A new immunomodulator, FR-901235.

ABSTRACT

FR-901235 is a new type of immunoactive substance produced by an imperfect fungus, Paecilomyces carneus F-4882. The mitogen-induced lymphocyte proliferation which had been suppressed by addition of immunosuppressive factor, was restored to a normal level by the addition of FR-901235. Furthermore, the subsequent administration of FR-901235 partially restored the impaired delayed-type hypersensitivity to sheep red blood cells in tumor-bearing mice.