Neonatal expression of a cross-reactive idiotype associated with anti-phenylarsonate antibodies in strain A mice.

Abstract

AbstractData are presented which indicate that B cells expressing the cross‐reactive idiotype associated with anti‐p‐azophenylarsonate antibodies of A/J or allotype‐congenic C.AL‐20 mice are present in neonatal mice. Data were obtained by direct immunization of neonatal mice or by adoptive transfer of cells from neonatal C.AL‐20 mice into idiotype‐negative BALB/c recipients. These findings, together with those previously reported for antibodies to phosphocholine in BALB/c mice, support the generalization that major cross‐reactive idiotypes may usually be found early in the life‐span of a mouse. The contrast between the frequency of appearance of the major cross‐reactive idiotypes and “private” idiotypes with the same antigen‐binding specificity, which are found after immunological suppression of the major idiotype, is consistent with the possibility that cross‐reactive idiotypes are the product of germ line genes or minor somatic variants of germ line genes while private idiotypes arise through somatic diversification. Alternatively, regulatory mechanisms may account for the striking difference. The present results are therefore consistent with the early expression of germ line genes controlling the major idiotype or of corresponding regulatory genes. The average concentration of idiotype, per unit weight of anti‐phenylarsonate antibody, is somewhat lower in neonatal than in adult A/J mice indicating that the major idiotype does not account for all of the antibody produced in response to this hapten in the neonate.