BALB/c mice immunized with phosphocholine-conjugated keyhole limpet hemocyanin respond with two major groups of antibodies that differ with respect to fine specificity and idiotype. Group I antibodies predominantly bear the T15 idiotype, and show appreciable affinity for the haptens PC and nitrophenyl PC (NPPC), whereas group II antibodies have appreciable affinity for NPPC only and are T15 idiotype negative. Previous studies indicated that group II binding characteristics may derive from the use of novel V gene segments not observed in group I antibodies. To determine the nature of V(H) gene usage in the group II antibody response, we examined the V(H) region of a prototype group II hybridoma, PCG1-1. The nucleotide sequence obtained from the VDJ region indicates that PCG1-1 utilizes a V(H) gene not observed in the group I response, one that belongs to the Q52 V(H) family. The PCG1-1 V(H) nucleotide sequence shares 97% identity with the myeloma M141 V(H) gene. In addition, PCG1-1 utilizes a D segment most closely related to DSP2.6 rearranged to J(H)-3. These data indicate that M141, a V(H) gene not seen in group I anti-PC antibodies is utilized by PCG1-1 to generate a PC-protein-binding group II antibody. PCG1-1 was previously shown to express the V(κ)1-3 light chain, a characteristic shared by several group II hybridomas. Furthermore, here we examined the V(H) gene rearrangements in four λ1-bearing group II hybridomas that share a common J(H) rearrangement with PCG1-1 by Southern blot analysis. A V(H)-specific probe that detects M141 V(H) rearrangements revealed that all four λ1 hybridomas as well as PCG1-1 share an identical V(H) gene rearrangement to J(H)-3. Thus the M141 V(H) gene product is able to utilize two distinct light chains to generate group II-like combining sites.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Immunology|
|State||Published - 1987|
ASJC Scopus subject areas
- Immunology and Allergy