Discovery of novel Streptococcus pneumoniae antigens by screening a whole-genome lambda-display library.
Streptococcus pneumoniae is a causative agent of otitis media, pneumonia, meningitis and sepsis in humans. For the development of effective vaccines able to prevent pneumococcal infection, characterization of bacterial antigens involved in host immune response is crucial. In order to identify pneumococcal proteins recognized by host antibody response, we created an S. pneumoniae D39 genome library, displayed on lambda bacteriophage. The screening of such a library, with sera either from infected individuals or mice immunized with the S. pneumoniae D39 strain, allowed identification of phage clones carrying S. pneumoniae B-cell epitopes. Epitope-containing fragments within the families of the histidine-triad proteins (PhtE, PhtD), the choline-binding proteins (PspA, CbpD) and zinc metalloproteinase B (ZmpB) were identified. Moreover, library screening also allowed the isolation of phage clones carrying three distinct antigenic regions of a hypothetical pneumococcal protein, encoded by the ORF spr0075 in the R6 strain genome sequence. In this work, Spr0075 is first identified as an expressed S. pneumoniae gene product, having an antigenic function during infection.
Beghetto
Elisa
E
Kenton Srl, Pomezia, Rome, Italy.
Gargano
Nicola
N
Ricci
Susanna
S
Garufi
Gabriella
G
Peppoloni
Samuele
S
Montagnani
Francesca
F
Oggioni
Marco
M
Pozzi
Gianni
G
Felici
Franco
F
D000328:Adult; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay; D018985:Epitopes, B-Lymphocyte / Q000276:immunology; D016680:Genome, Bacterial; D006801:Humans; D006867:Hydrolases / Q000235:genetics / Q000276:immunology; D008297:Male; D008666:Metalloendopeptidases / Q000235:genetics / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA; D019151:Peptide Library; D011993:Recombinant Fusion Proteins; D044967:Serum / Q000276:immunology; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000276:immunology*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D018985:Epitopes, B-Lymphocyte; D019151:Peptide Library; D011993:Recombinant Fusion Proteins; C097552:histidine triad protein; C051592:pneumococcal surface protein A; C412019:ZmpB enzyme; D006867:Hydrolases; D008666:Metalloendopeptidases