Adaptive Immunity Flashcards
Innate immunity
nonspecific defenses against any pathogen
adaptive immunity
induced resistance to a specific pathogen
specificity
resistance to a specific pathogen
memory
body responds more quickly if exposed to pathogen a secon time
humoral immunity
B cells (B lymphocyte) produce antibodies that directly target antigens
cell-mediated immunity
activated T cells (T lymphocytes) control antibody production and can directly kill infected host cells
The immune system does not recognize the _____ microbe, but innumerable tiny ______ of it.
whole; pieces
Each small segment of an _______ that elicits an immune response is called an _____ or an antigenic determinant.
antigen; epitope
Antigen =
Anti(body) Gen(erating)
Antigen (Ag)
a substance that causes the body to produce specific antibodies or sensitized T cells
Antibodies interact with ________ or ________ ___________.
epitopes; antigenic determinants
Haptens
low molecular weight (small) compound that is not antigenic on its own; antigenic only when bound to a larger “carrier” molecule
Once the antibody is formed against a hapten, the antibody is _______ against the hapten ________ presence of the carrier molecule.
active; without
Antibodies
made in response to a specific antigen; can recognize and bind to specific antigen
Another name for an antibody is:
immunoglobulins (Ig)
Antibody Structure:
Four poplypeptide chains (2 heavy & 2 light)
Each polypeptide has a:
constant region and a variable region
constant region
same within a particular class of Ig
variable region
recognize antigenic epitope; same between arms of antibodies
The Antibody is in the shape of a Y. The Fc region is the _____ while the Fab region is the ____.
stem; arms
The Fc region:
the site that binds to the cell
Fab region:
binds to the antigen
Neutralization
antibodies prevent a virus/toxic protein from binding their target
Opsonization
a pathogen tagged by antibodies is consumed by a macrophage/neutrophil
Complement activation
antibodies attached to the surface of a pathogen cell activate the complement system
Five types of Antibodies:
IgG, IgA, IgE, IgM, & IgD
Which Ab’s are monomers?
IgG, IgD, & IgE
Which Ab’s are pentamers?
IgM
Which Ab’s are dimers?
IgA
What is the only Ab known to cross the placenta? What type of immunity is this called?
IgG; Naturally acquired passive immunity
3 functions of IgG Abs?
- enhance phagocytosis through opsonization
- Neutralize toxins (antitoxins-exotoxins) and viruses
- Activate complement through the classical pathway
IgG makes up what percentage of serum antibodies?
80%
IgM makes up what % of serum antibodies?
5-10%
3 functions of IgM antibodies?
- First Ab produced in response to infection
- Agglutinate microbes
- Activate complement through the classical pathways
IgA makes up what percentage of serum antibodies?
10-15%