immune response Flashcards
role of primary lymphoid tissue
bone marrow and thymus which produce both B and T cells
role of secondary lymphoid tissue
lymph nodes and spleen which is where B and T cells search for matching antigen
MHC
genes that code for proteins that help immune system recognize foreign substances
why are HLA so unique
random assortment of allotypes
location and role of MHC 1
found on all nucleated cells, functions as identifying factor (shows its not mutated, tumor, etc.) leads to cell killing
location and role of MHC 2
found on antigen presenting cells and leads to antibody production
immune response women vs men
women have stronger immune response thought to be because they need to protect the fetus
Site of B cell development
produced in bone marrow where they are undergo genetic rearrangement and reactivity tests, then second lymphoid tissue
site of T cell developmetn
produced in bone marrow, then go to thymus for maturation and genetic rearrangement, then second lymphoid tissue
3 types of antigen presenting cells
B cell, Macrophages, and dendritic cells
Macrophages expression
presents processed antigens via MHC II
Dendritic cells expression
presents processed antigens via MHC I and II
structure and function of TCRs
heterodimer with alpha and beta chain connected by disulfide bond
its function is to bind to antigens
how does human genome code for antibodies and TCRs specific to an almost infinite number of immunogens
idiotypic determinants
role of T cells in body
helper: recognize specific antigens –> MHC 1
cytotoxic: recognize specific antigen –> MHC 2
regulatory: suppress self reactivity
CD4 T cells vs CD8 T cells
CD4 = helper
CD8 = cytotoxic (killer)
interaction between CD4 and MHC 2
when MHC 2 molecule on APC will present antigen to CD4 which will drive antibody production and cellular response
interaction between CD8 and MHC1
when MHC 1 molecule on APC will present antigen to CD8 which will end up killing cell
Th1 role
faciliates cell mediated immune response
Th2 role
facilitate humoral immune response
interlukin 12
increase growth and activity of b and T cells
NK cells vs CD8
innate and do not require MHC 1 to kill (no TCR)
NK cells
MHC 1 receptor inhibits NK cell activity and tells it not to kill
T dependent vs independent response
D: T cell is required to stimulate antibody production
I: formation of antibodies without T cell (signal comes from antigen)
B cell surface markers
IgG and IgM are both present as receptors on B cell surface
role of CD28 and B7
when these interact, it activates the second signal in the T-cell dependent response
Maturation and differentiation of T and B cells
B cells will undergo VDJ and mature to either a plasma cell (antibodies) or memory cell (amnestic response
memory cells
responsible for anmestic response; they do not product antibodies, they already carry them on surface
redunancy
many cytokines have the same function
synergy
two cytokines working together speeds the effect
antagonism
one cytokine will block the other to slow effect
types of change cytokines can trigger
cell proliferation (cloning)
differentiation (irreversible change in function)
transient gene activity (reversible change in function)
