Specific mechanisms by which tumor infiltrating lymphocytes (TIL) become dysfunctional remain poorly understood. Here, we employed a two-pronged approach using single-cell mass cytometry and tissue imaging technologies to dissect TILs from 25 resectable and 35 advanced non-small cell lung cancer (NSCLC) patients. We identified a burned-out CD8 + TIL subset (Ebo) that specifically accumulated within the tumor microenvironment (TME), but not in adjacent non-tumoral tissues. Ebo showed the highest expression of proliferation and activation markers, but produced the lowest amount of IFN and were the most apoptotic CD8 + TIL subset. Using a humanized patient-derived tumor xenograft model, we demonstrated that Ebo expansion occurred within the TME in a PD-1/B7-H1 pathwaydependent manner. Ebo abundance in baseline tumor tissues was associated with resistance to anti-PD therapy in NSCLC patients. Our study identifies a dysfunctional TIL subset, with distinct features from previously described exhausted T cells, and implies strategies to overcome immunotherapy resistance.

Dopamine is a catecholamine with multiple physiological functions, playing a key role in nervous system; however its participation in reproductive processes and sperm physiology is controversial. High dopamine concentrations have been reported in different portions of the feminine and masculine reproductive tract, although the role fulfilled by this catecholamine in reproductive physiology is as yet unknown. We have previously shown that dopamine type 2 receptor is functional in boar sperm, suggesting that dopamine acts as a physiological modulator of sperm viability, capacitation and motility. In the present study, using immunodetection methods, we revealed the presence of several proteins important for the dopamine uptake and signalling in mammalian sperm, specifically monoamine transporters as dopamine (DAT), serotonin (SERT) and norepinephrine (NET) transporters in equine sperm. We also demonstrated for the first time in equine sperm a functional dopamine transporter using 4-[4-(Dimethylamino)styryl]-N-methylpyridinium iodide (ASP+), as substrate. In addition, we also showed that dopamine (1 mM) treatment in vitro, does not affect sperm viability but decreases total and progressive sperm motility. This effect is reversed by blocking the dopamine transporter with the selective inhibitor vanoxerine (GBR12909) and non-selective inhibitors of dopamine reuptake such as nomifensine and bupropion. The effect of dopamine in sperm physiology was evaluated and we demonstrated that acrosome integrity and thyrosine phosphorylation in equine sperm is significantly reduced at high concentrations of this catecholamine. In summary, our results revealed the presence of monoamine transporter DAT, NET and SERT in equine sperm, and that the dopamine uptake by DAT can regulate sperm function, specifically acrosomal integrity and sperm motility.

Postmortem muscle temperature affects the rate of pH decline in a linear manner from 37.5°C to 0–2°C. The pH decline is correlated with the enzymatic degradation of glycogen to lactate and this process includes the metabolic coupling between glycogenolysis and glycolysis, and that are strongly upregulated by the AMPK. In this study, we used 12 samples previously characterized by have different muscle glycogen concentration, lactate and AMPK activity, selected from 38 steers that produced high final pH (>5.9) and normal final pH (<5.8) carcasses at 24 h postmortem. Moreover, we evaluated changes in the AMPK activity in samples from both categories incubated at 37, 25, 17 and 5°C and supplemented with exogenous glycogen. Finally, we analysed if there were structural differences between polymers from both categories. Our results showed that “in vitro” enzymatic AMPK activity evaluated at both 0.5 or 24 h was greater in samples from normal then high pH categories (p <0.01), and in all temperature of incubation analysed (17, 25 and 37°C). For other hand, a greater AMPK activity were obtained in samples incubated at 17 that 25 or 37°C, in normal carcasses at both 0.5 or 24 h (p < 0.01), as also in samples from carcasses categorized as high pH, but at 24 h (p < 0.05). Interestingly, AMPK activity was totally abolished at 5°C, independent of final pH category of carcasses, and was confirmed that the incubation temperature at which the maximum activity was obtained (p < 0.01), at least in carcasses with a normal pH is at 17°C. The enzymatic AMPK activity did not change in relation to excess glycogen (p > 0.05) and we did not detect structural differences in the polymers present in samples from both categories (p > 0.05), suggesting that postmortem AMPK activity may be highly sensitive to temperature and not to in vitro changes in glycogen concentration (p > 0.05). Our results allow concluding that normal concentrations of muscle glycogen immediately at the time of slaughter (0.5 h) and an adequate cooling managing of carcasses are relevant to let an efficient glycogenolytic/glycolytic flow required for lactate accumulation and pH decline, through the postmortem AMPK signalling pathway.

