lecture 5 Flashcards
T cells circulate via blood and lymphatics through?
secondary lymphoid tissue
the t cells binds to an antigen on an APC the t cell does what
proliferated and differentiates
after this binding the naive t cells become what cells
effector t cells or memory t cells
what is the effector function of CD8 cells
kill infected cells (cytotoxic)
what is the effector function of CD4 cells
secrete cytokines (helper t cells)
what do t cells go through to get to lymph node from blood
High endothelial venule (HEV)
t cells not activated exit the lymph node via what
the cortical sinuses
what ligand binds to its receptor on the surface of T cells to tell them where to go
chemokines
what allows the t cell to contact the APC initially to see if theres a peptide being presented that binds to the TCR
CAMs (cell adhesion molecules)
if there is recognition what happens
affinity of CAM interactions
T cell divides
differentiate to effector cells
what is signal 1
naive T cells receive a signal from TCR contacting MHC on APC
co stimulation (signal 2)
APC express co stimulatory molecules B7.1/2 which binds to what on the T cell
CD28
signal 3:
APCs release what
cytokines
the cytokines bind to the cytokine receptors and tell the T cell what?
what type of T cell it needs to become
what is the type of CAM on a CD4 t cell
LFA-1
what CAM does LFA-1 bind to on the APC
ICAM-1
if the naive t cell gets all 3 signals it becomes an
effector t cell
once T cells activated what what molecules do they release to turn off activation of T cells
ICOS and CTLA-4
what does ICOS do
binds to ICOSL on APC to induce cytokine secretion
what does CTLA-4 do
CTLA-4 binds to B7.1/2 better than CD28 so displaces CD28
antagonist of CD28 to limit the t cell response so effector cells dont keep getting made
mutations in CTLA-4 causes autoimmune diseases e.g
type 1 diabetes
signal 3 (differentiation)
what type of effector cells can CD4 t cells become
T helper 1
T helper 2
T helper 17
T follicular helpers
T regulatory cells
release of IL-4 from APC causes differentiation to which T cell type
T helper 2 cells
release of IL-12 and IFN-γ from APC causes
T helper 2 cells
