Substrate oxidation coupled to transport of electrons through a chain of carriers in the membrane to an acceptor molecule. More efficient than fermentation

Oxidative phosphorylation

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113
Q

H2o2

A

Hydrogen peroxide
When electrons and protons are transferred to O2 as final acceptor

Catalase or peroxidase

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114
Q

o2

A

Superoxide anion

Produced as intermediate when O2 is reduced

Superoxide dismutase

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115
Q

Organisms that lack catalase and superoxide disumates are_____

A

Strict anaerobes

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116
Q

Obligate Aerobes

A

Require O2 to grow

Respiration only

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117
Q

Obligate anaerobes

A

Can not grown when O2 is present

Fermentation only

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118
Q

Faculative Aerobes

A

Contains genes for fermentation and or respiration can grow with or without O2

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119
Q

Aerotoleratn anaerobes

A

Anaerobic metabolism-fermentation but can tolerate oxygen

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120
Q

Acidophiles

A

Optimal growth at low pH

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121
Q

Alkaliphiles

A

Optimal growth above pH 7

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122
Q

Neutrophils

A

Optimal growth at neutral pH

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123
Q

Halophile

A

Require high concentration of salt for growth

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124
Q

Osmophile

A

Capable of growth in high sugar concentrations

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125
Q

thermophile

A

Organism that can grown between 45 and 122 c

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126
Q

Doubling time

A

Time it takes a single bacteria to divide in tow

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127
Q

Phase of Growth

A

Lag phase

Exponential phase

Stationary phase

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128
Q

Chromosomal Replication

A

Initiation
Elongation
Termination

Bidirectional
Semi conservative

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129
Q

Rate of DNA replication is determined by

A

Rate of initiation

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130
Q

Base Subsitution

A

When a nucleotide is changed

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131
Q

Insertion

A

When a nucleotide is inserted

Frame shift

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132
Q

Deletion

A

When nucleotide is deleted

Frame shift

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133
Q

Nonsense

A

When a nucleotide change results in a stop codon

Truncated protein

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134
Q

Missense

A

When a nucleotide change results in a amino acid change

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135
Q

Duplication

A

When DNA sequence is abnormally copied

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136
Q

Double stranded break model of homo recombination

A

Donor DNA must have large region of identical nucleotide sequence to host chromosome

Recipient cell must have recA gene which controls the entire process

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137
Q

Natural transformation

A

Ability to take DNA from the environment

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138
Q

Conjugation

A

Transfer of plasmid DNA through sex pili

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139
Q

Transduction

A

Bacteria phage accidentally inject bacterial DNA into host bacterial cell

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140
Q

Transposable elements

A

DNA that can insert or excise itse self from the chromosomes or plasmid

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141
Q

Bacterial Transformation

A

Once in the cell DNA either:
gets degraded by nuclease used for raw material

Integrated into he chromosome via recombination pathway

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142
Q

Natural transformation mediated by______

A

Quorum sensing-peptide pheromones produced by other bacteria are sensed by bacteria and tun on genes for competence

Ability to take DNA from the environment

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143
Q

Conjugation

A

Transfer of DNA usually by sex pili

plasmid DNA gets degraded and recombined with chromosome

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144
Q

Transposable ELemnts

A

DNA that insert or excise itself

If is elemnts insertt into the coding sequence of a gene they cause a mutattion

Larger transposing carry genes for antibiotic resistance or virulence genes

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145
Q

Bacterial genetic regulation

A

Making mRNA and protein is energetically expensive
-bacteria must tightly control expression of genes so that only the proteins needed for a particular condition are expressed

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146
Q

Bacteria can sense their environment through quorum sensing

A

Control when certain proteins are made

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147
Q

Promoter Elements

A

RNA polymerase binds to promoter located upstream of gene start codon

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148
Q

Virulence Factors

A

Genes directly related to ability of bacteria to cause disease-knockout of these genes reduces or eliminates virulence

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149
Q

Some genes are

A

Essential others are dispensable

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150
Q

Mammalian Immune response

A

Innate or adaptive

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151
Q

Innate

A

No specific
Rapid inflammatory response
Very broad

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152
Q

Adaptive Immune Response

A

Targeted to a specific antigen
Delayed response
Memory

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153
Q

After birth, hematopoietic occurs in the bone marrow

A 
Platelets
RBC
WBC
-myeloid
-lymphoid
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154
Q

Myeloid Lineage: Granulocytes

A

Neutrophils
Basophils
Eosinophils

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155
Q

Neutrophils

A

Most abundant leukocyte in circulation

Also called polymorphonuclear leukocyte

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156
Q

Basophils

A

Involved inflammatory and allergic responses

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157
Q

Eosinophils

A

Involved in combating parasitic infections and allergic response

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158
Q

Myeloid Lineage: Phagocytes

A

Monocytes
Macrophages
Conventional Dendritic Cells

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159
Q

Monocytes

A

Phagocytosis

Circulate in the blood then enter tissue to differentiate into macrophage or dendritic cell

