Viruses — Flashcards

Flashcard 341: Natural infection is an example of _____ immunization

Answer: active

Flashcard 342: IFN-y _____ NK cells and NKT cells

Answer: stimulates

Flashcard 343: Does IgM cross the placenta?_____

Answer: No

Flashcard 344: Which class of helper T cell secretes IL-17, -21, and -22? _____ *What does each do?

Answer: Th17 • **IL-17**: Recruits neutrophils (inflammation) • **IL-21**: Autocrine stimulation (promotes Th17 differentiation) • **IL-22**: Maintains epithelial barrier integrity

Extra: Th17 cells are primarily involved in the host defense against extracellular bacteria and fungi. • **Induced by**: TGF-β, IL-6 • **Inhibited by**: IFN-γ, IL-4 • **Clinical correlation**: STAT3 mutations lead to deficiency in Th17 cells, causing **Hyper-IgE (Job) syndrome** (characterized by "cold" staphylococcal abscesses and chronic candidiasis).

Flashcard 345: Which immunoglobulin is released into secretions (tears, saliva, mucus)? _____

Answer: IgA

Flashcard 346: IL-_____ receptor deficiency is characterized by a decreased Th1 response

Answer: 12

Flashcard 347: Which class of helper T cell promotes cell-mediated immunity?_____

Answer: Th1

Flashcard 348: _____ is an immunologic test used to detect the presence of either a specific antigen or antibody in a patient's blood sample

Answer: Enzyme-linked immunosorbent assay (ELISA) (not Coombs test)

Flashcard 349: Which interleukin is responsible for activating NK cells and inducing differentiation of T cells into Th1 cells?_____

Answer: IL-12

Flashcard 350: Which class of helper T cell helps maintain specific immune tolerance by suppressing CD4 and CD8 T-cell effector functions? _____

Answer: Regulatory T (TReg) cells