front 1 what are the two phases of the CD8 cytotoxic T cell response? | back 1 activation and differentiation of naive CD8+ T cells - secondary lymphoid tissue CTLs recognize MHC class I peptide antigen complexes and induce apoptosis in the target cell (periphery) |
front 2 what is cross-presentation? | back 2 the blending of exogenous and endogenous pathways. it requires that antigens acquired from extracellular sources, normally handled by the exogenous pathway leading to MHC class II presentation, are redirected towards a class I loading pathway |
front 3 what is DC licensing? | back 3 Ag is processed via exogenous pathway which leads to activation of CD4+ T cells activated CD4+ T cell induces co-stimulatory molecule expression in the DC via cytokines licensing allows the DC to present antigen to CD8+ T cells |
front 4 what are the three signals for CTL activation? | back 4 TCR recognizes antigen/MHC class I complex CD28 recognizes CD80/86 IL-2R recognizes IL-2 generated by helper T cell and by CTL itself |
front 5 how do CTLs kill? | back 5 CTLs induce the cell undergo apoptosis directional release of granzymes and perforins Fas/FasL interaction |
front 6 what are perforins? | back 6 Ca2+ induces the perforin monomers to undergo a conformational change that allows them to insert themselves into the target cells membrane Ca2+ allows the perforin monomers to polymerize perforin polymers form pores |
front 7 what is granzyme B? | back 7 granzymes induce apoptosis via DNA fragmentation; they activate apoptotic pathways that result in the cell's DNA cutting itself up |
front 8 what is Fas/FasL? | back 8 when FasL on CTL binds to Fas on target cell, the target cell is induced to undergo apoptosis |
front 9 what are the general characteristics of NK cells? | back 9 involved in cell-mediated immunity named for their ability to kill tumor cells without prior exposure derived from the common lymphoid progenitor important in defense against tumor cells, infected cells, and stressed cells important in defense against infection prior to initiation of adaptive immunity peak at 3 days post infection secrete cytokines such as IFNy |
front 10 what are inhibitory NK cell ligands? | back 10 MHC class I |
front 11 what are activating NK cell ligands? | back 11 MHC class I "like" molecules-not associated with B2 molecules that are expressed on distressed cells viral proteins |
front 12 what is ADCC? | back 12 antibody-dependent cellular cytotoxicity |