Unit 3 lecture 11-15 Flashcards
Define Immune system
multilevel network that provides complete protection against infection
what does first line of defense include and what is its purpose
- impede entry of microbes and all foreign matter
- physical barriers
- chemical barriers
- genetic barriers
physical barriers
- skin and mucous membranes
major factors that inhibit growth on skin
dry, salty, acidic
define mucous membrane
epithelial layer that secreted mucus
prevents drying and traps microbes
major tracts lined with mucus membrane
- respiratory
- urinary
- gastrointestinal
- reproductive
stratum corneum
top layer of epidermis
epidermis
top layer of skin
dermis
layer below epidermis
sebaceous layer
layer below dermis
sweat gland
looks like hall of noodles
sebaceous/oil gland
circular pores extending from hair follicle
chemical barriers
- sebaceous glands
- meibomian glands
- lysozyme
- sweat
- hydrochloric acid
- act as natural anti microbials
where are sebaceous glands found
dermis layer of skin
where are meibomian glands found
eye lid secretions
where are lysozymes found
tears, saliva, blood tissue, nasal secretions
where is sweat found
acidic salty secretions of skin
where is hydrochloric acid found
stomach
what are genetic barriers
natural barrier created by pathogen specifically for specific host
- stops the spread of disease based on genetic differences
2nd line of defense includes…
- phagocytosis
- inflammation
- fever
- interferons
- compliment
define phagocyte
scavenger WBCs that engulf and destroy particulate matter
main WBC involved in second line of defense
Phagocyte
neutrophils
- 60-70 percent WBCs
- short lifespan
- bone marrow
- enter tissue
- highly motile
macrophages
- 5 percent WBCs
- months to years
- blood vessel walls
- enter tissue
4 steps of phagocytosis
- ingestion of bacteria by phagocytes
- chemotaxis
- adherence
- ingestion
- digestion
Chemotaxis
- wbc moves toward microbe
adherence
close contact between WBC and microbe (PAMPs)
WBC has (PRRs) recognize and bind to PAMPs
ingestion
microbe internalized by WBC by phagosome
digestion
phagolysozomes released called residual bodies that fuse with the plasma membrane and are released
4 hallmarks of inflammation
heat, redness, swelling, pain
process of inflammation
- tissue damage
- chemicals released
- vasodilation and increased permeability of blood vessels
- chemotactic factors released
- phagocytes respond
- tissue repair
define fever
abnormal elevated body temp
universal sign of infection
benefits of fever
- inhibits multiplication of temp sensitive microbes
- decreases availability of iron
- increases phagocytic activity
- stimulates inflammation
- stimulate squire IR
define interferons
protein released in response to viral entry that inhibit viral replication
not virus specific but host specific
genetic engineering of interferons
- protein production: pharmaceuticals and vaccines
- alter organisms: pesticides
- source of DNA for study
what is the compliment cascade and what is the end result
sequential physiological response that involves at least 26 blood proteins that work in concert to destroy bacteria
- result in lysis: small punctures
what is the third line of defense
acquired immunity
response once infection has surpassed first and second line
humoral response and cell mediated response
major cell types of third line of defense
- macrophages and dendritic cells
- lymphocytes
-b cells
-T cells - natural killer cells
function of macrophages
process antigen and present to lymphocytes
- ingest and kill foreign cells
functions of dendrites
process antigen and present it to lymphocytes
function of lymphocytes
migrate in and out of foreign tissue
function of B cells
differentiate into plasma cells and form antibodies (humoral response)
mature in bone marrow
function of T cells
assist b cells and kill foreign cells (cell mediated immunity)
mature in thymus
T helper cells
- TH1
- TH2
function of TH1 and TH2
- TH1: activate T cytotoxic cells and macrophages
- TH2: activate B cells
T cytotoxic cells
seek out and lyse infected cells in the body
B cell receptors
immunoglobulin cells
IgD or IgM
T cell receptors
TRC complex and CD3 protein
Natural killer cells
active against cancerous and virally infected cells
MHC-1receptors
found on all nucleated cells of the body
MHC-2 receptors
present on macrophages and B cells
clonal selection theory
when foreign antigen enters body, only lymphocytes having receptors specific for that antigen will be activated to proliferate
What is the humoral response
production of antibodies
define antigen
foreign matter that triggers a specific immune response
define epitope
small portion of antigen to which antibody binds
define hapten
too small to induce synthesis. must first conjugate to large carrier protein
define antibody
- glycoproteins produced in response to specific antigen
5 classes of antibodies
- IgG
- IgM
- IgA
- IgE
- IgD
IgG
- primary secondary response
- only class that crosses placental barrier
- eliminates gram - and gram +
- 80 percent of total Igs
- neutralization of viruses and toxins
