Adaptive Immunity Flashcards
4 characteristics of adaptive immunity
- Inducible
- Specific
- Long-lived and systemic
- Memory
Clonal diversity
large population of B and T cells before birth capable of recognizing different antigens
Humoral immunity
antibodies circulate in the blood
Clonal selection
infection occurs, B cells develop into plasma cells; T cells develop into (Thelper, Tcytotoxic, Tregulatory)
Cellular immunity
T cells in the blood and tissues defend against intracellular pathogens
Active immunity
individuals develops antibodies to antigens; long-lived
Acquired immunity
maternal antibodies pass through placenta to newborn; short-lived
Haptens
too small to be immunogens, but can combine with larger molecules (carriers for hapten)
5 Classes of Immunoglobulins
i. IgG: most abundant, cross placenta
ii. IgA: in blood and bodily secretions
iii. IgM: largest
iv. IgE: low concentration; allergy and parasite
v. IgD: low concentration, antigen receptor on early B cells
Fabs (Antigen-binding fragments)
receptor site
Fc (crystallizable fragment)
biological function of antibodies
Light chain contains
variable region- Complementarity Determining Regions (CDRs)- specificity of antibodies to antigen
Heavy chain contains
constant region
Epitope
(on antigen): antigenic determinant
Functions of Antibodies (direct and indirect mechanisms)
§ Direct mechanism:
§ Neutralization
§ Agglutination
§ Precipitation
§ Indirect mechanism:
§ Fc portion activate components of the innate immune response, complement and phagocytes