Mechanisms of HAHV-1 Interaction with Hemocytes in Haliotis diversicolor supertexta: An In Vitro Study

Haliotid herpesvirus 1 (HAHV-1) causes significant damage to the abalone aquaculture industry. Knowledge of HAHV-1 invasion and host defense mechanisms is limited due to the lack of stable molluscan cell lines. The present study established an in vitro infection model of HAHV-1 using the primary suspension cultures of hemocytes from Haliotis diversicolor supertexta and Haliotis discus hannai. The cytopathic effects of HAHV-1 on adherent-cultured hemocytes of both species were also investigated. The HAHV-1 DNA loads were firstly monitored by means of quantitative PCR during the development of viral infection, and subsequently the mechanism of interaction between HAHV-1 and hemocytes was explored by means of a transcriptome analysis. H. diversicolor supertexta hemocytes exhibited a high degree of susceptibility to HAHV-1, with viral loads reaching a peak of 4.0 × 10⁷ copies/ng DNA. In contrast, no significant replication was observed in H. discus hannai hemocytes. Transcriptome analysis revealed that HAHV-1 evades the host immune response in the early stages of infection, and hijacks the host's energy and redox metabolism to promote its replication at the late stages. Consequently, this study provides a valuable reference point for the investigation of virus-host interaction between HAHV-1 and abalone in vitro.