Effects of soluble mediators generated during growth of the Landschütz ascites carcinoma on the chemotaxis of normal and Corynebacterium parvum-stimulated peritoneal leucocytes.

The influence of ascites fluid on the chemokinetic and chemotactic responses of mouse peritoneal leucocytes was investigated using modified Boyden chambers and the 'leading front' technique. The migration of normal cells towards endotoxin-activated mouse serum was significantly enhanced at high concentrations of fluid (40 and 20%) but was inhibited at lower concentrations (5 and 1%). By comparison, the chemotactic responsiveness of cells harvested 3 days after Corynebacterium parvum (C. parvum) injection was uniformly and more markedly increased over a wide range of fluid concentrations (0.1-50%). These effects were attributed to the presence of strong chemokinetic and chemotactic material in ascites fluid, which was not inactivated by heating. The activity was also demonstrated in the serum of tumour-bearing animals, was present to a much lesser extent in inflammatory exudate fluid and was absent from normal mouse serum. Detailed morphological studies of migrating cells revealed that although the ascites fluid contained a potent chemo-attractant for neutrophils, it inhibited the migration of mononuclear cells.