phagocytes and other antigen-presenting cells (APCs), such as B cells and dendritic cells.
MHCII proteins are found on phagocytes, suppressor T cells, and plasma cells. MHCII stands for Major Histocompatibility Complex II, and these proteins are responsible for presenting antigens to helper T cells so that they can initiate an immune response. While all nucleated cells possess MHC class I proteins, MHCII proteins are primarily found on antigen-presenting cells like phagocytes (e.g., macrophages and dendritic cells), suppressor T cells, and plasma cells. Red blood cells, however, do not possess MHCII proteins.
