Project: Research project

Project Details


A long-term goal of this project is to better understand the molecular
basis of B lymphocyte development and immunoglobulin (Ig) gene
rearrangement and expression. Two genes, lambda5 and VpreB, are expressed
specifically in B cell precursors but not in B cells, and their gene
products are associated with the mu H (heavy) chain on the pre-B cell
surface. The function of these molecules is, at present, unknown. In this
project we propose to test the hypotheses that lambda5 and VpreB are
involved in a) pre-B cell adherence to or stimulation by stromal cells, b)
induction of kappa light chain gene rearrangement, and/or c) inhibition of
further H chain variable to diversity, joining (V to DJ) gene
rearrangement. The normal cell populations which express lambda5 and VpreB
will be identified and the molecular mechanisms which regulate the cell-
stage specificity of their expression will be determined. Studies to
directly test the above hypotheses will be performed by modulating the
expression of these genes in early precursor or differentiating pro- and
pre-B cell lines.

This project will develop pro- and pre-B cell lines by IL-3 culture and
Abelson murine leukemia virus (A-MuLV)-transformation of fetal liver and
bone marrow and measure lambda5 and VpreB expression in these. Expression
of lambda5, VpreB and mu H chains in normal cell populations will be
analyzed by PCR (polymerase chain reaction) of cDNA and by the binding of
anti-lambda and anti-mu-antibodies. Antibodies to lambda5 and VpreB
peptides and the lambda5/VpreB/mu protein complex will be prepared.
Transcriptional regulation will be measured by cloning discrete DNA
fragments from the genomic clone of VpreB1 and lambda5 into CAT vectors and
transfecting cell lines representing different stages of B cell
differentiation. Expression of lambda5 and VpreB will be inhibited by
anti-sense RNA and antibody in the cell lines derived above and the effect
of this inhibition on pre-B cell-stromal adherence/stimulation and on
subsequent H and L gene rearrangement will be determined.
Effective start/end date7/1/926/30/96


  • National Institute of Allergy and Infectious Diseases
  • National Institute of Allergy and Infectious Diseases
  • National Institute of Allergy and Infectious Diseases


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