Biased utilization of DHQ52 and JH4 gene segments in a human Ig transgenic minilocus is independent of antigenic selection.
We have assessed the effect of antigenic selection on human Ig heavy chain D and JH gene segment utilization in mice that contain transgenes composed of 2 VH (psi VH3-105 and VH5-251), 10 D, 6 JH, C mu, and C gamma 1 human gene segments. Human heavy chains using the functional VH5-251 gene segment are expressed in the serum and on the surface of murine B cells. The second VH gene segment (psi VH3-105) is not expressed as a protein but is rearranged and transcribed into mRNA. We previously reported that the functional VH5-251 mu transcripts preferentially used the DHQ52 and JH4 gene segments similar to their use in the human repertoire. Here, we demonstrate that the nonfunctional (psi VH3-105) gene segment shows the same bias in D and JH gene segment utilization. Because transcripts using the pseudo-VH gene segment cannot be subjected to antigenic selection, we conclude that the restricted repertoire observed is Ag independent. Analysis of pseudo VH gene segment recombination products reveals no bias in D gene segment reading frame utilization. Finally, we demonstrate that in the human transgene coding sequence complementarities can affect the recombination site and that D inversion is common.
Tuaillon
N
N
University of Texas Southwestern Medical Center, Department of Microbiology, Dallas 75235.
Miller
A B
AB
Longberg
N
N
Tucker
P W
PW
Capra
J D
JD
D000818:Animals; D000941:Antigens / Q000276:immunology*; D001483:Base Sequence; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D006801:Humans; D007144:Immunoglobulin J-Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007138:Immunoglobulin delta-Chains / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009154:Mutation; D014158:Transcription, Genetic
D000941:Antigens; D007144:Immunoglobulin J-Chains; D007135:Immunoglobulin Variable Region; D007138:Immunoglobulin delta-Chains