An important defense function of Tc cells in viral infection is to:
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85%
Lyse virus infected cells
6%
Produce cytokines
9%
Neutralize free virus particles
0%
Lyse viral capsids
Natural killer (NK) cells are:
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11%
Killer (cytotoxic) T cells
0%
Increase by immunization
0%
MHC restricted
89%
Able to kill virally-infected cells without prior sensitization
0%
Recognize antigens specifically
All of the following describe natural killer cells EXCEPT:
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3%
They are large granular lymphocytes
10%
b-They become LAK cells in presence of IL-2
70%
Like all T lymphocytes depend on MHC innovation
17%
Important against viral infections
Which of the following statements about NK cells is True?
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8%
They lack Fas protein in their membrane
16%
They lack Fc receptors in their membrane
12%
They secrete interleukin (II)-1
64%
They kill malignant cells by inducing perforation in the target cell membrane
How do effector T-cells differ from naive T-cells?
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29%
They can be triggered without the need for antigen-presenting cell
54%
They can be triggered without the need for co-stimulatory malestule
8%
They can be triggered without the need for CD4 or CD8 molecules
8%
They can be triggered without the need for signal transmission by CD3
Regarding the vesicular pathogens, which statement is CORRECT?
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22%
They are degraded in the cytoplasm.
4%
Their peptides bind to MHC I molecules
9%
They are presented to CDB-T cells.
65%
They include intracellular bacteria.
Which cytokine inhibits the development of Th2 cells
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76%
IFN-Y
4%
IL-6
8%
IL-4
12%
TNF-a
The main function of the humoral immune response is:
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8%
Destruction of intracellular pathogens
75%
Destruction of extracellular pathogens
17%
Helping other cells of the immune system
0%
Production of Cytokines
A surface molecule on B cells essential for antigen presentation is:
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30%
B cell receptor (BCR)
9%
CD40
61%
MHCII
0%
Immunoglobulin
Activation of naΓ―ve mature B cells requires the following EXCEPT:
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10%
Surface antibody contact with antigen
10%
T cell cytokine stimulation
14%
8 cell CD40 interaction with T cell CD40
67%
Antigen presentation to T cell via class I MHC
The second signal in activation of naΓ―ve B cells includes all of the following EXCEPT:
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37%
Antigen binding to B cell receptor
5%
Activated helper T cells
37%
Engulfment and degradation of the bound antigen by B cell
21%
Peptide presentation on the B cell surface in association with MHC II
The role of macrophages during antibody formation is:
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11%
Production of cytokines
84%
Processing and presentation of antigens to CD4 T helper cells
0%
Activation of CD8 T cytotoxic cells
5%
Promotion of development of Thi cells
Which of the following has an effect on humoral immunity?
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11%
Activation of cytotoxic CD8 T cells
11%
Lysis of virus infected cells
74%
Processing and presentation of antigen to T helper cells
5%
Activation of NK cells
All of the following statements about memory cells are true EXCEPT:
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6%
They are produced in response to thymus-dependent antigens
6%
They are responsible for immunological memory
89%
They are short-lived cells
0%
They are produced following the primary immune response
Thymus Independent (TI) antigens
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6%
Can stimulate B cells through T cell help
89%
Do not produce memory cells.
6%
Can stimulate immunoglobulin class switching
0%
Can only induce the production of IgG
The heavy chain of immunoglobulin consists of:
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10%
One variable and two constant domains
20%
Two variable and one constant domain
10%
One variable one constant domain
60%
One variable and three or four constant domains
Opsonization depend on presence of the following structures on surface of phagocytic cells:
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5%
Foreceptors
32%
C3b receptors
0%
CBCR
47%
a&b
16%
a&c