Previous Article | Next Article ![]()
Mol Cell Biol. 1993 July; 13(7): 3890-3899
Department of Pathology, Tufts University School of Medicine, Boston, Massachusetts 02111.
ABSTRACT
To probe the factors controlling immunoglobulin heavy-chain gene rearrangement, we analyzed Abelson virus-transformed pre-B-cell lines that fail to undergo VH-to-DJH joining at an appreciable frequency. Despite this feature, some of these cell lines (rechi) rearrange an extrachromosomal recombination substrate at levels normal for transformed pre-B cells. Others (reclo) rearrange these substrates at levels characteristic of nonlymphoid hematopoietic cells. The DJH rearrangements from a representative rechi cell line were aberrant, suggesting that these cells probably fail to complete heavy-chain gene assembly because some of the necessary cis-acting signals are missing. In contrast, both DJH rearrangements from a reclo cell line appeared normal in structure, indicating that trans-acting factors necessary for recombination might be missing. Introduction of the RAG-1 and RAG-2 genes, genes encoding two such factors, failed to confer a rechi phenotype to these cells. However, fusion of the reclo cells to a rechi cell line generated a high frequency of rechi hybrids. In addition, most of the hybrids rearranged the endogenous kappa light-chain locus. Neither the rechi phenotype nor kappa-chain rearrangement correlated with levels of RAG-1 and RAG-2 expression in all of the hybrids. Thus, both gene transfer and cell fusion experiments indicate that RAG-1 and RAG-2 are not sufficient to activate immunoglobulin gene recombination in at least some pre-B-cell lines. In addition, the fusion experiments suggest that two gene products in addition to RAG-1 and RAG-2 may be required for kappa-gene rearrangement.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|