During positive selection, if the selecting MHC molecule is class I, then a. gene expression of CD8 is halted b. the thymocyte is committed to the CD8 lineage c. continued α-chain rearrangement occurs on the other locus to produce a mature T cell with two receptors d. the thymocyte differentiates into a CD4 T cell e. gene expression of CD4 is enhanced.

During positive selection, if the selecting MHC molecule is class I, then a. gene expression of CD8 is halted b. the thymocyte is committed to the CD8 lineage c. continued α-chain rearrangement occurs on the other locus to produce a mature T cell with two receptors d. the thymocyte differentiates into a CD4 T cell e. gene expression of CD4 is enhanced.

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter12: Body Defenses

Section12.4: B Lymphocytes: Antibody-mediated Immunity

Problem 3CYU

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Similar questions

The high degree of polymorphism in MHC class I molecules that present antigens to CD8 T cells is found in _______ because _______ is/are monomorphic: a. β2-microglobulin; the heavy chain b. both the α and β chains; none c. HLA-DOβ; HLA-DOα d. the heavy chain; β2-microglobulin e. HLA-E and HLA-G; HLA-F.
Which of the following statements regarding CD4 is incorrect? a. MHC class II molecules present antigens to CD4 T cells. b. CD4 is the receptor used for HIV entry into CD4 T cells. c. CD4 is made up of two separate membrane-bound chains. d. Late in the progression of an HIV infection, the number of CD4 T cells in the circulation diminishes. e. CD4 is referred to as a T-cell co-receptor.
If a T-cell receptor on a double-positive thymocyte binds to a self-peptide:self-MHC class I complex with low affinity the result is a. negative selection and apoptosis b. cell proliferation c. rearrangement of the second β-chain locus d. positive selection of a CD4 T cell e. positive selection of a CD8 T cell.
Homing of effector T cells to inflamed tissue is facilitated by the upregulation of _____ on the surface of the effector T cell. a. VLA-4 b. L-selectin c. CD28 d. VCAM-1 e. B7.
Loss-of-function mutations in the common γ chain (γc) gene are particularly damaging to the immune system because _____. a. homozygotes and heterozygotes fail to make sufficient γc protein for lymphocyte activation b. T cells fail to develop in the thymus c. T-cell dependent and T-cell independent B-cell responses are inhibited d. multiple cytokine receptors cannot signal e. MHC class II genes are unable to be expressed.
Which of the following is true about antigen presentation, MHC involvement or T cell activation? Check all that apply. A. TCR on CD8 T cells recognizes MHC II-peptide complexes as signal 1 for T cell activation B. Signal 2 and 3 for T cell activation involve interaction of B7.1/B7.2 (CD80/CD86) on APC with CD28 on T cells and cytokine release, respectively C. Many cell types express MHC I and load antigen on it, whereas professional APC present antigen loaded on MHC II D. CD4 interacts with MHC II and CD8 with MHC I for antigen presentation by APC E. TCR on CD4 T cells recognizes MHC II-peptide complexes as signal 1 for T cell activation
Which of the following statements regarding T cells activated by specific antigen is incorrect? a. They receive co-stimulatory signals through CD28. b. They suppress expression of sphingosine 1-phosphate (SIP). c. They take several days before differentiating into effector T cells. d. They cease to secrete and respond to interleukin-2 (IL-2). e. They begin to express CTLA4, which serves to limit T-cell proliferation.
There are different pathways through which B cells can be activated, one of which is CD4 T - independent cells, in which the antigen is large and has repeating patterns that make crosslinking and activation of several BCRs at the same time. A.true B.false
The T-cell co-receptor CD4 interacts with _______ bound to the surface of _______: a. MHC class I; antigen-presenting cells b. MHC class I; T cells c. MHC class II; antigen-presenting cells d. MHC class II; T cells e. none of the above.
All of the following are characteristic of regulatory T cells except a. they express CD25 b. they facilitate the proliferation of naive T cells interacting with the same antigen-presenting cell c. they express CD4 d. they express the transcriptional repressor FoxP3 e. they express MHC class II-restricted T-cell receptors specific for self antigen.
MHC restriction is best described as a. elimination of thymocytes bearing T-cell receptors that are unable to interact with self-MHC molecules b. preferential survival and proliferation of thymocyes that survive negative selection c. T-cell recognition of a peptide antigen only when it is bound to a particular form of MHC molecule d. a state of non-responsiveness to a peptide antigen e. a condition in which either MHC class I or class II molecules are not expressed on cells.
Which of the following is NOT true of Innate Lymphoid Cells (ILCs)? A) Each ILC type responds to a different category of pathogens. b.)) ILCs are derived from the common lymphoid precursor. c. )) ILCs rearrange their antigen receptors in a similar way to T-cells. d. ))Each ILC type is distinguished by the cytokines that it produces. e. ))Development of each ILC type is driven by unique transcription factors.