Immunity Flashcards
Innate a immunity is present at birth, what does it consist of?
What do they do?
Skin
Mucous Membranes
Antimicrobial substances
Inflammation
Fever
Phagocytes
They Ingest and Break Down Microbes
Skin: tightly packed cells that are difficult to _______
______ removes attached microbes; ______ inhibits growth of many species
Penetrate
Shedding
Dryness
Mucous membranes line what tracts?
What do they secrete? And what do the secretions consists of?
gastrointestinal, respiratory, and genitourinary tracts
Secretes mucus that contain Cilia
Mucus: viscous glycoprotein produced by ____ _____
– Traps microbes
– Also contains other secreted compounds like ______ which
targets the cell wall of bacteria
Goblet cells
Lysozyme
What is the ciliary escalator ?
transports microbes trapped in mucus away from the lungs, toward throat (1-3 cm
What is the ph of the stomach?
2 - 2.5 pH
What does lysozyme attack?
Pepticloglycan, disrupting cell wall
What is phagocytosis?
What does phago mean?
What does Cyte mean?
The ingestion of microbes or particles by cell (phagocyte)
Phago= eat
Cyte=cell
What are the 2 types of phagocytes?
Neutrophils (polymorphonuclear leukocytes; PMN’s)
Macrophages (differentiated monocytes)
What are the 2 types of macrophages?
Where are they located?
Fixed macrophages (lungs, liver, other tissues)
Free (wandering) macrophages moves to site of infection
What are the steps of Phagocytoses?
- ATTACHMENT to surface of phagocytic cell. Antibody/complement aid in binding
- Pseudopods EXTEND and ENGULF organism
- Invagination TRAPS organism within phagosome
- Lysosome FUSES into phagosome. Enzymes cleave macromolecules and taste oxygen, DESTROYING organism
(1. Attachment 2. Extend & Engulf 3. Trapping 4. Fusion & Destroyment)
What does adaptive immunity consists of?
True or False: they are present at birth
What component do they have?
Humoral and cellular immunity.
False: They are not fully developed at birth
They consists of a memory component
Innate: ____ response vs _____ pathogen
Adaptive: ______ response vs ______ pathogen
General response vs. Any pathogen
Specific responses vs. Certain pathogens
Microbes possess unique structures called ______ ______ _____ _____ (MAMPs) that are recognized by ____ ____ ____ (TLRs) and other receptors present on host cells.
Microbe-associated molecular patterns
Toll like receptors
What does the binding of MAMPs by host cell receptors activate?
Stimulates phagocyte to release _____ that attract other phagocytes to site of ______
– Initiate _______
Activate immune mechanisms
Cytokines
Site of infection
Initiate phagocytosis
Give 3 example of MAMPs
Flagella (mobile bacteria)
Peptidoglycan (gram positive)
Lipopolysacchande ( LPS) (gram negative)
Bubonic plague
Causative agent?
Transmitted from? To what? By?
Once at 37° C,it breaks down ________ on cell surface so that _____ can’t see it anymore. Making it invisible, escaping _____
Yersenia pestis
Transmittedfrominfectedrats(reservoir)
to humans by the rat flea (vector)
Lipopolysacchande (LPS)
TLR4
Escaping phagocytosis
True or False: A single phagocyte can engulf
Serval microbes at one time
True
What is the difference between a lysozyme and lysosome?
Lysozyme: enzyme we make that attacks peptidoglycan
Lysosome: vesicles full of “nasty stuff”
Phagosome fuses with lysosome
what does it resultin?
Microbial cells are attacked by what two things?
Give a description of both
Resulting in phagolysosome
- digestive enzymes ( lysozyme, proteases, nucleuses
-toxic oxygen products (degrades microbes)
Salmonella prevents what?
Actively prevents fusion of phagosome with lysosome
Listeriosis grows at ____° C
Can break out of phagosome and can bust out of one cell to another
4°C
What is opsonization?
What are 2 examples of opsonins?
• Opsonization is the coating of a microbe by host proteins to enhance phagocytosis by promoting attachment of microbe to phagocyte
• Examples of opsonins:
- antibodies
- complement proteins
Phagocytes have a receptor for antibodies which finds them and ____ microbes
Ingest
Antigens are macromolecules that interacts with the immune system. What are antigens made up of?
