The genus Henipavirus (HNVs) includes two fatal viruses, namely Nipah virus (NiV) and Hendra virus (HeV). Since 1994, NiV and HeV have been endemic to the Asia–Pacific region and responsible for more than 600 cases of infections. Two emerging HNVs, Ghana virus (GhV) and Mojiang virus (MojV), are speculated to be associated with unrecognized human diseases in Africa and China, respectively. Despite many efforts to develop vaccines against henipaviral diseases, there is presently no licensed human vaccine. As HNVs are highly pathogenic and diverse, it is necessary to develop universal vaccines to prevent future outbreaks. The attachment enveloped glycoprotein (G protein) of HNVs mediates HNV attachment to the host cell’s surface receptors. G proteins have been used as a protective antigen in many vaccine candidates for HNVs. We performed quantitative studies on the antibody responses elicited by the G proteins of NiV, HeV, GhV, and MojV. We found that the G proteins of NiV and HeV elicited only a limited cross-reactive antibody response. Further, there was no cross-protection between MojV, GhV, and highly pathogenic HNVs. We then constructed a bivalent vaccine where the G proteins of NiV and HeV were fused with the human IgG1 Fc domain. The immunogenicity of the bivalent vaccine was compared with that of monovalent vaccines. Our results revealed that the Fc-based bivalent vaccine elicited a potent antibody response against both NiV and HeV. We also constructed a tetravalent Fc heterodimer fusion protein that contains the G protein domains of four HNVs. Immunization with the tetravalent vaccine elicited broad antibody responses against NiV, HeV, GhV, and MojV in mice, indicating compatibility among the four antigens in the Fc-fusion protein. These data suggest that our novel bivalent and tetravalent Fc-fusion proteins may be efficient candidates to prevent HNV infection.

Brucella spp. are Gram-negative, facultative intracellular pathogens that cause brucellosis in both humans and animals. The B. abortus vaccine strain 104 M is the only vaccine available in China for the prevention of brucellosis in humans. Although the B. abortus 104 M genome has been fully sequenced, the current genome annotations are not yet complete. In addition, the main mechanisms underpinning its residual toxicity and vaccine-induced immune protection have yet to be elucidated. Mapping the proteome of B. abortus 104 M will help to improve genome annotation quality, thereby facilitating a greater understanding of its biology. In this study, we utilized a proteogenomic approach that combined subcellular fractionation and peptide fractionation to perform a whole-proteome analysis and genome reannotation of B. abortus 104 M using high-resolution mass spectrometry. In total, 1,729 proteins (56.3% of 3,072) including 218 hypothetical proteins were identified using the culture conditions that were employed this study. The annotations of the B. abortus 104 M genome were also refined following identification and validation by reverse transcription-PCR. In addition, 14 pivotal virulence factors and 17 known protective antigens known to be involved in residual toxicity and immune protection were confirmed at the protein level following induction by the 104 M vaccine. Moreover, a further insight into the cell biology of multichromosomal bacteria was obtained following the elucidation of differences in protein expression levels between the small and large chromosomes. The work presented in this report used a proteogenomic approach to perform whole-proteome analysis and genome reannotation in B. abortus 104 M; this work helped to improve genome annotation quality. Our analysis of virulence factors, protective antigens and other protein effectors provided the basis for further research to elucidate the mechanisms of residual toxicity and immune protection induced by the 104 M vaccine. Finally, the potential link between replication dynamics, gene function, and protein expression levels in this multichromosomal bacterium was detailed.

Lassa virus (LASV) is a rodent-borne arenavirus circulating in West African regions that causes Lassa fever (LF). LF is normally asymptomatic at the initial infection stage, but can progress to severe disease with multiorgan collapse and hemorrhagic fever. To date, the therapeutic choices are limited, and there is no approved vaccine for avoiding LASV infection. Adenoviral vector-based vaccines represent an effective countermeasure against LASV because of their safety and adequate immunogenicity, as demonstrated in use against other emerging viral infections. Here, we constructed and characterized a novel Ad5 (E1-, E3-) vectored vaccine containing the glycoprotein precursor (GPC) of LASV. Ad5-GPC_LASV elicited both humoral and cellular immune responses in BALB/c mice. Moreover, a bioluminescent imaging-based BALB/c mouse model infected with GPC-bearing and luciferase-expressing replication-incompetent LASV pseudovirus was utilized to evaluate the vaccine efficacy. The bioluminescence intensity of immunized mice was significantly lower than that of control mice after being inoculated with LASV pseudovirus. This study suggests that Ad5-GPC_LASV represents a potential vaccine candidate against LF.

