Hypersensitivity pneumonitis in strain II guinea pigs. II. Immunologic features.

A model of hypersensitivity pneumonitis (HP) in syngeneic animals would allow experiments designed to determine immunopathogenesis of HP. Strain II guinea pigs were treated with Micropolyspora faeni and challenged with intratracheal M. faeni. Skin test, serum antibody, hilar lymph node lymphocyte proliferation and bronchoalveolar macrophage migration inhibition (MMI) response to M. faeni antigen were determined. Sensitized animals had positive delayed skin tests, serum antibody and bronchoalveolar cell MMI, but not M. faeni-induced hilar node lymphocyte proliferation. We conclude that this model is suitable for examination of the importance of various mechanisms which might be important in HP.