Antibody Structure

Antibody Structure

B cell activation

Antibody-Mediated Effector Functions

Antibody ClassesImmunoglobulin G (IgG)

Most abundant class Four subclassesActivate complement system

Antibody ClassesImmunoglobulin M (IgM)

Pentamer1st class produced in responseto an antigenActivates complement system

Antibody ClassesImmunoglobulin A (IgA)

Predominant class in secretions Secretory IgA

Antibody ClassesImmunoglobulin E (IgE)

Hypersensitivity reactions

Antibody ClassesImmunoglobulin D (IgD)

Major membrane-bound immunoglobulin expressed by mature B cells.

Antigenic determinants on immunoglobulins

IsotypeAllotypeIdiotype

Humoral and Cellular Immunity

•Cellular immunity – Host defenses that are mediated by antigen-specific T cells and various nonspecific cells of the immune system.

•Humoral immunity – Host defenses that are mediated by antibody present in the plasma, lymph and tissue fluids.