Background: Previous studies suggested that diverse cells in cancer microenvironment can interact with CD8+ T cells via exosomes. We designed this study to explore the potential interaction between exhausted CD8+ T cells and normal CD8+ T cells via exosome.
Methods: Fluorescence activated cell sorting was used to get PD1+TIM3+/PD1-TIM3-CD8+ T cells. Exosomes from the cell culture medium were collected by ultracentrifugation. Microarrays were performed to analyse the lncRNA expression profile in exosomes.
Results: Functional exhausted CD8+ T cells could secrete vast exosomes, which can be uptake by normal CD8+ T cells, and impaired their proliferation (Ki67), cell activity (CD69) and the production of cytokines such as interferon-γ and interleukin-2. Microarray detection identified 257 candidate lncRNAs differently expressed in exosomes derived from exhausted CD8+ T cells and non-exhausted CD8+ T cells. Functional enrichment analysis indicated that these lncRNAs actively participated in the regulation of diverse process of CD8+ T cell activity, like metabolism, gene expression, biosynthetic process and so forth.
Conclusions: The exosomes derived from exhausted CD8+ T cells could be uptake by non-exhausted CD8+ T cells and subsequently impaired the function of receipt cells. Exosomes secreted from exhausted CD8+ T cells have distinct lncRNA expression profiles which are significantly different from those in exosomes secreted by non-exhausted CD8+ T cells.
Keywords: CD8+ T Cells; T cell exhaustion; exosome; lncRNA.
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