PI3K/AKT mediated De novo fatty acid synthesis regulates RIG-1/MDA-5-dependent type I IFN responses in BVDV-infected CD8+T cells.

Bovine viral diarrhea virus (BVDV) has caused massive economic losses in the cattle business worldwide. Fatty acid synthase (FASN), a key enzyme of the fatty acid synthesis (FAS) pathway, has been shown to support virus replication. To investigate the role of fatty acids (FAs) in BVDV infection, we infected CD8+T lymphocytes obtained from healthy cattle with BVDV in vitro. During early cytopathic (CP) and noncytopathic (NCP) BVDV infection in CD8+ T cells, there is an increase in de novo lipid biosynthesis, resulting in elevated levels of free fatty acids (FFAs) and triglycerides (TG). BVDV infection promotes de novo lipid biosynthesis in a dose-dependent manner. Treatment with the FASN inhibitor C75 significantly reduces the phosphorylation of PI3K and AKT in BVDV-infected CD8+ T cells, while inhibition of PI3K with LY294002 decreases FASN expression. Both CP and NCP BVDV strains promote de novo fatty acid synthesis by activating the PI3K/AKT pathway. Further investigation shows that pharmacological inhibitors targeting FASN and PI3K concurrently reduce FFAs, TG levels, and ATP production, effectively inhibiting BVDV replication. Conversely, the in vitro supplementation of oleic acid (OA) to replace fatty acids successfully restored BVDV replication, underscoring the impact of abnormal de novo fatty acid metabolism on BVDV replication. Intriguingly, during BVDV infection of CD8+T cells, the use of FASN inhibitors prompted the production of IFN-α and IFN-ß, as well as the expression of interferon-stimulated genes (ISGs). Moreover, FASN inhibitors induce TBK-1 phosphorylation through the activation of RIG-1 and MDA-5, subsequently activating IRF-3 and ultimately enhancing the IFN-1 response. In conclusion, our study demonstrates that BVDV infection activates the PI3K/AKT pathway to boost de novo fatty acid synthesis, and inhibition of FASN suppresses BVDV replication by activating the RIG-1/MDA-5-dependent IFN response.

PEI-PLGA nanoparticles significantly enhanced the immunogenicity of IsdB137-361 proteins from Staphylococcus aureus.

INTRODUCTION: Staphylococcus aureus seriously threatens human and animal health. IsdB137-361 of the iron surface determinant B protein (IsdB) from S. aureus exhibits the strong immunogenicity, but its immunoprotective effect is still to be further promoted. Because PEI-PLGA nanoparticles are generated by PEI conjugate with PLGA to develop great potential as a novel immune adjuvant, the immunogenicity of IsdB137-361 is likely be strengthened by PEI-PLGA. METHODS: Here, PEI-PLGA nanoparticles containing IsdB137-361 proteins were prepared by optimizing the entrapment efficiency. Mice were immunized with IsdB137-361 -PEI-PLGA nanoparticles to assess their anti-S. aureus effects. The level of IFN-γ, IL-4, IL-17, and IL-10 cytokines from spleen lymphocytes in mice and generation of the antibodies against IsdB137-361 in serum was assessed by ELISA, the protective immune response was appraised by S. aureus challenge. RESULTS: IsdB137-361 proteins loaded by PEI-PLGA were able to stimulate effectively the proliferation of spleen lymphocytes and increase the secretion of IFN-γ, IL-4, IL-17, and IL-10 cytokine from spleen lymphocytes, and significantly enhance generation of the antibodies against IsdB137-361 in serum, reduce the level of bacterial load in liver, spleen and kidney, and greatly improve the survival rate of mice after challenge. CONCLUSION: These data showed that PEI-PLGA nanoparticles can significantly enhance the immunogenicity of IsdB137-361 proteins, and provide an important reference for the development of novel immune adjuvant.

Anti-BVDV Activity of Traditional Chinese Medicine Monomers Targeting NS5B (RNA-Dependent RNA Polymerase) In Vitro and In Vivo.

