Status of kappa L chain gene rearrangements and c-kit and IL-7 receptor expression in stromal cell-dependent pre-B cells.
Studies from several laboratories have provided evidence that distinct stromal cell-derived signals are involved in the maturation of pre-B cells into surface Ig expressing B lymphocytes. In order to define the stage of development at which these stimuli act, various polymerase chain reaction strategies were used to characterize the status of kappa L chain gene rearrangements in nontransformed, stromal cell dependent pre-B cells. These cells were obtained from lymphoid colonies whose growth was potentiated by factors from a stromal cell line. kappa L chain genes in cells from many of these colonies were rearranged, and analysis of the Jk genes used indicated a bias toward the most 3' loci. However, the use of a reverse transcriptase PCR strategy failed to detect mature kappa transcripts, indicating that stromal cell mediators exist that allow pre-B cells to progress to the stage at which L chain genes are rearranged but not expressed. Reverse transcriptase PCR further revealed that no transcripts for c-kit (the receptor for kit-ligand) and the IL-7R could be detected in these cells. This suggests that these receptors are no longer expressed by the time cells have undergone kappa rearrangements and minimize a role for stromal cell-derived kit-ligand and IL-7 in mediating the pre-B to B cell transition.
Henderson
A J
AJ
Division of Biomedical Sciences, University of California, Riverside 92521-0121.
Narayanan
R
R
Collins
L
L
Dorshkind
K
K
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000502:physiology*; D001483:Base Sequence; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D002478:Cells, Cultured; D005260:Female; D015870:Gene Expression; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D005803:Genes, Immunoglobulin; D006410:Hematopoiesis; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D019009:Proto-Oncogene Proteins c-kit; D012333:RNA, Messenger / Q000235:genetics; D011971:Receptors, Immunologic / Q000235:genetics*; D020395:Receptors, Interleukin-7; D013154:Spleen / Q000166:cytology
D007145:Immunoglobulin kappa-Chains; D009838:Oligodeoxyribonucleotides; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D020395:Receptors, Interleukin-7; D019009:Proto-Oncogene Proteins c-kit