Abstract 67: Paralleled convergence of antigen load, disease progression and systemic T cell exhaustion in lung cancer and HIV-1 infection

Abstract

Abstract Fatal immune failure in untreated HIV-1 infection is co-defined by evolution of viral escape mutants, increasing antigen diversity and concomitant T cell exhaustion. We have recently described mutational heterogeneity as a negative prognostic factor in primary non-small cell lung cancer (NSCLC), highlighted pathways of neoantigen-driven immune escape and reported a program of TMB-associated T cell exhaustion. Here we present interim analysis from a direct comparison of antigen evolution, peripheral T cell exhaustion and disease progression in 279 longitudinal samples from 64 HIV-1 infected volunteers in the retrospective IAVI protocol C cohort and 85 longitudinal samples from 35 NSCLC patients in the TRACERx study. Systemic PD1hi TOX+TCF7- Tex cell subsets were associated with virus load and CD4 loss in HIV-1 infection and tumour burden and disease progression in NSCLC. Levels of systemic Tex cells in NSCLC tracked with the extent of compartment-wide intra-tumoral CD4 and CD8 T cell dysfunction. Tex populations contracted upon antigen loss via ART in HIV-1, a process paralleled during surgical resection in NSCLC. Resurrection of systemic Tex populations was observed at disease recurrence in NSCLC, mediated in-part by post-operative persistence and re-expansion of minor circulating Tex subsets. These data highlight a common convergence of T cell exhaustion, antigen load and disease progression in distinct clinical conditions of impaired immune surveillance and chronic antigen stimulation. Citation Format: James L. Reading, Rachel Rosenthal, Lucas Black, Seng Kuong Ung, Claire Streatfield, Dominic Wooding, Joakim Esbjornsson, Eric Hunter, Sergio A. Quezada, Jonathan Hare, Charles Swanton. Paralleled convergence of antigen load, disease progression and systemic T cell exhaustion in lung cancer and HIV-1 infection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 67.