USE OF ENCAPSULATED SINGLE-CHAIN ANTIBODIES FOR INDUCTION OF ANTIIDIOTYPIC HUMORAL AND CELLULAR IMMUNE-RESPONSES

The use of biodegradable poly(lactic-co-glycolic acid) (PLGA) microsph eres as a cancer vaccine delivery system for induction of anti-idiotyp ic responses has been investigated using a single chain antibody scFv- pDL10, which recognizes the human ovarian cancer antigen CA125. Immuni zation of mice with scFv-pDL10 encapsulated in PLGA microspheres resul ted in enhanced humoral and cellular immune responses when compared to scFv-pDL10 alone. Induced anti-idiotypic antibodies (Ab2) which mimic the original antigen CA125 compete with CA125 for the epitope. A cell ular response (T2 induction) was also observed. These results raise th e possibility of anti-idiotypic antibody induction by a single chain a ntibody, encapsulated in biodegradeble microspheres, as a potential va ccine for ovarian carcinoma.