Mouse Anti-Human TCR V beta 12 monoclonal antibody, clone T622

Clonality assessment through Southern blot (SB) analysis of TCRB genes or polymerase chain reaction (PCR) analysis of TCRG genes is important for diagnosing suspect mature T-cell proliferations. Clonality assessment through reverse transcription (RT)-PCR analysis of V beta -C beta transcripts and flow cytometry with a V beta antibody panel covering more than 65% of V beta domains was validated using 28 SE-defined clonal T-cell receptor (TCR)alpha beta (+) T-ALL samples and T-cell lines. Next, the diagnostic applicability of the V beta RT-PCR and flow cytometric clonality assays was studied in 47 mature T-cell proliferations. Clonal V beta -C beta RT-PCR products were detected in all 47 samples, whereas single VP domain usage was found in 31 (66%) of 47 patients. The suspect leukemic cell populations in the other 16 patients showed a complete lack of V beta monoclonal antibody reactivity that was confirmed by molecular data showing the usage of V beta gene segments not covered by the applied V beta monoclonal antibodies. Nevertheless, this could be considered indirect evidence for the "clonal" character of these cells. Remarkably, RT-PCR revealed an oligoclonal pattern in addition to dominant V beta -CP products and single V beta domain expression in many T-LGL proliferations, providing further evidence for the hypothesis raised earlier that T-LGL derive from polyclonal and oligoclonal proliferations of antigen-activated cytotoxic T cells. It is concluded that molecular V beta analysis serves to assess clonality in suspect T-cell proliferations. However, the faster and cheaper V beta antibody studies can be used as a powerful screening method for the detection of single V beta domain expression, followed by molecular studies in patients with more than 20% single V beta domain expression or large suspect T-cell populations (more than 50%-60%) without V beta reactivity, (C) 2001 by The American Society of Hematology.

Inbred rat strains provide a rich source of genetic diversity in immunologically relevant genes. We have characterized the alleles of one of these genes, encoding the rat T-cell receptor C-beta-1 chain, by Southern blots and nucleic acid sequencing. The Cb1 gene segments from DA and LEW rats display complex allotypic variation: both coding and noncoding regions contain multiple nucleotide substitutions. In addition, there is a polymorphic insertion of a rat repetitive LINE element 3' to the coding region. The Cb1 alleles are one part of larger Tcrb haplotypes, containing V-beta, D-beta, and J-beta elements; complete Cb1 genomic nucleotide sequences, and a partial list of the strain distribution of the two alleles, are described in this report.