Which cells have CD4 markers and which MHC class do they recognize?

Prepare for your Anatomy and Physiology II Exam with our comprehensive exam resources. Utilize flashcards, multiple choice questions with hints, and detailed explanations. Boost your readiness for success!

Multiple Choice

Which cells have CD4 markers and which MHC class do they recognize?

Explanation:
CD4 serves as a co-receptor on helper T cells and guides recognition of antigens presented by MHC class II molecules. MHC class II is expressed on professional antigen-presenting cells like dendritic cells, macrophages, and B cells, which display extracellular peptides to CD4+ helper T cells. This interaction activates helper T cells to coordinate the immune response, including aiding B cells and other T cells. By contrast, cytotoxic T cells use CD8 and recognize peptides with MHC class I, which are found on nearly all nucleated cells presenting intracellular or endogenous antigens. NK cells operate via different receptors and do not rely on CD4/MHC II recognition. Therefore, the cells with CD4 markers are helper T cells, and they recognize MHC class II.

CD4 serves as a co-receptor on helper T cells and guides recognition of antigens presented by MHC class II molecules. MHC class II is expressed on professional antigen-presenting cells like dendritic cells, macrophages, and B cells, which display extracellular peptides to CD4+ helper T cells. This interaction activates helper T cells to coordinate the immune response, including aiding B cells and other T cells. By contrast, cytotoxic T cells use CD8 and recognize peptides with MHC class I, which are found on nearly all nucleated cells presenting intracellular or endogenous antigens. NK cells operate via different receptors and do not rely on CD4/MHC II recognition. Therefore, the cells with CD4 markers are helper T cells, and they recognize MHC class II.

More practice questions