# Establishment of a STING-Deficient HepG2 Cell Line through CRISPR/Cas9 System and Evaluation of Its Effects on Salmonella Replication

## TL;DR

This study creates a STING-deficient HepG2 cell line and finds that Salmonella replication increases in these cells, suggesting STING plays a role in controlling bacterial infections.

## Contribution

Establishes a STING-deficient HepG2 cell line and demonstrates its impact on Salmonella replication and immune gene expression.

## Key findings

- STING-deficient HepG2 cells showed reduced proliferation compared to wild-type cells.
- Salmonella Typhimurium replication was increased in STING-deficient cells.
- Expression of type I interferon-related genes like IFNB1 and ISG15 was inhibited in infected STING-deficient cells.

## Abstract

Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) is a common food-borne pathogen that causes gastroenteritis and can lead to life-threatening systemic disease when it spreads to vital organs, such as the liver. Stimulator of interferon genes (STING) is a crucial regulator of the host's innate immune response to viral infections, while its role in bacterial infections remains controversial. This study aims to establish a STING-deficient HepG2 cell line through the CRISPR/Cas9 system and evaluate its effects on Salmonella replication.

In this study, a STING knockout HepG2 cell line was constructed through the application of CRISPR/Cas9 technology. We assessed cell viability and proliferation using the CCK-8 assay. Subsequently, we investigated the effect of STING deletion on Salmonella replication and the expression of type I interferon-related genes.

The STING knockout HepG2 cell line was successfully constructed using the CRISPR/Cas9 system. The proliferation capability was diminished in STING-deficient HepG2 cells, while Salmonella Typhimurium replication in these cells was augmented compared to the wild-type (WT) group. Following Salmonella infection, the transcriptional responses of type I interferon-related genes, such as IFNB1 and ISG15, were inhibited in STING-deficient HepG2 cells.

We successfully constructed a STING-deficient cell line. Our finding of increased Salmonella Typhimurium replication in STING-deficient HepG2 cells provides the basis for further studies on pathogen-host interactions.