Induction of intestinal pro-inflammatory immune responses by lipoteichoic acid.
JOURNAL OF INFLAMMATION-LONDON 2012;
9:7. [PMID:
22423982 PMCID:
PMC3325164 DOI:
10.1186/1476-9255-9-7]
[Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/16/2012] [Indexed: 02/02/2023]
Abstract
Background
The cellular and molecular mechanisms of inflammatory bowel disease are not fully understood; however, data indicate that uncontrolled chronic inflammation induced by bacterial gene products, including lipoteichoic acid (LTA), may trigger colonic inflammation resulting in disease pathogenesis. LTA is a constituent glycolipid of Gram-positive bacteria that shares many inflammatory properties with lipopolysaccharide and plays a critical role in the pathogenesis of severe inflammatory responses via Toll-like receptor 2. Accordingly, we elucidate the role of LTA in immune stimulation and induced colitis in vivo.
Methods
To better understand the molecular mechanisms utilized by the intestinal microbiota and their gene products to induce or subvert inflammation, specifically the effect(s) of altered surface layer protein expression on the LTA-mediated pro-inflammatory response, the Lactobacillus acidophilus surface layer protein (Slp) genes encoding SlpB and SlpX were deleted resulting in a SlpB- and SlpX- mutant that continued to express SlpA (assigned as NCK2031).
Results
Our data show profound activation of dendritic cells by NCK2031, wild-type L. acidophilus (NCK56), and purified Staphylococcus aureus-LTA. In contrary to the LTA-deficient strain NCK2025, the LTA-expressing strains NCK2031 and NCK56, as well as S. aureus-LTA, induce pro-inflammatory innate and T cell immune responses in vivo. Additionally, neither NCK2031 nor S. aureus-LTA supplemented in drinking water protected mice from DSS-colitis, but instead, induced significant intestinal inflammation resulting in severe colitis and tissue destruction.
Conclusions
These findings suggest that directed alteration of two of the L. acidophilus NCFM-Slps did not ameliorate LTA-induced pro-inflammatory signals and subsequent colitis.
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