Which types of cells can utilize MHC class II molecules?

MHC class II molecules are primarily utilized by specialized antigen-presenting cells (APCs) that include dendritic cells, B cells, and macrophages. These cells are crucial for the adaptive immune response, as they present processed antigen fragments to CD4+ T helper cells. The ability to present antigens using MHC class II molecules allows these APCs to activate T helper cells, which then provide help to other immune cells, such as B cells and cytotoxic T cells, thus playing a pivotal role in orchestrating the immune response.

Dendritic cells, in particular, are the most efficient APCs and are essential for the initiation of T cell responses. They capture antigens from the environment, process them, and present them on their surface bound to MHC class II, allowing for effective communication with T cells. B cells also express MHC class II molecules and can present antigens that they have bound through their immunoglobulin receptors, which is fundamental for T cell activation and subsequent antibody production. Macrophages enhance their phagocytic function and inflammatory response by presenting antigens via MHC class II, further contributing to the adaptive immune response.

In contrast, somatic cells, T cells, and neutrophils do not utilize