Type IV hypersensitivity is primarily mediated by which cells?

Type IV hypersensitivity is primarily mediated by which cells?

• A. B cells
• B. T cells
• C. Antibodies
• D. Macrophages

Answer: (B)

Type IV hypersensitivity is primarily mediated by T cells, specifically CD4+ T helper cells and CD8+ cytotoxic T cells. This form of hypersensitivity is also known as delayed-type hypersensitivity because the response typically takes hours to days to develop after exposure to the antigen. In Type IV hypersensitivity reactions, T cells recognize antigens presented by antigen-presenting cells (APCs) and subsequently release cytokines, which attract and activate other immune cells, including macrophages. This leads to an inflammatory response that contributes to tissue damage. T cells play a crucial role in this process by orchestrating the immune response rather than producing antibodies, which is characteristic of other types of hypersensitivity. Therefore, understanding the pivotal role of T cells is essential in the context of immune responses and their implications in various conditions related to Type IV hypersensitivity, such as contact dermatitis and graft-vs-host disease.

Type IV hypersensitivity is primarily mediated by T cells, specifically CD4+ T helper cells and CD8+ cytotoxic T cells. This form of hypersensitivity is also known as delayed-type hypersensitivity because the response typically takes hours to days to develop after exposure to the antigen.

In Type IV hypersensitivity reactions, T cells recognize antigens presented by antigen-presenting cells (APCs) and subsequently release cytokines, which attract and activate other immune cells, including macrophages. This leads to an inflammatory response that contributes to tissue damage.

T cells play a crucial role in this process by orchestrating the immune response rather than producing antibodies, which is characteristic of other types of hypersensitivity. Therefore, understanding the pivotal role of T cells is essential in the context of immune responses and their implications in various conditions related to Type IV hypersensitivity, such as contact dermatitis and graft-vs-host disease.