Tailoring gut immune responses with lipoteichoic acid-deficient Lactobacillus acidophilus

Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida Gainesville, FL, USA
Frontiers in Immunology 02/2013; 4:25. DOI: 10.3389/fimmu.2013.00025
Source: PubMed


As highlighted by the development of intestinal autoinflammatory disorders when tolerance is lost, homeostatic interactions between gut microbiota, resident immune cells, and the gut epithelium are key in the maintenance of gastrointestinal health. Gut immune responses, whether stimulatory or regulatory, are dictated by the activated dendritic cells (DCs) that first interact with microorganisms and their gene products to then elicit T and B cell responses. Previously, we have demonstrated that treatment with genetically modified Lactobacillus acidophilus is sufficient to tilt the immune balance from proinflammatory to regulatory in experimental models of colitis and colon cancer. Given the significant role of DCs in efficiently orchestrating intestinal immune responses, characterization of the signals induced within these cells by the surface layer molecules, such as lipoteichoic acid (LTA), and proteins of L. acidophilus is critical for future treatment and prevention of gastrointestinal diseases. Here, we discuss the potential regulatory pathways involved in the downregulation of pathogenic inflammation in the gut, and explore questions regarding the immune responses to LTA-deficient L. acidophilus that require future studies.

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    • "Interestingly, the presence of SlpA on an slpB - slpX mutant actually increases the pro-inflammatory action of LTA compared with the LTA-expressing parental strain (Zadeh et al. 2012). Thus, a role for SlpB and SlpX in regulating LTAinduced inflammation has been suggested (Lightfoot and Mohamadzadeh 2013). A mutant lacking SlpB and SlpX but carrying SlpA also tends to be cleared from the mouse gastrointestinal tract more rapidly than the wild type, but the mechanism is not known (Zadeh et al. 2012). "
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