Propionate reduces the viability of Salmonella enterica Serovar Typhi in macrophages by propionylation of PhoP K102

Propionylation of Fis K32 in Salmonella enterica serovar Typhi: a key modification affecting pathogenicity

AIM

This study aims to explore the role of propionylation at the K32 residue of the global regulator Fis in Salmonella enterica serovar Typhi (S. Typhi) and its influence on the pathogenicity of the bacteria.

MATERIALS & METHODS

Bacterial strains were cultured in media with sodium propionate supplementation. The propionylation status of Fis was determined through Western blot and mass spectrometry analyses. The DNA-binding capability of Fis was assessed using EMSA. The invasion and survival capacities of S. Typhi were examined using T84 cells and THP-1 macrophages.

RESULTS

Propionylation at the K32 site of Fis was found to down-regulate its DNA-binding ability, leading to a reduction in the invasion and survival of S. Typhi within host cells. The K32Q mutant exhibited significantly decreased invasion and survival capabilities compared to the wild-type and K32R mutant strains.

CONCLUSION

Propionylation of Fis at the K32 residue impacts the pathogenicity of S. Typhi, shedding light on the role of post-translational modifications in bacterial infections.

Gut microbiota as a key regulator of intestinal mucosal immunity

Gut microbiota is a complex microbial community with the ability of maintaining intestinal health. Intestinal homeostasis largely depends on the mucosal immune system to defense external pathogens and promote tissue repair. In recent years, growing evidence revealed the importance of gut microbiota in shaping intestinal mucosal immunity. Therefore, according to the existing findings, this review first provided an overview of intestinal mucosal immune system before summarizing the regulatory roles of gut microbiota in intestinal innate and adaptive immunity. Specifically, this review delved into the gut microbial interactions with the cells such as intestinal epithelial cells (IECs), macrophages, dendritic cells (DCs), neutrophils, and innate lymphoid cells (ILCs) in innate immunity, and T and B lymphocytes in adaptive immunity. Furthermore, this review discussed the main effects of gut microbiota dysbiosis in intestinal diseases and offered future research prospects. The review highlighted the key regulatory roles of gut microbiota in intestinal mucosal immunity via various host-microbe interactions, providing valuable references for the development of microbial therapy in intestinal diseases.