Lactiplantibacillus plantarum 0111 Protects Against Influenza Virus by Modulating Intestinal Microbial-Mediated Immune Responses.

There are some limitations of traditional influenza vaccines concerning novel mutant strains. Therefore, it is particularly important to develop preventive means for antigen-unrelated types of influenza viruses. Recent studies have shown that probiotics can modulate the immune system and reduce the severity of viral infections. In this study, we investigated the potential of Lactiplantibacillus plantarum 0111 against influenza virus H9N2. Challenge experiments showed that L. plantarum 0111 pretreatments could effectively improve mice's survival rate and weight loss and reduce the inflammatory cytokines IL-6 and TNF-α in the lungs and bronchoalveolar lavage fluid (BALF) along with the degree of lung and intestinal injury. FMT experiment demonstrates that the protective effect produced by L. plantarum 0111 is associated with gut microorganisms. In addition, 16S high-throughput sequencing of the mouse intestinal microbiota showed that L. plantarum 0111 remodeled the intestinal microbiota after H9N2 infection and maintained the gut microbiota balance. In a mouse model, the oral administration of L. plantarum 0111 increased IFN-ß expression in the serum and BALF. At the same time, the transcript levels of IFN-ß and related ISGs in the intestine and lungs of mice were also increased. In addition, the activation and polarization of T cells in mesenteric lymph nodes (MLNs) and the spleen were detected by flow cytometry, and the results showed that L. plantarum 0111 modulated cytokines in T cells and increased IgA expression in B cells in the MLNs and spleen. Thus, L. plantarum 0111 may improve gut microbiota-mediated immune responses and thus, resist infection by the influenza virus, and it could be used as an effective preventive measure against the influenza virus.

Lactobacillus plantarum Surface-Displayed ASFV (p14.5) Can Stimulate Immune Responses in Mice.

African Swine Fever Virus (ASFV) has spread worldwide, and the lack of vaccines severely negatively impacts the pig industry. In this study, the p14.5 protein encoded by ASFV was used as the antigen, and the p14.5 gene was expressed in vitro using the Lactobacillus expression system. Three new functionally recombinant Lactobacillus plantarum (L. plantarum) were constructed and the expressions of the p14.5 protein, p14.5-IL-33-Mus fusion protein and CTA1-p14.5-D-D fusion protein were successfully detected using Western blot analysis. After oral immunization of SPF mice with recombinant L. plantarum, flow cytometry and ELISA were performed to detect the differentiation and maturity of T lymphocytes, B lymphocytes and DCs of the mice, which were higher than those of the control group. Specific antibodies were produced. The immunogenicity of the adjuvant group was stronger than that of the single antigen group, and the IL-33 adjuvant effect was stronger than that of the CTA1-DD adjuvant.

Analysis of lncRNAs and mRNA Expression in the ZBTB1 Knockout Monoclonal EL4 Cell Line and Combined Analysis With miRNAs and circRNAs.

In previous experiments, we identified the effect of deletion of the Zbtb1 gene on circRNAs and microRNAs. In this study, we examined the expression profiles of lncRNAs and mRNAs using the RNA-seq method for Zbtb1-deficient EL4 cells and performed a clustering analysis of differentially expressed lncRNAs and mRNAs. GO term histograms and KEGG scatter plots were drawn. For the experimental results, a joint analysis was performed, which predicted the regulatory relationships among lncRNAs, mRNAs, microRNAs and circRNAs. For the regulatory relationship between lncRNAs and target genes, the chromatin structure and the degree of openness were verified for the possible target gene locations regulated by lncRNA using experimental methods such as Hi-C and ATAC-seq. Ultimately, the possible differential regulation of the Brcal and Dennd5d genes by lncRNAs and the differential changes in transcription factor binding sites in the promoter region were identified. For neRNA-regulated target genes with significantly differentially expressed mRNAs, a combined screen was performed, and the final obtained candidate target genes were subjected to GO and KEGG term enrichment analyses. Our results illustrate that the Zbtb1 gene can not only function as a regulatory factor but also regulate EL4 cells from multiple perspectives based on ceRNA theory.

African swine fever virus MGF505-11R inhibits type I interferon production by negatively regulating the cGAS-STING-mediated signaling pathway.

African swine fever (ASF) is an acute, hemorrhagic, and highly contact infectious disease caused by African swine fever virus (ASFV) infecting domestic pigs or wild boars, the mortality rate up to 100 %. Evasion of host innate immunity plays a vital role in the pathogenesis of ASFV. Studies have showed that the MGF505 genes involve in regulating the IFN-I response, but its mechanism of action remains poorly understood. In our present study, ASFV MGF505-11R inhibited IFN-ß and ISRE activation induced by cGAS, IRF7, IRF3-5D, STING, IKKε and TBK1 accompanied by decreases of IFN-ß, ISG15 and ISG56 mRNA transcription. ASFV MGF505-11R interacted with STING, degrading STING expression by the lysosomal, ubiquitin-proteasome and autophagy pathways. Moreover, ASFV MGF505-11R could inhibit the phosphorylation of TBK1 and IRF3 stimulated by cGAS/STING overexpression. Finally, the truncation mutation analysis indicated that the 1-191 aa and 182-360 aa of ASFV MGF505-11R could inhibit cGAS-STING-mediated activation of IFN-ß promoters. In short, these results demonstrated that ASFV MGF505-11R involved in regulating the IFN-I response by negatively regulating the cGAS signaling pathway. In summary, this study preliminarily clarified the molecular mechanism of ASFV MGF505-11R gene antagonizing IFN-I-mediated antiviral, which will helpfully provide new strategies for treatment and prevention of ASF.