title: Induction of sustained and elevated immune responses to weakly immunogenic synthetic malarial peptides by encapsulation in biodegradable polymer microspheres.
abstract: Biodegradable microspheres (MS) based on poly(D,L-lactide) and poly(D,L-lactide-coglycolide) have the capacity to release encapsulated antigens over defined lengths of time depending on their composition and to elicit and sustain strong and long-lasting immune responses to protein antigens. In the present study, two synthetic multiple antigenic peptides (MAP), P30B2 and (NANP)6P2P30, were incorporated into MS of different compositions. P30B2 and (NANP)6P2P30 are composed of one or two universal T helper epitopes from tetanus toxin, 947-967 (P30) and 830-843 (P2), and of a B cell epitope derived from the repeat sequence of Plasmodium berghei or Plasmodium falciparum, respectively. BALB/c mice were immunized with these two peptides in different formulations, including individual MS or mixtures of MS with various release properties, Incomplete Freund's adjuvant (IFA) or as soluble peptides. MS formulations elicited strong and sustained proliferative and antibody responses comparable to those obtained with the IFA preparations. Furthermore, MS formulations induced specific isotype/ subclass antibodies similar to those induced by IFA. No significant augmentation of total serum IgE was detected during this study. In addition, a boosting effect was obtained when the immunized mice were reinjected with a small antigen dose in IFA several months later. These results indicate that biodegradable MS may be a suitable vaccine delivery system/adjuvant not only for protein antigens but also for weakly immunogenic synthetic peptides.
authors.affiliation: Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland.
authors.forename: Y
authors.initials: Y
authors.lastname: Men
authors.forename: B
authors.initials: B
authors.lastname: Gander
authors.forename: H P
authors.initials: HP
authors.lastname: Merkle
authors.forename: G
authors.initials: G
authors.lastname: Corradin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001672:Biocompatible Materials; D004337:Drug Carriers; D016503:Drug Delivery Systems; D000939:Epitopes / Q000008:administration & dosage* / Q000276:immunology; D005260:Female; D007136:Immunoglobulins / Q000097:blood*; D019344:Lactic Acid; D008198:Lymph Nodes / Q000276:immunology; D017780:Malaria Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D010962:Plasmodium berghei / Q000276:immunology*; D010963:Plasmodium falciparum / Q000276:immunology*; D011091:Polyesters; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D013601:T-Lymphocytes / Q000276:immunology; D013744:Tetanus Toxin / Q000276:immunology; D013745:Tetanus Toxoid / Q000276:immunology; D013997:Time Factors; D014614:Vaccines, Synthetic / Q000008:administration & dosage
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D000939:Epitopes; D007136:Immunoglobulins; D017780:Malaria Vaccines; C091828:P30 tetanus toxin peptide; D010446:Peptide Fragments; D011091:Polyesters; D011108:Polymers; D013744:Tetanus Toxin; D013745:Tetanus Toxoid; D014614:Vaccines, Synthetic; C093151:tetanus toxoid (830-843); D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide)