Cell-mediated immunity Flashcards
In cell-mediated immunity is when
- An antigen is recognized and bound
- A small number of T cells proliferate and differentiate into a clone of effector cells
- The antigen is eliminate
Antibody-mediated immunity is when
- An antigen is recognized and bound
- Helper T cells costimulate the B cell so the B cell can
proliferate and differentiate into a clone of effector
cells that produce antibodies - The antigen is eliminated
IgG
-most abundant
-protects against bacteria and viruses
IgA
Found mainly in sweat,tears,saliva,mucus,breast milk, and digestive secretions
IgM
first antibody class to be secreted by plasmocytes after initial exposure to antigen
IgD
mainly found on surfaces of B cells as antigen receptors
IgE
involved in allergic and hypersensitivity reactions:provides protection against parisitic worms
Naturally acquired active immunity follows exposure to a microbe
antigen recognition by B cells and T cells and costimulation lead to formation of antibody-secreting plasmocytes, cytotoxic T cells, and B and T memory cells.
Naturally acquired passive immunity is when
IgG antibodies are transferred from mother to fetus
across placenta, or IgA antibodies are transferred
from mother to baby in milk during breast-feeding
Artificially acquired active immunity
Antigens introduced during vaccination stimulate
cell-mediated and antibody mediated immune
responses, leading to production of memory cells
Artificially
acquired passive
immunity
is
Intravenous injection of immunoglobulins
(antibodies)
Cytotoxic T cell
Kills host target cells
Helper T cell
Cooperates with B cells to amplify antibody production