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160
Q

Macrophages

A

Phagocytosis cells reside in all tissues

Antigen presenting cell

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161
Q

Conventional Dendritic Cells

A

Similar function to a macrophage

Can activate naive T cells

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162
Q

Mast Cells

A

Contain preformed granules but not a granulocyte

Involved in defense against parasitic worms and ALLERGIC response

163
Q

Lymphoid Lineage

A

T Lymphocytes
B lymphocytes
NK cells

164
Q

T Lymphoytes

A

Cytotoxic (CD8)
Helper (CD4)
Suppressor regulatory

165
Q

B Lymphocytes

A

Differentiate into plasma cells Antibody production

166
Q

Natural Killer Cells

A

Involved in innate Immune Response (NOT antigen specific)

167
Q

Antigen

A

Ag molecule capable of inducing an immune response

168
Q

Antibody

A

An protective protein made by B cells that RECOGNIZES 1 SPECIFIC Ag

169
Q

Cell Communication

A

Secretion of Signaling molecules

  • Cytokines
  • Chemokines

Activation of receptors

  • Internal
  • External
170
Q

Cytokines

A

Group of secreted proteins that are involved in regulating the innate and adaptive immune responses

Activation/proliferation

Inflammation

Cell migration and movement

Immunosuppression

171
Q

Lymphoid Tissue: Follicle

A

Organized clusters

172
Q

Lymphoid Tissue: Patch

A

Many follicles grouped together

Peters patches

173
Q

Lymphoid Tissue: organ

A

Groups of follicles that are encapsulated

174
Q

Primary Lymphoid Tissue

A 
Bone marrow (hematop.)
Thymus (T cell differentiation and proliferation)
175
Q

Secondary Lymphoid Tissues

A

Lymphoid Nodes
Spleen
MALT (NALT, BALT, GALT)
Skin associated Lymphoid Tissue (SALT)

176
Q

Immune Cell movement

A

Follow chemokines

Tethering then start rolling until activation. This slows them downs hits the brakes. Then they transmigrate through the cells.

177
Q

Can Lymphocytes recirculate

A

Yup

178
Q

Importance of Innate Immune Response

A

Helps maintain physical and chemical barriers against microbial entry

Initial response to pathogen

Removal of damaged cells

Initiates tissue repair and wound healing

Stimulates adaptive immune response

179
Q

Innate Immunity

A

NONSPECIFIC

Response can be triggered by infectious or non infection material

Innate response helps coordinate the adaptive immune response and in turn the adaptive immune response helps to boost the innate response

180
Q

Innate Mechanisms

A

Inducible

Noninducible

181
Q

Non-Inducible Innate Mechanisms

A

Physical

  • skin
  • mucus
  • commensalism bacteria
Chemical
-lysozyme
-antimicrobial peptides 
—defensins 
—cathelicidin
182
Q

Inducible Innate Mechanisms

A 
Innate Immune Cells
Neutrophils
Macrophages
Dendritic cells
NK cells
Mast cells

Neutralizing antibodies
Secretory IgA

183
Q

How do we activate our innate immune cells

A

NOT specific

They can recognize non-self cells and danger signals through the recognition of certain patterns

184
Q

PAMPs: Bacterial

A

Pathogen associated molecular patterns

Bacterial-Lipopolysaccharide, peptidoglycan CpG flagellum

185
Q

PAMPs: Viral

A

Double stranded RNA, Single stranded RNA

186
Q

PAMPs: Fungal

A

Chitin Zymosan

187
Q

Pattern Recognition Molecules

A

PAMPs
DAMPS (damage )
Pattern recognition Receptors (PRRs)

188
Q

DAMPs

A

Complement productions-C3b C4b

Reactive oxygen intermediates- H2O2, OH, O2

Stress induced molecules-heat shock proteins, chaperone proteins, lactose rein, hyaluronic acid fragments

Metabolic products-potassium, ATP, uric acid, cholesterol saturated fatty acids

Nucleus acids-mRNA, ssRNA, chromatin components

Exogenous substances-Alum, Silica, asbestos

189
Q

PRRs

A

Can be cell associated or unassociated

Toll like
NOD
RIG
C type
Scavenger
Collections
190
Q

Toll Like Receptors

A

Membrane Bound Receptors

TLR1:TLR2

TLR2: TLR6

191
Q

TLR2

A

Bacterial Peptidoglucan

192
Q

TLR4

A

LPS

193
Q

TLR5

A

Bacterial Flagellin

194
Q

TLR1

A

Bacterial lipopeptides

195
Q

TLR6

A

Bacterial lipopeptides

196
Q

TLR9

A

CpG DNA

197
Q

TLR3

A

dsRNA

198
Q

TLR7

A

SsRNA

199
Q

TLR8

A

ssRNA

200
Q

Toll like receptors are highly expressed in

A

Dendritic cells
Monocytes/macrophages
Neutrophils

201
Q

Toll Like Receptors

A

Activation leads to:

