NKG2A Immune Checkpoint in Vδ2 T Cells: Emerging Application in Cancer Immunotherapy

Cancers (Basel). 2023 Feb 16;15(4):1264. doi: 10.3390/cancers15041264.

Abstract

Immune regulation has revolutionized cancer treatment with the introduction of T-cell-targeted immune checkpoint inhibitors (ICIs). This successful immunotherapy has led to a more complete view of cancer that now considers not only the cancer cells to be targeted and destroyed but also the immune environment of the cancer cells. Current challenges associated with the enhancement of ICI effects are increasing the fraction of responding patients through personalized combinations of multiple ICIs and overcoming acquired resistance. This requires a complete overview of the anti-tumor immune response, which depends on a complex interplay between innate and adaptive immune cells with the tumor microenvironment. The NKG2A was revealed to be a key immune checkpoint for both Natural Killer (NK) cells and T cells. Monalizumab, a humanized anti-NKG2A antibody, enhances NK cell activity against various tumor cells and rescues CD8 αβ T cell function in combination with PD-1/PD-L1 blockade. In this review, we discuss the potential for targeting NKG2A expressed on tumor-sensing human γδ T cells, mostly on the specific Vδ2 T cell subset, in order to emphasize its importance and potential in the development of new ICI-based therapeutic approaches.

Keywords: NKG2A; cancer immunotherapy; immune checkpoint inhibitors; inhibitory receptors; therapeutic monoclonal antibodies; γδ T cells.

Publication types

  • Review

Grants and funding

This work was supported by the Italian Ministry of Health (Bando Ricerca Finalizzata PE-2016-02363915 to D.M.), Associazione Italiana per la Ricerca sul Cancro (IG 14687 to D.M.), Intramural research and clinical funding programs of Humanitas Research Hospital (5 X 1000 to D.M.) and University of Milan (to D.M.), Wellbeing of Women (RG2331 to F.C.) and Wellcome Investigator Award (200841/Z/16/Z to F.C). V.C. is a recipient of a competitive fellowship awarded from the Ph.D. Program of Experimental Medicine at the University of Milan.