[Infection of human normal lung epithelial cells by Hantaan virus (HTNV) and its impact on innate immunity and metabolism].

Objective To confirm that Hantaan virus (HTNV) can infect BEAS-2B human normal lung epithelial cells and examine the host immune response and metabolic changes induced by HTNV infection by transcriptomic analysis. Methods Western blotting, quantitative real-time PCR and immunofluorescence assay were used to assess the viral load in BEAS-2B cells, and RNA sequencing was employed for transcriptomic analysis. Results Following the infection of BEAS-2B cells with HTNV, there was an increase in the expression of HTNV nucleocapsid protein (NP) and small segment (S) over time. A transcriptomic analysis of these infected cells at 48-hour mark identified 328 genes that were differentially expressed. GO and KEGG enrichment analysis revealed that these differences were primarily associated with interferon response and innate immune pattern recognition receptor pathways. Protein-protein interaction network analysis identified several genes related to innate immune responses, including four genes encoding disintegrin and metalloproteinase with thrombospondin motifs. Metabolic pathway analysis showed three genes related to terpenoid backbone biosynthesis, two genes related to glycolysis/gluconeogenesis and two genes related to steroid hormone biosynthesis. Subcellular localization analysis indicated that many of the differentially expressed genes were located in mitochondria. Conclusion HTNV is capable of effectively infecting BEAS-2B cells, making them a suitable in vitro model for studying HTNV infection in human lung epithelial. By utilizing bioinformatics methods to screen for differentially expressed genes and metabolic pathways associated with HTNV infection, researchers can establish a theoretical foundation for investigating the molecular mechanisms underling HTNV infection.

T-cell immunoglobulin and mucin 1 (TIM-1) mediates infection of Hantaan virus in Jurkat T cells.

Hantaan virus (HTNV) is a major public health concern due to its ability to cause hemorrhagic fever with renal syndrome (HFRS) in Eurasia. Symptoms of HFRS include fever, hemorrhage, immune dysfunction and renal impairment, and severe cases can be fatal. T cell-mediated adaptive immune responses play a pivotal role in countering HTNV infection. However, our understanding of HTNV and T cell interactions in the disease progression is limited. In this study, we found that human CD4+ T cells can be directly infected with HTNV, thereby facilitating viral replication and production. Additionally, T-cell immunoglobulin and mucin 1 (TIM-1) participated in the process of HTNV infection of Jurkat T cells, and further observed that HTNV enters Jurkat T cells via the clathrin-dependent endocytosis pathway. These findings not only affirm the susceptibility of human CD4+ T lymphocytes to HTNV but also shed light on the viral tropism. Our research elucidates a mode of the interaction between the virus infection process and the immune system. Critically, this study provides new insights into the pathogenesis of HTNV and the implications for antiviral research.

Acacetin Attenuates Sepsis-induced Acute Lung Injury via NLRC3-NF-κB Pathway.

Acacetin, a flavonoid derived compound has been recognized for its diverse biological activities, such as anti-oxidative and anti-inflammatory effects. Acute lung injury (ALI) is a severe condition characterized by respiratory insufficiency and tissue damage, commonly triggered by pneumonia and severe sepsis. These conditions induce an inflammatory response via Toll-like receptor 4 (TLR4) signaling activation. This study explored acacetin's therapeutic potential against lipopolysaccharide (LPS) induced ALI in mice, focusing on its ability to modulate the NF-κB pathway via regulation of the Nod-like receptor family CARD domain containing 3 (NLRC3), a signal sensor that plays an important role in the regulation of inflammation and the maintenance of homeostasis. Our findings revealed that high-dose acacetin reduced the mortality rate of ALI mice, significantly ameliorated LPS-induced lung pathological changes, reduced lung edema, and decreased the expression of inflammatory mediators in lung tissues. This protective impact of acacetin appears to stem form its capacity to enhance NLRC3 expression, which, intern, can inhibit the activation of NF-κB and subsequently inhibit the production of inflammatory mediators. NLRC3 deficiency inhibits the protective effect of acacetin on ALI mice. Molecular docking also verified that acacetin tightly bound acacetin to NLRC3. Additionally, acacetin was found to influence macrophage recruitment dynamics via NLRC3, inhibiting the overactivation of NLRC3-NF-κB related pathways. Taken together, our results indicate that acacetin inhibited LPS-induced acute lung injury and macrophage overrecruitment to the lungs in mice by upregulating NLRC3.

