Respiratory syncytial virus (RSV) infects the central nervous system, resulting in neurological symptoms. However, the precise underlying pathogenic mechanisms have not been elucidated. In the present study, the infectivity of RSV on N2a neuronal cells and the possible roles of Toll-like receptor 4 (TLR4) and nucleolin (C23) during RSV infection were investigated. We compared two experimental groups (infected and non-infected) and monitored the RSV viral titers in the culture supernatant by a viral plaque assay. We also inspected the morphology of the nucleus in infected N2a cells. We measured the level of RSV F protein and studied its co-localization with TLR4 and nucleolin using immunofluorescence assays and laser confocal microscopy. The potential interaction of RSV F protein with TLR4 and nucleolin was examined by coimmunoprecipitation. The expression changes of TLR4, nucleolin, TLR3 and TLR7 proteins in N2a cells and IL-6 and TNF-α in the culture supernatant were investigated by Western Blot analysis and ELISA assay. Changes in neuronal cell apoptosis status was examined by flow cytometry. The results demonstrated prolific RSV infection of N2a cells, which triggered a decrease of NeuN protein expression, coinciding with an increase of nuclear lesions, F protein expression, RSV viral titers, and late apoptotic levels of N2a cells. RSV infection induced co-localization of RSV F protein with TLR4 and nucleolin, which could potentially lead to a direct interaction. Furthermore, it was found that TLR4 and nucleolin levels increased early after infection and decreased subsequently, whereas TLR3 and TLR7 expression increased throughout RSV infection. The RSV Long strain can prolifically infect N2a neuronal cells, modulating the expression of TLR4 and nucleolin, as well as TLR3, TLR7 and their downstream inflammatory factors, and inducing the co-localization of the RSV F protein with TLR4 and nucleolin.

Background and purpose: In recent years, there has been extensive research on the role of exercise as an adjunctive therapy for cancer. However, the potential mechanisms underlying the anti-tumor therapy of exercise in lung cancer remain to be fully elucidated. As such, our study aims to confirm whether exercise-induced elevation of epinephrine can accelerate CD8⁺ T cell recruitment through modulation of chemokines and thus ultimately inhibit tumor progression. Method: C57BL/6 mice were subcutaneously inoculated with Lewis lung cancer cells (LLCs) to establish a subcutaneous tumor model. The tumor mice were randomly divided into different groups to performed a moderate-intensity exercise program on a treadmill for 5 consecutive days a week, 45 min a day. The blood samples and tumor tissues were collected after exercise for IHC, RT-qPCR, ELISA and Western blot. In addition, another group of mice received daily epinephrine treatment for two weeks (0.05 mg/mL, 200 µL i.p.) (EPI, n = 8) to replicate the effects of exercise on tumors in vivo. Lewis lung cancer cells were treated with different concentrations of epinephrine (0, 5, 10, 20 µM) to detect the effect of epinephrine on chemokine levels via ELISA and RT-qPCR. Results: This study reveals that both pre- and post-cancer exercise effectively impede the tumor progression. Exercise led to an increase in EPI levels and the infiltration of CD8⁺ T cell into the lung tumor. Exercise-induced elevation of EPI is involved in the regulation of Ccl5 and Cxcl10 levels further leading to enhanced CD8⁺ T cell infiltration and ultimately inhibiting tumor progression. Conclusion: Exercise training enhance the anti-tumor immunity of lung cancer individuals. These findings will provide valuable insights for the future application of exercise therapy in clinical practice.

Background: Despite significant strides in lung cancer immunotherapy, the response rates for Kirsten rat sarcoma viral oncogene homolog ( KRAS )‐driven lung adenocarcinoma (LUAD) patients remain limited. Fibrinogen‐like protein 1 (FGL1) is a newly identified immune checkpoint target, and the study of related resistance mechanisms is crucial for improving the treatment outcomes of LUAD patients. This study aimed to elucidate the potential mechanism by which FGL1 regulates the tumor microenvironment in KRAS ‐mutated cancer. Methods: The expression levels of FGL1 and SET1 histone methyltransferase (SET1A) in lung cancer were assessed using public databases and clinical samples. Lentiviruses were constructed for transduction to overexpress or silence FGL1 in lung cancer cells and mouse models. The effects of FGL1 and Yes‐associated protein (Yap) on the immunoreactivity of cytotoxic T cells in tumor tissues were evaluated using immunofluorescence staining and flow cytometry. Chromatin immunoprecipitation and dual luciferase reporter assays were used to study the SET1A‐directed transcriptional program. Results: Upregulation of FGL1 expression in KRAS ‐mutated cancer was inversely correlated with the infiltration of CD8 ⁺ T cells. Mechanistically, KRAS activated extracellular signal‐regulated kinase 1/2 (ERK1/2), which subsequently phosphorylated SET1A and increased its stability and nuclear localization. SET1A‐mediated methylation of Yap led to Yap sequestration in the nucleus, thereby promoting Yap‐induced transcription of FGL1 and immune evasion in KRAS ‐driven LUAD. Notably, dual blockade of programmed cell death‐1 (PD‐1) and FGL1 further increased the therapeutic efficacy of anti‐PD‐1 immunotherapy in LUAD patients. Conclusion: FGL1 could be used as a diagnostic biomarker of KRAS ‐mutated lung cancer, and targeting the Yap‐FGL1 axis could increase the efficacy of anti‐PD‐1 immunotherapy.

Respiratory syncytial virus (RSV) infects neuronal cells in the central nervous system (CNS), resulting in neurological symptoms. In the present study, we intended to explore the mechanism of RSV infection‐induced neuroinflammatory injury from the perspective of the immune response and sought to identify effective protective measures against the injury. The findings showed that toll‐like receptor 4 (TLR4) was activated after RSV infection in human neuronal SY5Y cells. Furthermore, TLR4 activation induced autophagy and apoptosis in neuronal cells, promoted the formation of the NOD‐like receptor family pyrin domain containing 3 (NLRP3) inflammasome, and increased the secretion of downstream inflammatory cytokines such as interleukin‐1β (IL‐1β), interleukin‐18 (IL‐18) and tumour necrosis factor‐α (TNF‐α). Interestingly, blockade of TLR4 or treatment with exogenous melatonin significantly suppressed TLR4 activation as well as TLR4‐mediated apoptosis, autophagy and immune responses. Therefore, we infer that melatonin may act on the TLR4 to ameliorate RSV‐induced neuronal injury, which provides a new therapeutic target for RSV infection.

Multiple Endocrine Neoplasia 1 gene (MEN1), which is known to be a tumor suppressor gene in lung tissues, encodes a 610 amino acid protein menin. Previous research has proven that MEN1 deficiency promotes the malignant progression of lung cancer. However, the biological role of this gene in the immune microenvironment of lung cancer remains unclear. In this study, we found that programmed cell death‐ligand 1 (PD‐L1) is upregulated in lung‐specific Kras^G12D mutation‐induced lung adenocarcinoma in mice, after Men1 deficiency. Simultaneously, CD8⁺ and CD3⁺ T cells are depleted, and their cytotoxic effects are suppressed. In vitro, PD‐L1 is inhibited by the overexpression of menin. Mechanistically, we found that MEN1 inactivation promotes the deubiquitinating activity of COP9 signalosome subunit 5 (CSN5) and subsequently increases the level of PD‐L1.