Self-assembled multiepitope nanovaccine based on NoV P particles induces effective and lasting protection against H3N2 influenza virus.

Current seasonal influenza vaccines confer only limited coverage of virus strains due to the frequent genetic and antigenic variability of influenza virus (IV). Epitope vaccines that accurately target conserved domains provide a promising approach to increase the breadth of protection; however, poor immunogenicity greatly hinders their application. The protruding (P) domain of the norovirus (NoV), which can self-assemble into a 24-mer particle called the NoV P particle, offers an ideal antigen presentation platform. In this study, a multiepitope nanovaccine displaying influenza epitopes (HMN-PP) was constructed based on the NoV P particle nanoplatform. Large amounts of HMN-PP were easily expressed in Escherichia coli in soluble form. Animal experiments showed that the adjuvanted HMN-PP nanovaccine induced epitope-specific antibodies and haemagglutinin (HA)-specific neutralizing antibodies, and the antibodies could persist for at least three months after the last immunization. Furthermore, HMN-PP induced matrix protein 2 extracellular domain (M2e)-specific antibody-dependent cell-mediated cytotoxicity, CD4+ and CD8+ T-cell responses, and a nucleoprotein (NP)-specific cytotoxic T lymphocyte (CTL) response. These results indicated that the combination of a multiepitope vaccine and self-assembled NoV P particles may be an ideal and effective vaccine strategy for highly variable viruses such as IV and SARS-CoV-2. Electronic Supplementary Material: Supplementary material is available in the online version of this article at 10.1007/s12274-023-5395-6.

A biepitope, adjuvant-free, self-assembled influenza nanovaccine provides cross-protection against H3N2 and H1N1 viruses in mice.

Currently, the incorporation of multiple epitopes into vaccines is more desirable than the incorporation of a single antigen for universal influenza vaccine development. However, epitopes induce poor immune responses. Although the use of adjuvants can overcome this obstacle, it may raise new problems. Effective antigen delivery vehicles that can function as both antigen carriers and intrinsic adjuvants are highly desired for vaccine development. Here, we report a biepitope nanovaccine that provides complete protection in mice against H3N2 virus as well as partial protection against H1N1 virus. This vaccine (3MCD-f) consists of two conserved epitopes (matrix protein 2 ectodomain (M2e) and CDhelix), and these epitopes were presented on the surface of ferritin in a sequential tandem format. Subcutaneous immunization with 3MCD-f in the absence of adjuvant induces robust humoral and cellular immune responses. These results provide a proof of concept for the 3MCD-f nanovaccine that might be an ideal candidate for future influenza pandemics.

A self-assembling nanoparticle vaccine targeting the conserved epitope of influenza virus hemagglutinin stem elicits a cross-protective immune response.

Various vaccine strategies have been developed to provide broad protection against diverse influenza viruses. The hemagglutinin (HA) stem is the major potential target of these vaccines. Enhancing immunogenicity and eliciting cross-protective immune responses are critical for HA stem-based vaccine designs. In this study, the A helix (Ah) and CD helix (CDh) from the HA stem were fused with ferritin, individually, or in tandem, yielding Ah-f, CDh-f and (A + CD)h-f nanoparticles (NPs), respectively. These NPs were produced through a prokaryotic expression system. After three immunizations with AS03-adjuvanted NPs in BALB/c mice via the subcutaneous route, CDh-f and (A + CD)h-f induced robust humoral and cellular immune responses. Furthermore, CDh-f and (A + CD)h-f conferred complete protection against a lethal challenge of H3N2 virus, while no remarkable immune responses and protective effects were detected in the Ah-f group. These results indicate that the CDh-based nanovaccine represents a promising vaccine platform against influenza, and the epitope-conjugated ferritin NPs may be a potential vaccine platform against other infectious viruses, such as SARS-COV-2.

Hemagglutinin-based DNA vaccines containing trimeric self-assembling nanoparticles confer protection against influenza.

Influenza viruses continue to threaten public health, and currently available vaccines provide insufficient immunity against seasonal and pandemic influenza. The use of recombinant trimeric hemagglutinin (HA) as an Ag provides an attractive alternative to current influenza vaccines. Aiming to develop an effective vaccine with rapid production, robust immunogenicity, and high protective efficiency, a DNA vaccine was designed by fusing influenza virus HA with self-assembled ferritin nanoparticles, denoted as HA-F. This candidate vaccine was prepared and purified in a 293-6E cell eukaryotic expression system. After BALB/c mice were immunized with 100 µg of HA-F DNA 3 times, HA-F elicited significant HA-specific humoral immunity and T cell immune responses. The HA-F DNA vaccine also conferred protection in mice against a lethal infection of homologous A/17/California/2009/38 (H1N1) virus. These results suggest that the HA-F DNA vaccine is a competitive vaccine candidate and presents a promising vaccination approach against influenza viruses.

Bioinspired Dual-Enzyme Colloidosome Reactors for High-Performance Biphasic Catalysis.

In this paper, a novel method for the construction of colloidosomes as a microreactor for dual-enzyme cascade biphasic reaction has been reported. A lipase-glucose oxidase (GOx) enzyme pair is employed in this system. A water-soluble enzyme GOx is compartmentalized inside the colloidosomes. A hydrophobic environment-favored enzyme Candida Antarctica lipase B (CalB) is adsorbed on the outer surfaces of the colloidosomes. The catalysis system is set up by introducing these dual-enzyme-immobilized microcapsules into acetic ether. H2O2 is produced in the aqueous phase by the doped GOx, and then H2O2 diffused out of the microcapsules is utilized by CalB to catalyze the oxidation of ethyl acetate. Finally, the formed peracids oxidized N-heteroaromatic in situ. Furthermore, no obvious yield decline is observed in four reaction cycles. Thus, our work provides a new strategy for the design of high-performance biomimicking reactors for multiple enzyme cascade reactions and further expands the potential application area of colloidosomes.

[The image diagnosis of dysbaric osteonecrosis].

OBJECTIVE: To investigate the imaging features of dysbaric osteonecrosis. METHODS: The imaging appearances of four patients with dysbaric osteonecrosis caused by diving, were analyzed retrospectively. RESULTS: In four cases with dysbaric osteonecrosis including case 1 with stage I, case 2 with stage II, case 3 and case 4 with stage III, there were a case with the lesion in a bone and other 3 cases with lesions in multiple bones,and a case with the lesion in unilateral bone and 3 cases with the lesions in lateral bones. (1) The juxta-articular lesions: there were 10 long bones with the head lesions, including 6 humerus with the head lesions and 4 femurs with the head lesions in 4 cases. In four cases, 10 sclerosis lesions appeared in the heads of long bones, each case had a "snow-capped" sclerosis lesion for case 2, case 3 and case 4. There were 7 small radiolucent lesions and a large radiolucent lesion involved in femur neck. The ringlike, linear, bending and punctuate calcification lesions were found on CT films of case 2. The osseous collapse in one femur head and the fragmentations in three femur heads could be seen in case 3 and case 4; 2 crescent signs can be seen in the bilateral femur heads of case 4 with secondary osteoarthritis in left hip joint. (2) The diaphyseal and metaphyseal lesions: the X ray film of case 4 showed the streak and irregular calcifications in the shaft of right humerus; there are strip calcifications in diaphyseal and metaphyseal of the left humerus on MPR coronal view in case 2. CONCLUSION: The diagnosis of dysbaric osteonecrosis suggested that the increased bone density or sclerosis lesions appeared in the heads of long bones, and osteonecrosis lesions were found in multiple bones or lateral bones.