NECTIN4 regulates the cell surface expression of CD155 in non-small cell lung cancer cells and induces tumor resistance to PD-1 inhibitors.

The development of immune checkpoint inhibitors has changed treatment strategies for some patients with non-small cell lung cancer (NSCLC). However, resistance remains a major problem, requiring the elucidation of resistance mechanisms, which might aid the development of novel therapeutic strategies. The upregulation of CD155, a primary ligand of the immune checkpoint receptor TIGIT, has been implicated in a mechanism of resistance to PD-1/PD-L1 inhibitors, and it is therefore important to characterize the mechanisms underlying the regulation of CD155 expression in tumor cells. The aim of this study was to identify a Nectin that might regulate CD155 expression in NSCLC and affect anti-tumor immune activity. In this study, we demonstrated that NECTIN4 regulated the cell surface expression and stabilization of CD155 by interacting and co-localizing with CD155 on the cell surface. In a syngeneic mouse model, NECTIN4-overexpressing cells exhibited increased cell surface CD155 and resistance to anti-PD-1 antibodies. Of note, combination therapy with anti-PD-1 and anti-TIGIT antibodies significantly suppressed tumor growth. These findings provide new insights into the mechanisms of resistance to anti-PD-1 antibodies and suggest that NECTIN4 could serve as a valuable marker in therapeutic strategies targeting TIGIT.