Background/Objectives: Immune checkpoint inhibitors have an established role in non-small cell lung cancer (NSCLC) therapy. The loss of HLA-class-I expression allows cancer cell evasion from immune surveillance, disease progression, and failure of immunotherapy. The restoration of HLA-class-I expression may prove to be a game-changer in current immunotherapy strategies. Autophagic activity has been recently postulated to repress HLA-class-I expression in cancer cells. Methods: NSCLC cell lines (A549 and H1299) underwent late-stage (chloroquine and bafilomycin) and early-stage autophagy blockage (ULK1 inhibitors and MAP1LC3A silencing). The HLA-class-I expression was assessed with flow cytometry, a Western blot, and RT-PCR. NSCLC tissues were examined for MAP1LC3A and HLA-class-I expression using double immunohistochemistry. CD8+ T-cell cytotoxicity was examined in cancer cells pre-incubated with chloroquine and anti-PD-L1 monoclonal antibodies (Moabs); Results: A striking increase in HLA-class-I expression following incubation with chloroquine, bafilomycin, and IFNγ was noted in A549 and H1299 cancer cells, respectively. This effect was further confirmed in CD133+ cancer stem cells. HLA-class-I, β2-microglobulin, and TAP1 mRNA levels remained stable. Prolonged exposure to chloroquine further enhanced HLA-class-I expression. Similar results were noted following exposure to a ULK1 and a PIKfyve inhibitor. Permanent silencing of the MAP1LC3A gene resulted in enhanced HLA-class-I expression. In immunohistochemistry experiments, double LC3A+/HLA-class-I expression was seldom. Pre-incubation of H1299 cancer cells with chloroquine and anti-PD-L1 MoAbs increased the mean % of apoptotic/necrotic cells from 2.5% to 18.4%; Conclusions: Autophagy blockers acting either at late or early stages of the autophagic process may restore HLA-class-I-mediated antigen presentation, eventually leading to enhanced immunotherapy efficacy.
背景/目的：免疫检查点抑制剂在非小细胞肺癌（NSCLC）治疗中已确立重要地位。HLA-I类分子的表达缺失会导致癌细胞逃避免疫监视、疾病进展及免疫治疗失败。恢复HLA-I类分子表达可能成为当前免疫治疗策略的关键突破点。近期研究提示自噬活性可抑制癌细胞中HLA-I类分子的表达。方法：对NSCLC细胞系（A549和H1299）进行晚期（氯喹和巴弗洛霉素）与早期自噬阻断（ULK1抑制剂及MAP1LC3A基因沉默）处理。通过流式细胞术、蛋白质印迹法和RT-PCR评估HLA-I类分子表达水平。采用双重免疫组化检测NSCLC组织中MAP1LC3A与HLA-I类分子的共表达情况。在经氯喹和抗PD-L1单克隆抗体预处理的癌细胞中检测CD8+ T细胞毒性。结果：A549和H1299癌细胞经氯喹、巴弗洛霉素及IFNγ处理后均呈现HLA-I类分子表达的显著提升，该效应在CD133+肿瘤干细胞中得到进一步验证。HLA-I类分子、β2-微球蛋白及TAP1的mRNA水平保持稳定。延长氯喹暴露时间可进一步增强HLA-I类分子表达。使用ULK1和PIKfyve抑制剂处理获得相似结果。永久沉默MAP1LC3A基因可增强HLA-I类分子表达。免疫组化实验中罕见LC3A+/HLA-I类分子双重表达。H1299癌细胞经氯喹和抗PD-L1单克隆抗体预处理后，凋亡/坏死细胞平均百分比从2.5%提升至18.4%。结论：作用于自噬过程晚期或早期的自噬阻断剂可能恢复HLA-I类分子介导的抗原呈递功能，最终提升免疫治疗效果。
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