Description Basic Immunology Functions and Disorders of the Immune System Test Bank 4th Edition – Abbas Sample Chapter Abbas: Basic Immunology, 4th EditionAbbas: Basic Immunology, 4th Edition Chapter 03: Antigen Capture and Presentation to Lymphocytes Test Bank MULTIPLE CHOICE 1. Antigen-presenting cells (APCs) perform which of the following functions in adaptive immune responses?A. Display major histocompatibility complex (MHC)-associated peptides on their cell surfaces for surveillance by B lymphocytesB. Initiate T cell responses by specifically recognizing and responding to foreign protein antigensC. Display MHC-associated peptides on their cell surfaces for surveillance by T lymphocytesD. Display polysaccharide antigens on their cell surfaces for surveillance by B lymphocytesE.

2012, 4th edition of Basic Immunology Functions and Disorders of the Immune System Latest new. See A Sample. What: TEST BANK; ISBN:; Year Published: 2012; Authors: Abbas; Edition: 4th. Category: Medical Test Banks Tags: immunology, Infectious Diseases, medication, sciences. Link full download: basic-immunology-functions-and-disorders-of-the-immune-system-4th- edition-by-abbas Test Bank for Basic Immunology Functions and Disorders of the Immune System 4th Edition by Abbas Chapter 04: Antigen.

Secrete peptides derived from protein antigens for binding to T cell antigen receptors ANS: CAntigen-presenting cells (APCs) degrade proteins derived from either the extracellular environment or the cytoplasm. They form complexes of peptide fragments of these proteins with major histocompatability complex (MHC) molecules and display these complexes on their cell surfaces, where T cells can “see” them. Neither processing nor MHC association of protein or polysaccharide antigens by B cells is required for recognition. APCs do not distinguish between self and foreign proteins and will display peptides derived from a sampling of all cytoplasmic and extracellular proteins. APCs do not secrete peptide antigens, and T cell antigen receptors do not bind free peptides. A child who suffers from a persistent viral infection is found to have a deficiency in lymphocyte production and very few T and B cells. Other bone marrow–derived cells are produced in normal numbers, and MHC molecule expression on cells appears normal.

Transfusion of mature T cells from an unrelated donor who had recovered from a previous infection by the same virus would not be expected to help the child clear his infection. Which one of the following is a reasonable explanation for why this therapeutic approach would fail?A. Viral infections are cleared by antibodies, not T cells.B. The patient’s own immune system would destroy the transfused T cells before they could respond to the viral infection.C. T cells recognize peptides, not viral particles.D. Donor T cell viral antigen recognition is restricted by MHC molecules not expressed in the patient.E.

In responding to the previous infection, the donor would have used up all his T cells specific for that virus. ANS: DT cells are “self MHC restricted,” meaning they specifically recognize infected cells that display microbial peptides displayed by self MHC molecules.

There may be no MHC molecules shared by donor and patient, and therefore the transfused T cells would not recognize virus-infected cells in the patient. Because the patient has very few B cells and T cells, his immune system is unlikely to be able to recognize and destroy (i.e., “reject”) the transfused T cells. T cells do not recognize structures on intact viral particles but rather peptides derived from viral proteins bound to MHC molecules.

Prior viral infection in the donor would be expected to generate memory T cells specific for the virus. Many vaccines now in development will include highly purified, recombinant, or synthetic peptide antigens. These vaccine antigens are expected to stimulate highly specific immune responses, but they are less immunogenic than vaccines containing intact killed or live microbes. Adjuvants are substances added to such vaccines to enhance their ability to elicit T cell immune responses. Which of the following statements about adjuvants is NOT correct?A. Adjuvants induce local inflammation, thereby increasing the number of antigen-presenting cells (APCs) at the site of immunization. John Deere Service Advisor Keygen on this page. B.

Adjuvants stimulate the expression of costimulators on local APCs.C. Adjuvants enhance local production of cytokines that promote T cell activation.D. Adjuvants prolong the expression of peptide-MHC complexes on the surface of APCs.E. Adjuvants bind to T cell antigen receptors and promote their proliferation. ANS: EAdjuvants are not necessarily T cell antigens. Some adjuvants may be T cell antigens, but their adjuvant activity is unrelated to their ability to be recognized, in peptide form, by T cells. Adjuvants are surrogates of the innate immune response to a microbe, required along with antigen component of a vaccine for naive T cell activation.