Abstract 575: Adaptive CD4 Th1 response against telomerase in blood counteracts T-cell exhaustion in non-small cell lung cancer

Despite the critical roles played by IFN-γ+ CD4 Th1 response in tumor immunity, the translation of their potential in clinic remains challenging. Here, we evaluate the clinical significance of circulating anti-tumor CD4 Th1 response in non-small cell lung cancer (NSCLC) patients. 170 naïve-treatment patients were enrolled in this immune monitoring study. The antitumor adaptive Th1 response was assessed by IFN-γ ELISPOT assay in blood lymphocytes using a mixture of eight highly promiscuous and Th1-polarized HLA class II-restricted epitopes from telomerase (TERT). The presence of anti-TERT Th1 response was detected in 59/170 patients (35%). We found an opposite link between anti-TERT Th1 and hyper exhausted T cells co-expressing PD-1+ and TIM-3+ in NSCLC patients. In contrast to hyper exhausted CD8 T cells, the presence of anti-TERT Th1 response was associated with a low rate of hyper exhausted CD4 T cells. We showed that NSCLC stage dissemination is associated with a decrease of anti-TERT Th1 response but an increase of circulating hyper exhausted PD-1+/TIM-3+ CD4 T cells. Notably, anti-telomerase Th1 response and hyper exhausted CD4 T-cells displayed opposite prognosis value in NSCLC. While high level of anti-TERT Th1 cells play a protective role, hyper-exhausted PD-1+TIM-3+ CD4 T cells negatively affect patients’ survival. By using these two circulating immune factors, we stratified patients in distinct prognostic group. Patients with anti-TERT Th1high/CD4 PD-1 TIM-3low immune profile had better overall survival than anti-TERT Th1low/CD4 PD-1 TIM-3high group (median OS : not reached versus 4 months respectively p Citation Format: Caroline Laheurte, Magalie Dosset, Dewi Vernerey, Elodie Lauret Marie Joseph, Laura Boullerot, Vincent Kaulec, Marion Jacquin, Laurie Cuche, Guillaume Eberst, Pascale Jacoulet, Virginie Westeel, Olivier Adotevi. Adaptive CD4 Th1 response against telomerase in blood counteracts T-cell exhaustion in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 575.