CD8+ and CD4+ T Cell Responses Quiz

Understanding CD8+ and CD4+ T Cell Responses in the Immune System

• CD8+ cytotoxic T cells are a crucial component of the adaptive immune system, targeting and eliminating infected host cells to control intracellular infections.
• MHC class I molecules present endogenous antigens, such as viral proteins synthesized within host cells, to CD8+ T cells.
• Viral proteins inside infected cells are broken down into antigen fragments by proteolytic enzymes and then bind to MHC class I molecules.
• Activated CD8+ T cells release cytotoxic molecules, inducing apoptosis in infected cells and limiting viral spread.
• CD4+ T cells, known as helper T cells, recognize antigens presented on MHC class II molecules from exogenous sources and coordinate the immune response.
• Activated CD4+ T cells release cytokines, differentiate into subsets, and stimulate B cells for antibody production (humoral immunity).
• CD4+ T cells also enhance the function of CD8+ cytotoxic T cells and regulate inflammation based on the immune response type.
• The CD8+ T cell response is triggered by the interaction of the T cell receptor with an antigen-MHC class I complex on infected host cells.
• Perforin and granzymes released by activated CD8+ T cells induce pore formation and cell death in infected cells, controlling intracellular pathogens.
• CD4+ T cells play a central role in orchestrating and regulating the immune response, stimulating B cells and enhancing CD8+ T cell activity.
• CD8+ T cells selectively destroy infected cells while sparing uninfected neighboring cells, essential for effective immune responses against intracellular pathogens.
• The immune system's ability to combat a wide range of pathogens is contributed by the coordinated responses of CD8+ and CD4+ T cells.