CD4 (Cluster Differentiation-4) as an immune response to the portal of entry mechanism of VNN (Viral Nervous Necrosis) infection in grouper

Abstract

Viral Nervous Necrosis (VNN) is a Nodaviridae virus that attacks groupers, especially in the larval and seed stages. VNN attacks the brain organs, rapidly attacks the grouper fish receptors and then spreads to the brain via blood circulation. The mechanism of viral infection can occur because of the bond between the VNN adhesive and its receptor molecules in the grouper organ. The aim of this study was to compare the CD4 (Cluster Differentiation-4) values of VNN-infected groupers and healthy fish using immunohistochemical (IHC) analysis. The method used in this study was experimental exploratory by comparing and analyzing the response of CD4 cells in healthy groupers with groupers infected with VNN through IHC observations. The results of IHC test showed that the immunogenic epitope of 32.5 kDa VNN protein had the ability to induce tissue receptors of Humpback grouper (Cromileptes altivelis) by forming immune cells qualitatively. There are CD4 cells that are immune to specific tissue organs, i.e. eyes of the groupers, which are labeled with anti-CD4 secondary antibodies. It seems that immunogenic protein VNN with a molecular weight of 32.5 kDa has the ability to stimulate the expression of Humpback grouper immune cells such as CD4 in tissue organs, especially the eye organs qualitatively.