on the B- cell arm under antigenic stimulus what is the first thing that happens?
B-lymphocytes become transformed into antibody-secreting plasma cells.
on the T-cell arm under antigenic stimulus what is the main thing that happens?
PreT-lymphocytes differentiate into several classes of effector T cells
T cells are responsible for what?
Mediate of the B-cell response to antigen
Recognize and destroy cells bearing foreign Ags on their surface
Produce a variety of diffusible immunoregulatory cytokines and/or lymphokines that direct or augment the B and T cell immune responses
Cytokines and lymphokines have the means of?
intercellular communication and are secreted by a cell to stimulate the activity of another cell.
Antibody-mediated immunity (AMI) is?
an Adaptive immunity mediated by soluble globular host proteins called antibodies or immunoglobulins.
Primary immune response begins...
when an antigen penetrates epithelial surfaces, then when the antigen comes in contact with other macrophages or antigen presenting cells.
in the primary immune response, after a antigen is eaten by a phagocytic cell then what happens?
it is "processed" by the phagocyte which becomes and antigen-presenting cell or APC.
what does the antigen-presenting cell do in the primary immune response?
it presents information about the AG to immunocompetent TH2 lymphocytes
after the APC presents its antigen information what else happens?
the TH2 (CD4+) cell recognizes the antigen together with the Class II MHC molecules, then secretes the various lymphokines that activate the B cells to become antibody-secreting plasma cells and memory B cells.
The components of the MHC II molecules are synthesized where?
in the endoplasmic reticulum of the phagocyte
TH2 cells produce lymphokines which stimulate B cells to do what?
divide and differentiate into plasma cells which make antibody (Ab) against that particular antigen on the surface of the APC
First to appear during the course of an infection and the first immunoglobulin to by synthesized by infants
appears on the surfaces of mature B cells as a transmembranous monomer where it functions as an antigen receptor
what are the two subclasses of IgA and what are they based on?
IgA1 and IgA2 and they are based on heavy chains
Secretory IgA is predominate where?
other mucous secretions of the body.
secretory IgA is Important in resistance to infection of
the mucosal surfaces of the body, particularly the respiratory, intestinal and urogenital tracts.
two antibody thought to function as mutually-interacting antigen receptors for control of B-cell activation and suppression.
IgD and IgM
IgE trigger the release of low-molecular weight vasoactive compounds
certain proinflammatory cytokines such as TNF-α and IL-5
next line of defense If an infectious agent succeeds in penetrating the IgA barrier
the MALT (mucosa-associated lymphoid tissues)
why is MALT important?
because they amplify the local inflammatory response that facilitates rejection of a pathogen.
Antibody-mediated immunity response defends host against pathogenic microbes by
Agglutination and Precipitation
Activation of Complement
Antibody-dependent cell cytotoxicity (ADCC)
Each antibody binds to a specific antigenic determinant (epitope), This is a function of the Fab portion of the molecule, Valence of an antibody (Ab) = # epitopes Ab molecule can bind (2 or more)