Quiz 5 Flashcards
What is the role of IL-2 in T cell activation?
drives mitosis and clonal expansion
Which T helper cells activate B cells for neutralization?
TH2
TFH
Which T helper cells activate phagocytic cells?
TH1
TH17
Which T helper cells help regulate immune response?
Treg
Depending on the type of infection, different __________ will be released by APC and mediate ___________
cytokines
differentiation into effector T cell subsets
What kinase regulates cytokine mediated T cell differentiation?
JAK
What is the process of cytokine mediated T cell differentiation?
- JAK is phosphorylated
- STAT is phosphorylated and dimerized
- STAT enters nucleus and turns on genes to determine effector function and cytokine production
What released by APCs mediates the differentiation into effector T cell subsets?
cytokines
_____ T cells require stronger activation between B7 and CD28 than ______ T cells
CD8
CD4
What 2 ways can dendritic cells present endogenous antigen to CD8 T cells on MHC I?
- DCs infected with an intracellular pathogen can activate CD8 independently
- DCs not infected can phagocytose intracellular pathogen before it can get into cell and use cross presentation
cytotoxic T cells induce ________ of target cell
apoptosis
What 2 things does cytotoxic T cells contain?
perforin
grazymes
What does FasL do for cytotoxic T cells?
binds to capase thats released into cytosol causing apoptosis of target cell
T/F?? The perforin/granzyme and Fas pathway both cause apoptosis.
True
What 3 things does TH1 induce?
- enhance macrophages
- differentiation of CD8 T cells into cytotoxic T cells
- B cell class switching
What does TH2 induce?
- B cells
granulocytes v. parasitic infections
What does TFH cells induce?
- activate and differentiation of B cells in germinal centers of secondary lymph tissues
What does TH17 induce?
recruitment of neutrophils
What does Treg maintain?
- maintains peripheral tolerance
- immune response
What signal does TH1 secrete to attract macrophages?
INF-gamma
How TH1 deal with macrophages that cannot clear infection?
induces FasL to causes apoptosis of infected macrophages
TH1 cells induce _________ in B cells which activates the classical complement pathway
class switching
TH1 secrete ____ and ______ to induce CD8 T cells to differentiate into CTL
IL-2
INF-gamma
What TH cell is specific for worm parasites (helminths) ?
TH2
What 2 cytokines are produced by TH2 cells and what do they induce?
IL-4 (class switching in B cells for IgE)
IL-5 (degranulation)
What cytokine does TFH cells produce to keep them in secondary lymph tissue?
CXCR5
What is called when TFH recognizes the antigen presented by B cells in secondary lymph tissue?
conjugate pair
What is it called when a cluster of proliferating TFH and B cells form in the germinal center?
primary focus
What cytokine does TH17 produce to recruit neutrophils?
IL-17
What T helper cells help with peripheral tolerance?
Treg
What T helper cells help prevent an overactive immune system?
Treg
How do Treg cells help prevent an overactive immune system?
deactivate CD4 and CD8 cells once they do their job
New cancer treatment decreases the function of what T helper cell?
Treg
What do natural killer T cells (NKT) express?
express TCR (adaptive)
express surface receptors of NK cells (innate)
On NKT cells, what does their alpha/beta receptors recognize?
glycolipids presented on CD1d
How do NKT cells kill infected cells?
- apoptosis via perforin/granzymes
- apoptosis via FasL
What is the T cell immunodeficiency, Omenn Syndome? (inherited)
Rag1/2 are mutated causing VDJ recombination to not occur
What is the T cell immunodeficiency, Mutations in Cytokine Receptor gamma(yc)-chain? (inherited)
prevent JAK3 activation preventing cytokines and important functions for T cells (like development, differentiation, activation and expansion)
What is the T cell immunodeficiency, ADA deficiency? (inherited)
ADA and PNP deficiency inhibiting DNA synthesis preventing cell proliferation
excess dGTP which is toxic to cells causing apoptosis
What is the T cell immunodeficiency, DiGeroge Syndrome? (inherited)
absence of a portion on chromosome 22
impacts thymus development = decreased T cells
What is the T cell immunodeficiency, Bare Lymphocyte Syndrome (BLS)? (inherited)
Class I: TAP (responsible for getting antigens from cytoplasm to ER for class I MHC) is mutated
Class II: MHC II isn’t expressed
What is the T cell immunodeficiency, Mutations in Signaling Proteins? (inherited)
CD3 and ZAP-70 are mutated preventing activation of T cells and clonal expansion
What is the T cell immunodeficiency, immunosuppressant drug cyclosporin? (aquired)
antiviral that prevents activation of NFAT and T cell activation
What is the T cell immunodeficiency, immunosuppressant drug corticosteroid? (aquired)
anti inflammatory that increases expression of IkB and blocks activation of NFkB, impairing T cells to clonal expansion
What is the T cell immunodeficiency, HIV and AIDS? (aquired)
reverse transcriptase of HIV infected CD4 cells and induces immunosuppression
What do drugs that treat HIV target?
reverse transcriptase
What 2 ways are self reactive T cells controlled?
negative selection
peripheral tolerance
What is an example of failure of central tolerance of T cells?
lack of AIRE results in incomplete negative selection causing autoimmunity
What is APECED?
absence of AIRE resulting in autoreactive cells that lead to malfunctions of endocrine glands that express tissue specific genes
What are 2 examples of failure of peripheral tolerance of T cells?
lack of CD28–B7 = no peripheral tolerance = anergic T cells and autoreactive T cells
lack of CTLA4 = prevents Treg = overactive T cells
What is IPEX?
mutation in FOXP3 causing loss of Treg resulting in autoimmune response
