Interleukin-7 protects CD8+ T cells from adenosine-mediated immunosuppression

Menée à l'aide d'un modèle murin de mélanome, cette étude met en évidence un mécanisme par lequel l'interleukine IL-7 prévient l'inhibition par l'adénosine de l'activité antitumorale des lymphocytes T CD8+

Résumé en anglais

Within the tumor microenvironment, the nucleoside adenosine accumulates and acts through its cell surface receptors to inhibit the activity of antitumor CD8+ T cells. To alleviate this immunosuppression, therapeutics that target either adenosine production or adenosine receptor signaling are being developed. Koyas et al. showed in mice that the actions of adenosine on tumor-infiltrating CD8+ T cells depended on the milieu within the tumor. In particular, signaling by the cytokine interleukin-7 (IL-7) counteracted the immunosuppressive effects of adenosine, leading to enhanced antitumor immunity in a melanoma model. Together, these findings suggest that targeting IL-7 signaling may alleviate the inhibition of tumor-infiltrating T cells.The nucleoside adenosine accumulates extracellularly in solid tumors and inhibits CD8+ T cells by activating adenosine receptors. The cytokine interleukin-7 (IL-7), which is produced by various tissues and tumors, promotes the survival and maintenance of T cells. Adenosine and IL-7 signaling are being clinically targeted separately or in combination with other therapies for solid tumor indications. Here, we found that IL-7 signaling promoted the accumulation of tumor-associated CD8+ T cells, in part, by preventing adenosine-mediated immunosuppression. Inhibition of the transcription factor FoxO1 downstream of IL-7 receptor signaling was important for protecting CD8+ T cells from suppression by adenosine. These findings have implications for the development of new approaches for cancer immunotherapies that target the adenosine pathway.