Dibefurin, a novel fungal metabolite inhibiting calcineurin phosphatase activity.

The novel calcineurin inhibitor, dibefurin, has been isolated from the fungal culture AB 1650I-759. The isolation was bioactivity-directed fractionation using an assay which measures the phosphatase activity of calcineurin. The compound was purified by countercurrent, reverse phase and gel filtration chromatographies.

Simple aromatics identified with a NFAT-lacZ transcription assay for the detection of immunosuppressants.

Determination of the mechanism of action of FK506 and cyclosporin A has yielded new molecular targets involved in signal transduction during T cell activation. A common target of FK506 and cyclosporin A is inhibition of activation of the NFAT transcription factor, for which a specific binding region is present in the promoter of the IL-2 gene. A reporter gene assay has been used to screen for agents that interfere with this early step in T cell activation.

Protection of mice against vaccinia and herpes simplex virus infection by Propionibacterium acnes.

Heat-killed cell suspension of several Propionibacterium acnes strains were prepared and studied for their protective activity in viral infection of mice and immunomodulating properties. Majority of the strains caused marked spleen enlargement in the treated mice. These changes persisted for several weeks.

Effect of dipyridamole on immune response in mice.

Dipyridamole in the dose of 50 mg/kg body weight stimulated the primary humoral response in BALB/c and C57Bl mice. The cell-mediated immune response was not influenced in BALB/c mice.

The influence of some thiosemicarbazone derivatives with antiviral activity on immune response in mice.

The aim of the present study was to examine the influence of the thiosemicarbazone-group of compounds with antiviral activity on the humoral and cellular immune response in R III, CBA and Balb/c mice, immunized with sheep erythrocytes or sensitized with oxazolon. The plaque forming cells test, according to Jerne's method and the oxazolon hypersensitivity test were performed. All of the examined compounds, inhibited the humoral immune response, and three of them decreased also the cellular response.