Question

When an immune response is initiated, it is controlled by a combination of stimulatory and inhibitory influences, including cytokines. Cytokines are small soluble proteins secreted by one cell that can alter the behavior or properties of the cell itself or of another cell. They are released by various cells of the immune system, in a cascade during the response to antigen. Most cytokines have a multitude of different biological effects when tested in biological assays in vitro. Th1 cells are associated with delayed-type hypersensitivity (DTH) reactions resulting in the recruitment and activation of macrophages. Th1 cells are characterized by the expression of what?

IL-4 and IL-5
IL-1 and IL-18
GM-CSF and TGF-β
IL-2 and IFN-γ
IL-6 and IL-2

Answer 1

Th1 cells express and secrete (4) IL-2 and IFN-γ, which are key cytokines involved in promoting the immune response against intracellular pathogens and enhancing the functionality of other immune cells.

Step-by-step explanation:

Th1 cells, a subgroup of helper T cells, are characterized by the expression and secretion of certain cytokines that promote the immune response against intracellular pathogens. In response to an antigen, Th1 cells predominantly produce IL-2 and IFN-γ. These cytokines are crucial for the activation and proliferation of T cells, including cytotoxic T cells (Tc) and the enhancement of macrophage bactericidal activity.

IL-2 is pivotal for T cell growth, whereas IFN-γ exerts a wider array of immunoregulatory functions, such as activating macrophages, enhancing antigen presentation, and fostering the development of the Th1 cellular immune response. Therefore, concerning Th1 cells and delayed-type hypersensitivity (DTH) reactions, the crucial cytokines are IL-2 and IFN-γ, not IL-4, IL-5, IL-1, IL-18, GM-CSF, TGF-β, or IL-6.