Reversal of pre-existing NGFR-driven tumor and immune therapy resistance

ABSTRACT: In spite of the remarkable clinical benefit from immune checkpoint blockade in melanoma, both intrinsic and acquired resistance prevent durable clinical responses in many patients. Whereas melanomas are known to acquire MART-1 T cell resistance by reversible phenotype switching to an NGFRhi state, less is known about mechanisms of intrinsic immune resistance. To mimic recurrent T cell attack, we chronically exposed a panel of (patient-derived) melanoma cell lines to clinically relevant MART-1 differentiation antigen-specific cytotoxic T cells. This led to strong enrichment of a pre-existing cell population that exhibited immune resistance in vitro and in mice. These fractions showed high expression of NGFR, were maintained stably, and were found to be present in patients’ melanomas prior to treatment. Remarkably, these NGFRhi melanoma cells also displayed resistance also to T cells recognizing antigens that are unrelated to melanoma differentiation. Furthermore, these cells exhibited multidrug-resistance to other therapies including BRAF + MEK inhibition, suggesting that they exist in a stable and distinct cellular state. Clinically corroborating these findings, a tumor-intrinsic NGFR signature predicted aPD-1 therapy resistance, while NGFRhi melanoma fractions in patients were associated with immune exclusion. Lastly, genetic or pharmacologic NGFR inhibition restored tumor sensitivity to T cell attack in vitro and in melanoma xenografts. These findings demonstrate the existence of a stable and pre-existing NGFRhi multitherapy-refractory melanoma subpopulation, which ought to be eliminated to revert intrinsic resistance to immunotherapeutic intervention.

ORGANISM(S): Homo sapiens

PROVIDER: GSE147091 | GEO | 2020/07/02

REPOSITORIES: GEO