t cells Flashcards
Cytotoxic T Cells (CTLs) (CD8+) = ?
killer t cells
what activates killer T cells?
MHC I
CD4+ = ?
helper, and regulatory t cells
these are Activated by MHC II on Antigen Presenting Cells
helper T (CD4)
What secretes: interleukin 2 (IL-2)•Interferon gamma (IFN-γ)•TNF
helper T (CD4)
Secretes IL-10 and TGFβ
regulatory t cells CD4
What must the TCR (t cell receptor) recognize for activation?
what must the Co-receptor recognize?
- cognate antigen
- MHC I or II
If the TCR sees non-self AND gets co-stimulated, the T cell is:
activated
TCR recognizes cognate antigen on MHC with no co-stimulation?
inactivated
TCR recognizes MHC plus self peptides?
apoptosis
Two types of TCR’s?
αβ-traditional(95%)
γδ-non-traditional
whats the name given to the group of signaling proteins
CD3
Most non-traditional T cells do not express either:
CD4 or CD8
what TCR is most abundant in the intestine uterus and tongue?
non traditional
B7 on APC, and CD28 on T cell is for?
co stimulation(activation)
TCR (α,β), and Co-Receptors (CD4 or CD8) are for?
recognition(activation)
CD3 (γ,δ,εand ζ), and CD28 on T cell are for?
signaling(activation)
what type of signal is CD4, what type of signal is CD8?
- help signal
- kill signal
receptor molecule on the T cell. When activated, it amplifies the signal and lowers the number of TCR crosslinks needed for activation?
CD28
what t cells have many rafts? what have few?
- experienced t-many
- naive-few
Remain in blood and lymph (node to node) providing help for B cells and CTLs
Leave the blood and enter battle sites providing help for soldiers on the front line
-roles of helper T cells
communication proteins for the immune system and others:
cytokines
TNF, IFN-γ, IL-4, IL-5, IL-6, IL-10, IL-17, IL-21 are all:
cytokines
senses LPS which is characteristic of Gram-negative bacteria, senses proteins made by certain viruses
TLR4
recognizes double-stranded RNA
TLR3
identifies proteins specific to Gram-positive bacteria
TLR2
Th1 Helper T Cells come in respone to:
viral or bacterial attack
Th2 Helper T Cells come in response to:
Parasitic attack or food contaminated with pathogenic bacteria
Th17 Helper T Cells come in response to:
Fungal attack and some extracellular bacteria
whats the response for intestines under attack?
Th2 Produces IL-4, IL-5, IL-13
Dendritic cells make TGFβand IL-6
Enhance neutrophil response Produces IL-17 and IL-21 is the response of what
Th17 helper t cells
important for the formation of germinal centers. Once germinal centers are formed, these cells are needed to maintain them and to regulate germinal center B cell differentiation into plasma cells and memory B cells.
TfH follicular helper cells
CTL delivers a package with perforin and granzyme B
CTL connects its Fas Ligand to the Fas protein on the target cell
these are:
ways killer t cells kill
enzymes and chemicals from the dying cell are released into surrounding tissue. This is extremely damaging
necrosis
enzymes and chemicals from the dying cell are neatly contained in vesicles. The vesicles are eaten and disposed of by macrophages
apoptosis
