Immunology Test 3 Study Guide

Which B cell subset makes antibody responses to protein antigens and requires T cells help?

Follicular B cells **remember they meet at the edges of follicular zones of germinal centers

Loading of antigen peptides into human MHC class II peptide binding pocket is mediated by which of the following molecules?

HLA-DM

Complement Activation, endothelial damage, inflammation and thrombosis in response to a graft insertion within minutes is considered:

Hyperacute Rejection

Immunoglobin's heavy chain class switching results in producing different classes of antibodies to effectively neutralize the microbes and toxins. Mucosal Immunity is best carried on by:

IgA

Little Johnny was playing in the backyard, suddenly he was stung by a bee, immediately there was redness and swelling and an anaphylaxis shock. This reaction is an example of:

IgE-mediated hypersensitivity

Which of the following best describes Type I Hypersensitivity

Immediate hypersensitivity which is caused by the release of mediators from mast cells triggered by antigen cross-linking of immunoglobulin E bound to IgE receptors

Which of the following statements best describes the T-dependent antibody response?

It is the response of B lymphocytes to a protein antigen and characterized by isotype-switched, high affinity antibodies; memory B cells, long-lived plasma cells

The activation of the B lymphocytes following contact with the antigen involves all of the following except:

MHC class II molecules

The terminal pathway of the complement activation results in the production of:

Membrane-Attack Complex (MAC)

Allergists sometimes treat patients by injecting them with the very allergen they are sensitive to it. Why?

The allergen may trigger the production of IgG, and thus prevent IgE-triggered responses

Immunological Tolerance to different self antigens may be induced when developing lymphocytes encounter these antigens in the generative (central) lymphoid organs. One of these mechanisms of this tolerance is the generation of regulatory lymphocytes which takes place during the development of:

The helper T lymphocytes

Pathgen-associated molecular patterns (PAMPS)

are found on many microorganisms

The CD8+ cytolytic T lymphocyte (CTL) uses different mechanisms to kill target cell. Which of the following intracellular molecules activate the cascade cascade:

granzymes

The life cycle of HIV consists of the following sequential steps:

infection of cells, production of viral DNA and its integration into the host genome, expression of viral genes, and production of viral particles

The DIRECT effector functions of antibodies include all of the following EXCEPT:

inflammation Direct effector functions: - neutralization of microbes and toxins - opsonization and phagocytosis of microbes - antibody-dependent cellular cytotoxicity (ADCC) - complement activation

Antigens are:

molecules that binds to an antibody or a T-cell Receptor

All of the following are effector cells of the adaptive immune system EXCEPT:

regulatory T lymphocytes Effector Cells: "perform effector functions such as secreting cytokines (helper T cells); killing microbes (macrophages); killing microbe-infected host cells (CTLS), or secreting antibodies (plasma cells)

X-linked agammaglobulinemia is characterized by

severe decrease or absence of antibodies

Helper T cells that have been activated to differentiate into effector cells interactions with antigen stimulated B lymphocytes at

the edges of lymphoid follicles

Peripheral Tolerance in T lymphocytes may take place by which of the following mechanisms

ALL OF THE ABOVE - cell-intrinsic anergy - suppression by regulatory T cells - deletion (apoptotic cell death)

Which of the following is NOT true of the gene segments that combine to make up a heavy-chain gene?

A 'v' segment and a 'J' segment are preselected by an antigen to make up the variable-region portion of the gene

The initiation of T cell responses requires multiple receptors on the T cells recognizing ligands on APCs. The MHC molecule located around the peptide-binding cleft is recognized by the:

CD4 or CD8 molecules

CD40 ligand (CD154) is expressed by which of the following?

Activated T lymphocytes

Inherited Risk for most autoimmune diseases is attributable to multiple gene loci, the risk of development of ankylosing spondylitis, an autoimmune diseases of the spine, is associated with

Alleles of the major histocompatibility complex (MHC) locus

All of the following statements about the T-cell antigen receptor(s) are true EXCEPT:

Antigen recognition is mediated by the Variable (V) regions of the heavy and light chains

Host cytolytic T lymphocytes against tumors are often induced by recognition of tumor antigens on host __________, which ingest tumor cells or their antigens and present the antigens to T cells?

Antigen-Presenting Cell

Major Histocompatibility Complex (MHC) class II molecules are expressed on all of the following cells except:

B lymphocytes Expressed on: - Macrophages - T lymphocytes - Dendritic Cells - Kupffer cells

Activated T lymphocytes express high affinity Interleukin -2 Receptor (IL-2R) complex, which is composed of which of the following chains?

Beta and gamma(c) chains

Central Tolerance by apoptosis of immature B lymphocytes which may recognize self-antigen takes place in the:

Bone Marrow

Captain America is a hero, while fighting against crime he was wounded and brought to hospital. He needed blood transfusion. During the transfusion, Captain America start to suffer from fever, hypotension, anxiety, and red-colored urine. You, being a smart Aggie physician and took Dr. Omrans immunology class, diagnosed the situation as mismatched blood transfusion reaction and you took the appropriate methods to save Captain America. The phenomenon can be explained as:

Both, a hyperacute graft rejection and an antibody-mediated/cytotoxic hypersensitivity

Analysis of Cytokine production by helper T (Th) cells has revealed that functionally distinct subsets of CD4+ T cells exist that produce different cytokines. The IL-4, IL-5, and IL-13 are the signature cytokines of:

CD4+ Effector T lymphocytes Type 2 (TH2)

Human Immunodeficiency Virus (HIV), the causative agent of acquired Immunodeficiency syndrome (AIDS) mainly affects the

CD4+ T lymphocytes and macrophages

The effector CD4+ cells (TH1) that recognize macrophage-associated antigens activate the macrophages by:

CD40L-CD40 interaction and IFNgamma

All of the following may be considered as tumor antigens EXCEPT:

Chemical carcinogens Tumor Antigens: - products of diverse mutated genes - products of oncogenes or mutated tumor suppressors - aberrantly expressed proteins - oncogenic viral antigens

A previously healthy 8-year-old is infected with an upper respiratory tract virus for the first time. During the first few hours of infection, which one of the following events occur?

The innate immune system responds rapidly to the viral infection and kept viral infection under control

The following statements are true about peripheral or secondary lymphoid tissues EXCEPT:

Where B and T lymphocytes mature True: - refer to tonsils, Peyer's patches, and spleen - refers to activated lymph nodes along the lymphatics - where naive B and T lymphocytes come in contact with the antigen

DiGeorge Syndrome (which is a congenital disease) is associated with:

absence of thymus gland

The tuberculin test, poison ivy, and the I diabetes are delayed type hyper sensitivity reactions. This makes them:

cell-mediated hypersensitivity

During the inflammatory process, leukocytes extravasation goes through the following phases: rolling Adhesion, Tight Adhesion, Transmigration, and Chemoattraction. Leukocyte migration to inflammatory site is the direct involvement of:

chemokine activation

All of the following are true with respect to IgE molecules, EXCEPT which one?

they will cross the placenta and fix complement