What is the name of the specific binding site on antigen? Can they have more than one?
Antigens are made up of proteins or large polysaccharides
The specific binding site on an antigen is called an Epitope, antigens can have more than one.
What is a Hapten?
Very small molecules that, when attached to a larger carrier protein, can act as an antigen.
True or false?
Haptens can stimulate antibody production alone
False, they can not.
Globular proteins also called ____, are involved in immune response to a specific antigen.
They can ____ and ____ to a specific antigen
Immunoglobulins (Ig)
Recognize and bind to a specific antigen
There are ____ # of antibodies
Antibody arms bind to _____.
5 antibodies
Bind to epitope
What structure does antibody’s have?
What are the regions?
What are the chains?
What is the bond?
Quaternary structure
Variable region and constant region
Light chain and heavy chain
Disulfide bond
What are the 5 types of antibodies?
IgG
IgM
IgA
IgD
IgE
(G)irl (M)ake (A)ll (D)ays (E)xciting
IgG
Dimer, Monomer, or Pentamer?
__ - __% of serum antibodies?
Only antibody class known to cross ______
-naturally acquired through?
-protects what?
Monomer
70- 80% of serum antibodies
Only antibody class known to cross placenta
–Naturally acquired passive immunity
–Protects fetus and newborn
IgG
Enhances _____ through ______ (binding to microbes, coating outside)
Neutralizes ____ and viruses
Activate _____ through classical pathway
Enhance phagocytosis through opsonization
• Neutralize toxins (antitoxins-exotoxins) and viruses
• Activate complement through the classical pathway
IgM
Dimer, monomer, or pentamer?
__-__% of serum antibodies
First Ab produced in response to ____
______ microbes
Activate complement through ____ _____
Produced by _____
• Pentamer
• 5–10% of serum antibodies
• First Ab produced in response to infection
• Agglutinate microbes
• Activate complement through the classical pathway
• Produced by fetus
IgA
Dimer, Monomer, or Pentamer?
__-__% of serum antibodies
Found in ____- mucosal protection, protects IgA from ______
-what does it prevent?
Some pathogens produce IgA ____ that destroy IgA antibodies
Dimer
15-20%
Found in secretions–mucosal protection
protects IgA from degradation
– prevent attachment of microbial pathogens to mucosal surfaces,
- Some pathogens produce IgA proteases that destroy IgA antibodies
– e.g. Haemophilus influenzae and Streptococcus pneumoniae
IgD Antibodies
Dimer, Monomer, Pentamer?
___% of serum antibodies
Abundant on surface of ___ cells
Involved in signaling ___ cells to begin producing antibodies
Monomer
0.02% of serum antibodies
B cells
IgE antibodies
Dimer, Monomer, Pentamer?
___% of serum antibodies
On mast cells, on _____, and in blood
Main antibodies involved in _______ reactions
MMA at be involved in lysis of _____ ____
Antibody dependent cell mediated __________
Monomer
0.002% of serum antibodies
Basophil
Allergic reactions
Lysis of parasitic worms
Cell-mediated cytotoxicity
What are the 5 protective mechanisms of binding antidotes to antigens? (Give small description of each)
• Agglutination (reduces number of infectious units to be dealt with)
• Activation of Complement (causes inflammation and cell lysis)
• Opsonization (Coating another with antibody enhanced phagocytosis)
• Anybody dependent cell mediated cytotoxicity (Antibodies attaches to target cell cause destruction by macrophages, eosinophils, and NK cells. ATTACKS LARGE PARASITIC WORMS)
• Neutralization (Blocks adhesion of bacteria and viruses to mucosa. NEUTRALIZES VIRUS/ TOXINS)
What are the 2 types of Adaptive Immunity?
• Humoral Immunity
• Cell mediated Immunity
Humoral Immunity
- ___ cells ( __ lymphocytes) produces antibodies that…..
-attacks ________ threats
- B cells, B lymphocytes produces antibodies that target antigens
- attacks extracellular threats
• Cell- mediated Immunity
– Activated __ cells (__ lymphocytes) control _____ _____ and can directly kill infected host cells
– Attacks infected cells
– Activated T cells (T lymphocytes) control antibody production and can directly kill infected host cells
- Activation of B cells
— Where are B cells produced? - Where do B cells have antibodies?
