Mobilization of neutrophils to fight infection in tissue is mediated by all except which a. TNF-a production by macrophages b. upregulation of selectins on blood vessel endothelium c. interferon response d. generation of a CXCL8 gradient e. extravasation across endothelium f. proteolysis of basement membrane of blood vessels

Which of the following is not a function of antibodies? Select one: a. They neutralize pathogens by masking the pathogen surface. b. They act as molecular adaptors that bridge together pathogen and phagocyte surfaces. c. They exert toxic effects directly. d. They act as opsonins that mediate phagocytosis. e. They activate complement fixation.

Complexes of IgG bound to soluble multivalent antigens can activate the classical pathway on the complex, targeting it for of complement, resulting in the deposition of endocytic uptake by cells bearing. Select one: a. C4b; CR2 and Fc receptors b. c. C5-9; CR1 and Fc receptors d. C3b; CR1 and Fc receptors e. C2a; CR2 and Toll-like receptors C3b; CR2 and Toll-like receptors

Which of the following does not accurately describe complement components?   A. made by the spleen   B. located in extracellular spaces   C. some function as proteases once activated   D. activated by a cascade of enzymatic reactions.   E. soluble proteins

Which of the following are true of interferons? Select all that apply. O They are a critical part of the innate immune system in fighting bacterial infections O They are a part of the second line of defense against viruses O They degrade viral DNA O They are signaling molecules produced by infected cells to help uninfected cells defend themselves agains viruses O They are part of innate immunity O They are part of adaptive immunity and are "trained" by the immune system to eliminate specific pathogens

The zone of contact between the T cell and a pathogen-infected cell is called a(n) Select one: a. immunoreceptor tyrosine-based activation motif (ITAM) b. polarization C. cross-presentation center d. granuloma e. immunological synapse

If a T-cell receptor on a double-positive thymocyte binds to a self-peptide:self-MHC class I complex with low affinity the result is a. negative selection and apoptosis b. cell proliferation c. rearrangement of the second β-chain locus d. positive selection of a CD4 T cell e. positive selection of a CD8 T cell.

The largest and most effective of the phagocytes are:  a. red blood cells b. lymph nodes c. macrophages

A young child is hospitalized with recurring bacterial infections, although she appears to make normal responses to viruses. Which of the following molecules might be defective in her immune system? (select all that could contribute to this condition) Select one or more: a.RAG1/RAG2 b.MCP or DAF c.C3 d.CXCL-8 e.IFN receptors

Apoptosis is Select one: A. equivalent to necrosis. B. caused by T cell anergy. C. involved in peripheral tolerance, but not central tolerance. D. impaired in Fas-deficient systems. E. involved in central tolerance, but not peripheral tolerance. O O O O