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Immune Checkpoint Inhibitors Regulate K+ Channel Activity in Cytotoxic T Lymphocytes of Head and Neck Cancer Patients

Authors :
Vaibhavkumar S. Gawali
Ameet A. Chimote
Hannah S. Newton
Manuel G. Feria-Garzón
Martina Chirra
Edith M. Janssen
Trisha M. Wise-Draper
Laura Conforti
Source :
Frontiers in Pharmacology, Vol 12 (2021)
Publication Year :
2021
Publisher :
Frontiers Media S.A., 2021.

Abstract

Programmed death receptor-1 (PD-1) and its ligand (PD-L1) interaction negatively regulates T cell function in head and neck squamous cell carcinoma (HNSCC). Overexpression of PD-1 reduces intracellular Ca2+ fluxes, and thereby T cell effector functions. In HNSCC patients, PD-1 blockade increases KCa3.1 and Kv1.3 activity along with Ca2+ signaling and mobility in CD8+ peripheral blood T cells (PBTs). The mechanism by which PD-L1/PD-1 interaction regulates ion channel function is not known. We investigated the effects of blocking PD-1 and PD-L1 on ion channel functions and intracellular Ca2+ signaling in CD8+ PBTs of HNSCC patients and healthy donors (HDs) using single-cell electrophysiology and live microscopy. Anti-PD-1 and anti-PD-L1 antibodies increase KCa3.1 and Kv1.3 function in CD8+ PBTs of HNSCC patients. Anti-PD-1 treatment increases Ca2+ fluxes in a subset of HSNCC patients. In CD8+ PBTs of HDs, exposure to PD-L1 reduces KCa3.1 activity and Ca2+ signaling, which were restored by anti-PD-1 treatment. The PD-L1-induced inhibition of KCa3.1 channels was rescued by the intracellular application of the PI3 kinase modulator phosphatidylinositol 3-phosphate (PI3P) in patch-clamp experiments. In HNSCC CD8+ PBTs, anti-PD-1 treatment did not affect the expression of KCa3.1, Kv1.3, Ca2+ release activated Ca2+ (CRAC) channels, and markers of cell activation (CD69) and exhaustion (LAG-3 and TIM-3). Our data show that immune checkpoint blockade improves T cell function by increasing KCa3.1 and Kv1.3 channel activity in HNSCC patients.

Details

Language :
English
ISSN :
16639812
Volume :
12
Database :
Directory of Open Access Journals
Journal :
Frontiers in Pharmacology
Publication Type :
Academic Journal
Accession number :
edsdoj.3988e8398cf542708e8c547c9f888c29
Document Type :
article
Full Text :
https://doi.org/10.3389/fphar.2021.742862