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|Title:||Molecular genetics of the T cell receptor alpha chain|
|Author(s):||Roth, Matthew E.|
|Doctoral Committee Chair(s):||Kranz, David M.|
|Department / Program:||Biochemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Health Sciences, Immunology|
|Abstract:||The polymerase chain reaction (PCR) was used in combination with oligonucleotide probe and nucleotide sequence analysis to examine T cell receptor (TCR) alpha chain diversity in fetal and adult thymi. Transcripts were amplified using various V$\alpha$ and C$\alpha$ specific primers and the cloned PCR products were hybridized with J$\alpha$ specific oligonucleotide probes in order to determine J gene segment use. It was found that the use of J$\alpha$ gene segments was not random but varied among the V genes analyzed. The preferential expression of particular V$\alpha$J$\alpha$ combinations was related to the chromosomal location of both the V and J gene segment and to the stage of development. Nucleotide sequences of many of the transcripts were determined in order to evaluate the extent of base pair addition and deletion at the V-J junction. Whereas nucleotide additions occurred primarily in adult animals and were therefore developmentally regulated, nucleotide deletions were evident throughout development.
It has been shown that transcription of unrearranged immunoglobulin V genes correlates with their rearrangement. Since B cells and T cells are thought to use the same recombinase, it was of interest to determine whether transcription of germline TCR V genes also occurred. A PCR based assay was designed to detect TCR V gene germline transcripts. Using this assay, germline transcripts derived from V$\alpha$3, V$\alpha$8 and V$\beta$8 were amplified from adult thymus. V$\alpha$3 germline transcripts were also amplified from day 18 fetal thymus. Two of the V$\alpha$3 germline transcripts which extended well past the heptamer-nonamer region were sequenced. One of these isolates could encode an in-frame protein that extended beyond the V$\alpha$ coding region. The second isolate contains two frame-shift mutations but exhibited some similarity to known transcriptional regulatory proteins. The possibility that these transcripts may encode functional proteins and the implications of this in regard to gene rearrangement are discussed. Results from each of these studies provide information about the fundamental mechanisms which govern the rearrangement of T cell receptor genes.
|Rights Information:||Copyright 1991 Roth, Matthew E.|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9210970|