Screening and characterization of a primary hamster kidney celladapted strain of tick-borne encephalitis virus
10.13200/j.cnki.cjb.004630
- VernacularTitle:森林脑炎病毒原代地鼠肾细胞适应株的筛选及鉴定
- Author:
MIAO Hui
1
Author Information
1. Changchun Institute of Biological Products Co., Ltd., Changchun 130012, Jilin Province, China
- Publication Type:Journal Article
- Keywords:
Tick-borne encephalitis virus(TBEV);
Primary hamster kidney cells(PHKCs);
Adaptive passaging;
Vaccine candidate
- From:
Chinese Journal of Biologicals
2026;39(01):1-6+16
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the adaptability of the “Sen Zhang” master seed strain of tick-borne encephalitis virus(TBEV) during serial passaging in primary hamster kidney cells(PHKCs), screen tick-borne encephalitis(TBE) vaccine candidate strains, and perform serological identification and morphological observation of the virus.Methods The mouse brain-adapted “Sen Zhang” master TBEV strain was serially passaged 10 times in PHKCs. Plaque purification was conducted based on viral titration, and clones with E protein amino acid sequences identical to the parental strain were selected to undergo an additional 10 passages in PHKCs. The virus titers were monitored across generations, and the E protein amino acid sequences from the 1 st and 10 th passages were compared. Experimental vaccines were prepared by 2% formaldehyde inactivation. After 35 female Kunming mice were immunized three times, the mouse brain-derived virus was injected intraperitoneally, and the immunoprotective index was calculated based on the number of mouse deaths within 21 days.Serological identification was performed on the vaccine candidate strains, and the viral morphology was analyzed via transmission electron microscopy(TEM).Results The PHKC-adapted TBEV achieved a maximum titer of 8. 90 lgLD50/mL,stabilizing at(8. 85 ± 0. 059 6) lgLD_(50)/mL. Plaque assays demonstrated uniform visible circular plaques with sharp boundaries. Among 27 purified clones, #7, #14, and #17 retained E protein sequences identical to the parental strain. The virus titers remained 8. 60-8. 90 lgLD_(50)/mL stably during passaging. Clone #7 exhibited minimal E protein mutations and the highest immunoprotective index 2. 3 × 10~6. The serological neutralization index reached 3 162, and TEM revealed spherical enveloped particles with a diameter of about 50 nm, consistent with the vaccine strain.Conclusion A PHKCadapted TBEV strain with high genetic stability was successfully isolated, which meets the critical criteria of vaccine candidate strains and can elicit robust immune responses.
