Exam 2: Review (limited) Flashcards
A rabbit hunter in Arkansas is diagnosed with ulceroglandular tularemia and treated with streptomycin. Within a week, he returns to the hospital. The tularemic papule, lymphadenopathy, and bacteremia have resolved, but he has now developed a raised, itching skin rash and a fever. The drug was discontinued, and the symptoms subsided. What was the role of streptomycin in this case?
A. It acted as a B-cell mitogen
B. It acted as a hapten
C. It acted as a provider of costimulatory signals D. It acted as a superantigen
E. It acted as an immunogen
B. It acted as a hapten
A 2-year-old child who has suffered recurrent bacterial infections is evaluated for immunologic deficiency. The child has age-normal numbers of CD19+ and CD3+ cells in the peripheral blood and an extreme neutrophilia (neutrophilia refers to a higher than normal number of neutrophils). The nitroblue tetrazolium dye reduction test used to assess phagocyte function is normal. What is the most likely defect in this child?
A. Absence of CCR4 B. Absence of CD18 C. Absence of IL-1 D. Absence of IL-4 E. Absence of TNF-a
B. Absence of CD18
Human infections with Mycobacterium leprae express a spectrum of clinical presentations depending on the extent and expression of their immune response to the intracellular organism. On one end of the spectrum, patients with tuberculoid leprosy produce an effective cell-mediated immune response, which is successful at killing the intracellular organisms and, unfortunately, produces tissue damage. Patients with tuberculoid leprosy have granulomas that have elevated amounts of IL-2, IFN-, and TNF-. Which of the following immune cell is responsible for this pattern of cytokine production?
A. Cytotoxic T lymphocyte B. Epithelioid cell C. Macrophage D. Th1 cell E. Th2 cell
D. Th1 cell
There is evidence that the immunologic pathway that distinguishes the selection between the two polar forms of leprosy depends on the initial means of antigen presentation, as well as individual human differences in response. If early events of antigen recognition elicit production of IL-4, IL-5, IL-6, and IL-10, lepromatous leprosy is more likely to result, with the outcome of failure to mount a protective immune response. What differential characteristic of the lepromatous form is predicted based on the fact of overproduction of IL-4, IL-5, IL-6, IL-10, IL-13 and TGF in lepromatous lesions?
A. Autoimmunity B. Granuloma formation C. Hypergammaglobulinemia D. Immediate hypersensitivity E. Inflammation
C. Hypergammaglobulinemia
An elderly man with diabetes develops a blister on the heel of his foot, which becomes infected. Although nursing staff in the home where he is a resident clean and treat the wound with topical antibiotic ointment, he develops a fever and hypotension, and a desquarnating rash spreads from the site of the original blister. How does the toxin responsible for his symptoms cause these signs?
A. It acts as an IL-1 homologue
B. It activates B lymphocytes polyclonally
C. It activates complement
D. It cross-links MHC class II molecules to TCRs polyclonally
E. It stimulates neutrophils
D. It cross-links MHC class II molecules to TCRs polyclonally
It has been learned in several experimental systems that proliferation and differentiation of T lymphocytes in response to tumor cells is low because tumor cells lack the necessary costimulatory molecules for lymphocytes activation. If melanoma cells from a patient were induced to express these costimulatory molecules by transfection, production of an effective anti-tumor response might occur. Which of the following molecules would be the best candidate for transfection of tumor cells to achieve this end?
A. B7 B. CD2 C. CD4 D. CD28 E. LFA-1
A. B7
A 50-year-old woman with severe rheumatoid arthritis is started on infliximab (anti-tumor necrosis factor-alpha). This therapy has been shown to increase the production of CD25- positive T cells. Which of the following is likely, therefore, to become elevated in this patient?
A. Interferon-gamma B. Interleukin- 1 C. Interleukin-2 D. IL-10 E. Interferon-alpha/beta
D. IL-10
A 26-year-old obstetric patient becomes ill during the first trimester of pregnancy with fever and lymphadenopathy. She is found to have a rising titer of anti-Toxoplasma gondii antibodies. She delivers a full-term baby with no apparent signs of in utero infection. The best test to diagnose acute infection in the neonate would be a parasite-specific ELISA for which isotype of immunoglobulin?
A. IgA B. IgD C. IgE D. IgG E. IgM
E. IgM
