MUCOSAL IMMUNOGENICITY ELICITED IN MICE BY ORAL VACCINATION WITH PHOSPHORYLCHOLINE ENCAPSULATED IN POLY (D,L-LACTIDE-CO-GLYCOLIDE) MICROSPHERES

Poly(D,L-lactide-co-glycolide) microspheres loaded with phosphorylchol ine linked to thyroglobulin (PC-Thyr) as protein carrier were prepared . The entrapment efficiency reached 80% when the initial protein:polym er ratio was 1:8. Ninety-four percent of the loaded microspheres had a diameter less than or equal to 10 mu m. The encapsulation process did not alter PC-Thyr absorbance nor PC antigenic reactivity. Oral admini stration of these microspheres induced a specific IgA response in inte stinal, pulmonary and vaginal secretions, as well as a strong specific systemic immune response in female Balb/c mice. This suggests the nee d to explore further the potential ability of PC-Thyr loaded microsphe res to protect against infections caused by PC-bearing microorganisms which invade or colonize different mucosal sites. (C) 1998 Elsevier Sc ience Ltd. All rights reserved.