— Mostly found in what class of antibodies? - True or False: Antibodies on a particular B cell do not recognize or bind to the same epitope
— When do B cells become activated? - Activated B cells divides and differentiates into what 2 cells?
- in the bone marrow
- have antibodies on cell surface
- mostly in IgM and IgD
- False, Antibodies on a particular B cell will bind and recognize to the same epitope
- B cells become activated when the surface antibodies bind their specific epitope
- Plasma cells and Memory cells
What are the First 3 steps of B cell activation?
Antibody on surface of B cell recognize epitope (antigens)
Antigens internalized
Antigens bind to MHC class II within B cell
B cell Activation
T- helper cells recognizes _____ ___ - __
T- helper cell is activated
T-helper cell produces _____
_____ activates B cell
MHC II - Ag
Produces cytokines
Cytokines activates B cell
Activated B cell divides (_____ _____) to produce a large population of cells
Some of these cells become _____ cells, which produces antibodies
Some of these cells become long lived ____ cells
Clonal Expansion
Plasma cells
Memory cells
What is the function of plasma cells?
Plasma cells produce hundreds to thousands of antibodies per second (antibody factories)
What is the function of Memory Cells?
– Long-lived
– Responsible for rapid, enhanced immune response after later exposure to same antigen
What are the two types of Immunological memory? When do they occur?
Primary response- occurs after initial contact with antigen
Secondary (memory) response- occurs after second exposure
True or false: B cells can be activated by T-dependent and T- independent antigens.
True
T- dependent antigens
-antigen present with ____ __ to ___ cell
____ cell produces cytokines that activated B cell
MHC II to tH cell
tH cell
T- independent antigens
What do they stimulate?
Have repeating units (______) that can bind multiple antibodies on surface of B cell -_____ of the B cell
(Give Example)
– Stimulate the B cell to make antibodies without T-helper cells
– (epitopes)
– capping of the B cell
• e.g. polysaccharides, capsule
T-independent antigens
-strong or weak immune response?
-no class switching, production of ____
Does it have memory cell production?
Weaker immune response
Production of IgM
Weak/no memory cell production
T cells recognize antigens derived from intercellular pathogens such as:
T cells also recognize “non self cells” such as:
Viruses and intercellular bacteria & parasites
Tumor cells
There are two Major Histocompatibility Complex (MHC,) where is the first one found? Describe each of them
MHC class I: found on all nucleated cells – Markers of “self” (found in or an cells ands is protects against our immune system so they do not get destroyed)
• MHC class II: found on antigen presenting cells – e.g. B cells
What are the two types of T cells?
Helper T cells (tH cells) and Cytotoxic T cells (Tc cells)
Helper T cells
Surface glycoprotein ____, which binds to _____ ______ __ molecules on B cells and order Antigen presenting cells
-Assist on _____ of B cells and other T cells
CD4 which binds you MHC class II molecules
Assists on activation of B cells
Cytotoxic T cells (tC cells)
Surface glycoprotein ____ which binds to ____ ____ __ molecules (that display antigens from internal pathogens)
-differentiate into cytotoxic ___ lymphocyte
Destroy _____ and _____ host cells
CD8 bind to MHC class I
T lymphocyte (CTL)
Destroy bacteria and infected host cells
CTL attacks appeared self cell by
• releasing ______: forms pores in target cell
• releasing ____: induce apoptosis
- Perforin
- granzymes
Harmful B cells that recognize self antigens are eliminated in a process called ____ ____
MHC molecules involved in _____ _____
-95% of T cells are eliminated by this
-T cells that bind to strongly to MHC (bind “self” instead of “non self”) are eliminated
Clonal deletion
Thymic selection
What is a vaccine?
a suspension of organisms (live, attenuated, killed) or fractions of organisms that is used to induce immunity
There are vaccines developed against bacteria, viruses, and toxins. Have there been vaccines developed for fungal diseases?
No there are no vaccines for fungal diseases yet.
Weakened (attenuated) or killed pathogens OR fragments of the pathogen are used
They (usually) do not cause ______
Trigger _____ response
** Induce ______ cells **
Usually do not cause disease
Trigger immune response
Induce memory cells
What are the 5 types of vaccines?