DC maturation
Stimulation of antigen presentation
Phagocytosis 
Cellular activation
Productions of proinflammatory cytokines/chemokines
202
Q

NOD-like Receptors

A

Free cytoplasmic receptors

Can recognize PAMPs and DAMPs

Some NLRs can form large complexes called inflammasomes

  • leads to cascade 1 activation
  • needed to fully activate IL-1 and IL-18

NLR activation can also lead to apoptosis

203
Q

Toll-like receptors and NOD Like Receptors often

A

Work together

204
Q

Retinoids Acid inducible Gene 1: RIG receptors

A

Cytoplasmic receptors

Recognize Viral RNA

Activation leads to the production of antiviral proteins
-interferon alpha and beta

205
Q

C-Type Lectin Receptors

A

Lectin:proteins that bind to carbs

CLRs recognize carbs based DAMPs and PAMPs

Group 1-Mannose

Group 2- Asialgycoprotein

206
Q

Scavenger Receptros

A

Bind to lipids

-Can be from host or foreign

207
Q

Collectins

A

Collagen domain fused to a Lectin domain

Found in blood

Upon binding their ligand (carbs) they can:
Activate complement
Phagocytosis
Agglutination

208
Q

Complement Activation

A

Serum based mechanism to destroy pathogens

NO cells involved (30proteins)

Outcomes:
Pathogen destruction
Pathogen ospsonization
Clearance of immune complexes
Creation of peptides to help the inflammatory response
209
Q

3 ways to activate complement

A

Classical pathway
Lectin Pathway
Alternate pathway (C3 hydrolysis)

All activate C3b

Results in lysis of pathogen

210
Q

Which of the 3 pathways is very delayed

A

Classical pathway

211
Q

Steps of complement activation

A 
C3a: inflammation
—->
C3b: opsoniaztion and phagocytosis 
—->
C5a: INflammation

—> lysis of microbe

212
Q

Other Roles of C3b

A

Solubilization of Immune complexes

Virus neutralization

213
Q

Late Stage Complement Activation: MAC complex formation

A

C5b binds to C6 and C7

—> binds to membrane—>C8 binds to complex—>c9 bind and polymerizes—> form a pore

214
Q

Macropinocytosis

A

Engulfment of fluid and macromolecules

215
Q

Clathrin mediated endocytosis

A

Similarly to macropinocytosis but is Receptor mediated

216
Q

Phagocytosis

A

Ingestion of large Extracellular particles, receptor mediated

217
Q

Which 2 cells can phagocytosis a pathogen

A

Neutrophils and macrophages

218
Q

Commensalism

A

Coexist neutral relationship

219
Q

Opportunistic pathogens

A

Take advantage of breaks in host defense

220
Q

Primary pathogens

A

Cause disease on their own

221
Q

Pathogen

A

A bacterial species able to cause disease when present with favorable circumstances

222
Q

Pathogenicity

A

Ability of any bacterial species to cause disease in a susceptible human host

223
Q

Virulence

A

Presumes pathogenicity but allows expression of degrees from to extremely high

224
Q

Primary pathogens must

A

Breach human cellular and an atomic barriers

Avoid host defenses

Transmission (ability to replicate )

225
Q

Modes of pathogen transmission

A 
Airborne 
Food
Vector
Water
Blood
226
Q

Inducible innate immunity

A 
PAMPs
DAMPs
AMPs
IgA
Complement
Phagocytes
227
Q

Non-inducible innate immunity

A 
Lysozyme
Cilia
Stomach acid
Mucus
Intact skin
Commensalism bacteria
Flushing of urinary tract
Sequestrion of iron
228
Q

Three stages to establish an infection

A

Adherence
Colonization
Damage

229
Q

Entry: pathogen breach host innate defense

A

Many pathogens have unique mechanisms that allow them to get past innate defenses

  • attachment to unique host molecules
  • IgA protease
  • Inherent restraint to lysozyme
  • Siderophores
230
Q

Entry adherence

A

Some bacteria can attach to host cells through specific pili or receptors

Many have multiple attachment mechanisms

231
Q

Beating Host Innate Defenses

A

Some pathogens have enzymes that degrade immunoglobulin

sIgA protease

232
Q

SIgA

A

Secreted into mucus prevents pathogens from adhering to mucosal surfaces

233
Q

Beating Host Defense:Lysozyme

A

Outer membrane of gram - bacteria prevents penetration of lysozyme

234
Q

Beating Host Defense: Siderophores

A

Bacteria need iron to grown ECF contains very low levels.

