Analysis of T cell receptor repertoire based on Vβ chain in patients with breast cancer

To find out if the T cell repertoire is efficiently and specifically provoked in patients with breast cancer, we have investigated the clonotypes of main T cell subsets (based on V beta-Chain) in tumor draining lymph nodes. CD4+ helper, CD8+ cytotoxic and (CD4+CD127(dim)CD25+) regulatory T cells, were negatively selected, and isolated, from lymph node mononuclear cells of 14 untreated patients with breast cancer. Four non-malignant patients, who underwent surgical operation, were also recruited as the control group. Based on sequences and new nomenclature of the T cell Receptor beta Variables (TRBVs) available in the international ImMunoGeneTics (IMGT) database, 28 TRBV specific forward primers and two TRB Constant region (TRBC) specific reverse primers were developed to amplify all functional alleles. Fluorescent-labeled PCR products were then run on an ABI PRISM 310 Genetic-Analyzer. The data was analyzed by GeneMapper software version 3.1. Clonotype analysis suggested that activated T cells are present in breast cancer. More TRBV usage were detected among CD4+ helper and regulatory subsets, with Gaussian-like pattern in the majority of functional TRBV families; whereas CD8+ cytotoxic T cells showed oligoclonality in almost all TRBV families with one or two dominant peaks in each family. Similar pattern in some of these TRBVs were also observed among controls. Having no expression or polyclonality in the controls, the oligoclonal pattern observed in the TRBV18, however, appears to be specific to breast cancer patients. This phenomenon may reflect the existence of new antigenic stimulation(s) in BC patients, preferentially activating those clones of T cells that express TRBV18.