20.2 : Adaptive Immunity to Virus Flashcards
what are the 3 functions of the antibody to the adaptive immune response?
- block attachment
- aggregate for phagocytosis
- activate the complement for MAC attack
how does the antibody block attachment?
binds to virus and prevents viral penetration (Neutralizing the antibody)
what happens when the antibody aggregates for phagocytosis?
multiple viral particles are aggergated together and removed from circulation by monocytes and myeloid cells in the liver
T/F all viruses are susceptible to mediated complement activation (classical pathway)
false, only some
what part of adaptive immunity is most important to fighting viral infection?
cytotoxic T cell (CD8+) mediated killing
T/F patients with a T cell deficiency will have overwhelming viral infections
true
outline the 5 steps in Tc cell activation and killing
- some virus taken up by DC (by inducing RNAase)
- DC process viral antigen and take it to draining node
- DC present antigen in context of Cl. 1 MHC
- Tc are activated and travel to site of infection
- kill infected cells
T/F only DC can do cross presentation
true
what happens if a cell other than a DC takes antigen from outside?
they can only present it to cl. 2 MHC rather than Cl. 1 MHC
what is the role of B2 globulin in activation of CD8 T cells?
stabilizes cl 1 MHC because MHC only has 1 chain
the “kiss of death” occurs between what two cells?
CD8+ T cell and cytotoxic T lymphocytes
what 2things are released during the kiss of death?
perforin and grnazyme
the entrance of granzyme into an infected cell activates __ enzymes for __
caspase; apoptosis
what is the backup plan to granzyme to induce apoptosis in an infected cell?
FASL: FAS is produced by stressed (infected cells) which activates the FAS pathways and leads to apoptosis
what are 2 ways in which the virus can fight back?
- down regulate Cl. 1 MHC
2. produce immune regulatory proteins
