Abstract: The present invention provides compositions wherein endogenous lectins are used as transport vehicles for facilitating the cell-specific binding and cellular uptake of therapeutic agents useful in the treatment of lysosomal storage diseases. In accordance with one embodiment, lectin-glycosidase conjugates are provided for enzyme replacement therapy of cells containing deficient enzyme activity. In accordance with another embodiment, compositions comprising lectin-nucleic acid constructs are provided for gene therapy of cells containing deficient enzyme activity. A third embodiment of the present invention relates to lectin-oligonucleotide compositions provided for antisense therapy to modulate production of mutant and defective lysosomal enzymes.

Abstract: The present invention provides a process for preparing a carbohydrate-binding lectin derivative for use as immune modulators or immunoconjugates. The polymer-lectin conjugate produced in accordance with the process is polyethylene glycol Ricinus communis agglutinin I (PEG-RCAI). The lectin is coupled to the polymer by activating the polymer with a coupling agent such as 1,1-carbonyldiimidazole. The polymer-lectin conjugate is biologically active, biocompatible and is expected to be substantially non-immunogenic.