Enhanced lysophospholipase activity in sensitized mice challenged with Trichinella spiralis: a role for cell-cooperation.

The relation between lysophospholipase activity and eosinophils was studied using in vivo and in vitro systems. The results support a role for cell cooperation in the eosinophils production of lysophospholipase during a parasitic infection. In vivo experiments demonstrated that the enzyme activity and numbers of tissue eosinophils in immune mice challenged with 200 Trichinella spiralis larvae were not temporally related as previously hypothesized. The data showed that the peak tissue enzyme response occurred well before that of the eosinophil, suggesting increased tissue lysophospholipase activity to be due to more than an increase in numbers of eosinophils infiltrating parasitized tissue. In vitro experiments demonstrated that the eosinophils production of lysophospholipase was influenced by lymphocytes and macrophages after antigen stimulation. We hypothesize that a significant amount of lysophospholipase in parasitized tissue results from each eosinophil synthesizing more of the enzyme after interaction with these cells of the specific immune system.