Reference no: EM131036398
1 Considering development of CD4+ T cells, which of the following is incorrect?
A) their antigen specificity is determined prethymically
B) they are derived from CD8+CD4+ precursors
C) they undergo negative selection in the thymus
D) they are positively selected on thymic stromal cells
2 Which of the following statements is correct ?
A) the αβ receptor transduces a signal in to the T cell
B) T cells with fully rearranged α and β receptors are not found in the thymus
C) T cells expressing the γδ receptor are found only in the thymus
D) CD3-ζζ transmits intracellular signals in T cells
3 Which of the following cell types is not found in the thymus
A) Stromal cells
B) Nurse cells
C) Interdigitating dendritic cells
D) Macrophages
E) B cells
4 CD8
A) binds to an invariant portion of MHC class II molecules
B) binds to an invariant portion of MHC class I molecules
C) binds directly to peptide antigen
D) binds to adhesion molecules on the target cell surface
E) binds to the peptide-binding site of MHC class I
5 Which of the following statements is incorrect concerning the TCR and Ig ?
A) in both B- and T-cell precursors, multiple V-, D-, J-, and C-region genes exist in an unrearranged configuration
B) rearrangement of both TCR and Ig genes involves specific recombinase enzymes that bind to specific regions of the genome
C) only TCR is able to switch C-region and class switch
D) both Ig and TCR exhibit allelic exclusion
E) both Ig and the TCR use combinatorial association of V, D, and J genes and junctional imprecision to generate diversity
6 The most likely cells to be lysed when treated with anti-CD4 antibody and complement are
A) cytotoxic T cells
B) macrophages
C) T helper cells
D) B cells
E) Erythrocytes
7 Positive selection
A) occurs after T cells enter in to circulation
B) occurs in the double positive T cell population in the thymic cortex
C) enables T cells with a high affinity for antigen and self MHC to exit to the periphery
D) promotes affinity maturation of B cells in germinal centers
8 Indicate which of the following statements is true
A) CD3 molecule is expressed on monocytes
B) CD3 molecule is associated with CD28
C) CD3 molecule highly variable in each cell
D) CD3 is expressed only by CD8+ T cells
E) CD3 is expressed in association with TCR
9 This molecule plays a role in dephosphorylation of a tyrosine residue of p56lck and p59fyn
A) CD2
B) CD4
C) CD16
D) CD45
E) CD3
10 This protein is associated with cytoplasmic tail of CD4 or CD8 molecules
A) Fyn
B) ZAP-70
C) NFAT
D) Lck
E) Syk
11 Which would you expect to activate cytotoxic CD8+ T cells
A) a small protein such as chicken -globulin
B) a killed virus that has retained its antigenic properties but cannot replicate
C) an attenuated (altered) viral preparation that can still replicate within the host's cells
D) all of the above
E) None of the above
12 Which of the following is not a function of T cells
A) production of cytokines
B) direct cellular killing of target cells
C) involvement in response to viral and bacterial proteins
D) induction of B-cell isotype switching
E) antibody directed cytotoxicity (ADCC)
13 Indicate which of the following statements is correct
A) CD25 antibody recognizes the IL-1 receptor on T cells
B) All cytokines are produced by T cells
C) IL-12 and IL-10 act synergistically
D) IL-4 induces IgE production
E) IL-2 induces type I hypersensitive reactions
14 Which of the following is incorrect concerning the cytokines ?
A) one cytokine may act on many different target cells
B) each cytokine binds to a specific cell surface receptor
C) Only T cells produce cytokines
D) within T cells, activation of cytokine genes occurs within hours
E) cytokine receptor expression may be regulated by the cytokine itself
15 Infection with vaccinia virus results in the priming of virus-specific CD8+ T cells in the patients. These cells are subsequently removed from the individual, which of the following cells will be killed by these CD8 in vitro?
A) vaccinia-infected cells expressing MHC class II molecules from any individual
B) influenza-infected cells expressing the same MHC class I molecules as the individual
C) uninfected cells expressing the same MHC class I molecules
D) vaccinia-infected cells expressing the same MHC class I molecules as the individual
E) vaccini-infected cells expressing the same MHC class II molecules as the individual