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Jia Z.,National Institutes for Food and Drug Control | Wu X.,National Institutes for Food and Drug Control | Wang L.,National Institutes for Food and Drug Control | Li X.,Beijing Institute of Biological Products Co. | And 7 more authors.
Biologicals | Year: 2017

Severe fever with thrombocytopenia syndrome (SFTS) is caused by a phlebovirus of the Bunyaviridae family, which is designated as SFTS virus (SFTSV). To our knowledge, no efficient SFTSV vaccine exists. Here, we report the identification of a standard virus strain for the eight major SFTSV strains circulating in China for use in evaluating the SFTSV vaccine. Rabbits were immunized with the SFTSV strains and the cross-neutralization capacities of SFTSV anti-sera were determined in microculture cytopathic effect (CPE)-inhibition assays. The mean cross-neutralization capacity of the eight SFTSV anti-sera ranged from 62.4 to 142.6%, compared to autologous strains. The HB29 strain demonstrated strong cross-reactivity with heterologous antibodies, and 33 serum samples from SFTS patients efficiently neutralized HB29, suggesting its broad cross-reactivity. In addition, HB29 demonstrated good replication in Vero and MRC-5 cells (8.0 and 6.0 lg 50% cell culture-infectious dose/mL, respectively) and significant CPE, which satisfied the requirements for a standard virus strain. The HB29 isolate was proven identical to the reported HB29 strain by DNA sequencing, and showed high homology in the S segments with other SFTSV strains (94.8-99.7%). Our results suggest that HB29 may be the best candidate standard strain for use in SFTS vaccine development in China. © 2017 International Alliance for Biological Standardization.


Zhang F.,Chinese National Institute for Viral Disease Control and Prevention | Hao C.,Beijing Institute of Biological Products Co. | Zhang S.,Chinese National Institute for Viral Disease Control and Prevention | Li A.,Chinese National Institute for Viral Disease Control and Prevention | And 7 more authors.
Virology Journal | Year: 2014

Background: Enterovirus 71 (EV71) is the etiologic agent of hand-foot-and-mouth disease (HFMD) in the Asia-Pacific region, Many strategies have been applied to develop EV71 vaccines but no vaccines are currently available. Mucosal immunization of the VP1, a major immunogenic capsid protein of EV71, may be an alternative way to prevent EV71 infection. Results: In this study, mucosal immunogenicity and protect function of recombinant VP1 protein (rVP1) in formulation with chitosan were tested and assessed in female ICR mouse model. The results showed that the oral immunization with rVP1 induced VP1-specific IgA antibodies in intestine, feces, vagina, and the respiratory tract and serum-specific IgG and neutralization antibodies in vaccinated mice. Splenocytes from rVP1-immunized mice induced high levels of Th1 (cytokine IFN-γ), Th2 (cytokine IL-4) and Th3 (cytokine TGF-β) type immune responses after stimulation. Moreover, rVP1-immunized mother mice conferred protection (survival rate up to 30%) on neonatal mice against a lethal challenge of 103 plaque-forming units (PFU) EV71. Conclusions: These data indicated that oral immunization with rVP1 in formulation with chitosan was effective in inducing broad-spectrum immune responses and might be a promising subunit vaccine candidate for preventing EV71 infection. © 2014 Zhang et al.; licensee BioMed Central Ltd.


Jin Y.-Q.,Beijing Institute of Biological Products Co. | Hou J.-W.,Beijing Institute of Biological Products Co. | Zhang J.,Beijing Institute of Biological Products Co. | Chen S.,Beijing Institute of Biological Products Co. | Li Q.-M.,Beijing Institute of Biological Products Co.
Chinese Journal of Biologicals | Year: 2013

Objective: To evaluate the immune effect of virus-like particles (VLPs) of L1 protein of Hansenula polymorph-based human papillomavirus type 58 (HPV58). Methods: The recombinant H. polymorph for expression of HPV58 L1 was transferred to 3.7 L fermenter and induced with methanol for 15 h, then collected and broken by high pressure homogenization, from which recombinant HPV58 L1 protein was purified by affinity chromatography, reconstituted, and observed for morphology of VLPs by transmission electron microscopy. The sizes and their distributions of before and after reconstitution were compared by dynamic light scattering analyzer. BALB / c mice divided into two groups and immunized with 1 μg/ml HPV58 L1 and 1 μg/ml HPV58 L1 + 0.41 mg/ml aluminium adjuvant respectively, of which sera were collected 4 weeks later to compare the immune effect by pseudovirus neutralization test. Five groups of mice, were immunized with 1 μg/ml HPV58 L1 + 0.41 mg/ml aluminium adjuvant at weeks 0, 1, 3, 5 and 7, of which sera were collected at weeks 1, 2, 4, 6 and 8 after the first immunization to evaluate the immune effect by pseudoviurs neutralization test. Results: The purified recombinant HPV58 L1 reached a purity of about 90% and showed specific binding to mouse monoclonal antibody against HPV58 L1, which showed a specific band with a relative molecular mass of about 56 000 on SDS-PAGE profile. The VLPs of reconstituted HPV58 L1 were at a mean diameter of about 50 nm, with clear border and high homogeneity, of which the morphology was similar to that of natural virus. Compared with those before reconstitution, the hydrodynamic diameter of VLPs after reconstitution was close to that of natural virus particles, while the size distribution was even, and no monomers at small sizes or pentamers were observed. The serum neutralizing antibody titers of mice in HPV58 L1 + adjuvant group were significantly higher than those in HPV58 L1 group(P < 0.05). The serum neutralizing antibody titers of mice in five groups increased one week after the first immunization and reached the peak value at week 6. The reconstituted HPV58 L1 induced high neutralizing antibody level in mice. Conclusion: Aluminium adjuvant-containing HPV58 L1 VLPs showed high immunological activity, which might be used as the component antigen of polyvalent HPV vaccine.

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