Two BALB/c anti-arsonate idiotype families: two heavy chain variable regions (V h) shared with anti-DNP antibodies are used by one family while a V h similar to anti-GAT antibodies is used by the other

Abstract

Amino terminal amino acid sequences were obtained for both the heavy (H) and light (L) chains of seven BALB/c anti-arsonate (Ar) monoclonal antibodies representing the 5AF6 and 3C6 idiotype (id) families described in this strain. 5AF6 family H chains showed strong homology to the germ-line gene sequence for the A strain 36–60 family. However, four to five identical H chain sequence differences for two of these antibodies (5AF6 and 95B5), as well as two previously reported related sequences (92D5, 94B10), suggested they were encoded by a different V h. The 36–60 family V h genes have been shown to be identical to the V h gene of the anti-DNP binding myeloma M460 [Dzierzak et al., J. Immun. 136, 1864–1870 (1986)]. H chains amino acid sequences derived from an id-460 + anti-DNP hybridoma and a germ-line gene differing from the 30–60-like V h sequence [Dzierzak et al., J. Immun. 136, 1864–1870 (1986)] were found to be virtually identical to the 95B5 and 5AF6 V h sequences. This suggests that the same two related H chains making up two subsets of the 5AF6 anti-Ar id family are also both used in two subsets of the id-460 anti-DNP response. 5AF6 family L chains were highly homologous to the other V k2 L chains of the 36–60 family. 3C6 family H chains can be placed in the V h 1 group, are unrelated to the described anti-Ar H chain families, and have been placed in a new anti-Ar V h family, Ars-E. The 3C6 H is similar, however, to a V h used by a BALB/c anti-GAT idiotype family of antibodies. 3C6 L chains were of the murine kappa chain group, V k 8, and most resembled an L chain from an A strain monoclonal anti-Ar having no defined idiotype.