Immune System Flashcards
antibodies/immunoglobulins produced by
B cells
when are antibodies/immunoglobulins produced?
stimulated by antigen binding
antigenic determinants
site on foreign molec that are recognized by immune system, interact with antibodies and T cell receptors
2 types of antigen receptors
antibodies (B cell receptors) and T cell receptors
T cell receptors
found on the surface of T cells, recognize and destroy virus infected cells, coordinates immune system response
foreign material
antigens
how do antibodies get rid of foreign material?
tag foreign material as antigens, gets disposed of directly by effector cells (eg macrophages)
can also be directly lysed by a set of nonspecific serum proteins (complement)
how do B cells amplify their response?
displays on surface a membrane bound version of their antibodies, antigen binding leads to the secretion of many copies of the antibody
how do T cell receptors get rid of foreign material?
not direct like antibodies, only recognizes antigen determinants when complexed w/MHC molecules, triggers T cell to kill infected cell
2 types of immune systems
Cellular and Humoral
Cellular immune system
-targets own cells that have been infected, virus particles and infecting bacteria
‐key players: Macrophages, killer T cells (Tc), inflammatory T cells (TH1)
Humoral “fluid” immune system
-targets extracellular pathogens and foreign proteins
‐makes soluble antibodies
‐keeps “memory” of past infections
‐key players: B‐lymphocytes and helper T‐cells (TH2)
Immunoglobulin chains
2 heavy chains: each have 3 constant, 1 variable domain
2 light chains: each have 1 constant, 1 variable domain
where do antigens bind?
antigen binding site on each variable domain, both are hypervariable (has high antigen specificity)
Immunoglobulin structure
heterotetramer, linked by disulfide bonds, hinge region on heavy chain gives flexibility