Pathogens produce siderophores which compete with human proteins for available iron

235
Q

Phagocytosis avoidance

A

Invade and survive inside host cells

Avoid contact with phagocytes

Inhibit phagocytic engulfment

236
Q

Pathogens come in 3 varieties

A

Extracellular,
facultative intracellular bacteria,
obligate intracellular bacteria

237
Q

Extracellular pathogen

A

Not able to invade host cells

238
Q

Facultative intracellular bacteria

A

Can invade host cells but can also serve in Extracellular environment

239
Q

Obligate intracellular bacteria

A

Require host cells for survival

240
Q

Invasins

A

Any protein produced by bacteria that allows the bacteria to invade no phagoycitc host cells or host tissues

  • effector proteins
  • secreted enzymes
  • proteins that bind integrins
241
Q

Effector proteins

A

Injected by a type III secretion systems allow invasion

Promote invasion of host cell or suppress host cell defenses

242
Q

Secreted enzymes

A

Disrupt tight junction between cells allow invasion

243
Q

Proteins that bind integrins

A

On host cell and facilite uptake and invasion

244
Q

Invasions: Endocytosis

A

Endosome usually fuse with lysosomes creating an endolysome

Invasive pathogens must disrupt normal cell vehicle trafficking

Or

Be able toe scape the endosome into the cytoplasm

  • Modify endosome
  • Escape endosome
  • Block endosome fusion
245
Q

Avoid contact with phagocytes

A

Invade locations not surveillance by phs

Avoid inflammatory response

Inhibit phs chemotaxis

Something pathogens bind host molecules to hide antigenic surface no-opsonization by antibodies minimizes phs

246
Q

Inhibit Phagocytosis

A

Some bacteria can avoid engulfment by phs through specialized surface adaptations

247
Q

Antigenic variation

A

Varying surface antigens prevents PAMPs from being recognized

248
Q

Induction of apoptosis of host cells

A

Some pathogens can activate apoptosic pathways in phs killing them

Prevents alarm bells and decreases defenders

249
Q

Exotoxins

A

Bacterial secreted proteins-local and systemic if in blood

Have host cell specifity
Can be inhibitory stimulators or fatal

B subunit binds host cell surface receptor
A subunit gets transported by direct fusion or endocytosis into host cell

250
Q

Endotoxin

A

Lipid A portion of LPS of gram - bacteria stimulates cytokines release

251
Q

Hydrolytic enzymes

A

Facilitate tissue invasion

252
Q

Superantigen

A

Exotoxins stimulate massive cytokines secretion

253
Q

Inflammation

A

Prolonged immune response to bacteria can damage host tissues

254
Q

Membrane active Exotoxins

A

Creates pores in host cell membrane

Causes loss of cell integrity and leakage through pore (DAMPs)

255
Q

Biofilm

A

Multicellular community of bacteria attached to a surface encased in a self produced Extracellular polymer substance

256
Q

Quorum Sensing

A

Form of bacterial communication-allows bacteria to coordinate and regulate gene expression in response to size of population or environmental cues.

257
Q

Autoinducer Molecule

A

Secreted by all members of a species-binds to a transcriptional regulator and signals transcription of target genes when the autoinducer molecule reaches a threshold

258
Q

Quorum sensing can regulate

A 
Can regulate expression of 
Toxins
DNA uptake
Adherence factors
Secretion systems
Biofilm formation
259
Q

Oral cavity is dominated by

A

Streptococci

S. Minis is found in every location in mouth

Sanguis is and gordonni were found on tooth surface

260
Q

Major species in plaque

A

S sanguinis
S gordonii
S Oralia

(Mitis major group)

(Mutans minor)

261
Q

Non Specific Plaque Hypothesis

A

Dental caries results from a perturbation in bacterial populations due to a disruption in the environment rather than a specific bacteria or infectious agent

262
Q

Treatment of Dental Caries

A

Probiotics-commensalism bacteria associate with health

263
Q

S. Oligofermentans

A

Metabolizes lactic acid

264
Q

S. Austrtalis

A

Arginoluytic strains

Produce NH3 which raise plaque pH

265
Q

S. Gordonii

A

Degrades CSP from s mutans

266
Q

Periodontitis

A

A biofilm induced chronic inflammatory disease which affects the tooth supporting tissues or periodontist and also increases a patients risk of developing atherosclerosis diabetes and rheumatoid arthritis

267
Q

Socransky’s Red Complex

A

Periodontal most common bacterial species

Porphyromanos gingivalis
Tannerella forsythia
Treponema denticola

268
Q

P. gingivalis virulence factors

A

Capsule-antiphagocytic

Gingipains-degrades Extracellular matrix

Fimbriae-bind to host cell

LPS-Lipid A modification

269
Q

S. Mutans

A

Can contribute to disease because it is acidogenic (lowers mouth pH) acid tolerant (growth at low pH) has glycosyltransferases and glycan binding proteins

