Chapter 8: T Cell-Mediated Immunity

Match each cytokine or cytotoxin with the correct effector T cell that produces it. Some cell types may have more than one correct answer and some cytokines/cytotoxins may need to be matched to more than one cell type.

CD8 T cells : IFN-γ, lymphotoxin and perforin TH17 cells:IL-17 TH2 cells::TGF-β, IL-10 and IL-4 Treg cells : IL-10 and TGF-β TH1 cells : IFN-γ and lymphotoxin

What is the name given to the type of protein made by T cells that kills a target cell?

Cytotoxic

Which of the following are correct statements about Treg-cell function?

Treg-cell function involves interaction with dendritic cells. Treg-cell function is necessary to sustain life. Treg-cell function involves contacting effector T cells.

What cell-surface molecule ensures that effector T cells home to infected tissues?

VLA-4 VLA-4 replaces L-selectin in effector T cells. VLA-4 binds to adhesion moleculeson the surface of activated endotheliumat sites of inflammation. This ensures that circulating effector T cells home to inflamed tissues but not to secondary lymphoid organs.

How do the inhibitory proteins called suppressors of cytokine signaling (SOCS) facilitate their suppressive effects?

by binding to and blocking phosphorylated tyrosine residues on cytokine receptors and janus kinases

What is involved in shaping the effector CD4 T-cell response?

cytokines made during the innate immune response tissue of origin of the activated dendritic cell the nature of the pathogen

Which type of bone marrow-derived cell collects pathogen antigens at the site of infection and delivers them to secondary lymphoid tissues?

dendritic cells

In the lymph node, what is the primary role of macrophages?

filter the lymph

What clinical feature is characteristic of lepromatous leprosy?

hypergammaglobulinemia High levels of pathogen-specific antibodies are made in lepromatous leprosy, but they are inaccessible to the intracellular bacteria, leading the bacteria to multiply unchecked and causing a disease that is eventually fatal.

What is associated with activated macrophages?

pathogen killing by hydrolytic degradative enzymes increased synthesis of oxygen radicals changes in gene expression production of nitric oxide (NO) more efficient fusion of phagosomes with lysosomes

Which of the following are correct statements about potential outcomes of virus-derived peptides that are processed by dendritic cells via the endocytic pathway?

-Viral peptides are presented by MHC class I molecules by cross-presentation after their delivery to the endoplasmic reticulum. -Viral peptides are presented by MHC class II molecules after they intersect the endosomal route of transport to the cell surface.

At the site of infection, immature dendritic cells are activated through interaction of their receptors such as ________________ with pathogen constituents. Migrating dendritic cells are induced to leave the lymph and enter a secondary lymphoid tissue by ___________________ acting on ____________________. Mature or activated dendritic cells lose their ability of _______________ but gain the capacity of __________________________

1. Toll-like receptors 2.the chemokine CCL21 3.the receptor CCR7 4.phagocytosis 5.activation of naive T cells

Many cytokines signal through a pathway in which an intracellular protein phosphorylates and activates a transcriptional activator. The process of cytokine signaling begins with cytokine binding to its receptor, thereby dimerizing the

1. cytokine receptor 2. JAK 3.STAT 4.nucleus

Naive T cells that have left the______Naive T cells that have left the_____are activated by antigen on_____in the area of the lymph node called the

1. thymus 2.arterial blood 3.dendritic cells 4.cortex

Large multicellular parasites are eradicated from tissues and body surfaces by the production of IgE, which works with basophils, mast cells, and eosinophils. Its production is dependent on TH2 CD4 T cells, which are differentiated from naive T cells under the influence of cytokine IL-4.

IGE

Which of the following are correct statements regarding the cytokine interleukin-2 (IL-2)?

IL-2 acts as an autocrine cytokine. The synthesis of IL-2 requires the transcription factor NFAT. Co-stimulation increases its synthesis by about 100-fold. It is needed for proliferation and differentiation of T cells.

Which of the following are correct statements about Treg cells?

In the presence of TGF-β, naive CD4 T cells undergoing activation can commit to the Treg cell lineage. Some Treg cells commit to regulatory function during thymic development. Treg cells play an important role in minimizing secondary infections.

Click on the parts of the following figure that represent the route or entry points for naive T cells to enter a lymph node.

Naive T cells can move from one lymph node to another if they are connected via the lymphatics. They travel from an 'upstream' lymph node through the efferent lymphatic vessel and enter a 'downstream' lymph node through an afferent lymphatic vessel.

What effector T cell does not act at an infected site outside lymphoid tissue?

TfH

What is the term for when TH1 or TH2 cells dominate as a result of cytokine-driven positive feedback?

polarized response

What is the most effective way that B cells obtain antigen for the purpose of antigen presentation to TFH cells?

using surface immunoglobulin as an endocytic receptor