Adaptive Immune System Flashcards
What does it mean when the adaptive immune system is acquired?
An adaptive response will not occur until a pathogen is encountered for the very first time.
What does it mean when the adaptive immune system is specific?
It is targeted to a specific feature of a bacterium, virus, toxin. Immunity to one pathogen will not confer immunity to another.
What is the memory component of the adaptive immune system?
Produces a more effective response when a pathogen is encountered for the second time-faster and stronger
What are the two components of the immune system?
- Humoral (antibody mediated) immunity
- Cell mediated immunity
What are antibodies?
Glycosylated proteins produced by the immune system that bind and inactivate foreign antigen.
What is an immunogen?
Any foreign material that has the ability to activate the adaptive immune system (protein, polysaccharide, lipid material)
Epitopes
Portion of ANTIGEN that binds to the antibody that increases the ability of an antigen to activate the immune system and requires a distinct antibody
What is immunogenicity?
Increasing the ability of an antigen to activate the immune system
Whats the difference between immunogens and antigens?
All immunogens are antigens, but not all antigens are immunogens.
What is a hapten?
Non-immunogenic low molecular weight compound that is too small to activate adaptive immunity. It can bind to other molecules such as protein in blood and tissues which becomes strongly immunogenic.
What are the subunits for antibodies (Ab)/ immunoglobulin (Ig)?
- 2 identical heavy chains
- 2 identical light chains
- assembled creating the 2 Fab region and 1 Fc region.
What is the difference between the Fab region and the Fc region in an antibody?
Fab regions: variable; provide specificity of the antibody
Fc region: constant; allows for interaction with immune cells based on differences in the Fc region; 5 types.
What is immunoglobulin M? Where is it found? What can it do?
Pentameric molecule (5 antibody units) that acts as the primary antibody response (first to be produced). It is found on the surface of B lymphocytes and remains in the blood, unable to enter tissues. Binds to antigen weakly, but is very good at agglutination.
What is immunoglobulin G (IgG)?
Monomer that is most predominate antibody in the blood, also present in the tissues. Binds to the antigen very strongly.
What is Immunoglobulin A (IgA)
Dimer secreted at mucosal sites (saliva, tears, mucous) and is an important defense against respiratory, reproductive, and digestive tract infections.
What is immunoglobulin D (IgD)?
Monomer located on the surface of B cells that activates B cells to begin producing antibody against a specific antigen.
What is Immunoglobulin E (IgE)?
Monomer whose Fc region binds to receptors on the surface of mast cells and basophils. Binding of IgE-antigen complex triggers degranulation and histamine release.
What are the 5 functions of antibodies?
- neutralizatoin
- opsonization
- Agglutination
- Antibody mediated cytotoxicity
- complement activation
What does antibody neutralization work?
Antibodies bind to antigen blocking attachment sites, preventing bacteria, virus ad toxin entry into tissues and host cells
How does antibody opsonization work?
Antibodies coat the surface of the bacterial cell and attract phagocytes. Greatly enhances the rate of phagocytosis as phagocytes have the ability to interact with the Fc region.
How does antibody agglutination work?
Each class of antibody can bind to a minimum of 2 identical antigen units to allow phagocytosis to occur more efficiently
How does antibody mediated cytotoxicity work?
Attachment of antibody to parasites recruits eosinophils to attach to Fc component and release reactive oxygen species and. hydrolytic enzymes to destroy the parasite.
How does antibody complement activation work?
complement (series of proteins in blood) can be activated by antibody that is bound to a bacterial cell and creates a cascade of immune responses when activated (such as Membrane Attack Complex)
What does the membrane attack complex do?
Activated complement proteins form a pore in a bacterial cell, allowing the contents of the cell to leak.
