451. Which of the following statement regarding macrophage is TRUE?
A. Macrophage acts as antigen presenting cell for T cells.
B. Macrophage are important in immunosurveillence & lyses tumor cells.
C. Macrophage secrete ILl & TNFa to induce inflammatory & fibrogenic responses.
D. Macrophage are important effector cells in cell mediated immunity
E. All of the above

452. Which of the following statement is FALSE?
A. Langerhan & dendritic cells has no phagocytic activity.
B. Dendritic cells act as antigen presenting cells.
C. NK cells does not secrete cytokines.
D. NK cells are important in antibody dependent cytotoxicity.
E. NK cells represents 10% of peripheral lymphocytes.

453. Function of cytokines include the following EXCEPT:
A. mediates natural immunity
B. regulates lymphocyte growth & differentation
C. activation of inflammatory cells
D. opsonization
E. stimulates hematopoiesis

454. Which of the following statement regarding cytokines is TRUE?
A. Each cytokine is produced by 1 cell type.
B. Each cytokine may act on many different cell types.
C. Cytokine only act in paracrine fashion, with no long distance (endocrine) action.
D. Some cytokines does not have specific receptor sites on target cells.
E. All of the above.

455. Which of the following statement is TRUE?
A. MHC] is expressed on the surfaces of all nucleated cell & platelets.
B. MHC] bind to viral envelope peptides.
C. CD4+ T cells are MHC] restricted.
D. MHCu is presented with extracellular antigen on the surface of antigen presenting cells.
E. None of the above.

456. The following statement regarding Type I hypersensitivity reaction is FALSE:
A. The initial response is characterized by intense eosinophil infiltration & mucosal epithelial damage.
B. Late phase response occur without further exposure to antigen
C. It is initiated by antigen cross-linking of the IgEs on mast cell surface.
D. Histamine is the chief primary mediator of type I hypersensitivity.
E. All of the above.

457. The following stimuli mediates anaphylactoid reaction EXCEPT:
A. Anaphylatoxins
B. Monokines
C. IgE
D. Morphine
E. Bee venom

458. Which of the following is NOT an action of histamine?
A. Inhibition of platelet aggregation
B. Enhancement of mast cell mediator release
C. Chemotactic action
D. Bronchial smooth muscle contraction
E. All of the above

459. Which of the following agents are important in mediating bronchoconstriction in Type I hypersensitivity reaction?
A. Histamine
B. Adenosine
C. LTC4 and LTD4
D. PgD2
E. All of the above

460. Which of the following statement regarding Type 2 Hypersensitivity reaction is TRUE?
A. It only occur when antibody dependent cytotoxicity is involved.
B. It always involve complement activation
C. The cells binding to the IgG Ab in type 2 hypersensitivity reaction is not sensitized.
D. SLE is an example of Type 2 hypersensitivity reaction
E. All of the above