chapter 5! Flashcards
what are the two intracellular microbes that cause activation of t cells by cell associated antigens
phagocyte (intracellular bacteria, fungi, protozoa)
and
nonphagocytic cell (epithelial cell: viruses, rickettsiae, protozoa)
briefly explain the induction and effector phases of cell-mediate immunity
- antigen recognition in lymphoid organs
- t cell expansion and differentiation
- differentiated effector t cells enter circulation
- migration of effector t cells and other leukocytes to site of antigens
- effector t cells encounter antigens in peripheral tissues
- activation of effector t cells
- t cell effector functions:
leukocyte activation (inflammation): phagocytosis and killing of microbes
and
CTL killing of infected cell
adhesion molecules on tcells stabilize binding to APCs.
what receptor and signaling molecules of CD4 lymphocyte and ligands of class II MHC expressing APC promotes adhesion (for antigen recognition and costimulation)
LFA-1 is integrin protein on t lymphocyte and ICAM-1 on APC is ligand
what is important for the role of costimulation in t cell activation?
important for activating niave t cell and stimulating cytokine secretion by APC SOOOO t cell proliferation and differentiation can occur
B7 on activated APC
CD28 on niave t cell
cytokine: IL-12
these receptors are necessary for limiting/terminating immune responses
(can be useful for things such as cancer/tumors)
inhibitory receptors such as CTLA-4 and B7 or
PD-1 and B7
APCs that engulf virus infected cells (source of class II MHC peptides) and also are infected themselves (sources of class I MHC peptides) will have:
so what does this mean?
:antigens presented by both class I and II MHC molecules
means these APCs engage both CD4 t cells via class II MHC and CD8 t cells via class I
sooo Cd4 t cell helps activate the cd8 t cell
this expression of proteins for cell division, differentiation, and effector functions are important for following recognition of antigens and costimulators
t cell expression
these two medications are both used in transplant surgery to prevent graph rejection
cyclosporine and rapamycin
what are the transcription factors in the signal transduction pathways in t lymphocytes
NFAT
NF-kB
AP-1
these will enter nucleus???
the costimulator B7 and CD28 create ______ cytokine.
then, what is added to this cytokine that makes it much more active in binding? (amps it up/ higher affinity)
IL-2RByc
adds a to it
what is the principle function of IL-2?
survival and proliferation of antigen-specific t cells
what t cell remains in lymphnodes and migrates into follicles?
follicular helper t cells (Tfh)
what cell in lymphnode organ help B cells to produce high affinity antibodies
tfh- follicular helper t cells
what is another co-receptor action that is only expressed in effector functions of CD4 helper t cells that deals with macrophage activation and killing of phagocytosed microbes for cell-mediated immune response?
can also be important for humoral immunity for the secretion of antibodies with enhanced abilities to neutralize and eliminate antigens
role of CD40L
these 3 are important for niave t cells forming tight bonds with endothelium in lymphnode and migrating thru into lymphnode tissue itself
selectin (l-selectin)
integrin (LFA-1: b2-integrin)
chemokine receptor (CCR7)
