A combination influenza mRNA vaccine candidate provided broad protection against diverse influenza virus challenge.

Influenza viruses present a significant threat to global health. The production of a universal vaccine is considered essential due to the ineffectiveness of current seasonal influenza vaccines against mutant strains. mRNA technology offers new prospects in vaccinology, with various candidates for different infectious diseases currently in development and testing phases. In this study, we encapsulated a universal influenza mRNA vaccine. The vaccine encoded influenza hemagglutinin (HA), nucleoprotein (NP), and three tandem repeats of matrix protein 2 (3M2e). Twice-vaccinated mice exhibited strong humoral and cell-mediated immune responses in vivo. Notably, these immune responses led to a significant reduction in viral load of the lungs in challenged mice, and also conferred protection against future wild-type H1N1, H3N2, or H5N1 influenza virus challenges. Our findings suggest that this mRNA-universal vaccine strategy for influenza virus may be instrumental in mitigating the impact of future influenza pandemics.

Enhanced NK cell activation via eEF2K-mediated potentiation of the cGAS-STING pathway in hepatocellular carcinoma.

BACKGROUND: Liver cancer, particularly hepatocellular carcinoma (HCC), is characterized by a high mortality rate, attributed primarily to the establishment of an immunosuppressive microenvironment. Within this context, we aimed to elucidate the pivotal role of eukaryotic elongation factor 2 kinase (eEF2K) in orchestrating the infiltration and activation of natural killer (NK) cells within the HCC tumor microenvironment. By shedding light on the immunomodulatory mechanisms at play, our findings should clarify HCC pathogenesis and help identify potential therapeutic intervention venues. METHODS: We performed a comprehensive bioinformatics analysis to determine the functions of eEF2K in the context of HCC. We initially used paired tumor and adjacent normal tissue samples from patients with HCC to measure eEF2K expression and its correlation with prognosis. Subsequently, we enrolled a cohort of patients with HCC undergoing immunotherapy to examine the ability of eEF2K to predict treatment efficacy. To delve deeper into the mechanistic aspects, we established an eEF2K-knockout cell line using CRISPR/Cas9 gene editing. This step was crucial for verifying activation of the cGAS-STING pathway and the subsequent secretion of cytokines. To further elucidate the role of eEF2K in NK cell function, we applied siRNA-based techniques to effectively suppress eEF2K expression in vitro. For in vivo validation, we developed a tumor-bearing mouse model that enabled us to compare the infiltration and activation of NK cells within the tumor microenvironment following various treatment strategies. RESULTS: We detected elevated eEF2K expression within HCC tissues, and this was correlated with an unfavorable prognosis (30.84 vs. 20.99 months, P = 0.033). In addition, co-culturing eEF2K-knockout HepG2 cells with dendritic cells led to activation of the cGAS-STING pathway and a subsequent increase in the secretion of IL-2 and CXCL9. Moreover, inhibiting eEF2K resulted in notable NK cell proliferation along with apoptosis reduction. Remarkably, after combining NH125 and PD-1 treatments, we found a significant increase in NK cell infiltration within HCC tumors in our murine model. Our flow cytometry analysis revealed reduced NKG2A expression and elevated NKG2D expression and secretion of granzyme B, TNF-α, and IFN-γ in NK cells. Immunohistochemical examination confirmed no evidence of damage to vital organs in the mice treated with the combination therapy. Additionally, we noted higher levels of glutathione peroxidase and lipid peroxidation in the peripheral blood serum of the treated mice. CONCLUSION: Targeted eEF2K blockade may result in cGAS-STING pathway activation, leading to enhanced infiltration and activity of NK cells within HCC tumors. The synergistic effect achieved by combining an eEF2K inhibitor with PD-1 antibody therapy represents a novel and promising approach for the treatment of HCC.

An Engineered Influenza a Virus Expressing the Co-Stimulator OX40L as an Oncolytic Agent Against Hepatocellular Carcinoma.

Background: Oncolytic virus (OV) therapy has emerged as a promising novel form of immunotherapy. Moreover, an increasing number of studies have shown that the therapeutic efficacy of OV can be further improved by arming OVs with immune-stimulating molecules. Methods: In this study, we used reverse genetics to produce a novel influenza A virus, termed IAV-OX40L, which contained the immune-stimulating molecule OX40L gene in the influenza virus nonstructural (NS1) protein gene. The oncolytic effect of IAV-OX40L was explored on hepatocellular carcinoma (HCC)HCC cells in vitro and in vivo. Results: Hemagglutination titers of the IAV-OX40L virus were stably 27-28 in specific-pathogen-free chicken embryos. The morphology and size distribution of IAV-OX40L are similar to those of the wild-type influenza. Expression of OX40L protein was confirmed by Western blot and immunofluorescence. MTS assays showed that the cytotoxicity of IAV-OX40L was higher in HCC cells (HepG2 and Huh7) than in normal liver cells (MIHA) in a time- and dose-dependent manner in vitro. We found that intratumoral injection of IAV-OX40L reduced tumor growth and increased the survival rate of mice compared with PR8-treated controls in vivo. In addition, the pathological results showed that IAV-OX40L selectively destroyed tumor tissues without harming liver and lung tissues. CD4+ and CD8+ T cells of the IAV-OX40L group were significantly increased in the splenic lymphocytes of mice. Further validation confirmed that IAV-OX40L enhanced the immune response mainly by activating Th1-dominant immune cells, releasing interferon-γ and interleukin-2. Conclusion: Taken together, our findings demonstrate the novel chimeric influenza OV could provide a potential therapeutic strategy for combating HCC and improve the effectiveness of virotherapy for cancer therapy.

NLRP6 deficiency suppresses colorectal cancer liver metastasis growth by modulating M-MDSC-induced immunosuppressive microenvironment.

Colorectal cancer liver metastasis (CRLM) a profound influence on the prognosis of patients with colorectal cancer (CRC), prompting a comprehensive inquiry into its underlying mechanisms. Amidst the multifaceted tumor microenvironment, myeloid-derived suppressor cells (MDSCs) have emerged as pivotal orchestrators of immune modulation. However, their specific contributions to the CRLM have not been explored. The role of NLRP6, a member of the NOD-like receptor family, is of interest. Employing a liver metastasis model, our investigation revealed a heightened accumulation of monocytic MDSCs (M-MDSCs) within metastatic sites, culminating in an immunosuppressive milieu characterized by depleted CD8+ T cell populations. Remarkably, the absence of NLRP6 disrupts this intricate immunosuppressive network, highlighting its nuanced role in sculpting the trajectory of CRLM. This study elucidates the interplay between NLRP6 and MDSCs, potentially guiding novel therapeutic strategies to recalibrate the immune microenvironment in CRLM and enhance patient outcomes.