Regulation of PD-L1 expression in non–small cell lung cancer by interleukin-1β

IntroductionProgrammed cell death–ligand 1 (PD-L1) is a biomarker for prediction of the clinical efficacy of immune checkpoint inhibitors in various cancer types. The role of cytokines in regulation of PD-L1 expression in tumor cells has not been fully characterized, however. Here we show that interleukin-1β (IL-1β) plays a key role in regulation of PD-L1 expression in non–small cell lung cancer (NSCLC).MethodsWe performed comprehensive screening of cytokine gene expression in NSCLC tissue using available single-cell RNA-Sequence data. Then we examined the role of IL-1β in vitro to elucidate its induction of PD-L1 on NSCLC cells.ResultsThe IL-1β gene is highly expressed in the tumor microenvironment, particularly in macrophages. The combination of IL-1β and interferon-γ (IFN-γ) induced a synergistic increase in PD-L1 expression in NSCLC cell lines. IL-1β and IFN-γ also cooperatively activated mitogen-activated protein kinase (MAPK) signaling and promoted the binding of downstream transcription factors to the PD-L1 gene promoter. Furthermore, inhibitors of MAPK signaling blocked upregulation of PD-L1 by IL-1β and IFN-γ.DiscussionOur study reports high levels of IL-1β in the tumor microenvironment may cooperate with IFN-γ to induce maximal PD-L1 expression in tumor cells via activation of MAPK signaling, with the IL-1β–MAPK axis being a promising therapeutic target for attenuation of PD-L1–mediated suppression of antitumor immunity

Pleuroparenchymal fibroelastosis secondary to autologous peripheral blood stem cell transplantation: A case report

Pleuroparenchymal fibroelastosis (PPFE) is a rare form of interstitial pneumonitis. Although most cases of PPFE are idiopathic, some cases of PPFE occur secondary to stem cell transplantation. We report a 41-year-old woman developed pneumonia after autologous peripheral blood system cell transplantation (PBSCT). Eleven years after PBSCT, she presented with dyspnea. A computed tomographic scan showed pleuroparenchymal thickening and predominantly in the upper lobes. She was diagnosed with PPFE secondary to PBSCT. She was started nintedanib and administered oxygen therapy. Most cases of PPFE secondary to stem cell transplantation have been reported. However, we experienced the case of PPFE post-autologous PBSCT