B-cells provide which type of immunity?

B-cells are primarily responsible for producing antibodies that circulate in the bloodstream and lymphatic system. This forms the basis of what is known as antibody-mediated immunity, also referred to as humoral immunity. When a B-cell encounters an antigen that it can recognize, it can differentiate into plasma cells that secrete large quantities of specific antibodies directed against that antigen. These antibodies help neutralize pathogens or mark them for destruction by other immune cells.

In contrast, cell-mediated immunity involves T-cells, which do not produce antibodies but instead function by directly attacking infected cells or coordinating other elements of the immune response. Active immunity refers to the protection formed after exposure to a pathogen or its components, leading to the production of memory cells; while antibody-mediated immunity can be a form of active immunity, the term is broader. Innate immunity encompasses the body's initial, non-specific defenses against pathogens, which are not specific to any particular pathogen as B-cells are. Thus, the role of B-cells specifically aligns with antibody-mediated immunity.