Related Experiment Video
Updated: Aug 26, 2026

Peptide:MHC Tetramer-based Enrichment of Epitope-specific T cells
Published on: October 22, 2012
Competition for self-peptide-MHC complexes and cytokines between naive and memory CD8+ T cells expressing the same or
Qing Ge1, Ailin Bai, Brendan Jones
1Center for Cancer Research and Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
To study competition between naïve and memory T cells, we examined proliferation of adoptively transferred naïve CD8(+) T cells in lymphopenic recipients or recipients containing a clonal population of CD8(+) T cells. We find a hierarchy in the extent of T cell proliferation that appears to correlate with the strength of T cell receptor (TCR)-self-peptide-MHC (pepMHC) interactions. CD8(+) T cells also proliferate in recipients containing a full complement of CD8(+) cells with a different TCR if the transferred T cells experience stronger TCR-self-pepMHC interactions than the resident T cells. Furthermore, CD8(+) T cells proliferate in recipients that contain memory CD8(+) cells with a different TCR, but in this case the relative strengths of TCR-self-pepMHC interactions are not as critical. In contrast, CD8(+) T cells do not proliferate significantly in recipients harboring naïve or memory CD8(+) cells that bear the same TCR as the transferred cells. These results suggest that, among naïve T cells and between naïve and memory T cells, CD8(+) cells having the same TCR compete for both self-pepMHC and cytokines, whereas TCR-different CD8(+) cells compete for cytokines. These competitive relationships probably help maintain the size and TCR diversity of naïve and memory T cell populations required for optimal immune responses.
To study competition between naïve and memory T cells, we examined proliferation of adoptively transferred naïve CD8(+) T cells in lymphopenic recipients or recipients containing a clonal population of CD8(+) T cells. We find a hierarchy in the extent of T cell proliferation that appears to correlate with the strength of T cell receptor (TCR)-self-peptide-MHC (pepMHC) interactions. CD8(+) T cells also proliferate in recipients containing a full complement of CD8(+) cells with a different TCR if the transferred T cells experience stronger TCR-self-pepMHC interactions than the resident T cells. Furthermore, CD8(+) T cells proliferate in recipients that contain memory CD8(+) cells with a different TCR, but in this case the relative strengths of TCR-self-pepMHC interactions are not as critical. In contrast, CD8(+) T cells do not proliferate significantly in recipients harboring naïve or memory CD8(+) cells that bear the same TCR as the transferred cells. These results suggest that, among naïve T cells and between naïve and memory T cells, CD8(+) cells having the same TCR compete for both self-pepMHC and cytokines, whereas TCR-different CD8(+) cells compete for cytokines. These competitive relationships probably help maintain the size and TCR diversity of naïve and memory T cell populations required for optimal immune responses.
Related Concept Videos
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
Antigens Involved in Adaptive Immunity
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
Cells of the Adaptive Immune Response
Diversity of Antigen Receptors
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...

