Marked anti-tumor effects of CD8⁺CD62L⁺ T cells from melanoma-bearing mice

Abstract

CD8⁺CD62L⁺ T cells have been shown to play pivotal roles in anti-viral immunity, chronic myeloid leukemia and renal cell carcinoma. Recently, CD8⁺CD62L⁺ T cells from naïve mice (nCD8⁺CD62L⁺ T cells) have shown superior anti-tumor properties in melanoma-bearing mice. Considering that antigen-specific memory T cells have shown to possess more potent immunity than non-specific memory T cells, we hypothesized that CD8⁺CD62L⁺ T cells from tumor-bearing individuals (mCD8⁺CD62L⁺ T cells) might have superior anti-tumor effect than nCD8⁺CD62L⁺ T cells. Therefore, we investigated phenotypes, functions and the in vivo distribution of mCD8⁺CD62L⁺ T cells in tumor-bearing mice. We found that, while keeping the features of central memory T cells, the frequency of mCD8⁺CD62L⁺ T cell in the spleen of tumor-bearing mice was significantly higher than that the one of nCD8⁺CD62L⁺ T cell in naive mice. Moreover, we demonstrated that mCD8⁺CD62L⁺ T cells had higher proliferation rate and IFN-γ production than nCD8⁺CD62L⁺ T cells, in vitro. We performed adoptive transfer of mCD8⁺CD62L⁺ T cells into melanoma-bearing mice and tracked them in spleen, lymph nodes and in melanoma tissues. Our results show that mCD8⁺CD62L⁺ T cells had stronger in vivo anti-tumoral activity than nCD8⁺CD62L⁺ T cells. This study highlights the therapeutic potential of mCD8⁺CD62L⁺ T cells in the immunotherapy of melanoma and possibly other tumors.

• Anti-tumor immunity
• CD8⁺CD62L⁺ T cells
• melanoma
• T subtypes

Acknowledgements

LY carried out the Flow cytometry, Immunohistochemistry and Immunofluorescence staining assays. PG performed the Statistical analysis. YT carried out the Real-time quantitative PCR. HM was responsible for animal breeding. HL performed the proliferation and apoptosis assays. BN helped design and draft the manuscript. YW designed the study and drafted the manuscript. All authors read and approved the final manuscript. This work was supported by a grant from the General Program of National Natural Science Foundation of China (No. 81071706).

Declaration of interest

All authors declare no financial or commercial conflict of interest. The authors alone are responsible for the content and writing of the paper.