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Updated: Jun 12, 2026

Examination of Thymic Positive and Negative Selection by Flow Cytometry
Published on: October 8, 2012
Positive selection of T cells, an in vitro view
Dzenetdina Dervović1, Juan Carlos Zúñiga-Pflücker
1Department of Immunology, University of Toronto and Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada.
The thymus provides a unique set of cues for the effective selection and differentiation of CD4 and CD8 T-cells from a pool of immature thymocytes. Several approaches have been used to elucidate the complex set of intrathymic interactions that mediate these selection and differentiation events. Over the years, a number of different in vitro approaches have been developed and employed to assist in the identification of the cellular and molecular players that underpin thymic function. Here we provide an overview of the advances, which were obtained by in vitro approaches, to our understanding of the process of positive selection and CD4/CD8 lineage commitment.
The thymus provides a unique set of cues for the effective selection and differentiation of CD4 and CD8 T-cells from a pool of immature thymocytes. Several approaches have been used to elucidate the complex set of intrathymic interactions that mediate these selection and differentiation events. Over the years, a number of different in vitro approaches have been developed and employed to assist in the identification of the cellular and molecular players that underpin thymic function. Here we provide an overview of the advances, which were obtained by in vitro approaches, to our understanding of the process of positive selection and CD4/CD8 lineage commitment.

