Middle East respiratory syndrome coronavirus (MERS-CoV), a new coronavirus that has been causing severe and fatal acute respiratory illnesses in humans since its outbreak in 2012, has raised public fear worldwide. The development of prophylactics and therapeutics is urgently needed to prevent and control MERS-CoV infections. In this study, a bacterium (Lactococcus lactis)-like particle (BLP) vaccine displaying the MERS-CoV receptor-binding domain (RBD) was developed, and gram-positive enhancer matrix (GEM) particles were used as substrates to externally bind to the MERS-CoV RBD through a protein anchor (PA). The designs included different numbers of lysin motif (LysM) repeats in the PAs linked by linkers (RBD-linker-PA2 (RLP₂), RBD-linker-PA3 (RLP₃) and RBD-PA3 (RP₃)), and three LysM repeats and a linker in the fusion proteins increased the binding activity to the RBD. The specific immune responses were tested by intranasally immunizing mice with RLP₃-GEM with or without the adjuvant GEL01. The results showed that GEL01-adjuvanted RLP₃-GEM increased the systemic humoral, cellular and local mucosal immune responses in the mouse model, especially in the intestinal tract. The above results indicate that the MERS-CoV BLP product has the potential to be developed into a promising mucosal candidate vaccine to protect against MERS-CoV infections.

Ebola virus infections lead to severe hemorrhagic fevers in humans and nonhuman primates; and human fatality rates are as high as 67%–90%. Since the Ebola virus was discovered in 1976, the only available treatments have been medical support or the emergency administration of experimental drugs. The absence of licensed vaccines and drugs against the Ebola virus impedes the prevention of viral infection. In this study, we generated recombinant baculoviruses (rBV) expressing the Sudan virus (SUDV) matrix structural protein (VP40) (rBV-VP40-VP40) or the SUDV glycoprotein (GP) (rBV-GP-GP), and SUDV virus-like particles (VLPs) were produced by co-infection of Sf9 cells with rBV-SUDV-VP40 and rBV-SUDV-GP. The expression of SUDV VP40 and GP in SUDV VLPs was demonstrated by IFA and Western blot analysis. Electron microscopy results demonstrated that SUDV VLPs had a filamentous morphology. The immunogenicity of SUDV VLPs produced in insect cells was evaluated by the immunization of mice. The analysis of antibody responses showed that mice vaccinated with SUDV VLPs and the adjuvant Montanide ISA 201 produced SUDV GP-specific IgG antibodies. Sera from SUDV VLP-immunized mice were able to block infection by SUDV GP pseudotyped HIV, indicating that a neutralizing antibody against the SUDV GP protein was produced. Furthermore, the activation of B cells in the group immunized with VLPs mixed with Montanide ISA 201 was significant one week after the primary immunization. Vaccination with the SUDV VLPs markedly increased the frequency of antigen-specific cells secreting type 1 and type 2 cytokines. To study the therapeutic effects of SUDV antibodies, horses were immunized with SUDV VLPs emulsified in Freund’s complete adjuvant or Freund’s incomplete adjuvant. The results showed that horses could produce SUDV GP-specific antibodies and neutralizing antibodies. These results showed that SUDV VLPs demonstrate excellent immunogenicity and represent a promising approach for vaccine development against SUDV infection. Further, these horse anti-SUDV purified immunoglobulins lay a foundation for SUDV therapeutic drug research.

West Nile virus disease (WND) is an arthropod-borne zoonosis responsible for nonspecific fever or severe encephalitis. The pathogen is West Nile virus belonging to the genus Flavivirus, family Flaviviridae. Every year, thousands of cases were reported, which poses significant public health risk. Here, we constructed a West Nile virus chimera, ChiVax-WN01, by replacing the prMΔE gene of JEV SA14-14-2 with that of the West Nile virus NY99. The ChiVax-WN01 chimera showed clear, different characters compared with that of JEV SA14-14-2 and WNV NY99 strain. An animal study indicated that the ChiVax-WN01 chimera presented moderate safety and immunogenicity for 4-week female BALB/c mice.

During arterial puncture or cannulation in mice, permanent ligation of the artery is often required due to difficulty achieving hemostasis after needle withdrawal. This leads to permanent ischemic injury in the supplied tissue region. Such localized ischemia frequently induces secondary complications, compromising experimental outcomes in animal models. The present method aims to seal the puncture site post-procedure while maintaining normal blood flow, thereby preventing postoperative ischemia. This method involves harvesting an adipose tissue fragment from the experimental animal itself, performing arterial puncture using standard techniques, and then wrapping the puncture site with the fat pad to achieve hemostasis while maintaining blood flow. In this study, bilateral common carotid artery puncture was performed on mice, followed by hemostasis using a fat-wrapping technique. Laser speckle contrast imaging(LSCI) revealed no differences in cerebral blood flow changes between the sham and operated groups of mice, and no significant changes were observed in preoperative versus postoperative cerebral blood flow measurements in the operated group. Histological assessment performed at 7, 14, and 28 days after surgery revealed that: (1) preserved brain architecture (H&E staining), (2) intact neuronal morphology without degenerative changes (Nissl staining), and (3) absence of pathological alterations in brain sections. This arterial hemostasis technique capitalizes on the pliable nature of adipose tissue and physiological coagulation mechanisms. The procedure involves: (1) wrapping autologous fat around the puncture site, (2) securing it with sutures to ensure optimal contact with the arterial adventitia, and (3) allowing escaping blood to permeate the fat-artery interface where it undergoes coagulation. This triple-action mechanism achieves reliable hemostasis while preserving arterial patency and preventing ischemic complications post-operatively. The method demonstrates notable procedural simplicity, clinical efficacy, and excellent translational potential.

During arterial puncture or cannulation in mice, permanent ligation of the artery is often required due to difficulty achieving hemostasis after needle withdrawal. This leads to permanent ischemic injury in the supplied tissue region. Such localized ischemia frequently induces secondary complications, compromising experimental outcomes in animal models. The present method aims to seal the puncture site post-procedure while maintaining normal blood flow, thereby preventing postoperative ischemia. This method involves harvesting an adipose tissue fragment from the experimental animal itself, performing arterial puncture using standard techniques, and then wrapping the puncture site with the fat pad to achieve hemostasis while maintaining blood flow. In this study, bilateral common carotid artery puncture was performed on mice, followed by hemostasis using a fat-wrapping technique. Laser speckle contrast imaging(LSCI) revealed no differences in cerebral blood flow changes between the sham and operated groups of mice, and no significant changes were observed in preoperative versus postoperative cerebral blood flow measurements in the operated group. Histological assessment performed at 7, 14, and 28 days after surgery revealed that: (1) preserved brain architecture (H&E staining), (2) intact neuronal morphology without degenerative changes (Nissl staining), and (3) absence of pathological alterations in brain sections. This arterial hemostasis technique capitalizes on the pliable nature of adipose tissue and physiological coagulation mechanisms. The procedure involves: (1) wrapping autologous fat around the puncture site, (2) securing it with sutures to ensure optimal contact with the arterial adventitia, and (3) allowing escaping blood to permeate the fat-artery interface where it undergoes coagulation. This triple-action mechanism achieves reliable hemostasis while preserving arterial patency and preventing ischemic complications post-operatively. The method demonstrates notable procedural simplicity, clinical efficacy, and excellent translational potential.