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As an immune checkpoint, programmed cell death 1 (PD‐1) and its ligand (PD‐L1) pathway plays a crucial role in CD8+ cytotoxic T lymphocytes (CTL) activation and provides antitumor responses. The N‐glycans of PD‐1 and PD‐L1 are highly core fucosylated, which are solely catalyzed by the core fucosyltransferase (Fut8). However, the precise biological mechanisms underlying effects of core fucosylation of PD‐1 and PD‐L1 on CTL activation have not been fully understood. In this study, we found that core fucosylation was significantly upregulated in lung adenocarcinoma. Compared to those of Fut8+/+OT‐I mice, the lung adenocarcinoma formation induced by urethane was markedly reduced in Fut8−/−OT‐I mice. De‐core fucosylation of PD‐1 compromised its expression on Fut8−/− CTL, resulted in enhanced Fut8−/− CTL activation and cytotoxicity, leading to more efficient tumor eradication. Indeed, loss of core fucosylation significantly enhanced the PD‐1 ubiquitination and in turn led to the degradation of PD‐1 in the proteasome. Our current work indicates that inhibition of core fucosylation is a unique strategy to reduce PD‐1 expression for the antilung adenocarcinoma immune therapy in the future. [ABSTRACT FROM AUTHOR]

Background: Many immune checkpoint inhibitors (ICIs) have been approved in China to treat non‐small cell lung cancer (NSCLC). However, in the long term, less than 20% of patients benefit from ICIs. To maximize the benefit for NSCLC patients, it is necessary to guide the choice of immunotherapy through biomarkers. Recent studies have shown that gut microbiota can affect tumor response to immunotherapy and might be a potential predictive biomarker. This study analyzed the relationship between intestinal flora structure and metabolomic characteristics in NSCLC and the efficacy of ICIs. Methods: Prospective analysis of samples from 63 patients with advanced NSCLC who attended the Department of Respiratory Medicine of the Peking Union Medical College Hospital from March 2018 to June 2019, and were prescribed programmed cell death 1 (PD‐1) inhibitors, was carried out. The follow‐up deadline was 31 December 2019. Stool samples were collected from all patients before the start of immunotherapy. DNA was extracted from all samples and libraries were constructed. This was followed by sequencing using the Illumina sequencing platform, and results were studied using a biological information data analysis process. We divided the data into two groups based on progression‐free survival (PFS) ≥ six months and PFS < six months. Results: The median PFS was 7.0 months, not reaching the median overall survival (OS). We obtained 373.5 G of original sequencing data. The phyla Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria accounted for most of the bacterial communities in the stool samples studied. Compared with the PFS < six‐month group, the patients in the PFS ≥ six‐month group had significantly higher β‐diversity in the intestinal microbiome at the baseline level. There were also differences in composition between the two groups. Samples in the PFS ≥ six‐month group were rich in Parabacteroides and Methanobrevibacter, while those in the PFS < six‐month group were rich in Veillonella, Selenomonadales, and Negativicutes. The KO, COG, and CAZy databases were used to study functional group protein families, yielding 390 (KO), 264 (COG), and 859 (CAZy) functional group abundances, with significant differences between the two groups. Bacterial metabolites analysis suggested significant differences in the metabolic potential of methanol and methane between the two groups. Conclusions: We found a close correlation between intestinal microbiome β‐diversity and anti‐PD‐1 immunotherapy response in Chinese patients with advanced NSCLC. The intestinal flora composition, functional group protein family, and KEGG metabolism also differed between the two groups. Differences in pathways and flora metabolites were also noted. [ABSTRACT FROM AUTHOR]

The recent emergence of immune checkpoint inhibitors for cancer therapy has created much excitement among cancer patients, drug and diagnostic developers, and health care professionals. This is due largely to the dramatic and sustained responses among some advanced cancers that were previously refractory to therapy. Unfortunately, these responses are difficult to predict, so the goal of the right drug for the right patient at the right time remains elusive. This is in part due to the complexity of the tumor immune microenvironment and its role in drug efficacy. The application of biomarkers to pathologic specimens to predict responses to therapy remains one of the key roles for pathologists in precision medicine. For the new immune checkpoint inhibitors, the emerging class of biomarkers revolves around the immunohistochemical detection of the drug target (or its ligand), programmed cell death ligand 1, on tumor cells or associated immune cells. The diagnostic terrain is already complex because of the involvement of different technology platforms, antibody clones, scoring systems, and indications for their use. The application of these biomarkers to cytologic specimens is critical because the current drug indications are for advanced‐stage cancers that are often sampled by minimally invasive cytologic means rather than surgical resection. This review summarizes the current state of biomarkers for immune checkpoint inhibitors with an emphasis on the opportunities for and threats to cytologic samples. Cancer Cytopathol 2018;126:11‐9. © 2017 American Cancer Society. [ABSTRACT FROM AUTHOR]

Background: The immune profile of sarcomatoid renal cell carcinoma (sRCC), including the programmed cell death ligand 1 (PD-L1) and programmed cell death 1 (PD-1) status, has not been well characterized.Methods: An immunohistochemical digital analysis of PD-L1, PD-1, CD4, and CD8 was performed on nephrectomy specimens from 118 sRCC patients and 92 nonsarcomatoid clear cell renal cell carcinoma (ccRCC) patients. The clinical characteristics of the population were compared between sRCC and ccRCC. Overall survival was estimated, and comparisons were made between PD-L1-positive and PD-L1-negative groups as well as tumor-infiltrating lymphocyte (TIL)-high and TIL-low groups.Results: The PD-L1 H-score of sRCC (mean, 3.7; range, 0-192.1) was significantly higher than the score of grade 4 ccRCC (P = .001), and 41.3% of sRCC cases showed a PD-L1 H-score ≥ 10. The PD-1-positive cell density was significantly higher in sRCC versus ccRCC within the tumor and at the invasive front. The intratumoral CD8-positive cell density was significantly higher in sRCC versus ccRCC. Forty-one percent in the sarcomatoid component of sRCC and 8% in the epithelioid component of sRCC had an adaptive immune resistance phenotype (PD-L1-positive and TIL-positive), whereas only 1% in ccRCC had the type I phenotype.Conclusions: sRCC showed higher PD-L1 expression and higher PD-1- and CD8-positive cell density than grade 4 ccRCC. The results indicate a notable immunosuppressive environment in sRCC. Despite advances in the treatment of advanced-stage renal cell carcinoma, sRCC still has a poor prognosis. This work describes highly immunosuppressive characteristics of sRCC in comparison with an appropriate ccRCC control. The results suggest PD-1/PD-L1 blockade therapy as a potential therapeutic approach for sRCC. Cancer 2017;123:4823-31. © 2017 American Cancer Society. [ABSTRACT FROM AUTHOR]