Defining the Immune Checkpoint Landscape in Human Colorectal Cancer Highlights the Relevance of the TIGIT/CD155 Axis for Optimizing Immunotherapy.

While immune checkpoint (IC) therapies, particularly those targeting the PD-1/PD-L1 axis, have revolutionized the treatment of melanoma and several other cancers, their effect remains very limited in colorectal cancer (CRC). To define a comprehensive landscape of ICs in the human CRC tumor microenvironment (TME), we evaluated, using multiparametric flow cytometry, their ex vivo expression via tumor-infiltrating lymphocytes (TILs) (n = 40 CRCs) as well as that of their respective ligands on tumor and myeloid cells (n = 29). Supervised flow cytometry analyses showed that (i) most CD3 TILs expressed PD-1 and TIGIT and, to a lesser extent, Tim-3, Lag3 and NKG2A, and (ii) EpCAM tumor cells and CD11b myeloid cells differed in their IC ligand expression profile, with a strikingly high expression of CD155 by tumor cells.

Targeting NKG2A to boost anti-tumor CD8 T-cell responses in human colorectal cancer.

Recently, the inhibitory CD94/NKG2A receptor has joined the group of immune checkpoints (ICs) and its expression has been documented in NK cells and CD8 T lymphocytes in several cancers and some infectious diseases. In colorectal cancer (CRC), we previously reported that NKG2A tumor-infiltrating lymphocytes (TILs) are predominantly CD8 αβ T cells and that CD94 overexpression and/or its ligand HLA-E were associated with a poor prognosis. This study aimed to thoroughly characterize the NKG2A CD8 TIL subpopulation and document the impact of NKG2A on anti-tumor responses in CRC.

24th "Nantes Actualités en Transplantation" and 4th "LabEx Immunotherapy-Graft-Oncology" NAT and IGO Joint Meeting "New Horizons in Immunotherapy".

The 24th edition of the annual NAT conference (Nantes Actualités Transplantation) and the 4th edition of the biennial LabEx IGO meeting (Immunotherapy Graft Oncology) were held jointly around a common theme: "New horizons in immunotherapy", on May 31st and June 1st 2021 to highlight new findings in the fields of transplantation, autoimmunity and cancer.

The inhibitory receptor CD94/NKG2A on CD8 tumor-infiltrating lymphocytes in colorectal cancer: a promising new druggable immune checkpoint in the context of HLAE/β2m overexpression.

We previously demonstrated that HLA-E/β2m overexpression by tumor cells in colorectal cancers is associated with an unfavorable prognosis. However, the expression of its specific receptor CD94/NKG2 by intraepithelial tumor-infiltrating lymphocytes, their exact phenotype and function, as well as the relation with the molecular status of colorectal cancer and prognosis remain unknown. Based on a retrospective cohort of 234 colorectal cancer patients, we assessed the expression of HLA-E, β2m, CD94, CD8, and NKp46 by immunohistochemistry on tissue microarray.