Gut dysbiosis caused by antibiotics impairs response to immune checkpoint blockade (ICB). Gut microbiota is becoming an attractive therapeutic target for cancer. The Clostridium butyricum MIYAIRI 588 strain is a probiotic therapy used to improve symptoms related to antibiotic-induced dysbiosis in Japan. We hypothesized that probiotic Clostridium butyricum therapy (CBT) may affect the therapeutic efficacy of ICBs. We retrospectively evaluated 118 patients with advanced non–small cell lung cancer treated with ICBs at Kumamoto University Hospital (Kumamoto-shi, Kumamoto, Japan). Survival analysis comparing patients given CBT before and/or after ICB was conducted using univariate analyses and Cox proportional hazards regression models using propensity score. Propensity score analyses confirmed that probiotic CBT significantly prolonged progression-free survival (PFS) and overall survival (OS). Probiotic CBT significantly associated with longer PFS and OS even in patients who received antibiotic therapy. This study suggests that probiotic CBT may have a positive impact on therapeutic efficacy of ICB in patients with cancer. See articles by Hakozaki et al., p. 1243, and Peng et al., p. 1251

Oral microbiota is associated with human diseases including cancer. Emerging evidence suggests that proton pump inhibitors (PPIs), which allow the oral microbiome to translocate into the gut, negatively influence the efficacy of immune checkpoint blockade (ICB) in cancer patients. However, currently there is no effective treatment that restores the decreased efficacy. To address this issue, we retrospectively evaluated 118 advanced or recurrent non-small cell lung cancer (NSCLC) patients treated with ICB and analyzed 80 fecal samples of patients with lung cancer by 16S metagenomic sequencing. Clostridium butyricum therapy using C. butyricum MIYAIRI 588 (CBM588), a live biotherapeutic bacterial strain, was shown to improve the ICB efficacy in lung cancer. Thus, we investigated how CBM588 affects the efficacy of ICB and the gut microbiota of lung cancer patients undergoing PPI treatment. We found that PPI treatment significantly decreased the efficacy of ICB in NSCLC patients, however, CBM588 significantly restored the diminished efficacy of ICB and improved survival. In addition, CBM588 prolonged overall survival in patients receiving PPIs and antibiotics together. The fecal analysis revealed that PPI users had higher abundance of harmful oral-related pathobionts and lower abundance of beneficial gut bacteria for immunotherapy. In contrast, patients who received CBM588 had lesser relative abundance of potentially harmful oral-related bacteria in the gut. Our research suggests that manipulating commensal microbiota by CBM588 may improve the therapeutic efficacy of ICB in cancer patients receiving PPIs, highlighting the potential of oral-related microbiota in the gut as a new therapeutic target for cancer immunotherapy.

Introduction: The emergence of SARS‐CoV‐2 has caused global public health and economic crisis. Human leukocyte antigen (HLA) is a critical component of the viral antigen presentation pathway and plays essential roles in conferring differential viral susceptibility and severity of diseases. However, the association between HLA gene polymorphisms and risk for COVID‐19 has not been fully elucidated. We hypothesized that HLA genotypes might impact on the differences in morbidity and mortality of COVID‐19 across countries.Methods: We conducted in silico analyses and examined an association of HLA gene polymorphisms with prevalence and mortality of COVID‐19 by using publicly available databases.Results: We found that a possible association between HLA‐A*02:01 and an increased risk for COVID‐19. HLA‐A*02:01 had a relatively lower capacity to present SARS‐CoV‐2 antigens compared with other frequent HLA class I molecules, HLA‐A*11:01 or HLA‐A*24:02.Conclusion: This study suggests that individuals with HLA‐A*11:01 or HLA‐A*24:02 genotypes may generate efficiently T‐cell‐mediated antiviral responses to SARS‐CoV‐2 compared with HLA‐A*02:01. The differences in HLA genotypes may potentially alter the course of the disease and its transmission.

A disruption of immune checkpoints leads to imbalances in immune homeostasis, resulting in immune-related adverse events. Recent case studies have suggested the association between immune checkpoint inhibitors (ICIs) and the disorders of the coagulation-fibrinolysis system, implying that systemic immune activation may impact a balance between clotting and bleeding. However, little is known about the association of coagulation-fibrinolysis system disorder with the efficacy of ICIs. We retrospectively evaluated 83 lung cancer patients who received ICI at Kumamoto University Hospital. The association between clinical outcome and diseases associated with disorders of the coagulation-fibrinolysis system was assessed along with tumor PD-L1 expression. Among 83 NSCLC patients, total 10 patients (12%) developed diseases associated with the disorder of coagulation-fibrinolysis system. We found that disorders of the coagulation-fibrinolysis system occurred in patients with high PD-L1 expression and in the early period of ICI initiation. In addition, high tumor responses (72%) were observed, including two complete responses among these patients. Furthermore, we demonstrate T-cell activation strongly induces production of a primary initiator of coagulation, tissue factor in peripheral PD-L1^high monocytes, in vitro. This study suggests a previously unrecognized pivotal role for immune activation in triggering disorders of the coagulation-fibrinolysis system in cancer patients during treatment with ICI.

Recent studies have shown that immune checkpoint pathways play a pivotal role in preventing destabilization of atherosclerotic lesions [1], implying a possible association between anti-programmed cell death-1 (PD-1) antibody therapy and cardiovascular diseases [2]. The present study proposes a possible mechanism of the onset of acute coronary syndrome (ACS) as the immune-related adverse events (irAE).

Invasive lung adenocarcinoma (LADC) can be classified histologically as lepidic, acinar, papillary, micropapillary, or solid. Most LADC tumors manifest several of these histological subtypes, with heterogeneity being related to therapeutic resistance. We report here that in immunodeficient mice, human LADC cells form tumors with distinct histological features, MUC5AC-expressing solid-type or cytokeratin 7 (CK7)-expressing acinar-type tumors, depending on the site of development, and that a solid-to-acinar transition (SAT) could be induced by the tumor microenvironment. The TGFβ-Smad signaling pathway was activated in both tumor and stromal cells of acinar-type tumors. Immortalized cancer-associated fibroblasts (CAF) derived from acinar-type tumors induced SAT in 3D cocultures with LADC cells. Exogenous TGFβ1 or overexpression of an active form of TGFβ1 increased CK7 expression and reduced MUC5AC expression in LADC cells, and knockdown of Tgfb1 mRNA in CAFs attenuated SAT induction. RNA-sequencing analysis suggested that angiogenesis and neutrophil recruitment are associated with SAT in vivo. Our data indicate that CAF-mediated paracrine TGFβ signaling induces remodeling of tumor tissue and determines the histological pattern of LADC, thereby contributing to tumor heterogeneity.Significance: CAFs secrete TGFβ to induce a solid-to-acinar transition in lung cancer cells, demonstrating how the tumor microenvironment influences histological patterns and tumor heterogeneity in lung adenocarcinoma.