immunology lecture 15 key points Flashcards

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)

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

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

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

CTLs induce the cell undergo apoptosis

directional release of granzymes and perforins

Fas/FasL interaction

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

granzymes induce apoptosis via DNA fragmentation; they activate apoptotic pathways that result in the cell's DNA cutting itself up

when FasL on CTL binds to Fas on target cell, the target cell is induced to undergo apoptosis

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

MHC class I

MHC class I "like" molecules-not associated with B2 molecules that are expressed on distressed cells

viral proteins

antibody-dependent cellular cytotoxicity