270
Q

Autophagy

A

is the process of cellular recycling. It is used for the clearance of intracellular pathogens such as viruses and some types of bacteria and parasites

271
Q

Immunoglobulin Proteins

A

(Antibody)

Large glycoproteins that recogonize specific Ag

  • Membrane bound
  • Nonmembrane bound (Ab)

A B cell can only produce one kind of heavy chain and light chain

272
Q

Papain

A

Can cleave heavy and light chains to view immunoglobulin

273
Q

Variable region vs Nonvariable region

A

Both heavy chain and light chain have variable region where Antigen binds

274
Q

Immunoglobulins are flexible

A

Can move side to side and twist better chance of making contact

275
Q

Hypervariable region

A

Amino acid sequence demonstrate extreme variability between different Ig molecules

  • occurs in 3 areas of variable region
  • 5-7 amino acids long
  • Enormous antigenic diversity
276
Q

Constant Region

A

Very little variation
There can be minor differences that can affect the
-size
-charge
-solubility
-and structure of an Ig molecule giving rise to different isotopes

277
Q

Light Chain Isotypes

A

Kappa
Lambda

Help contribute to diversity but not function

278
Q

Heavy Chain Isotypes

A 
IgM-Mu
IgD-Delta
IgG-Gamma
IgE-Epsilon
IgA- Alpha

There can also be subclasses

279
Q

Isotype Switching (class switching)

A

When a naive B cell first encounters Ag it will produce IgM

Genetic rearrangements of the constant heavy region can lead to class switching

280
Q

Which is an example of light chain isotype

A

Kappa

281
Q

Structural Isoforms

A

Membrane bound
-Found on B cell plasma. Also called B cell receptor. Little piece at bottom transmembrane

Secreted
-found in blood

Secretory
-Secretory portion found in tears or mucous don’t have transmembrane and

282
Q

Polymeric Immunoglobulins

A

IgM -5 bind together

IgA- 2 bound together

Both are secreted form

283
Q

J Chain

A

Keeps polymeric immunoglobulins together

284
Q

B Cell Receptors Complex

A

Always associates with IgAlpha and IgBeta to produce response by creating signaling pathway

285
Q

Introns

A

No coding

286
Q

Exons

A

Coding

287
Q

Immunoglobulin Genes: Variable Regions

A

Variable Region
Diversity Region
Joining Region

*The Light Chain does not have D segment

288
Q

V(D)J recombination

A

Somatic recombination characterized by random rearrangement of VD and J segments of the variable region

Occurs in EVERY naive B cell

Permanent, allows diversity, does not involve Ig isotype has to do with antigen binding

289
Q

Antigenic Determinant

A

Epitope

Antigens do not necessarily bind to the entire Ag binding site.

Tends to make most contacts with CDR3 of Ig H chain
-possible to undergo conformational changes to better bond

290
Q

During V(D)J recombination the constant region removes introns which contributes to antibody diversity: True or False

A

False

Not the constant region the variable region

291
Q

Affinity

A

The strenght of the non-covalent association between one antigen binding site and one antigenic epitope

292
Q

Avidity

A

The overall strenght of the bond between multitalented Ab and multitvalent Ag
-more chances of binding

293
Q

Cross Reactivity

A

Occurs when one epitope is shared by 2 Ag or when two epitope on separate Ag are similar in Structure

294
Q

Which of the following would have the greatest avidity

A

IgM

295
Q

B Cell Development occurs in 2 stages

A

Maturation

Differentiation

296
Q

Where does B cell Development occur

A

Occurs in bone marrow only

Or

Begins in bone marrow then finishes in secondary lymphoid organ

297
Q

B cell maturation

A

Begins in the bone marrow and ends in the periphery.

IN this stage B cells are naive

298
Q

B cell differentiation

A

Begins once a B cell recognizes its specific Ag, ends with the generation of Ag specific plasma cells and memory cells

299
Q

B cell maturation steps in bone marrow

A

Stem cell—early pro B—- late pro B——Pre B cell—-immature B cell

300
Q

Pro-genitor B cells

A

First hematopoietic Cells that are recognizable as B cells

Immunoglobulin genes are still in their germ line configuration

301
Q

Pre-cursor B cells

A

V(D)J recombination of both chains is complete

Late Pre B cells will produce membrane bound IgM plug IgAlpha/beta

302
Q

Immature B cells

A

Development of Central Tolerance

Immature B cells get one last chance to rearrange the Ig loci in a process called receptor editing 2% survive selection

