The pathogenesis of @entity30 , an intractable @entity32 , @entity73 and/or excessive activation of mucosal macrophages and T lymphocytes. @entity7938 ( @entity7938 ) and @entity2937 ( @entity2937 ) molecules are costimulatory molecules that are indispensable to T-cell activation by antigen-presenting cells. To elucidate the roles and characteristics of these antigen-presenting cells in @entity30 , in situ localization of @entity12750 (in relation to the distribution of T cells) was clarified by light and electron microscopic immunohistochemistry. The results were compared with those from a study of @entity31 . Normal colonic tissue expressed @entity7938 or @entity2937 only sporadically. In active @entity30 , however, an increase in the number of @entity7938 / @entity2937 + cells correlated with an increase in expression of HLA-DR and intercellular adhesion molecule-1. Most @entity7938 / @entity2937 + cells were identified as noncaseating @entity738 or as macrophages, which tended to form an aggregate especially in @entity1066 bases. In active @entity31 , the increase of @entity7938 / @entity2937 + cells was not as prominent as that in @entity30 . Double immunohistochemistry revealed a close cellular distribution between noncaseating @entity738 and T cells. Immunoelectron microscopy confirmed the expression of @entity7938 / @entity2937 along the plasma membranes of cytoplasmic processes of @entity738 cells, where lymphocytes were closely attached. The present study suggested that @entity738 formation in @entity30 is coupled with antigen presentation via a @entity7938 / @entity2937 - @entity1361 pathway, which may contribute to the pathogenesis of the disease.

Expression of costimulatory molecules @entity12750 in macrophages and XXXX of @entity30 : demonstration of cell-to-cell contact with T lymphocytes.

@entity32 :: ('MESH:D007249', 'Disease') :: ['inflammatory disease'] @entity2937 :: ('942', 'Gene') :: ['CD86', 'B7-2'] @entity738 :: ('MESH:D006099', 'Disease') :: ['granulomas', 'granuloma'] @entity12750 :: ('941;942', 'Gene') :: ['B7-1 and B7-2'] @entity7938 :: ('941', 'Gene') :: ['B7-1', 'CD80'] @entity73 :: ('MESH:D003072', 'Disease') :: ['involves impaired'] @entity31 :: ('MESH:D003093', 'Disease') :: ['ulcerative colitis'] @entity1066 :: ('MESH:D014456', 'Disease') :: ['ulcer'] @entity30 :: ('MESH:D003424', 'Disease') :: ["Crohn's disease"] @entity1361 :: ('940', 'Gene') :: ['CD28']
@entity738 :: (MESH:D006099,Disease) :: ['granulomas']
