L4 Flashcards
(33 cards)
two types of t cells
CD4 T-cells
CD8 T-cells
b cells originate and/or differentiate in the _____
and
bone marrow
t-cells ____ in bone marrow
originate
t cells differentiate to _____ in the ____
mature t cells
thymus
what do t cells differentiate into in the thymus?
helper t cells
cytotoxic t cells
jacques miller discovered what
thymectomised mice (no thymus)
as we age, our thymus ___
shrinks
CD3
not involved in antigen recognition
interacts with TCR to mediate intracellular signalling
for a t-cell how does it recognize antigen peptide?
APC presents it to the tcell TCR via MHC (antigen presenting cell)
antigen has to be processed and presented
MHC - major histocompatibility complex
how does b cell recognize pathogen
binds to pathogen via BCR
in humans what is MHC called
HLA - human leukocyte antigen
where is MHC-1
most nucleated cell
MHC II has restricted expression
yes - macrophages, b cells
alpha and beta chains in MHC-I AND II
I - long alpha chain is bound to membrane and non-covalently linekd to 2 beta chains
II - both chains have transmembrane domains
the space between where MHC molecules bind peptides is called
cleft
polygenic
contains several different MHC class I and II genes
polymorphic
multiple variants of each gene within the population
only MHC class ___ and ___ are involved with antigen presenting to T-cells
I and II
alpha chain of MHC-I is encoded by the ___, ____ and ___ loci in humans
A B C
B2-microglobulin is encoded by a ___ in a ____
gene
different chromosome
MHC II encoded by the ___, ___ and ____ regions in humans
DP, DQ, AND DR
(they encode alpha and beta chains)
examples of polymorphism
hair eye colour
MHC genes are ___ expressed
co-dominantly
MHC class I and II = highly specialized antigen presenting molecules that form complexes with ___
peptide ligands