Wei Sun1, Lin Chen1, Jun Tang2, Chengcheng Zhang1, Yihui Wen1, Weiping Wen1. 1. Department of Otorhinolaryngology-Head and Neck Surgery; Guangzhou Key Laboratory of Otorhinolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. 2. Department of Otorhinolaryngology Head and Neck Surgery, The First People's Hospital of Foshan, Foshan, China.
Abstract
OBJECTIVE: Regulatory T cells (Tregs) are critical factors that impair antitumor immunity. Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is one of the most pathogenic factors in nasopharyngeal carcinoma (NPC). However, the role of EBV-encoded LMP1 in regulating Treg generation in NPC remains unclear. MATERIALS AND METHODS: The in vitro stability of activated Tregs (aTregs) influenced by LMP1 was analyzed by flow cytometry. The inhibitory effects of LMP1-HONE1 antigen-induced aTregs on tumor-associated antigen (TAA)-specific T cells were analyzed in vitro and in vivo. Finally, the expression of LMP1, Foxp3, and enhancer of zeste homolog 2 (EZH2) were analyzed in samples from 86 NPC patients by immunohistochemistry and immunofluorescence. RESULTS: LMP1 upregulated the expression of EZH2, which increased the stability of aTregs in vitro. EZH2 inhibitor, DZnep, depleted LMP1-HONE1 antigen-induced aTregs in vitro and led to potent TAA-specific T cell antitumor immunity in vivo. In NPC tissues, LMP1 expression level was positively correlated with the number of EZH2+ Tregs, which was positively correlated with clinical stage and overall survival. CONCLUSIONS: EZH2 is essential for maintaining the stability and inhibitory functions of aTregs that are induced by EBV-encoded LMP1 in NPC.
OBJECTIVE: Regulatory T cells (Tregs) are critical factors that impair antitumor immunity. Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is one of the most pathogenic factors in nasopharyngeal carcinoma (NPC). However, the role of EBV-encoded LMP1 in regulating Treg generation in NPC remains unclear. MATERIALS AND METHODS: The in vitro stability of activated Tregs (aTregs) influenced by LMP1 was analyzed by flow cytometry. The inhibitory effects of LMP1-HONE1 antigen-induced aTregs on tumor-associated antigen (TAA)-specific T cells were analyzed in vitro and in vivo. Finally, the expression of LMP1, Foxp3, and enhancer of zeste homolog 2 (EZH2) were analyzed in samples from 86 NPC patients by immunohistochemistry and immunofluorescence. RESULTS: LMP1 upregulated the expression of EZH2, which increased the stability of aTregs in vitro. EZH2 inhibitor, DZnep, depleted LMP1-HONE1 antigen-induced aTregs in vitro and led to potent TAA-specific T cell antitumor immunity in vivo. In NPC tissues, LMP1 expression level was positively correlated with the number of EZH2+ Tregs, which was positively correlated with clinical stage and overall survival. CONCLUSIONS: EZH2 is essential for maintaining the stability and inhibitory functions of aTregs that are induced by EBV-encoded LMP1 in NPC.
Entities:
Keywords:
Enhancer of zeste homolog 2; immunity; latent membrane protein 1; nasopharyngeal carcinoma; regulatory T cells