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Immune evasion by cancer cells poses a significant challenge for natural killer cell–based immunotherapy. Pyroptosis, a newly discovered form of programmed cell death, has shown great potential for enhancing the antitumor immunity of natural killer cells. Consequently, targeting pyroptosis has become an attractive strategy for boosting natural killer cell activity against cancer. In this study, various assays were conducted, including natural killer cell cytotoxicity assays, flow cytometry, xenograft tumor models, real-time polymerase chain reaction, and enzyme-linked immunosorbent assay, to assess natural killer cell–mediated cell killing, as well as gene and protein expressions. The results indicated that euphohelioscopin A, a potential pyroptosis activator, enhances natural killer cell–mediated lysis of tumor cells, resulting in inhibiting tumor growth that could be reversed by natural killer cell depletion. Furthermore, we found that euphohelioscopin A significantly enhanced IFNγ production in natural killer cells and synergistically upregulated GSDME with IFNγ in cancer cells. Euphohelioscopin A also increased the cleavage of GSDME, promoting granzyme B–induced pyroptosis, which could be reversed by GSDME knockdown and IFNγ blockade. Overall, the findings suggested that euphohelioscopin A enhanced natural killer cell–mediated killing of cancer cells by triggering pyroptosis, making euphohelioscopin A a promising pyroptosis activator with great potential for use in natural killer cell–based cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Immunotherapy has been a research hotspot due to its low side effects, long-lasting efficacy, and wide anti-tumor spectrum. Recently, NK cell-based immunotherapy has gained broad attention for its unique immunological character of tumor identification and eradication and low risk of graft-versus-host disease and cytokine storm. With the cooperation of a drug delivery system (DDS), NK cells activate tumoricidal activity by adjusting the balance of the activating and inhibitory signals on their surface after drug-loaded DDS administration. Moreover, NK cells or NK-derived exosomes can also be applied as drug carriers for distinct modification to promote NK activation and exert anti-tumor effects. In this review, we first introduce the source and classification of NK cells and describe the common activating and inhibitory receptors on their surface. Then, we summarize the strategies for activating NK cells in vivo through various DDSs. Finally, the application prospects of NK cells in tumor immunotherapy are also discussed. [ABSTRACT FROM AUTHOR]

Background and purpose: Neuropathic pain is the typical symptom of brachial plexus root avulsion (BPRA), and no effective therapy is currently available. Electroacupuncture (EA), as a complementary and alternative therapy, plays a critical role in the management of pain-associated diseases. In the present study, we aimed to reveal the peripheral immunological mechanism of EA in relieving the pain of BPRA through the IL-17–CD4+ T lymphocyte–β-endorphin axis. Methods: After receiving repeated EA treatment, the pain of BPRA in rats along with the expressions of a range of neurotransmitters, the contents of inflammatory cytokines, and the population of lymphocytes associated were investigated. CD4+ T lymphocytes were either isolated or depleted with anti-CD4 monoclonal antibody. The titers of IL-17A, interferon-γ (IFN-γ), and β-endorphin were examined. The markers of T lymphocytes, myeloid-derived suppressor cells (MDSCs), dendritic cells (DCs), macrophages, and natural killer (NK) cells were assessed. The activation of the nuclear transcription factor κB (NF-κB) signaling pathway was tested. Results: The pain of BPRA was significantly relieved, and the amount of CD4+ T lymphocytes was increased after EA treatment. The release of β-endorphin was up-regulated with the up-regulation of IL-17A in CD4+ T lymphocytes. The titer of IL-17A was enhanced, leading to an activated NF-κB signaling pathway. The release of β-endorphin and the analgesic effect were almost completely abolished when CD4+ T lymphocytes were depleted. Conclusion: We, for the first time, showed that the neuropathic pain caused by BPRA was effectively relieved by EA treatment via IL-17–CD4+ T lymphocyte–β-endorphin mediated peripheral analgesic effect, providing scientific support for EA clinical application. [ABSTRACT FROM AUTHOR]

Background: The tumor microenvironment (TME) has a deep influence on cancer progression and has become into a new target for cancer treatment. In our previous study, we found that Yu-Ping-Feng (YPF), an ancient Chinese herbal decoction, significantly inhibited the Lewis lung cancer (LLC) tumor growth in a subcutaneous xenograft tumor model, and prolonged the survival of tumor-bearing mice. But the regulation of Yu-Ping-Feng on tumor microenvironment is unknown. Methods: To access the effect of Yu-Ping-Feng on non-small cell lung cancer, an orthotopic luciferase stably expressed Lewis lung cancer tumor model was established on C57BL/6 mice, and then the survival and the tumor growth were evaluated. To address the tumor microenvironment immune regulation, the percentages of CD4+ T cells, CD8+ T cells, natural killer cells (NK), regulatory T cells (Treg), macrophages, and myeloid-derived suppressor cells (MDSC) in spleens and tumor tissues, the macrophage polarization and CD4+ T cell cytotocixity were analyzed by flow cytometry, biophotonic cell killing activity assay, real-time PCR and western-blot. Results: Yu-Ping-Feng significantly prolonged orthotopic lung tumor-bearing mouse survival, and increased the percentages of CD4+ T cell and M1 macrophages and the cytotoxicity of CD4+ T cells. Yu-Ping-Feng significantly enhanced macrophage-mediated lysis of LLC in a concentration-dependent manner, and had no effect on CD4+ T cell-mediated lysis of LLC, but significantly increased CD4+ T cell-mediated lysis after co-incubated with macrophages. In addition, Yu-Ping-Feng induced M1 macrophage polarization through promoting the phosphorylation of STAT1. Conclusion: Yu-Ping-Feng induced M1 macrophages polarization, and then activated CD4+ T lymphocytes, resulting in killing of LLC cells. Yu-Ping-Feng was a potent regulator of M1 macrophage polarization and might have a promising application in tumor immunotherapy. [ABSTRACT FROM AUTHOR]