Abstract: The invention relates to a novel ribosome-binding protein derived from Bougainvillea spectabilis having a molecular weight of about 26,000 daltons by polyacrylamide gel electrophoresis under reducing and non-reducing conditions, a pI of about 9.0, and a specified amino-terminal amino acid sequence. The invention further relates to a conjugate of the protein with a targeting ligand, such as an antibody, to form an immunotoxin. The protein and the conjugate are useful in therapy, for example, in the control of tumour cells or viruses.

Abstract: The invention relates to a novel ribosome-binding protein derived from Bougainvillea speotabilis having a molecular weight of about 26,000 daltons by polyacrylamide gel electrophoresis under reducing and non-reducing conditions, a ph of about 9.0, and further comprising a specified amino-terminal amino acid sequence, as well as to a conjugate of said protein with a targeting ligand, such as an antibody, to form an immunotoxin. The protein and the conjugate are useful in therapy, for example in the control of tumour calls or viruses.

Abstract: An immunotoxin molecule is described which comprises an antibody specific for human CD40L antigen located on the surface of a human cell, coupled to a toxin molecule or active fragment thereof, wherein the binding of the immunotoxin to the CD40L molecule results in the killing of the CD40L expressing cell. The toxin molecule is especially a type-1 ribosome inactivating protein, or an active fragment thereof. The immunotoxin can be used for the treatment of autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus, or T-cell malignancies.