Natural products have emerged as "rising stars" for treating viral diseases and useful chemical scaffolds for developing effective therapeutic agents. The nonstructural protein NS5B (RNA-dependent RNA polymerase) of NADL strain BVDV was used as the action target based on a molecular docking technique to screen herbal monomers for anti-BVDV viral activity. The in vivo and in vitro anti-BVDV virus activity studies screened the Chinese herbal monomers with significant anti-BVDV virus effects, and their antiviral mechanisms were initially explored. The molecular docking screening showed that daidzein, curcumin, artemisinine, and apigenin could interact with BVDV-NADL-NS5B with the best binding energy fraction. In vitro and in vivo tests demonstrated that none of the four herbal monomers significantly affected MDBK cell activity. Daidzein and apigenin affected BVDV virus replication mainly in the attachment and internalization phases, artemisinine mainly in the replication phase, and curcumin was active in the attachment, internalization, replication, and release phases. In vivo tests demonstrated that daidzein was the most effective in preventing and protecting BALB/C mice from BVDV infection, and artemisinine was the most effective in treating BVDV infection. This study lays the foundation for developing targeted Chinese pharmaceutical formulations against the BVDV virus.

Short-term treatment with zingerone ameliorates dextran sulfate sodium-induced mouse experimental colitis.

BACKGROUND: Ulcerative colitis (UC) is a relapsing and chronic inflammatory disease of the gastrointestinal tract, which seriously threatens human health. Zingerone (ZO) has been proven to be effective for many diseases. The purpose of this study is to investigate the protective effects and potential mechanisms of ZO extracted from ginger on dextran sulfate sodium (DSS)-induced mouse ulcerative colitis (UC). RESULTS: The results showed that ZO alleviated the weight loss of UC model mice, reduced the disease activity index scores, and inhibited the shortening of colon length. ZO also improved DSS-induced pathological changes in colon tissue and inhibited the secretion of pro-inflammatory cytokines in colon and mesenteric lymph nodes. Further mechanism analysis found that ZO inhibited DSS-induced nuclear factor-κB pathway activation, and regulated peroxisome proliferator-activated receptor γ (PPARγ) expression. To further explore whether PPARγ was involved in the anti-UC effect of ZO, PPARγ inhibitor GW9662 was used. Although ZO also showed a protective effect on GW9662-treated colitis mice, the protective role was significantly weakened. Importantly, the administration of GW9662 significantly aggravated UC compared with the ZO + DSS group. In addition, we preliminarily found that ZO had the effects of inhibiting DSS-induced oxidative stress, maintaining intestinal barrier, and inhibiting the content of LPS and the population of Escherichia coli. CONCLUSIONS: These results indicated that supplementation with ZO might be a new dietary strategy for the treatment of UC. © 2022 Society of Chemical Industry.

The novel combinations of CTB, CpG, and aluminum hydroxide significantly enhanced the immunogenicity of clumping factor A 221-550 of Staphylococcus aureus.

Here, we prepared the novel combined adjuvants, CTB as intra-molecular adjuvant, CpG and aluminum hydroxide (Alum) to strengthen the immunogenicity of clumping factor A221-550 of Staphylococcus aureus (S. aureus). The protein-immunoactive results showed CTB-ClfA221-550 elicited the strong immune responses to serum from mice immunized with CTB and ClfA221-550, respectively. The mice immunized with CTB-ClfA221-550 plus CpG and Alum adjuvant exhibited significantly stronger CD4+ T cell responses for IFN-γ, IL-2, IL-4, and IL-17 and displayed the higher proliferation response of splenic lymphocytes than the control groups, in addition, these mice generated the strongest humoral immune response against ClfA221-550 among all groups. Our results also showed CTB-ClfA221-550 plus CpG and Alum adjuvant obviously increased the survival percentage of the mice challenged by S. aureus. These data suggested that the novel combined adjuvants, CTB, CpG, and Alum, significantly enhance the immune responses triggered with ClfA221-550, and could provide a new approach against infection of S. aureus. ABBREVIATIONS: CTB: Cholera Toxin B; CpG: Cytosine preceding Guanosine; ODN: Oligodeoxynucleotides; Alum: Aluminum hydroxide; TRAP: Target of RNAIII-activating Protein; TLR9: Toll-like Receptor 9; TMB: 3, 3', 5, 5'-tetramethylbenzidine; mAbs: Monoclonal Antibodies; OD: Optical Densities; S. aureus: Staphylococcus aureus; ClfA: Clumping factor A; FnBPA: Fibronection-binding protein A; IsdB: Iron-regulated surface determinant B; SasA: Staphylococcus aureus Surface Protein A; GapC: Glycer-aldehyde-3-phosphate dehydrogenase-C.