IgM
- 5 to 10 percent antibodies
- largest Ig
- first Ig to increase in antigen response
- lysis of gram - bacteria
- M: macroglobulin
IgA
- 1st line of defense
- monomer form: serum
- diner form: mucus secretions
- respiratory, genitoruinary, intestinal, and breast milk
- 1-15%
IgE
- 0.002 %
- responsible for allergic reactions
- Fc portion bound tightly to basophils and mast cells
- desensitization programs
steps in T cell dependent pathway
- protein based
- APC-TH2 Cells- B cells- plasma cells - antibodies
steps in T cell independent pathway
- simple carbs
- B cells-plasma cells-antibodies
what cells are responsible for amnesties response
memory cells
what is amnestic response
rapid production of antibody following second contact with antigen
primary response to antigen
- occurs directly after exposure
- IgM responds first then IgG
secondary response to antigen
- antigen exposed to body for the second time
- me rory cells produced that allow body to respond quickly and effectively
- IgG primary response and increases significantly
6 roles of antibodies
- activation of compliment
- inflammation
- cytotoxicity
- neutralization
- opsonization
- agglutination
cell mediated response
- cell-cell contact leading to destruction of infected/abnormal cells
- defends against bacteria, viruses, protozoa, worms, cancer cells
process of cell mediated response
- APC engulf, process, and display antigen fragments in MHC-2
- TH1 cells recognize MHC2/Ag and bind
- in response to cytokines: TH1 cells activated
- Activated TH1 cells produce additional cytokines which activate macrophages and T cytotoxic cells
define cytokine
secreted proteins of the immune system that have an affect on other cells
process of T cytotoxic cell lysis
- T cells recognize specific antigen in context on MHC1
- granules within cell move to point of contact between 2 cells and fuse with membrane
- potent cytolytic enzymes cause lysis of target cells
- Tc cells released unharmed to seek out another target cell
T cytotoxic cells and natural killer cells
- both derived from bone marrow and target and lyse cells
- NKC do not recognize Ag/MHC-1
- important in killing malignant cells and antibody released cells
active immunity
- person exposed to antigen, antibody created, memory forms
- long term protection
passive immunity
preformed antibodies
immediate protection
short term
Natural active
immune response produced antibodies
artificial active
antigen exposure through vaccine
immune response produces antibodies
natural passive
antibodies pass from mother to fetus
artificial passive
anti-serum containing preformed antibodies
define vaccine
provides active acquired immunity to infectious disease
4 categories of vaccines
- killed bacteria or viruses
- living attenuated bacteria or virus
- toxoids/capsular material of bacteria
recombinant DNA technology (genetic engineering)
benefits of live vaccines
- grow in host
- stimulate antibody production for longer period of time
- stimulate numeral and cell mediated response
- induce production of IgA
why do some vaccine require boosters
to ensure an effective secondary response
define normal flora
organism found on consistent basis in specific body areas
- compete with and control pathogens
body parts with normal flora
- skin
- eyes
- nasal cavity, middle ear, auditory tube, pharynx (highly colonized)
- mouth, esophagus (highly colonized)
- large intestines(extreme numbers)
- external urethra
- reproductive tracts
sterile body parts
- larynx, trachea, lungs, bronchus
- stomach
- small intestines
- kidneys, ureters, urinary bladder
- blood and tissues
things to know about normal flora
- what is normal flora for one person may not be normal flora for another
- what is normal flora on one body part may not be normal flora on another
- gram (+) bacteria
what is the ciliary escalator
mucus traps organisms and particles and the cilia moves them up and out
streptococcus
- gram (+) cocci, catalase -
- grown in 5% sheep blood agar
- hemolysis
- species differentiated based on differences in C carbohydrates in cell walk
- denoted by group A-H, K-O
2 potential pathogens if streptococcus
- streptococcus pyogenes
- streptococcus pneumonia
Streptococcus pyogenes
- leading cause of strep disease
- > 80 types based on differences in M protein
virulence factors of strep pyogenes
- M protein: adherence
- capsule
- produce enzymes and toxins
2 sequellae of strep pyogenes
- rehuematic fever
- glomerulinephritis
streptococcus pneumonia
- alpha hemolytic
- > 100 types based on differences in capsule
virulence of strep pneumonia
- capsule
- secretions of pneumolysins: impair immune response
define hemolysis and 3 types
- destruction of WBC
- alpha: partial
- beta: complete
- gamma: none
Meningitis
- inflammation of meninges
define meninges
3 layers of connective tissue surrounding brain and spinal cord
3 leading causes of bacterial meningitis
- haemphilus influenza
- neisseria meningitidis
- strep pneumonia
Haemphilius influenza
- gram - coccobacilli
- type b
- vaccine: capsular material
- virulence: capsule and endotoxins
