Premium
Modulation of apoptosis in intestinal lymphocytes by a probiotic bacteria in Crohn's disease
Author(s) -
Carol Monica,
Borruel Natalia,
Antolin Maria,
Llopis Marta,
Casellas Francesc,
Guarner Francisco,
Malagelada JuanR.
Publication year - 2006
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.0405188
Subject(s) - lamina propria , biology , lactobacillus casei , immune system , apoptosis , tumor necrosis factor alpha , intestinal mucosa , cytokine , microbiology and biotechnology , immunology , inflammation , bacteria , epithelium , medicine , biochemistry , genetics
Apoptosis of active T lymphocytes constitutes a maor control mechanism of immune homeostasis and tolerance. In Crohn's disease, abnormal activation of mucosal T lymphocytes against enteric bacteria is the key event triggering intestinal inflammation. Resistance of lymphocytes to apoptosis has been proposed as the pathogenetic defect. We examined the influence of bacteria‐mucosa interactions on apoptosis of mucosal T lymphocytes. Ileal specimens were obtained at surgery from 12 patients with Crohn's disease. Mucosal explants from each specimen were cultured with nonpathogenic Escherichia coli ATCC 35345, Lactobacillus casei DN‐114 001, or no bacteria. Cytokine release was measured in supernatant, and mononuclear cells were isolated for phenotypic characterization and Bcl‐2 family protein expression. Coculture of inflamed tissue with L. casei significantly reduced the release of interleukin (IL)‐6 and tumor necrosis factor α ( P <0.05). In addition, coculture with L. casei significantly reduced the number of T cells displaying the IL‐2 receptor in the lamina propria. Expression of the antiapoptotic protein Bcl‐2 in lamina propria lymphocytes was also reduced after coculture with L. casei , and the percentage of deoxyuridine triphosphate nick‐end labeling positive lymphocytes increased. The nonpathogenic E. coli strain had no significant effect. In conclusion, L. casei reduces the number of activated T lymphocytes in the lamina propria of Crohn's disease mucosa. A balanced, local microecology may restore immune homeostasis.