%0 Journal Article %T Phenotypic CD8+ T Cell Diversification Occurs before, during, and after the First T Cell Division %+ Dynamiques des Réponses Immunes %+ Université Paris Diderot - Paris 7 (UPD7) %A Lemaitre, F. %A Moreau, H. D. %A Vedele, L. %A Bousso, P. %Z This work was supported by Institut Pasteur, INSERM, Fondation pour la Recherche Médicale, and a European Research Council starting grant (LymphocyteContacts). %< avec comité de lecture %@ 0022-1767 %J Journal of Immunology %I Publisher : Baltimore : Williams & Wilkins, c1950-. Latest Publisher : Bethesda, MD : American Association of Immunologists %V 191 %N 4 %P 1578 - 1585 %8 2013-08-15 %D 2013 %R 10.4049/jimmunol.1300424 %M 23836060 %Z Life Sciences [q-bio] %Z Life Sciences [q-bio]/ImmunologyJournal articles %X Effector T cell responses rely on a phenotypically and functionally heterogeneous population of cells. Whether this diversity is programmed before clonal expansion or in later phases as a result of stochastic events or asymmetric cell division is not fully understood. In this study, we first took advantage of a sensitive in vitro assay to analyze the composition of single CD8(+) T cell progenies. Heterogeneity was predominantly observed between progenies of distinct clones, but could also be detected within individual progenies. Furthermore, by physically isolating daughter cells of the first T cell division, we showed that differences in paired daughter cell progenies contributed to intraclonal diversification. Finally, we developed an in vivo limiting dilution assay to compare individual T cell progenies following immunization. We provided evidence for simultaneous intraclonal and interclonal diversification in vivo. Our results support the idea that T cell diversification is a continuous process, initiated before clonal expansion and amplified during the first and subsequent cell divisions. %G English %L pasteur-01410269 %U https://pasteur.hal.science/pasteur-01410269 %~ PASTEUR %~ UNIV-PARIS7 %~ ATP-IMMUN %~ UNIV-PARIS %~ FRM