Which MHC class is necessary for antigen recognition by CD4+ T cells? A.HLA-A, HLA-B, HLA-C

B. MHC class III

C. MHC class I

D. MHC class II

D. MHC class II

Amino acid variation among MHC class II allotypes that present antigens to CD4 T cells is concentrated

A. where the MHC contacts the CD4 and CD8 co-receptors

B. in the beta chain, because the alpha chain is monomorphic

C. the alpha chain because the beta chain in monomorphic

D. where the MHC molecule contacts peptide and the T cell receptor

D. where the MHC molecule contacts peptide and the T cell receptor

Which MHC molecule(s) contain(s) two transmembrane domains?

A. MHC class II

B. neither MHC class I nor MHC class II

C. both MHC class I and MHC class II

D. MHC class I

A. MHC class II

MHC molecules have promiscuous binding specificity. That means:

A. peptides bind with low affinity to MHC molecules

B. when MHC molecules bind to peptides, they (the peptides) are degraded

C. a particular MHC molecule has the potential to bind to different peptides

D.many alleles of MHC genes exist in the population

C. a particular MHC molecule has the potential to bind to different peptides

Peptides that bind to a particular MHC molecule molecule usually have either the same or chemically similar amino acids at two to three key positions that hold the peptide tightly in the peptide binding groove of the MHC molecule . The amino acids in these key positions are called __________.

A. pockets

B. anchor residues

C. alleles

D. restriction residues

E. invariant chains

B. anchor residues

Question 61 / 1 pts

Which of the following distinguishes the immunoproteosome from the constitutive proteosome?

A. it contains inducible catalytic subunits induced by cytokines to alter cleavage specificity

B. it transports peptides via TAP without the need for ATP

C. it is located in the ER rather than the cytosol

D. it directly loads peptides onto MHC class II

A. it contains inducible catalytic subunits induced by cytokines to alter cleavage specificity

Which of the following is a mechanism to generate antibody diversity in naive B cells?

A. nucleotide addition by TdT

B. all of these are mechanisms to generate antibody diversity in naive B cells

C. heavy chain/light chain combinatorial diversity

D. somatic recombination

B. all of these are mechanisms to generate antibody diversity in naive B cells

Which region of the antibody is involved in VDJ recombination?

A. the effector region

B. the hinge region

C. the hypervariable region

D. the constant region

C. the hypervariable region

Junctional diversity is mediated by which enzyme?

A. RAG1/2

B.DNA polymerase

C. TdT

D. recombinase

C. TdT

When do γδ T cells develop?

A. when the γ and δ chains successfully rearrange before the β chain rearranges

B. when successful rearrangement of γ and δ chains occurs before successful rearrangement of both the α and the β chains

C. when they express CD3ε, but not CD3α

D. when the Fc region rearranges before the Fab region

A. when the γ and δ chains successfully rearrange before the β chain rearranges

What drives hematopoietic precursors to become T cells rather than B cells?

A. activation of Pax-5

B. expression of AIRE

C. engagement of Notch receptors

D. signaling of IL-7

C. engagement of Notch receptors

At what stage of T-cell development is the pre-TCR expressed?

A. Double Negative (DN)

B. Double Positive (DP)

C. Pro-T cell

D. Single Positive (SP)

A. Double Negative (DN)

Of the following, which antibody isotype is expressed first?

A. IgE

B. IgG

C. IgA

D. IgM

D. IgM

During inflammation, TNFα is known to upregulate E-selectin on endothelial cells. Which trafficking step would be most impacted by this increased expression?

A. rolling

B. diapedesis

C. chemokine secretion

D. firm adhesion

A. rolling

After production, naïve lymphocytes travel briefly through the blood to the

A. spleen

B.mucosal associated lymphoid tissue

C. lymph nodes

D. all of these answers are correct

D. all of these answers are correct

What critical role does the fibroblastic reticular cell (FRC) network play?

