Basement membrane proteins and type III procollagen in murine schistosomiasis

The livers of female CBA mice were examined 9 to 10 weeks after subcutaneous infection with Schistosoma mansoni. Cryostat liver sections and isolated liver cells were examined by indirect immunofluorescence using specific antibodies against basement membrane proteins (laminin, fibronectin and type IV collagen and type III collagen precursor. Liver cells were isolated by collagenase digestion, purification on Percoll density gradients and centrifugal elutriation to yield enriched fractions of hepatocytes, endothelial and Kupffer cells (Fractions I, II, III respectively). Infected animals yielded more than three times the control number of non-parenchymal cells; electron microscopy revealed that the increase in Fraction II was due mainly to eosinophilic leucocytes and in Fraction III due to Kupffer cells and macrophages from the schistosomal granulomata. Studies of cryostat liver sections showed that the schistosomal granulomata contained dense deposits of type III collagen precursor and fibronectin in the distribution of the reticulin fibres but laminin and type IV collagen were conspicuous only in new vessels in the periphery of the granuloma. Isolated liver cells showed fibronectin on their surface. Immunofluorescence studies could not be performed on Kupffer and endothelial cell fractions because of marked non-specific fluorescence. These experiments indicate that centrifugal elutriation is a useful method for isolating the constituent cells of murine schistosomal granulomata.