Final answer:
Professional antigen-presenting cells include macrophages, dendritic cells, and B cells, which all express class II MHC molecules vital for the adaptive immunity response by aiding in the activation of T cells.
Step-by-step explanation:
Three types of professional antigen-presenting cells are crucial for the immune response. These are macrophages, dendritic cells, and B cells. Macrophages enhance phagocytosis by stimulating T cells to release cytokines. Dendritic cells are adept at phagocytosing pathogens and bringing antigens to regional draining lymph nodes, where most T cell responses are initiated.
B cells can present antigens to T cells, which is essential for certain types of antibody responses.These professional APCs express class II MHC molecules, which are critical in antigen presentation. This presentation plays a significant role in adaptive immunity.
where the immune system responds specifically to pathogens that it has encountered before. Class II MHC molecules facilitate the activation of helper T cells by presenting extracellular antigens that result from processes such as receptor-mediated endocytosis.