A. it produces IL-8 to recruit neutrophils

B. it inhibits chemokine gradients in the lymph node

C. it blocks S1P-S1PR1-mediated egress

D. it helps facilitate interaction between the dendritic cell and the T cell in secondary lymphoid tissues

D. it helps facilitate interaction between the dendritic cell and the T cell in secondary lymphoid tissues

Signal 2 of the three-signal model of CD4+ T cell activation corresponds to:

A. MHC class I-peptide recognition

B. CD80/CD86 on the APC binding to CD28 on the T cell

C. IFNγ binding to its receptor

D. IL-2 secretion by the T cell

B. CD80/CD86 on the APC binding to CD28 on the T cell

Activation of the JAK/STAT pathway during T cell polarization leads to:

A.rearrangement of TCR genes

B. expression of lineage-defining transcription factors

C.direct phosphorylation of ITAMs

D. increased expression of S1PR1

B. expression of lineage-defining transcription factors

At the immunological synapse of the T cell, which of the following is responsible for adhesion?

A. dSMAC

B. pSMAC

C. cSMAC

D. iSMAC

B. pSMAC

Which type of helper T cell inhibits/reduces inflammation?

A. Tregs

B. Th17

C. Th1

D. Th2

A. Tregs

which statement correctly contrasts B cells and T cells?

A. B cells are MHC-restricted; T cells are not.

B. B cells can recognize unprocessed antigen; T cells require peptide-MHC

C. both require antigen presentation by dendritic cells to activate

D. T cells secrete antibodies; B cells secret cytokines

B. B cells can recognize unprocessed antigen; T cells require peptide-MHC

In terms of B cells activation, immunoreceptors tyrosine-based activation motifs (ITAMs) are located on ----.

A. breakdown products of C3b deposited on pathogen surfaces

B. the cytoplasmic tails on IgM

C. the cytoplasmic tails of Iga and IgB

D. tyrosine kinases Blk, Fyn, and Lyn

C. the cytoplasmic tails of Iga and IgB

all of the following processes occur in mature B cells AFTER antigen encounter except:

A. Isotype switching

B. affinity maturation

C. somatic recombination

D. proliferation

E. somatic hypermutation

C. somatic recombination

what is the role of the Iga/IgB heterodimer that is associated with the BCR:

A. it contains ITAM motifs that initiate intracellular signaling upon antigen binding

B. it forms the FC region of secreted antibody

C. it is required for somatic hypermutation

D. it provides antigen-binding specificity

A. it contains ITAM motifs that initiate intracellular signaling upon antigen binding

According to the clonal selection theory, once a B cell bonds its specific antigen it will:

A. undergo receptor editing to increase affinity

B. immediately class-switch to IgG

C. proliferate to form clones bearing the same BCR

D. express both MHC class II and MHC class I

C. proliferate to form clones bearing the same BCR

CTLs mediate a powerful and lethal immune response to infected host cells Which of the following steps is not involved with CTL activation and function?

A. perforin and granzymes are released, triggering apoptosis in the infected cell.

B. histamine is released from cytoplasmic granules, recruiting macrophages to the site of infection

C. antigen is presented to both T_c and T_H cells

D. antigen presented with MHC class I is recognized by CTLs

B. histamine is released from cytoplasmic granules, recruiting macrophages to the site of infection

Perforin-deficient mice cannot form pores in target-cell membranes. which killing mechanism remains intact in these animals

A. complement-mediated lysis

B. antibody dependent cell-mediated cytotoxicity

C. Fas/FasL -mediated apoptosis

D. NK cell "missing self" recognition

C. Fas/FasL -mediated apoptosis

CTLs (cytotoxic lymphocytes) and NK (natural killer) cells have many similarities in terms of how they function Yet, there are some differences between them. Which of the following is an important difference between CTs and NK cell!

A. only one of these kills host cells by stimulating apoptosis

B. only one of them is derived from a lymphoid progenitor cell

C. only one of these recognizes and binds to MHC class !

D. only one of these has an antigen-specific receptor

D. only one of these has an antigen-specific receptor

at which of the following locations are naive T_C cells activated to become CTLs?

A. Bone marrow

B. lymph nodes

C. blood

D. thymus

B. lymph nodes

What would be the outcome if a B cell were to bind an antibody via surface-bound Fc gamma receptor 28 (FcyR2B; containing ITIM), while simultaneously binding a pathogen with its cell receptor (BCR, containing an ITAM?

A. a positive signal leading to isotype switching and the production of IgG, IgA, and/or IgE antibodies

B. a negative signal leading to inhibition of antibody production

C. a positive signal leading to the production of low-affinity antibodies

D. a positive signal leading to somatic hypermutation and production of high-affinity antibodies

B. a negative signal leading to inhibition of antibody production