Background: Plant-derived extracellular vesicles (PDEV) are emerging as natural nanomedicines for various diseases. Scutellaria baicalensis (S. baicalensis) is a traditional Chinese herb long used to treat intestinal inflammatory bowel disorders (IBD), with its therapeutic effects attributed to bioactive flavonoids such as baicalin and wogonin. However, whether SEV contribute to its anti-inflammatory activity remains unexplored. The assembled multi-component nature of SEV, which carry flavonoids, lipids, proteins, and miRNAs, suggests a potential to exert therapeutic effects against IBD through mechanisms distinct from isolated compounds, with potential advantages in bioavailability and multi-target engagement. Methods: We demonstrated that SEV exert potent antioxidant and anti-inflammatory effects in LPS-stimulated RAW264.7 macrophages and Caco-2 intestinal epithelial cells. Moreover, we assessed the therapeutic effects of SEV on dextran sulfate sodium (DSS)-induced IBD in a murine model. Results: In inflamed RAW264.7, SEV modulated the NF-κB/NLRP3 signaling axis to exert anti-inflammatory effects. They scavenged reactive oxygen species (ROS), restored mitochondrial membrane potential, upregulated the anti-inflammatory cytokine IL-10, and suppressed the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β. In Caco-2 intestinal epithelial cells, SEV also repaired intestinal barrier function by restoring expression of the tight junction proteins Zonula Occludens-1 (ZO-1), Claudin-1, and Occludin (OCLN), alongside reduced TNF-α levels. In vivo, SEV accumulated at colonic inflammatory loci to effectively alleviate IBD, as evidenced by improved body weight and increased colon length. This protective effect was mediated through inhibition of the NF-κB/NLRP3 signaling axis in colon tissues, which subsequently restored intestinal barrier integrity by increasing goblet cell numbers, upregulating OCLN proteins, and enhancing Mucin2 (MUC2) secretion, while simultaneously rebalancing inflammatory cytokines through suppression of TNF-α/IL-1β and promotion of IL-10 production. Conclusion: SEV have the potential to protect the colon against DSS-induced colitis by inhibiting the NF-κB/NLRP3 signaling pathway, providing a promising therapeutic candidate for IBD. Infographic on Scutellaria baicalensis extraction and its effects on inflammatory bowel disease.The process begins with grinding the plant, followed by centrifugation, filtering and ultracentrifugation to obtain SEV. Sucrose gradient centrifugation is used to separate SEV. The SEV is then shown to be administered to a model of IBD, where it restores the inflammatory colon microenvironment. The restoration is indicated by increased levels of ZO-1, Claudin-1 and OCLN. SEV intake affects the inflammatory response by reducing ROS and increasing MMP. It also impacts the NF-kB/NLRP3 pathway, reducing TNF-alpha, IL-6 and IL-1beta, while increasing IL-10. The cells involved in this process include RAW264.7 and CaCO2, which intake SEV, leading to these changes.

Edema toxin (ET), one of the main toxic factors of Bacillus anthracis (B. anthracis), is a kind of potent adenylate cyclase (AC). B. anthracis has adapted to resist macrophage microbicidal mechanisms in part by secreting ET. To date, there is limited information on the pathogenic mechanisms used by ET to manipulate macrophage function, especially at the transcriptome level. We used RNA sequencing to study transcriptional changes in RAW264.7 cells treated with ET. We aimed to identify molecular events associated with the establishment of infection and followed changes in cellular proteins. Our results indicate that ET inhibited TNF-α expression in the RAW264.7 mouse macrophage cell line by activating the cAMP/PKA pathway. ET challenge of macrophages induced a differential expression of genes that participate in multiple macrophage effector functions such as cytokine production, cell adhesion, and the inflammatory response. Furthermore, ET influenced the expression of components of the ERK1/2, as well as the NF-αB signaling pathways. We also showed that ET treatments inhibit the phosphorylation of the ERK1/2 protein. ET also attenuated NF-αB subunit p65 phosphorylation and transcriptional activity of NF-αB via the cAMP/PKA pathway in macrophages. Since the observed modulatory effects were characteristic only of the bacterial exotoxin ET, we propose this may be a mechanism used by B. anthracis to manipulate macrophages and establish systemic infection.