Self-reactive B lymphocytes detected in young adults, children and newborns after in vitro infection with Epstein-Barr virus.

B-lymphocytes from healthy children and young adults who were seronegative for autoantibodies and B lymphocytes from umbilical cord blood of newborns were induced to secrete a variety of autoantibodies upon infection with Epstein-Barr virus. Such autoantibody-secreting clones were obtained from different lymphoid tissues and occurred at frequencies of 1 in 10(6)-10(7) mononuclear cells. The autoantibodies were exclusively of the IgM class. They recognized normal cellular components, such as cytoplasmic, nuclear and cytoskeletal antigens. The fact that self-reactive clones were not efficiently eliminated during ontogeny suggests that suppressor mechanisms might be responsible for normal self tolerance.