The expression analysis of immune genes and microscopic morphology of CCF cells in response to Cyprinid herpesvirus 2 infection

The aims of the current study were to investigate the primary culture of dorsal fin from Prussian carp, Carassius auratus gibelio and its susceptibility to Cyprinid herpesvirus 2 due to the lack of commercial cell line supporting CyHV-2 infection. The cells detached from the tissues in 10 days and fully covered the bottom of 25 cm² culture bottle in 3 weeks. Cyprinid herpesvirus 2 (CyHV-2) continuously propagated in the cultured cells, as confirmed by a quantitive real time PCR, with the highest viral concentration of 10⁶ copies/mL at 3 days post infection. In addition, cell death was observed in the dorsal fin cells upon CyHV-2 infection. Cytopathic effects (CPE) were observed as early as 6 days post-inoculation, and as the infection progressed, CPE became more apparent with cell debris and cellular exudates in inoculated cultures. The expression levels of 8 immune important genes including IL-11, ITLN, PNP5a, MPO, KRT-8, DUSP-1, MHCⅠ and LYZ-C were significantly different after viral challenge, which were determined to be involved in host response to CyHV-2 infection previously. The results above should be helpful in further studies on CyHV-2, including elucidation of pathogenesis, host-pathogen interaction and development of anti-viral drugs that can ultimately lead to prevention of this viral disease.