Campylobacter jejuni Cas9 Modulates the Transcriptome in Caco-2 Intestinal Epithelial Cells

Area of Science:

• Microbiology
• Molecular Biology
• Cell Biology

Background:

• Campylobacter jejuni is a zoonotic pathogen that causes human illness.
• CjeCas9, a nuclease from C. jejuni's CRISPR-Cas system, is known to translocate into the nucleus and cause DNA damage.
• The specific cellular pathways CjeCas9 utilizes to induce cell death remain unclear.

Purpose of the Study:

• To elucidate the molecular mechanisms by which CjeCas9 induces cell death in human intestinal epithelial cells.
• To identify the specific cellular pathways modulated by CjeCas9 during C. jejuni infection.

Main Methods:

• Infection of Caco-2 human intestinal epithelial cells with wild-type C. jejuni and a cas9 deletion mutant.
• Transcriptome analysis to assess cellular pathway modulation.
• Analysis of DNA damage and inflammatory signaling pathways.

Main Results:

• CjeCas9 released by C. jejuni directly modulates Caco-2 cell transcriptomes within four hours of infection.
• CjeCas9 activates DNA damage response pathways (p53, ATM) and pro-inflammatory signaling (NF-κB).
• Infection with wild-type C. jejuni, but not the cas9 deletion mutant, leads to programmed cell death in Caco-2 cells.

Conclusions:

• CjeCas9 is a key virulence factor responsible for C. jejuni-induced cytotoxicity.
• CjeCas9 activates specific basal cellular pathways, including DNA damage and inflammation, leading to programmed cell death.
• This study provides RNA-level insights into the cytotoxic mechanisms of CjeCas9.