What role do macrophages, B lymphocytes, and dendritic cells serve in the immune system?

Macrophages, B lymphocytes, and dendritic cells all play critical roles in the immune system, particularly in the context of antigen presentation.

Macrophages are professional antigen-presenting cells (APCs) that engulf pathogens and other foreign entities. They process these antigens and present them on their surface bound to major histocompatibility complex (MHC) molecules. This presentation is essential for activating T lymphocytes, which then initiate a specific immune response.

Dendritic cells are also specialized APCs and are considered the most efficient at capturing and presenting antigens. They migrate from tissues to lymph nodes, where they present antigens to T cells, thus playing a pivotal role in linking the innate immune response to the adaptive immune system.

B lymphocytes primarily focus on the production of antibodies in response to antigens. While they do have the capability to present antigens to T cells, their primary function lies in humoral immunity, specifically in generating antibodies against identified pathogens.

Dendritic cells and macrophages serve as the main antigen presenters, while B lymphocytes are more involved in the antibody response once activated. Together, these cells coordinate the immune response, but antigen presentation remains a defining characteristic of macrophages and dendritic cells in the