| First Author | Hachemi-Rachedi S | Year | 2000 |
| Journal | Int Immunol | Volume | 12 |
| Issue | 3 | Pages | 385-95 |
| PubMed ID | 10700473 | Mgi Jnum | J:110537 |
| Mgi Id | MGI:3640459 | Doi | 10.1093/intimm/12.3.385 |
| Citation | Hachemi-Rachedi S, et al. (2000) Affiliation to mature B cell repertoire and positive selection can be separated in two distinct processes. Int Immunol 12(3):385-95 |
| abstractText | Using an 'oligoclonal' model, we have previously shown that mice transgenic for a mu chain (H3) and deficient for kappa chain expression display a mature B cell repertoire largely dominated by the H3/lambda1 pair, while the four H3/lambda available combinations can be observed in the immature B cell compartment. This led us to propose the existence of a positive selection process. To test this hypothesis, we have introduced the SJL lambda locus coding for a defective lambda1 chain (lambda1(s)) that creates a dysfunctional Ig receptor complex during B cell differentiation. Our results show that the lambda1(s) defect impairs the development of mature B cells when the H3-mu transgene insert is present in the hemizygous state. This suggests that the Gly --> Val substitution present in the C(lambda)1(s) chain at position 155 is sufficient to abrogate the selection of the H3/lambda1 pair. Unexpectedly, when the H3-mu transgene array is present in a homozygous state in lambda1(s) mice but not in 'wild-type' lambda1 mice (lambda1(+)), a significant number of mature B cells expressing all H3/lambda combinations can be developed. These results indicate that the overriding H3/lambda1 dominance observed in lambda1(+) mice is due to a positive selection process and not to a negative selection of other H3/lambda combinations. They also show that the export of B cells to the periphery can be controlled by the expression of the mu chain. |
