Flagellar-based motility accelerates IgA-mediated agglutination of Salmonella Typhimurium at high bacterial cell densities

Frontiers in Immunology

Immunology

Samantha K. Lindberg¹  Nicholas J. Mantis¹  Graham G. Willsey² 

[1] Department of Biomedical Sciences, University at Albany School of Public Health, Albany, NY, United States;Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, United States;Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, United States;

关键词: antibody;    IgA;    Salmonella;    agglutination;    motility;    cyclic-di-GMP;    enteric;   

DOI  :  10.3389/fimmu.2023.1193855

 received in 2023-03-25, accepted in 2023-05-03,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionSecretory IgA (SIgA) protects the intestinal epithelium from enteric pathogens such as Salmonella enterica serovar Typhimurium (STm) through a process known as immune exclusion, where invading bacteria are aggregated via antibody cross-linking, encased in mucus, and then cleared from the intestinal tract via peristalsis. At high cell densities, the STm aggregates form a tightly packed network that is reminiscent of early bacterial biofilms. However, the underlying mechanism of how SIgA mediates this transition from a motile and invasive state to an avirulent sessile state in STm is currently unknown.MethodsIn this report, we developed and validated a methodology known as the “snow globe” assay to enable real-time imaging and quantification of STm agglutination by the mouse monoclonal IgA Sal4.ResultsWe observed that agglutination in the snow globe assay was dose-dependent, antigen-specific, and influenced by antibody isotype. We determined that flagellar-based motility was a prerequisite for rapid onset of agglutination, even at high cell densities where cell-cell contacts are expected to be frequent. We also investigated the roles of individual cyclic-di-GMP metabolizing enzymes previously implicated in motility and biofilm formation in Sal4 IgA-mediated agglutination.DiscussionTaken together, our results demonstrate that IgA-mediated agglutination is a dynamic process influenced by bacterial motility and cell-cell collisions. We conclude that the snow globe assay is a viable platform to further decipher the molecular and genetic determinants that drive this interaction.

【 授权许可】

Unknown   
Copyright © 2023 Lindberg, Willsey and Mantis