Erschienen in:
European Journal of Immunology, 33 (2003) 12, Seite 3265-3274
Sprache:
Englisch
DOI:
10.1002/eji.200324124
ISSN:
0014-2980;
1521-4141
Entstehung:
Anmerkungen:
Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Interactions between APC and T lymphocytes have been implicated as a major factor contributing to inflammatory bowel disease. To test whether OX40/OX40L interaction plays a role in chronic intestinal inflammation, we induced chronic colitis using dextran sulfate sodium and treated the mice with a murine fusion protein (OX40–IgG). Treatment resulted in a dose‐dependent and significant reduction of intestinal inflammation (46%) as measured by a histologic score. IL‐10 and IL‐5 production from mesenteric lymph node cells increased 20‐fold and 18‐fold, respectively. In colonic tissue, IL‐10 mRNA levels increased and the expression of T‐bet was decreased to 30%. IL‐10 neutralization partly inhibited the beneficial effects of OX40–IgG treatment. Surprisingly, despite the reduction of inflammation we found the number and size of colonic lymphoid follicles increased, with an accumulation of CD4<jats:sup>+</jats:sup> cells in the mantle area. In contrast, the number of CD4<jats:sup>+</jats:sup> cells infiltrating the mucosa was significantly reduced, as was their CXCR5 expression (24‐fold). We conclude that OX40/OX40L interaction contributes to the perpetuation of chronic colitis partly by suppressing IL‐10 production. Furthermore, our data suggest that the OX40/OX40L‐induced CXCR5 expression on CD4<jats:sup>+</jats:sup> cells may be important for the inflammatory process by allowing migration to the germinal center for further differentiation of CD4<jats:sup>+</jats:sup> cells before they infiltrate the chronically inflamed mucosa.</jats:p>