PMCNA_RS00975 activates NF-κB and ERK1/2 through TLR2 and contributes to the virulence of .

INTRODUCTION

is a pathogenic bacterium known to cause hemorrhagic septicemia and pneumonia in poultry. Reports have indicated that certain proteins, either directly involved in or regulating iron metabolism, are important virulence factors of . Therefore, understanding virulent factors and analyzing the role of pro-inflammatory cytokines can help us elucidate the underlying pathogenesis.

METHODS

In this study, the PMCNA_RS00975 protein, a putative encapsuling protein encoded by a gene from a specific prophage island of the pathogenic strain of , was investigated. To further explore the impact of the PMCNA_RS00975 protein on pathogenicity, a gene mutant of strain was constructed using positive selection technology. Subcellular localization was performed to determine the location of the PMCNA_RS00975 protein within The recombinant protein PMCNA_RS00975 of was soluble expressed, purified, and its role in pro-inflammatory cytokines was investigated.

RESULTS

The mutant exhibited significantly reduced pathogenicity in the mice model. Furthermore, subcellular localization indicated that the PMCNA_RS00975 protein was located at the outer membrane and expressed during infection of Additionally, our experiments revealed that recombinant PMCNA_RS00975 protein promotes the secretion of the IL-6 pro-inflammatory cytokines triggered by the TLR2 receptor via NF-κB and ERK1/2 signaling pathways in the macrophages.

DISCUSSION

This study identified a novel virulence factor in the strain, providing a basis for understanding the pathogenesis and directions for the development of attenuated vaccines against