Project: Research project

Project Details


The long-term goal of this project is the characterization of the
antigen-receptors used by the family of murine B lymphocytes and T
lymphocytes involved in the immune response to a single antigen. We will
isolate genes encoding antigen-binding polypeptides from both helper (TH)
and suppressor (TS) T cells specific for the polypeptide antigen, GAT.
Several classes of GAT-specific lymphocytes have been cloned, including B
cells whose primary function is the synthesis of GAT-binding immunoglobulin
(Ig), helper T cells (TH) that function to augment GAT-Ig production, and
two subsets of suppressor T cells (TS1 and TS2) that diminish the immune
response to GAT. The genes encoding B-cell GAT-Ig have been isolated
previously. To clone the receptor genes from GAT-TS cells, TS1 and TS2 RNA
will be used in the construction of cDNA libraries. The cDNA will be
cloned into Lambdagtll, an expression vector, and screened with 1)
serological reagents to the I-J, idiotypic, and Tsu/Tind determinants on TS
cells, 2) oligonucleotide probes complementary to the mRNA predicted from
the sequences of secreted antigen-binding suppressive factors, and 3)
subtractive probes enriched for TS-specific transcripts. Isolated cDNA
clones that are transcribed only in T cells will then be confirmed using
functional criteria. The receptor genes from GAT-TH cells will be isolated
from a genomic library by hybridization to a TH-probe isolated from
non-GAT-TH cells. The T cell receptor genes will be used to characterize possible DNA
rearrangements, the genomic organization, and the mechanisms for generating
diversity. The chromosomal locations of the genes encoding TS antigen
receptors and the I-J, idiotypic, and Tsu/Tind determinants will be
ascertained using mouse-hamster hybrid lines. Also, the receptor genes
used by several different TH cells that bind GAT, but differ in their MHC
restriction, will be compared. Initial studies of the regulation of
transcription of the receptor genes in TH cells using various antigenic and
cellular stimuli are also described. By comparing the genetic sequences
used by the various lymphocyte classes to enclode GAT-binding polypeptides,
we will be in a unique position to study the molecular bases of antigen
recognition, MHC restriction, immune cellular interactions, and T and B
lymphocyte activation. A better understanding of the molecular controls
operating in the immune system is of primary importance in determining
basic mechanisms and defects in immune disease states.
Effective start/end date4/1/859/30/92


  • National Institutes of Health


  • Medicine(all)
  • Immunology and Microbiology(all)


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