Which lymphocytes are primarily responsible for humoral immunity?

B lymphocytes are primarily responsible for humoral immunity, which is the aspect of immunity that involves the production of antibodies. These white blood cells develop in the bone marrow and play a crucial role in identifying and neutralizing pathogens such as bacteria and viruses. When B lymphocytes encounter their specific antigen, they can differentiate into plasma cells that produce antibodies tailored to that antigen.

Additionally, B lymphocytes are essential for the formation of memory cells, which provide long-term immunity by remembering the specific antigens for future encounters. This leads to a faster and more effective immune response upon subsequent exposures to the same pathogen.

T lymphocytes, while also critical to the immune response, are primarily involved in cell-mediated immunity rather than humoral immunity. Macrophages and dendritic cells serve as antigen-presenting cells that help activate T lymphocytes and can aid in the overall immune response, but they do not directly produce antibodies. Thus, the key role of antibody production and humoral immunity is attributed to B lymphocytes.