Checkpoint-blocker-induced autoimmunity is associated with favourable outcome in metastatic melanoma and distinct T-cell expression profiles

Background Immune checkpoint blockers (ICBs) activate CD8⁺ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.Methods Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab—sICB) or combination (nivolumab and ipilimumab—cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8⁺ T cells was sequenced and differential gene expression according to irAE development assessed.Results 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9–33.4) versus not-reached (P = 2.8 × 10⁻⁶). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8⁺ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.Conclusions Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.Subject terms: Immunotherapy, Melanoma     

lncRNAPCGEM1对肺癌A549细胞恶性生物学行为的影响及其作用机制

目的：探讨长链非编码RNA（long-chain noncoding，lncRNA）PCGEM1 对肺癌A549 细胞恶性生物学行为的影响及其作用机制。方法：收集2016 年3 月至2018 年5 月湖北医药学院附属太和医院胸外科接受手术治疗的62 例肺癌（lung cancer，LC）患者癌组织及相应的癌旁组织标本，并用以上组织构建LC组织芯片。用qPCR检测lncRNA PCGEM1 及miR-148a 在LC组织相应的癌旁组织及LC细胞株中的表达。构建lncRNA PCGEM1 沉默细胞系A549-siPCGEM1 和阴性对照A549-NC，并以A549 细胞作为空白对照（Control 组），用MTT和平板克隆实验检测敲减PCGEM1 对A549 细胞增殖能力的影响，Transwell 和划痕实验检测敲减PCGEM1 对A549 细胞侵袭和迁移能力的影响。使用生物信息学网站StarBase 预测可互补结合PCGEM1的miRNA，再根据Targetscan 网站预测相应可靶向结合miRNA的基因；Western blotting 实验检测TGF-β2/Smad2 信号通路蛋白表达情况。结果：在LC组织中PCGEM1 的表达水平高于癌旁组织而miR-148a 的表达量明显低于癌旁组织（均P<0.05），PCGEM1 在5 种LC细胞株中的表达明显高于人肺成纤维细胞HLF-02（均P<0.05），且以A549 细胞中表达最高。敲减PCGEM1 后，与Control 组和A549-NC 组比较，A549-siPCGEM1 组A549 细胞增殖、侵袭和迁移能力显著降低（均P<0.05）。StarBase 和Targetscan 网站预测结果显示，PCGEM1 可与miR-148a 互补结合，miR-148a 与TGF-β2 存在靶向结合位点。与Control 组和A549-NC组比较，A549-siPCGEM1 组中miR-148a 表达明显升高，TGF-β2 及p-Smad2 蛋白的表达明显降低（均P<0.05）。结论：lncRNA PCGEM1在LC组织和细胞株中高表达，高表达的PCGEM1 可通过下调miR-148a 水平强化TGF β2/Smad2 信号通路，从而促进A549 细胞恶性生物学行为的进展。     

Antimicrobial activity of selected synbiotics targeted for the elderly against pathogenic Escherichia coli strains

The aim of the present study was to evaluate the antimicrobial activity of two synbiotic combinations, Lactobacillus fermentum with short-chain fructooligosaccharides (FOS-LF) and Bifidobacterium longum with isomaltooligosaccharides (IMO-BL), against enterohaemorrhagic Escherichia coli O157:H7 and enteropathogenic E. coli O86. Antimicrobial activity was determined (1) by co-culturing the synbiotics and pathogens in batch cultures, and (2) with the three-stage continuous culture system (gut model), inoculated with faecal slurry from an elderly donor. In the co-culture experiments, IMO-BL was significantly inhibitory to both E. coli strains, while FOS-LF was slightly inhibitory or not inhibitory. Factors other than acid production appeared to play a role in the inhibition. In the gut models, both synbiotics effectively inhibited E. coli O157 in the first vessel, but not in vessels 2 and 3. E. coli O86 was not significantly inhibited.