They're found primarily in bone marrow and are in charge of making antibodies. Like Inducer T and T8 lymphocytes , B cells require help from T4s . When B cells are activated, they release antibodies into the bloodstream and mucosal surfaces. These antibodies circulate and when they find a specific antigen, they bind to it. Antibodies help block toxins and viruses by either neutralizing them or removing its ability to bind to tissue.
Antibodies also help bring in a large number of phagocytes which remove the antigen.