POPULATION-CHANGES IN IMMUNOGLOBULIN-CONTAINING MONONUCLEAR-CELLS IN DEXTRAN SULFATE SODIUM-INDUCED COLITIS

To investigate the relation of immunoglobulin-containing cells in the colonic mucosa to mucosal inflammation, we immunohistochemically exami ned the localization of immunoglobulin-containing mononuclear cells in the lamina propria in dextran sulfate sodium induced colitis in mice. Mice were treated repeatedly with 3% dextran sulfate sodium (MW 54000 ) solution or distilled water for a total of 170 days (chronic model), or for 85 days (subacute model) or for 10 days (acute model). IgG, Ig A, and IgM-containing mononuclear cells were studied by enzyme immunos taining. The number of IgA- and IgG-containing cells gradually and sig nificantly increased in the acute, subacute, and chronic models, in th at order (P < 0,01 or 0.05). However, the numbers of IgM-containing ce lls in the three models were similar to that in the controls. These fi ndings resembled those of human ulcerative colitis. In this dextran su lfate sodium-induced colitis, IgA-containing mononuclear cells may pla y an essential role in the mucosal immune system is the acute, subacut e, and chronic phases. The finding that IgG-containing mon onuclear ce lls increased substantially in the chronic phase suggests that IgG pla ys an important role in the mucosal inflammatory reaction during the c hronic phase.