Is Flashcards
(31 cards)
What is the role of type I interferons?
Type I interferons, consisting of IFN-a and IFN-b, primarily function to interfere with viral replication and limit the expansion of activated cells.
What cells produce type I interferons?
Type I interferons are produced by dendritic cells.
How do type I interferons affect viral infections?
They induce production of proteins and pathways that directly interfere with viral replication and cell division, helping to limit the infection to a small area.
What is the effect of type I IFN on natural killer cells?
Type I IFN activates natural killer cells and enhances the expression of MHC class I proteins.
What is the main function of cytokines in adaptive immunity?
Cytokines in adaptive immunity are mainly secreted by T cells, especially T helper cells, and directly affect T- and B-cell function.
What influences the differentiation of T helper cells?
Differentiation into Th1, Th2, or T-reg cell lineages is influenced by the spectrum of cytokines expressed in the initial response.
What drives the Th1 lineage?
The Th1 lineage is driven by the expression of IL-12 by dendritic cells.
What is the primary function of Th2 cells?
Th2 cells drive antibody-mediated immunity and are developmentally regulated by IL-4.
What is the principal cytokine produced by Th1 cells?
Interferon Gamma (IFN-y) is the principal molecule produced by Th1 cells.
What genes are regulated by IFN-y?
IFN-y affects the RNA expression levels of more than 200 genes involved in the regulation and activation of CD4 Th1 cells, CD8 cytotoxic lymphocytes, NK cells, and bactericidal activities.
How does IFN-y affect antigen presentation?
IFN-y stimulates antigen presentation by MHC I and MHC II molecules, increasing the likelihood of antigen capture.
What stimulates IFN-y production in mature Th1 cells?
IFN-y production can be stimulated by ligation of the T-cell receptor (TCR) by MHC-peptide antigen presentation or cytokine stimulation by IL-12 and IL-18.
What is the role of IL-2?
IL-2, known as the T-cell growth factor, drives the growth and differentiation of both T and B cells and induces lytic activity in NK cells.
How do Th1 cells influence macrophages?
Th1 cells induce macrophage activation and delayed type hypersensitivity.
What antibodies do Th1 cells stimulate the production of?
Th1 cells stimulate the production of IgG1 and IgG3 opsonizing and complement-fixing antibodies by antigen-activated B cells.
What is the primary responsibility of Th2 cells?
Th2 cells are primarily responsible for antibody-mediated immunity.
What is the key cytokine regulating Th2 immune response?
Interleukin 4 (IL-4) is one of the key cytokines regulating Th2 immune response.
