Cyprinid herpesvirus 3 (CyHV-3) transmission and outbreaks in Iran: Detection and characterization in farmed common carp

Self-assembling ferritin nanoplatform for the development of infectious hematopoietic necrosis virus vaccine

Self-assembling protein nanoparticles are used as a novel vaccine design platform to improve the stability and immunogenicity of safe subunit vaccines, while providing broader protection against viral infections. Infectious Hematopoietic Necrosis virus (IHNV) is the causative agent of the WOAH-listed IHN diseases for which there are currently no therapeutic treatments and no globally available commercial vaccine. In this study, by genetically fusing the virus glycoprotein to the H. pylori ferritin as a scaffold, we constructed a self-assembling IHNV nanovaccine (FerritVac). Despite the introduction of an exogenous fragment, the FerritVac NPs show excellent stability same as Ferritin NPs under different storage, pH, and temperature conditions, mimicking the harsh gastrointestinal condition of the virus main host (trout). MTT viability assays showed no cytotoxicity of FerritVac or Ferritin NPs in zebrafish cell culture (ZFL cells) incubated with different doses of up to 100 µg/mL for 14 hours. FerritVac NPs also upregulated expression of innate antiviral immunity, IHNV, and other fish rhabdovirus infection gene markers (mx, vig1, ifit5, and isg-15) in the macrophage cells of the host. In this study, we demonstrate the development of a soluble recombinant glycoprotein of IHNV in the E. coli system using the ferritin self-assembling nanoplatform, as a biocompatible, stable, and effective foundation to rescue and produce soluble protein and enable oral administration and antiviral induction for development of a complete IHNV vaccine. This self-assembling protein nanocages as novel vaccine approach offers significant commercial potential for non-mammalian and enveloped viruses.

Detection of Carp pox virus (CyHV-1) from koi (Cyprinus carpio L.) in Iran; clinico-pathological and molecular characterization

Cyprinid herpesvirus 1 (CyHV-1) is the causative agent of carp pox characterized by epidermal papillomas in common carp and other cyprinids. In this study, we identified CyHV-1 in koi (Cyprinus carpio) from Iran in 2017 and 2019, showing clinical signs of the carp pox disease. Histopathology showed severe epidermal hyperplasia and the absence of club and goblet cells. Degenerative changes, including spongiosis and single-cell necrosis, were also observed. Keratinocyte dysplasia and a moderate lymphocytic infiltration were observed within the epidermis. PCR of the extracted DNA from skin lesions of affected koi from both outbreaks showed CyHV-1 specific TK amplicons, with high sequence identity (above 99%) among themselves and with other CyHV-1 isolates belong to Cluster I, as well as show 97% similarity to Cluster II isolates. To the best of our knowledge, this is the first report of Carp pox disease (CyHV-1) of koi in Iran and the Middle East.