303
Q

How could you distinguish between a pro B cell and pre B Cell

A

Pre B cells begin to express a membrane immunoglobulin

304
Q

Transitional B Cells

A

Bone Marrow—>Blood—>Spleen

305
Q

Transitional Type 1 B cells

A

Red purple then PALs

306
Q

Transitional Type 2 B cells

A

Express both IgM and IgD

Follicular B Cells
Marginal Zone B cells

307
Q

Mature B Cells

A

Express both IgM and IgD

Cannot undergo further V(D)J rearrangement
Considered naive

308
Q

B Cell antigens

A

T dependent
-usually follicular B cells

T-Independent
-marginal zone B cells

309
Q

B Cell activation

A

This process occurs in secondary lymphoid tissues

310
Q

B Cell Activation Steps: Signal 1

A

Binding of multiple Ag to BCR. signal transmitted via IgAlpha/Beta

311
Q

B Cell Activation Steps: Signal 2

A

Interaction with activated Ag specific T helper cell

312
Q

B Cell Activation Steps: Signal 3

A

Cytokines stimulation by activated Ag specific T helper Cell

313
Q

Plasma Cells: Long lived

A

Long Lived- Can live for months

Arise from germinal centers then migrate to the bone marrow, lymph node medulla or red pulp of spleen to secrete IgG, IgA or IgE

314
Q

Plasma Cells: Short Lived

A

6-10 days

Secrete low affinity IgM
Can be made in response to Ti and Td antigen

315
Q

What do Antibodies do

A

Aid with clearance and or destruction of antigen

1) Neutralizaiton
2) Classical Complement activation
3) Opsonization
4) Antibody dependent cell mediated cytotoxicity

316
Q

Opsonization

A

Coating of an antigen with host protein to trigger phagocytosis
-IgG1, IgG3

317
Q

MHC

A

Major histocompatability complex

The genes are polygenic extremely polymorphic and tend to be codominately expressed

Molecules are necessary to present Ag to T cells

318
Q

MHC Class I

A

Present on all nucleated cells

Generally displayed endogenous peptides (self peptide)

Present peptides to CD8+ T cells-ALWAYS (killer T cells)

319
Q

MHC Class II

A

Expressed on professional antigen presenting cells

Generally display exogenous peptides

Presents peptides to CD4+ T cells**

(2+2=4)

320
Q

Antigen Presenting cells and what MHC class do they express

A

B cells
Dendritic cells
Macrophages

MHC class II

321
Q

MHC II is associated with what

A

Peptides 13-18 amino acids in length

Exogenous peptides

322
Q

Antigen Processing

A

The break down of macromolecules into smaller fragments in order to prepare them for presentation to a T cell

323
Q

4 Major pathways of Ag processing

A 
Exogenous-MHC class II
C4
Endogenous-cell recycling anything in cell MHC class I
C8

Cross Presentation-

Autophagic-internal pathogen detected cd4 activation

324
Q

Dendritic Cells: Antigen presenting

A

High MHC 2

High capable of cross presentation
Activate Naive T cells
Activates effector memory T cells

325
Q

Macrophages: APCs

A

High MHC 2
Somewhat cross presentation
No naive T
Yes memory T

326
Q

B cells: APC

A

High MHC2

Yes/no cross presentation
No T naive
Yes memory T

327
Q

Dendritic cell APC process

A

Activates Navie T cell: differentiation into effector T cells

328
Q

Macrophage APC process

A

Effector t Cell activation

Cell mediated immunity

329
Q

B Cell APC process

A

Effector T cell activation

B cell activation and antibody production

Humoral Immunity

330
Q

Exogenous Pathway

A

1) uptake of extracellular proteins
2) Endosomal vesicles degrade antigen via lysozyme
3) MHC Class II molecules are assembled in the ER—Golgi—Endosome

Invariant chain is needed to keep alpha and beta chains stable

Lysine enzymes help break down invariant chain leaving CLIP molecule in peptide binding cleft. HLA-DM helps to remove CLIP so Ag can bind

MHC2 peptide travel via endosome to cell curface to present Ag to CD4 T cell

Macrophages B cells Dendrtiic cells use this

331
Q

Endogenous Pathway

A

Internal proteins are degraded via proteasome then transported to ER via TAP

MHC I is synthesized and loaded in the ER

MHC I/Ag is transported to golgi then plasma membrane to present to CD 8 T cell

332
Q

Cross presentation

A

APC ingests and processes virally infected cells. Viral proteins enter the cytoskeleton and is processed via endogenous pathway to activate a CD8 T cell via MHC 1

