Interleukin-17 signaling influences CD8 T cell immunity and tumor progression according to the IL-17 receptor subunit expression pattern in cancer cells.

IL-17 immune responses in cancer are controversial, with both tumor-promoting and tumor-repressing effects observed. To clarify the role of IL-17 signaling in cancer progression, we used syngeneic tumor models from different tissue origins. We found that deficiencies in host IL-17RA or IL-17A/F expression had varying effects on the growth of different solid tumors including melanoma, sarcoma, lymphoma, and leukemia.

Metabolic modulation of tumours with engineered bacteria for immunotherapy.

The availability of L-arginine in tumours is a key determinant of an efficient anti-tumour T cell response. Consequently, increases of typically low L-arginine concentrations within the tumour may greatly potentiate the anti-tumour responses of immune checkpoint inhibitors, such as programmed death-ligand 1 (PD-L1)-blocking antibodies. However, currently no means are available to locally increase intratumoural L-arginine levels.

Polyfunctional KLRG-1CD57 Senescent CD4 T Cells Infiltrate Tumors and Are Expanded in Peripheral Blood From Breast Cancer Patients.

Senescent T cells have been described during aging, chronic infections, and cancer; however, a comprehensive study of the phenotype, function, and transcriptional program of this T cell population in breast cancer (BC) patients is missing. Compared to healthy donors (HDs), BC patients exhibit an accumulation of KLRG-1CD57 CD4 and CD8 T cells in peripheral blood. These T cells infiltrate tumors and tumor-draining lymph nodes.

Limited Foxp3 Regulatory T Cells Response During Acute Infection Is Required to Allow the Emergence of Robust Parasite-Specific CD8 T Cell Immunity.

While it is now acknowledged that CD4 T cells expressing CD25 and Foxp3 (Treg cells) regulate immune responses and, consequently, influence the pathogenesis of infectious diseases, the regulatory response mediated by Treg cells upon infection by was still poorly characterized. In order to understand the role of Treg cells during infection by this protozoan parasite, we determined in time and space the magnitude of the regulatory response and the phenotypic, functional and transcriptional features of the Treg cell population in infected mice. Contrary to the accumulation of Treg cells reported in most chronic infections in mice and humans, experimental infection was characterized by sustained numbers but decreased relative frequency of Treg cells.

CD39 Expression Defines Cell Exhaustion in Tumor-Infiltrating CD8 T Cells.

The ability of CD8 T lymphocytes to eliminate tumors is limited by their ability to engender an immunosuppressive microenvironment. Here we describe a subset of tumor-infiltrating CD8 T cells marked by high expression of the immunosuppressive ATP ecto-nucleotidase CD39. The frequency of CD39CD8 T cells increased with tumor growth but was absent in lymphoid organs.