The properdin system and immunity. VII. Alterations in properdin levels and resistance to infection in mice following the administration of tissue polysaccharides.

High molecular weight polysaccharide complexes derived from normal and neoplastic mammalian tissues were found to combine with properdin and to inactivate C'3 in vitro. These polysaccharide preparations were also found to alter properdin levels and non-specific resistance to Gram-negative infection in mice. In these manifestations, the tissue polysaccharides bore a marked resemblance to bacterial lipopolysaccharides. Some implications of the interactions of tissue polysaccharides and properdin in certain disease states are considered.