Mitogenicity of cell wall fractions of Micropolyspora faeni.

Cell wall fractions of Micropolyspora faeni, a causative agent of hypersensitivity pneumonitis, have been shown to possess non-specific mitogenic activity for guinea pig, rabbit and human lymphocytes. This activity was unrelated to endotoxin and may not be associated with peptidoglycan. This lymphocyte proliferation stimulus may play a role in the adjuvant properties of this organism and in the etiology of hypersensitivity lung disease.