Regulation of Immune Response Flashcards
With decreased IL2R on T cells, what happens to them?
Apoptosis
Reduced exposure to antigen cause decreased expression of what cytokine and receptor?
IL2 and IL2R
At low levels of MHC and B7 expression on APC’s, what is the fate of T cells that bind to them?
Anergy or deletion
If a dendritic cell is expressing CD86, MHC, CD40, and CCR7 at high levels, what is it producing as cytokines?
IL12, TNFa
If a dendritic cell is expressing MHC, CD86, CD40 and CCR7 at low levels, what is the net effect?
anergy or deletion of T cells
What is deficient in IPEX and what is the effect?
Loss of FOXp3 so can’t make Tregs
To be able to suppress, Tregs need to be stimulated via their _____
TCR
What are the four ways in which Treg cells dampen immune response?
- Arrest T cells via cytokines
- Sequester IL2
- Cytolyse T cells via granzymes
- Stimulate production of kynurenin via dendritic cells, killing T cells
What cytokines are produced by Tregs to dampen T cell response?
IL-10
TGFb
IL-35
Grave’s disease, the overstimulation of thyroid hormones, is mediated by what cell type?
B cells’ autoantibodies
What are the four mechanisms by which B cells are selected for self tolerance?
- Clonal deletion after recognition of self antigen (cell death)
- Antibody receptor editing
- Intrinsic downregulation of BCR and upregulation of CD5 (leads to death due to inactivation)
- Lack of T cell help
Antigens exposed subcutaneously or intradermally evoke what kind of response?
Active immune response
Antigens given intravenously, orally, or aerosol invoke what kind of response?
Tolerance, or invoke a secondary CD4+ T cell response
This cytokine, when introduced early on in the immune response, can trigger Th2 differentiation.
IL-4
This cytokine, when introduced early on in an immune response, can trigger Th1 profile switch.
IFNa (or IL12)
Th2 cytokines promote what kind of immune response?
Humoral, or mucosal activation
What type of response is due a B cell that has its FcgRIII bound?
downregulation
What types of chemokine receptors are expressed by Th1 cells?
CXCR3, CCR5
What types of chemokine receptors are expressed by Th2 cells?
CCR3, CCR4, CCR8
What types of chemokine receptors are expressed by Th17 cells?
CCR6
What cytokines inhibit immune response in certain parts of the body?
IL10 and TGFb
What is the chemical that prevents NK cell activity the anterior chamber of the eye?
MIF (migratory inhibition factor)
Deficiency in C1q, C1r, and C1s causes predisposition toward what conditions?
Systemic lupus erythematosus and lupus nephritis
Deficiency in C3 leads to increased disposition toward what?
bacterial infection
What receptor defect causes an increase of TNFa when binding lipopolysaccharide?
TLR4
Individuals with decreased IL-7R expression result in what defect?
Less T cells
With a defect in a gamma chain (a common receptor chain) what cells are effected?
T, NK
B function decreased as a result
Mutations in an IFNg receptor or IL12 receptor are predisposed to what infection?
Mycobacteria
The gamma chain links with what important intracellular protein?
Jak3
A polymorphism in the TNFa promoter gene is linked with the following three infections:
Lepromatous leprosy
Mucocutaneous leishmaniasis
Death from meningococcal disease
Individuals homozygous for this mutation are highly resistant to HIV.
CCR5
