Comparative analysis of the course of infection and the immune response in rainbow trout (Oncorhynchus mykiss) infected with the 5 genotypes of infectious hematopoietic necrosis virus

Virology. 2021 Jan 2:552:20-31. doi: 10.1016/j.virol.2020.09.003. Epub 2020 Oct 6.

Abstract

Infectious hematopoietic necrosis virus (IHNV) is a pathogen of importance for salmonid aquaculture. In this study, we aimed to characterize virus behavior and defense mechanisms developed in rainbow trout (RT, Oncorhynchus mykiss) experimentally infected with isolates belonging to the five described genotypes of IHNV, i.e. L, U, M, E and J. Mortality was monitored for two months, and blood and target organs were sampled at different times post-infection to assess viral load and cellular and humoral immune responses. Profiles of virulence were highly linked to precocious viral replication but also to the innate and specific immunity elicited in the host. Seroneutralization test (SNT) used for specific antibodies detection exhibited reliable results, with efficient cross-neutralization observed in heterologous systems except for the Asian representative. These data bring new insights about IHNV/RT interaction and reinforce the interest of SNT as preventive and epidemiological tool.

Keywords: IHNV; Immunological parameters; Rainbow trout; Seroneutralization test; Virulence.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Cell Line
  • Genotype
  • Host Specificity
  • Immunity*
  • Infectious hematopoietic necrosis virus / immunology*
  • Infectious hematopoietic necrosis virus / metabolism*
  • Mortality
  • Neutralization Tests
  • Oncorhynchus mykiss / immunology*
  • Oncorhynchus mykiss / virology*
  • Viral Load
  • Virulence