[Immunostimulation by 2-cyanoethylurea: accelerated rejection of skin allografts in mice].

2-Cyanoethylurea (2; CEU or BA 1-4) obtainable from 1-carboxamido-2-cyanoaziridine (2; BA l) by ring fission possesses immunomodulating properties like its parent compound containing the intact aziridine ring, as well as other 2-cyanoaziridine (1) derivatives. As was shown in a mouse model, CEU accelerated the time of rejection of skin allografts (immunostimulation) and reduced the prolonged tolerance time of mice immunosuppressed with cyclophosphamide to values found in normal control animals (immunorestoration).