Complement and the regulation of humoral immune responses.

The complement component C3 is involved in the successful induction of a normal antibody response, but its mode of action is unclear. From studies with complement deficient guinea pigs Erik Böttger and Dieter-Suermann suggest that failure to stimulate antibody generation is the result of C3 depletion, rather than the suppression of activation by C3 fragments. In addition, they propose that complement may have a second regulatory function, being indirectly or directly involved in the suppression of the polyclonal activation of lymphocytes.