The antibody responses to myelin basic protein (BP) in Lewis rats: the effects of Bordetella pertussis

A time-course study was made of the systemic humoral immune response of Lewis rats to myelin basic protein (BP) as influenced by the dosage of ancillary pertussis adjuvant. Peak activities were observed 5 to 7 weeks after injection. When injected proximal to BP and Mycobacterium butyricum in complete Freund's adjuvant (CFA), Bordetella pertussis at the level of 4 billion organisms doubled the antibody-binding activity of rat sera for 125I-labeled BP as compared to activities obtained with 0, 2, 6, or 8 billion. The severity of clinical symptoms of experimental allergic encephalomyelitis (EAE) at the end of the 2nd week was greatest in rats receiving 64 billion organisms, the very same rats that displayed a severely dampened humoral immune response to BP 5 weeks later. When pertussis was injected i.p. rather than proximal to the CFA mixture, the time-course of the humoral immune response displayed a different profile--unusually high binding activities at the time of onset of EAE that fluctuated back and forth from high to low and that eventually dampened to an intermediate level.