Abstract
The leukocytosis and lymphocytosis-promoting factor (LPF) of Bordetella pertussis has been isolated in apparently pure form. LPF is a protein essentially free of lipid and carbohydrate with an estimated molecular weight of 67,000-73,600 daltons, Purified LPF induced both histamine sensitization and refractoriness to epinephrine-induced hyperglycemia and was a murine thymus-derived (T-) cell mitogen. Adenyl cyclase activity also appeared to be associated with LPF.