- Attenuated whole agent-vaccines
- inactivated whole agent vaccines
- toxoid vaccines
- subunit vaccines
- conjugated vaccines
- nuclei acid vaccines
Attenuated Whole Agent Vaccines
Describe the microbes (bacteria or virus) :
Microbe can be “_____” by multiple passages in the lavatory
______ immunity
May “back mutate” to ______ pathogen (rare)
Give examples:
- Live, attenuated (weakened) microbes: virus or bacteria
-weakened
-Lifelong immunity - back mutate to virulent pathogen
Examples: measles, mumps, rubella (MMR) vaccines
Inactivated whole agent vaccines
Microbe killed or inactivated by what three things?
Is it safer or more dangerous than live vaccines?
Less effective: often require ______ doses
Give examples:
– Microbe killed or inactivated by heat, chemical, or
radiation
– Safer than live vaccines
– require booster doses
– Examples: rabies, flu, polio (Salk polio vaccine)
Toxoid vaccines
Some diseases are caused by bacterial toxins, such as: _______ toxin caused by _______ ________
Toxoid are ________ by toxins:
• do not cause ________
• do not stimulate production of ______ (antitoxins)
Require ______ shots
Give examples:
- diphtheria toxin, toxin caused by Corynebacterium diphtheria
• Do not cause disease
• Do stimulate production of antibodies (antitoxin) – Require booster shots
Examples: tetanus, diphtheria
Subunit vaccine
-________ fragment of pathogen (virus or bacteria) that best stimulates _____ response
Safe or hazardous?
“______” vaccines using recombinant technology
Give examples:
Antigenic fragment, stimulates immune response
Safe
Recombinant vaccines
Example: Hepatitis B (genes for Hep B antigens have been inserted into Saccharomyces cerevisiae to produce antigens)
Conjugated vaccines
- large _______ can be __-dependent antigens, what do they result in? Do they contain memory cells?
______ combined (conjugated) with more antigenic protein (e.g ______ _____), results in better immunization
Give example:
-Large polysaccharides can be T-independent antigens. Result in weak immune response and no memory cells
Polysaccharide combined (conjugated) with antigenic protein (e.g tetanus toxoid)
– Example: Haemophilus influenzae type b (Hib)
Nuclei acid vaccines
-____ or _____ encoding pathogen protein injected into patient
-Patient produces antigen (______, then _______)
-Protein antigens not _______
Examples:
DNA vaccines to prevent _____ _____ approved for horses
No DNA vaccines approved in ______
Moderna abs Pfizer vaccines to prevent _______
-DNA or RNA
- produces antigens (transcription then translation)
Not polysaccharides
Examples:
Prevent West Nile
No DNA vaccines approved in humans
To prevent Covid
DTP vaccine licensed in _____
Polio vaccine licensed in _____
MMR vaccine licensed in ______
- 1948
- 1995
- 1971
Define Herd Immunity:
• Herd immunity (or herd protection) : If most of the population is immune to a disease, then the remaining individuals in the population are partially protected.
Herd immunity
Applies to infectious diseases spread by _____ to _____ contact
Give examples:
If most of the population is immune to a disease
• _____ or _____ survivor
Then remaining non immune individuals in population are directly protected, why?
• spread by person to person contact
Examples: pertussis or influenza, but not tetanus
• vaccinated or disease survivor
• Because there are not enough susceptible individuals in population to spread disease through person-to-person transmission
• For SOME diseases, vaccination of ____% of the population is sufficient to PROVIDE immunity
• For MOST diseases, vaccination of ____-____% is REQUIRED for herd immunity
40%
80-95%
Herd immunity is related to R0 “R Naught”
What does R0 represent?
What does it measure? When is it difficult to measure?
Infectious diseases with a high R0 require a high _______ coverage rate to achieve herd immunity and protection
The basic reproduction number R0 (“R naught”) is the number of secondary infections expected from an original infection in a completely susceptible population
-measures transmissibility of an infection
-difficult to measure during an outbreak
Require a high vaccine coverage
Vaccine Safety
True or false: there is medical and scientific proof of MMR vaccines being linked to autism
True or false: on rare occasions, vaccines cause disease
Decreased vaccination rates are linked to an increase in _______
False, there is no proof
True
Increase in disease cases
Who should not get vaccinated?
Because of age, health conditions, or other factors, some people should not get certain vaccines or should wait before getting them