Neisseria Meningitidis
- gram - diplococci
- vaccine: capsular material
virulence of neisseria meningitidis
- polysaccharide capsule
- fimbriae
- invade host cells and grow intracellularly
- large amount of endotoxins
streptococcus pneumonia
- gram (+) displococci
- vaccine: capsular material
3.) Bordetella Pertiussi (whooping cough)
- gram (-) coccobacilli
- virulence: fimbriae and toxin production
- vaccine: DT(aP): acellular fragments
4 stages of bordetella perfussis
- incubation: 7-10 days
- cattharal: sneezing, cough (1-2 weeks)
- spasmodic: violent cough, whooping sounds (1-6 weeks)
- convalescence: recovery (2wks-months)
4.) Corynebacterium Diptheria
- gram + rods
- vaccine: DTaP: inactivated diptheria toxin
- virulence: exotoxins and endotoxins
endotoxins of diphtheria
- 2 polypeptide chains
- a: steps protein synthesis in cell
- b: binding to host cell
5.) Mycobacterium
- acid fast organism (mycolic acid in cell wall)
- relatively non pathogenic
2 pathogens of micro bacterium
- tuberculosis
- leprae
advantage of acid fact
- increased generation time
- more resistant to chemicals
- resist destruction in macrophages
- cord factor
tuberculosis
- very contagious
- slow, chronic disease
- spread by inhalation of droplets
- form lesions on LRT
treatment of tuberculosis
multiple drugs over long period of time bc intracellular
Leprae
- not very contagious
- tuberculoid(neural): loss of sensation
- lepromatuous(progressive): disfigurement
treatment of leprae
multiple drugs over long period of time
6.) legionella pneumonia
- gram - type wall
- transmitted by inhalation of contaminated water
- resistant to normal chlorine levels
virulence if legionella pneumophila
- produce toxins
- invade and grow in macrophages
unusual prokaryotes
- mycoplasma pneumonia
- chlamydia
- coxiella burnetti
1.) mycoplasma pneumonia
- smallest organism that can grow and reproduce without host cell
- pack peptidoglycan cell wall
- membrane contains sterols
- highly pleomorphic
- fried egg colony appearance
2.) chalmydia
- obligate intracellular organism
- different developmental cycle
chalmydia cycle
elementary body
reticulate body
elementary body
3 types of chalmydia
- pistacii: birds (respiratory)
- pneumonia: person-person(respiratory)
- trachomatis: sexually transmitted
3.) Coxiella Burnetti
- gram - coccobacilli
- transmitted by anthropoid vectors: cattle and ticks
- form endospore like structure
- vaccine: killed organisms
Fungi
- acquired by inhalation of fungal spores
- dimorphic
- all capable of causing systemic infection
what is meant by dimorphic
- mold in nature
- year in body
what 2 infections were rare before AIDS
- cryptococcus neoformans
- pneumocystis carnii
1.) Blastomyces Dermatididis
- endemic in eastern region US
- source: soil especially if exposed to animal wastes
2.) Histoplasma Capsulatum
- endemic in central mid western US
- source: most soil; bird and bat feces
3.) Coccidioides immitis
- endemic in hot and arid regions: southwest US
source: soil in hot arid regions
4.) cryptococcus neoformans
- worldwide
- yeast cells have large capsule
- source: pigeons, most soil
- chronic meningitis can result in immune suppressed
5.) pneumocystis carnii
- worldwide
- very common
- life threatening pneumonia can result in immune suppressed
Viruses
- common cold viruses
- influenza
- adenovirus
- mumps
- measles
- rubella
- hentavirus
- varicella zoster
- variola
viral disease process
- attachment
- penetration
- uncoating
- assembly
- release
1.) common cold viruses
- all RNA
- rhinovirus (leading cause)
- parainfluenza
- respiratory syricytical virus
- coronavirus
- reovirus
2.) Influenza virus
- RNA
- spread through respiratory droplets
- frequent mutations
- viral spikes
- vaccine: grown in chick embryo; formalin inactivated
frequent mutations of influenza
- antigenic shift: major change in spike proteins
- antigenic drift: minor change spike proteins
influenza viral spikes
- hemagglutinin: recognition/attachment of virus to host cell
- neuromunidase: penetration of virus from host cell during budding
3.) Adenovirus
- DNA
- first isolated from adenoids
- can cause conjunctivitis
4.) Mumps
- RNA only one type
- becomes systemic and infects paranoid glands
- immunization: MMR, live attenuated
- spread through saliva/nasal secretions
5.) Measles
- RNA only one type
- becomes systemic
- koplik spots/rash
- can have serious consequences: encephalitis
- MMR vaccine
6.) Rubella
- RNA only one type
- rash: less severe than measles
- congenital rubella syndrome
- MMR vaccine
- flat red spots
7.) Hentavirus
- RNA
- transmitted by excretions from deer mice
- rapidly progress to respiratory failure and death
- no vaccine
8.) Varicella Zoster (chicken pox)
- DNA: in heroes family
- results in fluid filled blisters
- virus remains latent in host
- vaccine: live attenuated virus
recurrence of chicken pox
shingles (mostly adults)
9.) Variola virus (small pox)
- DNA
- lesions: leave disfiguring scars
- world wide immunization programs eradicated disease
- last case 1977
- live attenuated virus: vaccine