NLRX1: a key regulator in mitochondrial respiration and colorectal cancer progression.

Colorectal cancer (CRC) is a prevalent and aggressive malignancy with high mortality rates and significant risks to human well-being. Population-wide screening for tumor suppressor genes and oncogenes shows promise for reducing the incidence and fatality of CRC. Recent studies have suggested that NLRX1, an innate immunity suppressor, may play a role in regulating chronic inflammation and tumorigenesis. However, further investigation is needed to understand the specific role of NLRX1 in CRC. To evaluate the impact of NLRX1 on migration, invasion, and metastasis, two human colon cancer cell lines were studied in vitro. Additionally, a knockout mouse tumor-bearing model was used to validate the inhibitory effect of NLRX1 on tumor emergence and progression. The Seahorse XF96 technology was employed to assess mitochondrial function and glycolysis in colorectal cancer cells overexpressing NLRX1. Moreover, public databases were consulted to analyze gene and protein expression levels of NLRX1. Finally, the results were validated using a series of CRC patient samples. Our findings demonstrate that downregulation of NLRX1 enhances proliferation, colony formation, and tumor-forming capacity in HCT116 and LoVo cells. Conversely, overexpression of NLRX1 negatively impacts basal respiration and mitochondrial ATP-linked respiration in both cell lines, resulting in a notable decrease in maximal respiration during the standard mitochondrial stress test. Furthermore, analysis of data from the TCGA database reveals a significant reduction in NLRX1 expression in colon and rectal cancer tissues compared to normal tissues. This result was validated using clinical samples, where immunohistochemistry staining and western blotting demonstrated a notable reduction in NLRX1 protein levels in CRC compared to adjacent normal tissues. The decreased expression of NLRX1 may serve as a significant prognostic indicator and diagnostic biomarker for CRC patients.

Investigation of a subunit protein vaccine for HFRS based on a consensus sequence between envelope glycoproteins of HTNV and SEOV.

Due to the global resurgence of hemorrhagic fever with renal syndrome (HFRS), more attention is being focused on this dangerous illness. In China and Korea, the only vaccines available are the virus-inactivated vaccine against Hantaan virus (HTNV) or Seoul virus (SEOV), but their efficacy and safety are inadequate. Therefore, it is important to develop new vaccines that are safer and more efficient to neutralize and regulate areas with a high prevalence of HFRS. We employed bioinformatics methods to design a recombinant protein vaccine based on conserved regions of protein consensus sequences in HTNV and SEOV membranes. The S2 Drosophila expression system was utilized to enhance protein expression, solubility and immunogenicity. After the Gn and Gc proteins of HTNV and SEOV were successfully expressed, mice were immunized, and the humoral immunity, cellular immunity, and in vivo protection of the HFRS universal subunit vaccine were systematically evaluated in mouse models. These results indicated that the HFRS subunit vaccine generated elevated levels of binding and neutralizing antibodies, particularly IgG1, compared to that of the traditional inactivated HFRS vaccine. Additionally, the spleen cells of immunized mice secreted IFN-r and IL-4 cytokines effectively. Moreover, the HTNV-Gc protein vaccine successfully protected suckling mice from HTNV infection and stimulated GC responses. In this research, a new scientific approach is investigated to develop a universal HFRS subunit protein vaccine that is capable of producing effective humoral and cellular immunity in mice. The results suggest that this vaccine could be a promising candidate for preventing HFRS in humans.

