title: Mucosal immunisation with novel Streptococcus pneumoniae protein antigens enhances bacterial clearance in an acute mouse lung infection model.
abstract: Streptococcus pneumoniae contains many proteins that have not been evaluated as potential protective vaccine antigens. In this study we isolated proteins from a serotype 3 strain of S. pneumoniae for use in mouse immunisation studies. Separation of the protein mix was achieved by SDS-PAGE electrophoresis followed by electro-elution to isolate individual proteins. This procedure successfully separated 21 fractions from which six proteins were selected based on purity and quantity and were initially denoted by their molecular masses: 14-, 34-, 38-, 48-, 57- and 75-kDa. The immunogenicity of these proteins was investigated in a mucosal immunisation model in mice involving a primary inoculation to the intestinal Peyer's patches followed by an intra-tracheal boost two weeks later. The immune response was assessed by enhancement of pulmonary clearance of infection, recruitment of phagocytes to the lungs and induction of an antibody response. Two of the proteins, the 14-kDa identified as a L7/L12 ribosomal protein, and the 34-kDa identified as glyceraldehyde-3-phosphate dehydrogenase resulted in up to 99% and 94%, respectively, enhanced clearance of infection within 5 h following pulmonary challenge with S. pneumoniae. This study has shown that novel pneumococcal proteins have the potential to be vaccine candidates to enhance clearance of an acute mucosal S. pneumoniae infection.
authors.affiliation: Division of Health, Design and Science, Gadi Research Centre for Human and Biomedical Sciences, University of Canberra, Canberra ACT 2601, Australia.
authors.forename: Maha
authors.initials: M
authors.lastname: Jomaa
authors.forename: Jennelle M
authors.initials: JM
authors.lastname: Kyd
authors.forename: Allan W
authors.initials: AW
authors.lastname: Cripps
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology / Q000382:microbiology; D018928:Immunity, Mucosal; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010586:Phagocytes / Q000276:immunology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage; D011018:Pneumonia, Pneumococcal / Q000276:immunology* / Q000382:microbiology* / Q000628:therapy; D013296:Streptococcus pneumoniae / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D022242:Pneumococcal Vaccines