Abstract

Mice transgenic for γ2b Ig heavy chain were examined for alterations in B-cell differentiation and endogenous Ig gene rearrangement and expression. Fresh bone marrow from these mice was markedly reduced in BP-1+ cells and there were small reductions in B220+ and sIg+ cells. A-MuLV (Abelson murine leukemia virus) transformants from these bone marrow cells showed little alteration in Ig gene rearrangement and expression when compared to controls, however. Isolation of the B-lymphoid compartment from these mice in vitro using LBMC (lymphoid bone marrow cultures) enabled more detailed characterization of the effects of the transgene. LBMC derived from γ2b transgenic mice had similar growth kinetics, but a 4-5-week delay in the expression of endogenous mu Ig in comparison to control cultures. Nucleic acids derived from these early cultures prior to endogenous mu Ig expression showed reduced Ig JH rearrangements, some sterile mu transcription, low levels of BP-1 expression, and virtually undetectable TdT (terminal deoxynucleotidyl transferase) expression. Thus, this γ2b transgene appears able to affect early B-lymphocyte development.

Highlights

  • Mice transgenic for immunoglobulin genes have been utilized to study the control of expression of these genes as well as the regulation of the encoded antibody molecules

  • Fresh femoral bone marrow was harvested from these mice and stained with FITC-labeled reagents for sIgM, sIgG2b, B220 (Kincade, 1981) and BP-1 (Cooper et al, 1986)

  • The more mature B-cell population expresses sIgM while sIgG2b expression is rare in normal bone marrow, but present in a subpopulation of B cells transgenic for the y2b heavy chain

Read more

Summary

INTRODUCTION

Mice transgenic for immunoglobulin genes have been utilized to study the control of expression of these genes as well as the regulation of the encoded antibody molecules (reviewed in Storb, 1988). Cells expressing endogenous mu could be discriminated from those expressing the transgene, obviating the need for allotypic analysis (Herzenberg et al, 1987) or interspecies studies (Nussenzweig et al, 1988). These y2b transgenic mice were deficient in bone marrow pre-B cells, much as has been shown with other transgenic lines. Despite the presence of transcription at the IgH locus, terminal deoxynucleotidyl transferase (Alt and Baltimore, 1982; Landau et al, 1987) expression was markedly reduced The transcription of another early B-lymphocyte-development molecule, BP-1 (Cooper et al, 1986), was reduced in these cultures. The presence of this y2b transgene may affect B-lymphocyte differentiation as well as Ig recombination

RESULTS
A B CD mem sec sterile
DISCUSSION
MATERIALS AND METHODS
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.