Two structurally distinct and independently regulated idiotypic families associated with the A/J response to azophenylarsonate.

At least two distinct subpopulations of A/J anti-azophenylarsonate (Ars) antibodies can be defined on the basis of serological cross-reactivity and sequence homology of heavy and light chains. The most frequently occurring idiotype family, IdCR, was initially identified by a rabbit antiserum and is present only in A/J mice. Examination of several randomly selected hybridoma proteins which failed to express IdCR-associated determinants revealed a second set of closely related molecules. The second idiotype family, Id36-60, is recognized by a rabbit antiserum prepared against the hybridoma protein 36-60. It is present in practically all A/J and BALB/c, but not B10. A Ars immune sera. On average, A/J immune sera contain approximately one-fifth as much Id36-60 as IdCR. A/J mice can be suppressed for subsequent expression of either idiotype by neonatal injection of anti-IdCR or anti-Id36-60 antisera. Suppression of IdCR does not affect the production of Id36-60 and vice versa. Together, these idiotype systems provide two independent markers for monitoring network regulation of the anti-Ars antibody response in A/J mice.