Effect of D-alanine in teichoic acid from the Streptococcus thermophilus cell wall on the barrier-protection of intestinal epithelial cells.
D-Alanylation of teichoic acid (TA) affects various functions of Gram-positive bacteria, including immunomodulatory effects. We investigated in this study the impact of D-alanine (D-Ala) in TA from Streptococcus thermophilus ATCC 19258(T) on the barrier-protecting effect in human intestinal Caco-2 cells. ATCC 19258(T) suppressed the tumor necrosis factor-α-induced decrease in transepithelial electrical resistance (TER), an indicator of the barrier function. The D-alanylation of TA in ATCC 19258(T) was growth phase- and culture temperature-dependent. Treatment of ATCC 19258(T) with Mg(2+) decreased the dlt mRNA expression and D-Ala content in TA and also abolished the suppressive effect on the TER decrease. Supplementation with L-alanine (L-Ala) to the broth led to an increase of D-Ala in ATCC 19258(T) and of the intestinal barrier-protecting effect. Taken together, D-Ala in TA played an important role in the barrier-protecting effect of S. thermophilus in the intestinal epithelium, and these beneficial effects could be enhanced by exogenous L-Ala.
Graduate School of Biosphere Science, Hiroshima University, Higashi-hiroshima, Japan.
Eiji
E
Miyauchi
Maho
M
Morita
Mauro
M
Rossi
Hidetoshi
H
Morita
Takuya
T
Suzuki
Soichi
S
Tanabe
D000409:Alanine / Q000494:pharmacology*; D018938:Caco-2 Cells; D018929:Cell Culture Techniques; D002473:Cell Wall / Q000737:chemistry; D004847:Epithelial Cells / Q000502:physiology; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D010539:Permeability; D048249:Streptococcus thermophilus / Q000737:chemistry*; D013682:Teichoic Acids / Q000737:chemistry / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
D013682:Teichoic Acids; D014409:Tumor Necrosis Factor-alpha; D000409:Alanine