AUTHOR=Manjarrez-Orduño Nataly , Menard Laurence C. , Kansal Selena , Fischer Paul , Kakrecha Bijal , Jiang Can , Cunningham Mark , Greenawalt Danielle , Patel Vishal , Yang Minghui , Golhar Ryan , Carman Julie A. , Lezhnin Sergey , Dai Hongyue , Kayne Paul S. , Suchard Suzanne J. , Bernstein Steven H. , Nadler Steven G. TITLE=Circulating T Cell Subpopulations Correlate With Immune Responses at the Tumor Site and Clinical Response to PD1 Inhibition in Non-Small Cell Lung Cancer JOURNAL=Frontiers in Immunology VOLUME=Volume 9 - 2018 YEAR=2018 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2018.01613 DOI=10.3389/fimmu.2018.01613 ISSN=1664-3224 ABSTRACT=

Agents targeting the PD1–PDL1 axis have transformed cancer therapy. Factors that influence clinical response to PD1–PDL1 inhibitors include tumor mutational burden, immune infiltration of the tumor, and local PDL1 expression. To identify peripheral correlates of the anti-tumor immune response in the absence of checkpoint blockade, we performed a retrospective study of circulating T cell subpopulations and matched tumor gene expression in melanoma and non-small cell lung cancer (NSCLC) patients. Notably, both melanoma and NSCLC patients whose tumors exhibited increased inflammatory gene transcripts presented high CD4+ and CD8+ central memory T cell (CM) to effector T cell (Eff) ratios in blood. Consequently, we evaluated CM/Eff T cell ratios in a second cohort of NSCLC. The data showed that high CM/Eff T cell ratios correlated with increased tumor PDL1 expression. Furthermore, of the 22 patients within this NSCLC cohort who received nivolumab, those with high CM/Eff T cell ratios, had longer progression-free survival (PFS) (median survival: 91 vs. 215 days). These findings show that by providing a window into the state of the immune system, peripheral T cell subpopulations inform about the state of the anti-tumor immune response and identify potential blood biomarkers of clinical response to checkpoint inhibitors in melanoma and NSCLC.