Bomidin: An Optimized Antimicrobial Peptide With Broad Antiviral Activity Against Enveloped Viruses.

The rapid evolution of highly infectious pathogens is a major threat to global public health. In the front line of defense against bacteria, fungi, and viruses, antimicrobial peptides (AMPs) are naturally produced by all living organisms and offer new possibilities for next-generation antibiotic development. However, the low yields and difficulties in the extraction and purification of AMPs have hindered their industry and scientific research applications. To overcome these barriers, we enabled high expression of bomidin, a commercial recombinant AMP based upon bovine myeloid antimicrobial peptide-27. This novel AMP, which can be expressed in Escherichia coli by adding methionine to the bomidin sequence, can be produced in bulk and is more biologically active than chemically synthesized AMPs. We verified the function of bomidin against a variety of bacteria and enveloped viruses, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), herpes simplex virus (HSV), dengue virus (DENV), and chikungunya virus (CHIKV). Furthermore, based on the molecular modeling of bomidin and membrane lipids, we elucidated the possible mechanism by which bomidin disrupts bacterial and viral membranes. Thus, we obtained a novel AMP with an optimized, efficient heterologous expression system for potential therapeutic application against a wide range of life-threatening pathogens.

[Research progress in metabolic reprogramming of endothelial cells and T cells and potential therapeutic targets for chronic inflammation].

Metabolic reprogramming plays a very important role in the immunoregulatory process, and T cells, as the indispensable part in the immune response, realize the change of function and state through metabolic reprogramming. And endothelial cells exhibit similar metabolic reprogramming. This review explores the interaction between endothelial cells and T cells to reveal the mechanism of the former as non-professional antigen presenting cells to recruit and activate the latter and the specific mechanism of cytokines produced by the latter in inflammatory response to regulate the function and state of the former, aiming to find the potential therapeutic targets for chronic inflammation and provide new ideas for the treatment.

Nlrc3 Knockout Mice Showed Renal Pathological Changes After HTNV Infection.

Hantaan virus (HTNV) infects humans and causes hemorrhagic fever with renal syndrome (HFRS). The development of well-characterized animal models of HFRS could accelerate the testing of vaccine candidates and therapeutic agents and provide a useful tool for studying the pathogenesis of HFRS. Because NLRC3 has multiple immunoregulatory roles, we investigated the susceptibility of Nlrc3-/- mice to HTNV infection in order to establish a new model of HFRS. Nlrc3-/- mice developed weight loss, renal hemorrhage, and tubule dilation after HTNV infection, recapitulating many clinical symptoms of human HFRS. Moreover, infected Nlrc3-/- mice showed higher viral loads in serum, spleen, and kidney than wild type C57BL/6 (WT) mice, and some of them manifested more hematological disorders and significant pathological changes within multiple organs than WT mice. Our results identify that HTNV infected Nlrc3-/- mice can develop clinical symptoms and pathological changes resembling patients with HFRS, suggesting a new model for studying the pathogenesis and testing of candidate vaccines and therapeutics.

HTNV infection of CD8+ T cells is associated with disease progression in HFRS patients.

Hantaan viruses (HTNVs) are zoonotic pathogens transmitted mainly by rodents and capable of infecting humans. Increasing knowledge of the human response to HTNV infection can guide the development of new preventative vaccines and therapeutic strategies. Here, we show that HTNV can infect CD8+ T cells in vivo in patients diagnosed with hemorrhagic fever with renal syndrome (HFRS). Electron microscopy-mediated tracking of the life cycle and ultrastructure of HTNV-infected CD8+ T cells in vitro showed an association between notable increases in cytoplasmic multivesicular bodies and virus production. Notably, based on a clinical cohort of 280 patients, we found that circulating HTNV-infected CD8+ T cell numbers in blood were proportional to disease severity. These results demonstrate that viral infected CD8+ T cells may be used as an adjunct marker for monitoring HFRS disease progression and that modulating T cell functions may be explored for new treatment strategies.