Cancer treatment with immune checkpoint blockade (ICB) often induces immune-related adverse events (irAEs). We hypothesized that proteins coexpressed in tumors and normal cells could be antigenic targets in irAEs and herein described DITAS (discovery of tumor-associated self-antigens) for their identification. DITAS computed transcriptional similarity between lung tumors and healthy lung tissue based on single-sample gene set enrichment analysis. This identified 10 lung tissue–specific genes highly expressed in the lung tumors. Computational analysis was combined with functional T cell assays and single-cell RNA sequencing of the antigen-specific T cells to validate the lung tumor self-antigens. In patients with non–small cell lung cancer (NSCLC) treated with ICB, napsin A was a self-antigen that elicited strong CD8 + T cell responses, with ICB responders harboring higher frequencies of these CD8 + T cells compared with nonresponders. Human leukocyte antigen (HLA) class I ligands derived from napsin A were present in human lung tumors and in nontumor lung tissues, and napsin A tetramers confirmed the presence of napsin A–specific CD8 + T cells in blood and tumors of patients with NSCLC. Napsin A–specific T cell clonotypes were enriched in lung tumors and ICB-induced inflammatory lung lesions and could kill immortalized HLA-matched NSCLC cells ex vivo. Single-cell RNA sequencing revealed that these T cell clonotypes expressed proinflammatory cytokines and cytotoxic markers. Thus, DITAS successfully identified self-antigens, including napsin A, that likely mediate effective antitumor T cell responses in NSCLC and may simultaneously underpin lung irAEs.

Background: Sodium thiosulfate (Na 2 S 2 O 3 ) is a clinically established drug with antioxidant and sulphidereleasing properties. Na 2 S 2 O 3 mediated neuro-and cardioprotective effects in ischemia/reperfusion models and antiinflammatory effects in LPS-induced acute lung injury. Moreover, Na 2 S 2 O 3 improved lung function during resuscitation from hemorrhagic shock in swine with pre-existing atherosclerosis, characterized by decreased expression of cystathionine glyase (CSE), a major source of hydrogen sulfide (H 2 S) synthesis in the vasculature. Based on these findings, we investigated the effects of Na 2 S 2 O 3 administration during resuscitation from trauma-and-hemorrhage in mice under conditions of whole body CSE deficit. Methods: After blast wave-induced blunt chest trauma and surgical instrumentation, CSE knockout (CSE -/-) mice underwent 1 h of hemorrhagic shock (MAP 35 AE 5 mm Hg). At the beginning of resuscitation comprising retransfusion, norepinephrine support and lung-protective mechanical ventilation, animals received either i.v. Na 2 S 2 O 3 (0.45 mg g À1 , n ¼ 12) or vehicle (saline, n ¼ 13). Hemodynamics, acid-base status, metabolism using stable isotopes, and visceral organ function were assessed. Blood and organs were collected for analysis of cytokines, mitochondrial respiratory capacity, and immunoblotting. Results: Na 2 S 2 O 3 treatment improved arterial paO 2 (P ¼ 0.03) coinciding with higher lung tissue glucocorticoid receptor expression. Norepinephrine requirements were lower in the Na 2 S 2 O 3 group (P < 0.05), which was associated with lower endogenous glucose production and higher urine output. Na 2 S 2 O 3 significantly increased renal tissue IkBa and heme oxygenase-1 expression, whereas it lowered kidney IL-6 and MCP-1 levels. Conclusion: Na 2 S 2 O 3 exerted beneficial effects during resuscitation of murine trauma-and-hemorrhage in CSE -/mice, confirming and extending the previously described organ-protective and anti-inflammatory properties of Na 2 S 2 O 3 . The findings make Na 2 S 2 O 3 a potentially promising therapeutic option in the context of impaired CSE activity and/or reduced endogenous H 2 S availability.

