Epitopes described in "The blood of healthy individuals exhibits CD8 T cells with a highly altered TCR Vb repertoire but with an unmodified phenotype."

Article Authors:Nicolas Degauque; Fran├žoise Boeffard; Yohann Foucher; Caroline Ballet; Sophie Brouard; Jean-Paul Soulillou
Article Title:The blood of healthy individuals exhibits CD8 T cells with a highly altered TCR Vb repertoire but with an unmodified phenotype.
Reference Detail
Reference ID:1022274
Abstract:CD8 T cell clonal expansions (TCE) have been observed in elderly, healthy individuals as well in old mice, and have been associated with the ageing process. Both chronic latent and non-persistent viral infections have been proposed to drive the development of distinct non-functional and functional TCE respectively. Biases in TCR V repertoire diversity are also recurrently observed in patients that have undergone strong immune challenge, and are preferentially observed in the CD8 compartment. Healthy adults can also exhibit CD8 T cells with strong alterations of their CDR3 length distribution. Surprisingly, no specific investigations have been conducted to analyze the CD8 T cell repertoire in normal adults, to determine if such alterations in TCR V repertoire share the features of TCE. In this study, we characterized the phenotype and function of the CD8 population in healthy individuals of 25-52 years of age. All but one of the EBV-positive HLA-B8 healthy volunteers that were studied were CMV-negative. Using a specific unsupervised statistical method, we identified V families with altered CDR3 length distribution and increased TCR V/HPRT transcript ratios in all individuals tested. The increase in TCR V/HPRT transcript ratio was more frequently associated with an increase in the percentage of the corresponding V(+) T cells than with an absence of modification of their percentage. However, in contrast with the previously described TCE, these CD8(+) T cells were not preferentially found in the memory CD8 subset, they exhibited normal effector functions (cytokine secretion and cytotoxic molecule expression) and they were not reactive to a pool of EBV/CMV/Flu virus peptides. Taken together, the combined analysis of transcripts and proteins of the TCR V repertoire led to the identification of different types of CD8(+) T cell clone expansion or contraction in healthy individuals, a situation that appears more complex than previously described in aged individuals.
Affiliations:INSERM, UMR643, Nantes, France.
Reference Type:Literature
PubMed ID:21738624
Journal:PLoS One
Journal Volume:6
Article Pages:e21240
Journal ISSN:1932-6203
Article Chemical List:Receptors, Antigen, T-Cell;Receptors, Antigen, T-Cell, alpha-beta
Article MeSH List:Adult; Female; Humans; Male; Middle Aged; Phenotype; Receptors, Antigen, T-Cell(immunology); Receptors, Antigen, T-Cell, alpha-beta(metabolism)
Curation Last Updated:2015-06-07 20:05:12