In situ analysis of B7-2 costimulatory, major histocompatibility complex class II, and adhesion molecule expression in schistosomal egg granulomas
| Autor: | Rathore A, Sacristán C, Ricklan DE, Pedro Flores-Villanueva, Mj, Stadecker |
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| Rok vydání: | 1996 |
| Předmět: |
B-Lymphocytes
Granuloma Membrane Glycoproteins T-Lymphocytes Histocompatibility Antigens Class II Vascular Cell Adhesion Molecule-1 Cell Count Dendritic Cells Intercellular Adhesion Molecule-1 Immunohistochemistry Mice Inbred C57BL Mice Liver Antigens CD Animals Schistosomiasis Female B7-2 Antigen Ovum Research Article |
| Zdroj: | Europe PubMed Central |
| ISSN: | 0002-9440 |
| Popis: | Immunopathological damage in schistosomiasis consist of egg granuloma formation, which is a hypersensitivity reaction mediated by antigen-specific CD4+ T helper (Th) lymphocytes. Th cells are dependent on accessory cell-bound co-stimulatory signals for activation. The B7 molecules provide critical costimulation, as in their absence T cells are rendered unresponsive. We investigated the kinetics of B7-2 molecule expression in schistosomal egg granulomas by immunocytochemical analysis in situ. We also monitored major histocompatibility complex (MHC) class II, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) expression, as well as the presence of macrophages, T cells, and B cells. B7-2 expression was elevated in cells of the large granulomas of the acute (6-1/2 week) infection, and sharply declined thereafter. MHC class II expression was similarly elevated in the acute granulomas, but in contrast to B7-2, remained relatively constant throughout 12 1/2 weeks of infection. Moreover, ICAM-1 and VCAM-1 were expressed in acute and chronic granulomas. However, whereas ICAM-1 was constitutively expressed in normal liver, VCAM-1 was dramatically induced in the livers upon onset of disease. The findings suggest that the acute granulomas are rich in accessory cells with overall phenotypic configurations that support Th-cell activation, although at subsequent times, granulomas contain increasing numbers of B7-poor accessory cells capable of inducing Th-cell unresponsiveness. Thus, cellular interactions in early granulomas may be able to amplify egg-induced immunopathology, whereas interactions taking place in succeeding granulomas appear to precipitate its down-regulation. |
| Databáze: | OpenAIRE |
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