Monocolonization with Bacteroides ovatus protects immunodeficient SCID mice from mortality in chronic intestinal inflammation caused by long-lasting dextran sodium sulfate treatment.
This study was aimed to evaluate the role of commensal Gram-negative bacterium Bacteroides ovatus in murine model of chronic intestinal inflammation. The attempt to induce chronic colitis was done in Bacteroides ovatus-monoassociated, germ-free and conventional mice either in immunocompetent (BALB/c) mice or in mice with severe combined immunodeficiency (SCID), using 2.5 % dextran-sodium sulfate (DSS) in drinking water (7 days DSS, 7 days water, 7 days DSS). Conventional mice developed chronic colitis. Some of germ-free BALB/c and the majority of germ-free SCID mice did not survive the long-term treatment with DSS due to massive bleeding into the intestinal lumen. However, monocolonization of germ-free mice of both strains with Bacteroides ovatus prior to long-term treatment with DSS protected mice from bleeding, development of intestinal inflammation and precocious death. We observed that though DSS-treated Bacteroides ovatus-colonized SCID mice showed minor morphological changes in colon tissue, jejunal brush-border enzyme activities such as gamma-glutamyltranspeptidase, lactase and alkaline phosphatase were significantly reduced in comparison with DSS-untreated Bacteroides ovatus-colonized mice. This modulation of the enterocyte gamma-glutamyltranspeptidase localized to the brush border membrane has been described for the first time. This enzyme is known to reflect an imbalance between pro-oxidant and anti-oxidant mechanisms, which could be involved in protective effects of colonization of germ-free mice with Bacteroides ovatus against DSS injury.
Hudcovic
T
T
Department of Immunology, Academy of Sciences of the Czech Republic, Nový Hrádek, Czech Republic.
Kozáková
H
H
Kolínská
J
J
Štěpánková
R
R
Hrnčíř
T
T
Tlaskalová-Hogenová
H
H
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001439:Bacteroides / Q000254:growth & development*; D002908:Chronic Disease; D003092:Colitis / Q000139:chemically induced / Q000201:enzymology / Q000382:microbiology / Q000473:pathology / Q000517:prevention & control*; D003106:Colon / Q000382:microbiology* / Q000473:pathology; D016264:Dextran Sulfate; D004195:Disease Models, Animal; D007413:Intestinal Mucosa / Q000201:enzymology; D007583:Jejunum / Q000201:enzymology; D043322:Lactase / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D008871:Microvilli / Q000201:enzymology; D012720:Severity of Illness Index; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000378:metabolism
D016264:Dextran Sulfate; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase; D043322:Lactase