B cell abnormalities induced by a mu Ig transgene extend to L chain isotype usage.
We have analyzed the phenotype of B cell populations from mice transgenic for a rearranged Ig mu H chain gene. We find a decrease in the number of B cells in the spleens of these mice. Transgenic B cells have decreased surface levels of both IgM and IgD. The circulating IgM in these mice is 3- to 10-fold enriched in lambda L chains, compared with that in non-transgenic mice. Analysis of IgM-producing hybridomas, from transgenic mice that express the transgene at high levels, demonstrates that this higher lambda frequency is observed in transgene-nonexpressing as well as transgene-expressing hybridomas. A partial loss of L chain isotype exclusion is also noted in these hybridomas, and a significant proportion of primary B cells expressing both kappa and lambda L chains on their surface can be demonstrated. These findings suggest an ability of the transgenic Ig H chain to affect events in B cell ontogeny beyond the H chain locus. Our results support a quantitative model of exclusion for both the H chain alleles and the L chain isotypes.
Rath
S
S
Department of Biology, Rosenstiel Research Center, Brandeis University, Waltham, MA 02254.
Nisonoff
A
A
Selsing
E
E
Durdik
J M
JM
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D007075:Immunoglobulin M / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D007146:Immunoglobulin lambda-Chains / Q000032:analysis; D016130:Immunophenotyping; D051379:Mice; D008822:Mice, Transgenic; D011863:Radioimmunoassay
D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains