# Seneca valley virus VP4 protein regulates the transcription of different cytokines in vitro

## TL;DR

This study shows how the VP4 protein from Seneca valley virus affects immune-related genes in cells, offering insights into virus behavior and vaccine development.

## Contribution

The study reveals the VP4 protein's specific regulation of cytokine transcription, providing new insights into SVV pathogenesis.

## Key findings

- Overexpression of VP4 significantly promotes IL-1α and IL-1β transcription at 24 and 36 hours.
- CCL-2 and CCL-5 transcription is significantly increased at 36 hours, while CCL-10 is increased only at 12 hours.
- TNF-α transcription is significantly inhibited at all three time points.

## Abstract

To understand the effect of Seneca valley virus (SVV) VP4 protein on innate immune factors, the VP4 gene was cloned into the pEGFP-C1 expression plasmid to construct the pEGFP-C1-VP4 recombinant plasmid. After the recombinant plasmid was transfected into 293 T cells, the cell fluid was collected 24 h after transfection for western blot assay to identify the correctness of VP4 protein expression. Cell culture medium was collected from un-transfected and transfected cells at three time points (12, 24, and 36 h). mRNA expression levels of cytokines (IL-1α, IL-1β, CCL-2, CCL-5, CXCL-10, and TNF-α) at three time points were detected by quantitative real-time PCR (qPCR) method, and relative quantitative analysis was performed by 2-ΔΔCt method. The results indicated that the expressed SVV VP4 protein exhibits good activity in vitro. Overexpression of the VP4 protein could significantly promote the transcription of IL-1α and IL-1β at 24 and 36 h. In addition, the transcription of CCL-2 and CCL-5 was also significantly promoted at 36 h, whereas the transcription of CCL-10 was significantly promoted only at 12 h. The TNF-α transcription was significantly inhibited at all the three time points. This study provides an important basis for the pathogenic mechanism of SVV and vaccine design in the future.