Biodegradable microspheres containing group B Streptococcus vaccine: immune response in mice.
OBJECTIVE
This study seeks to show the feasibility of producing a group B Streptococcus (GBS) vaccine, which is capable of producing both a local IgA immune response at the mucosal surface where GBS is colonized and a humoral IgG response, which is capable of transplacental passive immunization.


METHODS
Inactivated GBS antigen was microencapsulated in poly (D, L-lactic-co-glycolic acid) (PLG) with a water-in-oil-in-water double emulsion technique. Immunostimulatory synthetic oligodeoxynucleotides containing cytidine-phosphate-guanosine (CpG) motifs were coencapsulated as a potent adjuvant. The ICR strain of mouse was used in these studies. Female mice with normal immune systems were immunized with the PLG microparticles containing GBS type III polysaccharide (GBS PS) vaccine and CpG adjuvant (PLG/GBS/CpG) via the oral, vaginal, or nasal routes or by the intramuscular or intraperitoneal routes. Booster doses were administered 4 weeks after the initial immunization. Vaginal washings and blood samples were obtained 3 weeks after the booster dose and examined for both IgG and secretory IgA (sIgA) GBS antibodies with the use of an enzyme-linked immunoabsorbent assay method.


RESULTS
PLG/GBS/CpG microparticles elicited a significantly higher GBS antibody response when compared with nonencapsulated GBS antigen or PLG-encapsulated GBS PS vaccine without the addition of the CpG adjuvant. IgG and secretory IgA (sIgA) antibodies to GBS antigen were documented in both the vaginal washings and blood samples.


CONCLUSIONS
Preliminary findings indicate that this novel PLG/GBS/CpG vaccine elicited both IgA and IgG antibody responses to the GBS PS antigen studied. This antibody response may provide both protection against maternal GBS colonization and passive transplacental immunization for the fetus and neonate.
Hunter
S K
SK
Department of Obstetrics & Gynecology, Division of Maternal-Fetal Medicine, University of Iowa Hospitals & Clinics, Iowa City 52242-1080, USA.
Andracki
M E
ME
Krieg
A M
AM
D020341:Absorbable Implants; D000818:Animals; D000917:Antibody Formation; D000942:Antigens, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000008:administration & dosage* / Q000276:immunology / Q000494:pharmacology; D005260:Female; D006016:Glycolates / Q000737:chemistry*; D007070:Immunoglobulin A / Q000096:biosynthesis* / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000276:immunology; D019344:Lactic Acid; D051379:Mice; D008813:Mice, Inbred ICR; D008863:Microspheres; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011134:Polysaccharides / Q000276:immunology; D013292:Streptococcus agalactiae / Q000276:immunology*
D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D006016:Glycolates; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D011134:Polysaccharides; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid