adaptive immunity (basics) (W11) Flashcards
name for lymphocyte is its never been activated
naïve lymphocyte
what occurs to a lymphocyte after it binds to their specific antigen
activated and differentiate into effector cells - either T cells or effector B cells
also differentiate into memory T/B cells
B cells function?
produce antibodies
what occurs to B cells once activated
become plasma cells (aka effector B cells)
variable region on antibody?
antigen binding site, varies between antibodies
T cells that kill virally infected cells?
CD8+ Cytotoxic T lymphocyte (CTL)
T cells which organise immune responses by producing different cytokines
CD4+ T helper cell (Th cell)
first thing that occurs after a T/B cell binds to its specific antigen
proliferates
some daughter cells go on to become memory cells
generation of BcR/TcR diversity - random
variable regions encoded by variable, diversity and joining gene segments (V,D,J).
gene must be rearranged (somatic recombination, DNA chopped out).
many different variable regions on one B cell receptor.
random mix of V D and J.
name for specific binding site of an antigen
epitope
2 classes of MHC and what they bind to
CD8+ CTLs bind antigen on class 1 MHC
CD4+ T helper cells bind antigen on class 2 MHC
where is class 1 MHC present? why?
on the surface of all nucleated cells
presents endogenous proteins of that cell on the cell surface
where is class 2 MHC present? which of these are the most important?
specialised antigen presenting cells (APC)
most important of which are dendritic cells
function of class 2 MHC?
present exogenous antigens
structure of class 1 MHC?
alpha chain (made of 3 domains) bound to beta-2 macroglobulin
alpha 1 and 2 domains make up peptide-binding cleft
