Chapter 20 Flashcards
describe adaptive and innate immunity. name the key cell players in each system
adaptive: ag specific host defense (t and b cells, APCs)
innate: early host defense (nph, eo, baso, mast, nk)
self tolerance is a combo of 2 types of tolerance known as ___ and __. These are learned where in development?
Central (during lymphocyte development in the thymus) and peripheral
b cell receptors recognize antigen directly. T helper cells recognize peptides presented on MHC __ and cytotoxic T cells recognize peptides presented on MHC __.
Which MHC complex is specific to antigen presenting cells? ___
Which is present on all cells in the body? __
What types of peptides are expressed or presented on MHC I? ___
What types are on MHC II? ___
II I II I I - shows endogenous peptides II - shows exogenous
define humoral immunity. what are the key players
Part of the adaptive immune response that has to do w aby mediated response.
B cells are key players.
T helpers nb to stimulate this response
define cell mediated immunity - what are the key players
Immunity initiated by activation of T lymphs Cytotoxic t lymphs are effectors
T helpers are nb to stimulate the response
What is the intracellular structure responsible for degrading endogenous proteins into small peptides for presentation to the MHC complex?
How are exogenous proteins degraded into peptides for presentation on MHC?
Proteosome
Endosomes w/in APCs
Cytotoxic T lymphs are primarily used to destroy cells infected by \_\_\_ and what other type of cells? \_\_\_ CTLs are CD4 or 8 positive? \_\_\_ And recognized peptides expressed on which class of MHC? \_\_\_ How do they kill their target cells? \_\_\_
viruses tumor cells 8 I perforin and granzymes
T helper cells are CD4 or 8+? __
They recognize peptides presented on what MHC complex? __
4
II
T helper cells are divided into TH1, TH2 and TH3 types.
TH1 cells secrete____
These cells are involved in what branch of the immune system? _____
List at least 3 cytokines secreted by TH2 cells. ___
They are involved in the activation of what cells and are nb in what branch of the immune system? ___
What is the main function on TH3 cells? ___
IL-2, IFNy, GMCSF CMI IL-4, IL5, IL10, IL13, GMCSF Activate B cells in humoral immunity Secrete TGF beta or IL-10 to regulate the immune system. Nb in maintaining peripheral tolerance
The large amt of variability in TCR has to do w/ gene rearrangement of the variable, diversity and joining segments of the gene. There are also 3 hypervariable regions referred to as the ___ which are nb for antigen recognition as they contact the peptide antigen. What part of the TCR complex is responsible for intracellular signalling?
complementary determining regions
CD3 intracellular signaling
CD28 is expressed by what cells? function?
on T cells, costim molecule for immune activation
IL-2 promotes growth of what cells?
All t cells including TH and CTLs
What interleukin is required by B cells for Aby production
IL-12
describe t cell development including where it occurs and the procceses of tolerance and selection
In the thymus.
If TCR interacts weakly w/ self MHC then there is positive selection, IF TCR interacts very strongly w/ MHC then there is negative selection (part of tolerance).
Self reactive thymocytes escape thymic detection dt proteins in the body existing o/s of the thymus and t/f not being present at the time of selection. (central tolerance = thymus). peripheral tolerance is needed for the problem of AG not present in the thymus. So, peripheral tolerance is the induction and maintenance of unresponsiveness in mature T cells to self AGs bc of TH3 cells.
what is anergy
unresponsiveness of t cells to their antigen (another way of having tolerance)
