Cell-Mediated Immunity Flashcards
What cytokine is responsible for mucous production and peristasis in a Th2 response?
IL-13
What is the primary cytokine released by Th1 cells? What is the function of the cytokine?
IFN-gamma targets macrophages to promote cytotoxicity
What cytokines stimulate differentiation to Th2 T cells?
IL-4 (by Eosinophils and Mast Cells)
What is the primary cytokine released by Th1 cells? What is the function of the cytokine?
IFN-gamma targets macrophages to promote cytotoxicity
Lymphocytes circulate throughout the body to secondary lymphoid organs. What is the process by which naive T cells exit the bloodstream and enter the cortex of a lymph node?
Controlled by interactions between L-selectin on the lymphocyte and carbohydrate ligands, GlyCAM-1 and CD34 on endothelial venules. Chemokines activate LFA-1 on the lymphocyte to bind ICAMs on the endothelial venule. The lymphocyte is then pulled into the tissue.
Th2 is associated with what types of infections?
Infections by helminths
What markers characterize an effector T cell?
CD25, IL-2, CD40L, CD69 with the absence of CCR7
The T-cell immune response requires three steps. What are these steps?
Activation, proliferation, differentiation
Where are naive T cells activated?
Secondary lymphoid tissues
What receptors on the CD4 T cell bind cytokines and mediate differentiation to a Th1 Cell?
STAT1 & STAT 4
What interaction is required activation and survival of naive T cells? What is the result of this interaction?
B7 on the APC with CD28 on the T cell. This leads to production of IL-2 and its high-affinity receptor on the T cell that receives cytokines released by the APC for differentiation
What markers characterize a memory T cell?
CD45RO, low CD62L, CD44
What cytokines stimulate differentiation to Th1 T cells?
IL-12 (by NK cells)
STAT4 & STAT1 on the T cell bind cytokines
What markers characterize Naive T cells?
L-selectin, CCR7, CD45RA with the absence of CD25, CD44, CD69, & CD45RO
How does the response of an activated CD4 T cell differ from that of a CD8 T cell?
CD4 T cells induce intracellular signaling and changes in gene expression. CD8 T cells release cytokines, but for cytotoxicity and not changes in gene expression.
What is the function of the PD-PDL interaction?
Inhibits the T cell response
What receptors on the CD4 T cell bind cytokines and mediate differentiation to a Th2 Cell?
STAT 6
True/False. Th2 responses are associated with disseminated infection and higher pathogen count.
True. Conversely, a Th1 response is associated with recovery or controlled infection.
The presence of IgG is associated with what effector T cell response?
Th1
What are the mechanisms by which neutrophils can kill pathogens?
Phagolysosome formation or neutrophil extracellular traps
What receptor activates NK cells to induce apoptosis? What receptor inhibits apoptosis?
Activates - CD16
Inhibits - MHC I
CD8 T cells can induce apoptosis by exoticizing granule contents. What is another mechanism by which CD8 cells induce apoptosis?
Fas ligand expressed on CD8 T cells bind to the Fas death receptor on cells and induce apoptosis.
How do Helper T cells activate and enhance the function of macrophages, dendric cells, and B cells?
CD40L on T cells binds CD40 on APCs and enhances their functions.
The B7-CD28 interaction is required to stimulate the immune response. What co-stimulatory molecule slows the immune response to regulate T cell activity?
CTLA-4
What is the funciton of IL-10?
Anti-inflammatory cytokine that inhibits the Th1 response and works in conjunction with TGF-beta
A person is diagnosed with Mycobacterium tuberculosis and develops granulomas in the lungs. What type of cell-mediated response is likely present?
Th1 - chronic stimulation of T cells and macrophages by IFNgamma
The leproid version of Mycobacterium leprae infection would be associated with what cell-mediated immune response?
Th2 - higher pathogen count and disseminated infection
A patient has a high Th17 cell count. What type of infection is this patient likely fighting?
Extracellular bacterial or fungal infection
Activation of a T cell by an antigen is the first step in the maturation of a naive T cell. What molecules are involved with the interaction?
MHC with the antigen binds to the T cell receptor. CD4 serves as a coreceptor that binds an invariant region of MHC.
What are the primary cytokines released by Th17 cells? What is the function of the cytokine?
IL-17, IL-22.
IL-17 recruits neutrophils. IL-22 induces epithelial defenses.
What receptors on the CD4 T cell bind cytokines and mediate differentiation to a Th1 Cell?
STAT3
What antibodies are produced in a Th2 response?
IgE
What drives differentiation of naive T cells?
Cytokines
What cytokines stimulate differentiation to Th17 T cells? What receptors on the CD4 T cell mediate this differentiation?
IL-1, IL-6, IL-23, TGF-beta (by Dendritic Cells)
CD8 T cells can induce apoptosis by exoticizing granule contents. What types of granules are released?
Perforins - Form pores in the target cell
Granzymes - Activate caspases that induce apoptosis
What antibodies are produced in a Th17 cell-mediated immune response?
IgA
What are the primary cytokines released by Th2 cells? What is the function of the cytokine?
IL-4, IL-5, IL-13.
IL-4 & IL-13 stimulate class switching to IgE. IL-5 activates eosinophils and mast cells
A patient is diagnosed with Chlymadia, an intracellular pathogen. What effector T cell will be induced?
Th1
What cells are activated by a Th1 response?
Macrophages & B cells
The presence of what protein indicates an active APC?
B7
What cytokine activates macrophages via the classical pathway?
IFN gamma