Background. Nine percent of Gastric Cancer (GC) is associated with Epstein-Barr virus (EBV-associated GC), with significant variations in the global prevalence rates. Emerging evidence shows that, in addition to cellular miRNAs, viral miRNAs can also bind human mRNAs. EBV miRNAs are examples of this binding and are associated with oncogenic capacities of EBV. ebv-miR-BART5-5p shares the exact seed sequence with hsa-miR-18a-5p. However, common mRNA targets have not been fully described. The aim of this study is to determine predicted targets shared by both miRNAs in EBV-associated GC. Methodology. By in house method we identified predicted mRNA targets for ebv-miR-BART5-5p and hsa-miR-18a-5p. These targets were queried in published results from the supplementary files of the STAD TCGA study and miRwalk 2.0 software. Validation was performed in 7 EBV-associated GC (cases) and 6 EBV-negative GC (controls) samples by miQ-PCR (ebv-miR-BART5-5p and hsa-miR-18a-5p) and qRT-PCR (predicted targets). Results. We identified 25 downregulated and 11 upregulated mRNAs in EBV-associated GC cases compared with EBV-negative tumors in validated databases. Interestingly CDH1, which has been associated with diffuse and hereditary GC, was among the predicted targets by miRwalk 2.0. In clinical samples of EBV-associated GC, ebv-miR-BART5-5p and hsa-miR-18a-5p were overexpressed compared with control samples (p=0.0253 and p=0.0205, respectively). Furthermore, CDH1 was downregulated in EBV-associated tumors (p=0.0290). Conclusion: We identified a common human mRNA target, the CDH1 transcript for ebv-miR-BART5-5p and hsa-miR-18a-5p in EBV-associated GC. An additive effect can be suggested between both miRNAs, which may explain the unique downregulation of CDH1 in EBV-associated GC. This work warrants future validation in vitro, as well as in a larger cohort of EBV-associated GC. Grant support: CONICYT-FONDAP-15130011, Fondecyt Regular-1191928 and Fondecyt PostDoc-3201028 Citation Format: Keila Torres, Natalia Landeros, Ignacio Wichmann, Allan Peñaloza-Otárola, Iva Polakovicova, Vinicius Maracaja-Coutinho, Maria Jose Maturana, Franz Villaroel-Espindola, Alejandro Corvalan. An additive effect of ebv-miR-BART5-5p and hsa-miR18a-5p in the downregulation of CDH1 transcript in Epstein-Barr virus associated gastric cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1400.

Post-mortem muscle temperature affects the rate of decline in pH in a linear manner from 37.5 °C down near 0 °C, and this pH decline is correlated with the enzymatic degradation of glycogen to lactate. This transformation occurs in an anaerobic context that includes the metabolic splice between glycogenolysis and glycolysis; and both processes are strongly upregulated by AMPK enzyme. In this study we reported changes (0.5 h and 24 h post-mortem) in muscle glycogen concentration, lactate and AMPK activity from 12 samples of Longissimus dorsi from 38 steers that produced high pH (>5.9) and normal pH (<5.8) carcasses at 24 h post-mortem. Moreover, we evaluated changes in AMPK activity in samples from both categories incubated at 37, 25, 17 and 5 °C and supplemented with exogenous glycogen. Finally, we analysed if there were structural differences between polymers from both categories. Our analyses show that enzymatic AMPK activity was significantly higher at 17 °C than at 37 °C or 25 °C (p<0.0001 and p<0.05 in samples from normal and high pH categories, respectively), and was near zero at 5 °C. On the other hand, AMPK activity did not change in relation with excess glycogen and we did not detect structural differences in the polymers present in samples from both categories. We concluded that postmortem AMPK activity level is highly sensitive to temperature and not at in vitro changes in glycogen concentration. Their results suggest that that normal levels of pre-mortem muscle glycogen and an adequate cooling managing of carcasses are relevant to let an efficient glycogenolytic/glycolytic flow required for lactate accumulation and pH decline, trough of post-mortem AMPK signalling pathway.