Immune responses of BALB/c mice to the idiotype of T15 and of other myeloma proteins of BALB/c origin: implications for an immune network and antibody multispecificity.

Normal adult BALB/c mice are virtually unresponsive to the idiotype of myeloma protein T15 when immunized with purified T15. However, antibodies to the T15 idiotype can be elicited by T15 in BALB/c mice that are reared in a germ-free environment or injected as newborns with an alloantiserum to the idiotype. Some germ-free and neonatally suppressed mice also produce helper cells (presumably T helpers) that enhance B-cell production of anti-DNP antibodies in response to DNP-T15. Taken together with previous studies, the present results mean that so far there are no exceptions to the rule that BALB/c mice have B and T cells that can respond to idiotypes of myeloma proteins of BALB/c origin. There appears to be a reciprocal relation between the natural prevalence of an immunoglobulin's idiotype and its immunogenicity in isologous individuals. The findings support proposals for an immune network of idiotypes and anti-idiotypes. Besides binding one or more extrinsic antigens, it is likely that each immunoglobulin also binds the idiotype of some other immunoglobulin. An immune network therefore implies multispecificity of antibodies.