333
Q

Class II must be degraded by

A

Lysozyme

334
Q

Class I must be degraded by

A

Proteasome

335
Q

Cross Reactivity

A

Reactions to something it was not suppose to react with

336
Q

T Cell Receptor

A

Responsible for Ag recognition

337
Q

AlphBeta T cells

A

Recognize MHC/Ag reside in secondary lymphoid Tissue

Must be able to recognize both

338
Q

GammaDelta T cells

A

Recognize processed/unprocessed ligand

Intra epitheal tissues

Tons in gut

339
Q

CD8

A

Cytotoxic cell

MHC 1

340
Q

CD4

A

Helper T cell

MHC 2

341
Q

What are the functions of CD4 and CD8

A

Signal transduction

342
Q

T Cell Development

A

Begins in bone marrow

VDJ recombination of variable region of TCR leads to antigenic diversity
At one point cells express both CD4 and CD8
Undergo positive and negative selection

343
Q

Thymocytes

A

After a leaving bone marrow they move to thymus to finish development

344
Q

T Cell Steps

A

Pro T—> Pre T—->Double positive (starts expressing CD4/8)—> single positive —> Mature T cell (periphery)

345
Q

Where does T cell positive and negative selection occur

A

Thymus

346
Q

Who presents to T cells CD4

A

Dendrtiic cells

347
Q

Naive T Cell Activation

A

Signal 1 Ag recognition

Signal 2 Costimulation

Signal 3 Cytokines

348
Q

CD28

A

B7

349
Q

Th1

A

Very good for intracellular pathogens

350
Q

Th2

A

Extracellular pathogens and humeral immunity

351
Q

Th17

A

Recruit neutrophils
Barrier function
Extracellular

352
Q

The ____ portion of the TCR is made up of ______ and CD4/8 when the ________ recognizes self _____ bound to specific peptide then CD4/_____ will initiate the signaling cascade by ____the _____ ______ on the cd3 molecules

A 
Signaling
CD3
TCR
MHC
CD8
Phosphorylation
ITAM
Segments
353
Q

Systemic Immune Response

A

APC processes Ag
APC migrates to draining lymph node

APC activates Naive T cell
T cell activates and differentiates into effector
TCell moves to circulation to find its way back to infection site
APC at infection site activates effector T cell

354
Q

Mucus contains

A

antimicrobial peptides enzymes

355
Q

Type I mucosae main Ab

A

SLgA

356
Q

Type II mucosae Ab is

A

IgG

357
Q

Non-Inducible Defense of the GI tract

A

Acidity
Motility
Mucous layer and glycocalyx
Tight Junctions

358
Q

NALT

A

Nasal submucoas glands
Tonsils
Epitheal cells (type II mucosa)

359
Q

BALT

A

Bronchial Submucosal glands
Epithelial cells (Type I mucosa)
Follicles and diffuse lymphocytes

360
Q

Macrophages in mucosa

A

Recognize microbes via pattern recognition receptors. This leads to activation of the macrophages and the ability to kill many microbes

—>also initiates inflammatory response

361
Q

Adaptive Response in the Gut

A

Usually biased towards SIgA

If the inflammatory response is needed a roubust Th1/17 Response will be activated

362
Q

Mucosal SIgA

A

Constitutively in mucus
Ag Specific but can bind adhesion molecules
Highly cross reactive
Does not activate complement well
Very resistant to host and microbial proteases

363
Q

Negative side to inflammation

A

Inflam ctyokines (TNF-alpha) can disrupt tight junctions between epithelial cells

364
Q

Cutaneous Immunity

A

Skin-Associated Lymphoid Tissue
Epidermis
Dermis

DC, mast cells, macrophages, T cells, but little to no B cells

Immune response: activation of nearby memory T cells or induction of systemic immunity

Often Th1/17 response

365
Q

Both ___ and ____ are critical to defend against extracellular bacteria

A

Innate and adaptive immune response

366
Q

Adaptive Immunity

A 
B Cells and antibody
T Cells (indirect help by helper CD4+ T cells)
367
Q

Innate Immunity

A

Macrophages

Neutrophils

368
Q

Examples of Extracellular Bacteria

A

Staph aureus
E. Coil
Strep. Pyogenes
Pseudo aeruginosa

369
Q

Phagocytosis of Extracellular Bacteria

A

Neutrophils and macrophages will remove particulate antigen by phagocytosis

370
Q

High Affinity Receptors

A

Mannose Receptor
Mac-1-Integrins
Scavenger Receptor

371
Q

Mannose Receptor

A

Binds mannose on microbial cell wall mediating cell microbe binding and initiating phagocytosis

372
Q

Mac-1-Integrins

A

Binds microbes opsonized with complement proteins

373
Q

Scavenger Receptor

A

Binds microbes in a non-mannose specific manner

374
Q

Opsonization

A

“Prepare for eating”
Antibodies
Complement protein
Lectin

Coated by an Opsonin to target it for phagocytosis

  • more efficient than mannose receptor mediated phagocytosis
  • Enhances inflammation and antimicrobicidal activity
375
Q

ROS

A

Reactive Oxygen Species

  • activated macrophages and neutrophils will convert molecule oxygen into ROS
  • oxygen ions
  • free radical
  • peroxide’s
376
Q

