Plant lectins as carriers of associated drug substances into animal and human cells

Abstract

The current invention involves the use of protein lectins produced by plants including the non-toxic carbohydrate binding subunits (B subunits) of plant “AB toxins” (PTB lectins) as delivery vehicles for mobilizing associated drug substances for delivery to animal and human cells. The resulting protein fusions or conjugates retain lectin carbohydrate specificity for binding to cells and cellular trafficking activity so as to deliver an associated drug compound to the site of disease manifestation. One embodiment of this invention concerns the ability of ricin toxin B subunit, as a model PTB lectin, to deliver enzyme replacement therapeutic drugs to cells of several organs of the body including the brain and central nervous system, eyes, ears, lungs, bone, heart, kidney, liver, and spleen for treating lysosomal diseases.

We claim: 
     
         1 . A compound comprising:
 a) a therapeutic agent or compound; and   b) a protein comprising a lectin or containing a carbohydrate binding domain that mediates delivery across the blood brain barrier;   
       wherein the therapeutic compound or agent is operatively linked or fused to the protein comprising the lectin or the carbohydrate binding domain. 
     
     
         2 . A method for treating a disorder or disease in a person or animal, wherein the method comprises administering a therapeutically effective amount of a compound of  claim 1 , wherein the therapeutic agent or compound is useful for treating or ameliorating the disorder or disease.