All species of the order Chlamydiales are obligate intracellular eubacterial pathogens of their various hosts. Two chlamydial species, Chlamydia trachomatis and Chlamydia pneumoniae, are primarily human pathogens, and each is known to cause important diseases. Some strains of C.
View Article and Find Full Text PDFSchistosomiasis mansoni, a tropical helminthic disease, is caused by disseminated worm eggs that induce CD4(+) T-cell mediated granulomatous inflammation and fibrosis. T suppressor cell activity has been proposed as one of the mechanisms active in the down-modulation of the murine disease during the chronic stage (16-20 weeks of the infection). In recent years a new category of the CD4(+) CD25(+) T regulatory (Treg) lymphocyte has been identified that maintains immune tolerance to self, and also functions in the regulation of parasite-induced immunopathology.
View Article and Find Full Text PDFSchistosomiasis mansoni is a tropical helminthic disease characterized by parasite egg-induced granulomatous inflammation and cumulative fibrosis. Because fibrosis is influenced by the imbalance between degradative matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), we analysed the resorption of fibrous tissue and MMP/TIMP expression in the livers of S. mansoni-infected and praziquantel-cured mice.
View Article and Find Full Text PDFHepatocellular carcinoma is associated with liver fibrosis. Murine schistosomiasis infection offers a model to study hepatic fibrogenesis. Single-stranded phosphorothiate oligodeoxynucleotides containing the TGF-beta regulatory element have been shown to regulate the transcription of this gene and effectively inhibit collagen synthesis in primary fibroblasts isolated from schistosomiasis-induced hepatic granulomas.
View Article and Find Full Text PDFSchistosomiasis mansoni is characterized by hepatic granuloma formation. Endothelial cell activation within these granulomas may contribute to their development and to increased vascularization in the granuloma periphery. The earliest event in granuloma formation is the lodging of schistosome eggs within presinusoidal capillaries.
View Article and Find Full Text PDFA previous study of the murine model of Schistosoma mansoni infection has implicated splenic CD19(+) B lymphocytes as Fas ligand (FasL)-bearing mediators of CD4(+) T-lymphocyte apoptosis. The present study shows that B-cell deficiency leads to decreased CD4(+) T-cell apoptosis during infection and compares FasL expression and killer function of B-1a- and CD5(-) B-lymphocyte subsets. B-1a cells from uninfected mice displayed constitutive expression of FasL compared with that of CD5(-) B cells.
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