Lung eosinophilia in response to intravenously injected Trichinella spiralis.

Mice were injected intravenously with killed muscle-stage larvae of the parasitic nematode Trichinella spiralis. This induced eosinophilic lung inflammation, the degree of eosinophilia was detected and measured by broncho-alveolar lavage. Subsequent in vivo restimulation by Trichinella antigens produced an enhanced lung response, showing that exposure to killed larvae generated an effective immunological memory. The kinetics and characteristics of the eosinophil response suggested that it was locally rather than systemically controlled. This conclusion is based on the fact that, in contrast to the situation seen after oral infection with T. spiralis, there was little change in bone marrow eosinophilopoiesis, blood eosinophil numbers or in serum interleukin-5 levels.