RNI

A

Reactive nitrogen intermediates

Nitric oxide

377
Q

Macrophages secrete

A

Proinflammatory cytokines (IL TNF) and chemokines (CCL) that induce inflammation and immune chemotaxis

378
Q

Neutrophils Role in Immunity against Extracellular microbes

A

Migrate toward the site of inflammation within an hour of tissue injury in response to chemotactic factors

Phacotyose microbes

Can also kill microbe by oxygen indecent mechanisms

379
Q

B cell role in immunity against extracellular microbes

A

B Cells produce antibody

  • neutralizaiotn
  • opsonization
  • memory

B cells express MHC II and can present antigen to T cells

bacterial products can directly activate B cells in a T cell independent manner

380
Q

T cell role. In immunity against extracellular microbes

A

CD4+ cells can make inflammatory cytokines

  • These activate macrophages and promote bacterial killing
  • Called Th1 cells when they make inflammatory cytoskeleton

CD4+ produce cytokines (IL4/5)

  • These cytokines are B cell growth factors which activate B cells
  • Called Th2 cells when they make these B cell promoting cytokines
381
Q

Mechanisms of immune Evasion by Extracellular Bacteria

A

Antigenic variation
Inhibition of complement activation
Resistance to phagocytosis
Scavenging of ROS

382
Q

Which T cell mediated response is necessary for intracellular pathogens

A

Th1 and CTL

383
Q

Dendritic Cell role in Immunity a gainst intracellular microbes

A

Professional APCs that present Ag to T cells

Carry Ag from site of infection to lymph node where they will present Ag to naive T cells

Produce cytokines such as IL-12 that regulate the differentiation of CD4+ T cells

384
Q

NK Cell Role in Immunity against intracellular microbes

A

Main function is to kill virus infected cells

Secrete cytokines required for macrophage and Th1 development

Activation of NK is regulated between signals from activating and inhibitory receptors

385
Q

CD4 +T cell Role in immunity against intracellular microbes

A

Recognize antigen in a MHC II restricted manner

Called Helper T cells as their main role is to help coordinate the response to other immune cells

Differentiate into Th1 or Th2 subsets producing distinct cytokines with distinct biological activity

386
Q

Th1

A

Intracellular

Th2 not needed

387
Q

CD*+T cell intracellular microbes

A

Recognize a tinge in MHC I Restricted manner

Called cytokines cells as they secrete performing and granzymes which will directly lose/kill infected cells

IFN and TNF alpha

388
Q

Cells involved in acute inflammation

A

Neutrophils
Monocytes/macrophages
Mast cells

389
Q

Cells involved in chronic inflammation

A

Monocytes/macro
T Cells
Neutrophils

390
Q

Inflammatory mediators

A

TNF-alpha
IL (interlukin) beta
IL-6

391
Q

Histamine

A

Released by mast cells involved in vasodilation

392
Q

Prostaglandins

A

INvolved in inflamation and fever

393
Q

Migration/recruitment

A

The general process of leukocyte movement from blood to tissue

394
Q

Selectins

A

Low affinity adhesion molecules involved in the early stages of leukocyte capture

395
Q

Integrins

A

Adhesion molecules involved in later stages of leukocyte migration, cab be low or high affinity

396
Q

Chemokines

A

Chemotactic cytokines named based on the location of the n termina cysteine residues

397
Q

Tethering

A

Slows the leukocyte down within the post capillary venue

Selectin mediated

398
Q

Selectins

A

Plasma membrane adhesion molecules

Low affinity

P selectin are stored in cytoplasmic granules so they can be expressed almost immediately

E Selectin can take upwards of 2 hours to be expressed

L selectin only one not on blood vessel

399
Q

Integrin Activation

A

Chemokines produced by tissue immune cells or nearby epithelial cells act on the rolling leukocyte

Chemokines interaction wit its chock in receptor changes integrin affinity from low to high

400
Q

Chemokines

A

Chemotactic cytokines

Can be produced by leukocytes epitheal cells fibroblasts

Unregulated by the recognition of microbes and proinflammatory cytokines

Diffrerent combination of receptors are expressed on different types of leukocytes

401
Q

Integrins

A

Cell adhesion molecules

High affinity integrins often cluster together to make more contacts with endothelial cell

402
Q

Adherence

A

High affinity integrins bind to their ligand on the endothelial cell

The leukocyte eventually makes so many contacts it stops and flattens out along the endothelium

403
Q

Diapedisis

A

The leukocyte can now move from the blood into the tissue after cytoskeleton is rearranged and loosen tight junction

The leukocyte follows Chemokines to the final site of infection

404
Q

Steps to cell Trafficking

A

Tethering
Integrin Activation
Adherence
Migration (diapedisis )

Micro/Immuno (3 decks)

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