Exhausted T cells and epigenetic status

Exhausted T cells are a group of dysfunctional T cells,which are present in chronic infections or tumors.The most significant characteristics of exhausted T cells are attenuated effector cytotoxicity,reduced cytokine production,and upregulation of multiple inhibitory molecular receptors(e.g.,PD-1,TIM-3,and LAG-3).The intracellular metabolic changes,altered expression of transcription factors,and a unique epigenetic landscape constitute the exhaustion program.Recently,researchers have made progress in understanding exhausted T cells,with the definition and identification of exhausted T cells changing from phenotypebased to being classified at the transcriptional and epigenetic levels.Recent studies have revealed that exhausted T cells can be separated into two subgroups,namely TCF1^(+)PD-1^(+)progenitor-like precursor exhausted cells and TCF1-PD-1^(+)terminally differentiated exhausted T cells.Moreover,the progenitor-like precursor cell population may be a subset of T cells that can respond to immunotherapy.Studies have also found that TOX initiates and dominates the development of exhausted T cells at the transcriptional and epigenetic levels.TOX also maintains T cell survival and may affect decisions regarding treatment strategies.In this review,we discuss the latest developments in T cell exhaustion in regards to definitions,subpopulations,development mechanisms,differences in diverse diseases,and treatment prospects for exhausted T cells.Furthermore,we hypothesize that the epigenetic state regulated by TOX might be the key point,which can determine the reversibility of exhaustion and the efficacy of immunotherapy.

The prognostic landscape of genes and infiltrating immune cells in cytokine induced killer cell treated-lung squamous cell carcinoma and adenocarcinoma

Objective:Patients with non–small cell lung cancer(NSCLC)respond differently to cytokine-induced killer cell(CIK)treatment.Therefore,potential prognostic markers to identify patients who would benefit from CIK treatment must be elucidated.The current research aimed at identifying predictive prognostic markers for efficient CIK treatment of patients with NSCLC.Methods:Patients histologically diagnosed with NSCLC were enrolled from the Tianjin Medical University Cancer Institute and Hospital.We performed whole-exome sequencing(WES)on the tumor tissues and paired adjacent benign tissues collected from 50 patients with NSCLC,and RNA-seq on tumor tissues of 17 patients with NSCLC before CIK immunotherapy treatment.Multivariate Cox proportional hazard regression analysis was used to analyze the association between clinical parameters and prognostic relevance.WES and RNA-seq data between lung squamous cell carcinoma(SCC)and adenocarcinoma(Aden)were analyzed and compared.Results:The pathology subtype of lung cancer was the most significantly relevant clinical parameter associated with DFS,as analyzed by multivariate Cox proportional hazard regression(P=0.031).The patients with lung SCC showed better CIK treatment efficacy and extended DFS after CIK treatment.Relatively low expression of HLA class II genes and checkpoint molecules,and less immunosuppressive immune cell infiltration were identified in the patients with lung SCC.Conclusions:Coordinated suppression of the expression of HLA class II genes and checkpoint molecules,as well as less immune suppressive cell infiltration together contributed to the better CIK treatment efficacy in lung SCC than lung Aden.