Controversial evidence is available regarding suitable targets for the arterial O2 tension (PaO2) after traumatic brain injury and/or hemorrhagic shock (HS). We previously demonstrated that hyperoxia during resuscitation from hemorrhagic shock attenuated cardiac injury and renal dysfunction in swine with coronary artery disease. Therefore, this study investigated the impact of targeted hyperoxemia in a long-term, resuscitated model of combined acute subdural hematoma (ASDH)-induced brain injury and HS. The prospective randomized, controlled, resuscitated animal investigation consisted of 15 adult pigs. Combined ASDH plus HS was induced by injection of 0.1 ml/kg autologous blood into the subdural space followed by controlled passive removal of blood. Two hours later, resuscitation was initiated comprising re-transfusion of shed blood, fluids, continuous i.v. noradrenaline, and either hyperoxemia (target PaO2 200 – 250 mmHg) or normoxemia (target PaO2 80 – 120 mmHg) during the first 24 h of the total of 54 h of intensive care. Systemic hemodynamics, intracranial and cerebral perfusion pressures, parameters of brain microdialysis and blood biomarkers of brain injury did not significantly differ between the two groups. According to the experimental protocol, PaO2 was significantly higher in the hyperoxemia group at the end of the intervention period, i.e., at 24 h of resuscitation, which coincided with a higher brain tissue PO2. The latter persisted until the end of observation period. While neurological function as assessed using the veterinary Modified Glasgow Coma Score progressively deteriorated in the control group, it remained unaffected in the hyperoxemia animals, however, without significant intergroup difference. Survival times did not significantly differ in the hyperoxemia and control groups either. Despite being associated with higher brain tissue PO2 levels, which were sustained beyond the intervention period, targeted hyperoxemia exerted neither significantly beneficial nor deleterious effects after combined ASDH and HS in swine with pre-existing coronary artery disease. The unavailability of a power calculation and, thus, the limited number of animals included, are the limitations of the study.

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IntroductionSodium thiosulfate (Na2S2O3), an H2S releasing agent, was shown to be organ-protective in experimental hemorrhage. Systemic inflammation activates immune cells, which in turn show cell type-specific metabolic plasticity with modifications of mitochondrial respiratory activity. Since H2S can dose-dependently stimulate or inhibit mitochondrial respiration, we investigated the effect of Na2S2O3 on immune cell metabolism in a blinded, randomized, controlled, long-term, porcine model of hemorrhage and resuscitation. For this purpose, we developed a Bayesian sampling-based model for 13C isotope metabolic flux analysis (MFA) utilizing 1,2-13C2-labeled glucose, 13C6-labeled glucose, and 13C5-labeled glutamine tracers.MethodsAfter 3 h of hemorrhage, anesthetized and surgically instrumented swine underwent resuscitation up to a maximum of 68 h. At 2 h of shock, animals randomly received vehicle or Na2S2O3 (25 mg/kg/h for 2 h, thereafter 100 mg/kg/h until 24 h after shock). At three time points (prior to shock, 24 h post shock and 64 h post shock) peripheral blood mononuclear cells (PBMCs) and granulocytes were isolated from whole blood, and cells were investigated regarding mitochondrial oxygen consumption (high resolution respirometry), reactive oxygen species production (electron spin resonance) and fluxes within the metabolic network (stable isotope-based MFA).ResultsPBMCs showed significantly higher mitochondrial O2 uptake and lower O2•− production in comparison to granulocytes. We found that in response to Na2S2O3 administration, PBMCs but not granulocytes had an increased mitochondrial oxygen consumption combined with a transient reduction of the citrate synthase flux and an increase of acetyl-CoA channeled into other compartments, e.g., for lipid biogenesis.ConclusionIn a porcine model of hemorrhage and resuscitation, Na2S2O3 administration led to increased mitochondrial oxygen consumption combined with stimulation of lipid biogenesis in PBMCs. In contrast, granulocytes remained unaffected. Granulocytes, on the other hand, remained unaffected. O2•− concentration in whole blood remained constant during shock and resuscitation, indicating a sufficient anti-oxidative capacity. Overall, our MFA model seems to be is a promising approach for investigating immunometabolism; especially when combined with complementary methods.