Abstract: Administration of monoclonal antibodies specific for IL-2R to xenograft recipients, or long-term to immunosuppression-intolerant or non-compliant patients over a period of time beyond the very early phase of organ transplantation, prevents transplant rejection.

Abstract: Use of a CD25 binding molecule which comprises at least one antigen binding site comprising at least one domain which comprises in sequence, the hypervariable regions CDR1, CDR2 and CDR3; said CDR1 having the amino acid sequence Arg-Tyr-Trp-Met-His, said CDR2 having the amino acid sequence Ala-Ile-Tyr-Pro-Gly-Asn-Ser-Asp-Thr-Ser-Tyr-Asn-Gln-Lys-Phe-Glu-Gly, and said CDR3 having the amino acid sequence Asp-Tyr-Gly-Tyr-Tyr-Phe-Asp-Phe, in the treatment of rheumatoid arthritis or inflammatory or hyperproliferative skin diseases.

Abstract: Administration of monoclonal antibodies specific for IL-2R to xenograft recipients, or long-term to immunosuppression-intolerant or non-compliant patients over a period of time beyond the very early phase of organ transplantation, prevents transplant rejection.

Abstract: Novel monoclonal antibodies capable of distinguishing between cyclosporins, e.g. Cyclosporine, and metabolites, e.g. Cyclosporins 17 and 18, are produced, e.g. starting from novel cyclosporins having an activated coupling group, e.g. activated carboxy group, e.g. (i) [(O-succinimidooxysuccinyl)-Thr].sup.2 -Cyclosporine and (ii) [(N-.epsilon.-succinimidooxysuccinyl)-(D)Lys].sup.8 -Cyclosporine. Cyclosporin starting materials required for the production of cyclosporins of type (ii), e.g. [(D)Lys].sup.8 -Cyclosporine are also new and additionally have utility in the preparation of novel labelled cyclosporin derivatives, as well as antibodies and antisera generally. Also claimed are novel antigenic conjugates and hybridoma cell lines used in the production of antibodies and antisera as aforesaid as well as assay kits comprising novel antisera, antibodies and/or labelled cyclosporins as aforesaid.

Abstract: Cyclic peptolides having the structure of a cyclosporin in which one amide linkage is replaced by an ester linkage are obtained by fermentation of fungal strains of the genus Cylindrotrichum Bonorden, or by cyclization of a hydroxy-undecapeptide. The cyclic peptolides have immunosuppressive, anti-inflammatory and anti-parasitic properties.