Induction of blood eosinophilia by pulmonary embolization of antigen-coated particles: the relationship to cell-mediated immunity.

A method of immunization has been described which consists of the i. v. injection into rats of large latex particles coated with human gamma-globulin (HGG). The coated particles embolize the pulmonary capillary bed and induce blood eosinophilia, which correlated strongly with the development of lymphocyte responsiveness to HGG in vitro. Sequential histologic studies of the lungs including ultrastructural analysis suggest a delayed hypersensitivity reaction to the coated particles. These studies support the concept that the induction of blood eosinophilia may be mediated by T lymphocytes.