T Cell Immunity Flashcards
Examples of non enveloped viruses
norovirus and poliovirus
cause cell lysis
examples of enveloped virus
influenza and HIV
how do enveloped viruses infect cells
insert into cell membrane, progeny buds off
what are virus envelope proteins targeted by?
antibody/complement
antibody dependent cytotoxic cells- apoptosis
how do t cells recognise virus particles
peptides bound to MHC on APCs or infected cells are recognised by TCRs
what is the main role of t cells
to eliminate microbes that survive inside cells mainly viruses
where do VJDC gene fusions occur
in thymus
what is thymic education
eliminates t cells that could potentially attack self antigens
what is the more common type of TCR
aBTCR (99%)
remainder ydTCR
what is positive selection
recognition of functional TCR and MCH
what is negative selection
deletion of self reacting t cells - apoptotic cell death
how many MHC copies do you inherit
one from mother one from father
co dominantly expressed - 2 of each 6 types
how many MHC class 1 genes are there
3 - A,B,C
one gene each - a chain protein
How many MHC class 2 genes are there
3 - DP, DQ, DR
2 genes each - a chain protein and B chain protein
where are MHC 1 proteins expressed
on surface of nucleated cells
where are MHC 2 genes expressed
on surface of APCs
to what cell does MHC class 1 present self and virus antigens
cytotoxic t cells
to what cell does MHC class 2 present foreign antigens
to helper t cells
where are MHC I proteins degraded
proteosomes
where are MHC II proteins degraded
endo lysosomes
how do dendritic cells cross present to both t helper and ctls
present via MHC II to naive CTL
proteins transported to cytosol and enter MHC I pathway to Th cells
