Immunization with polyamine transport protein PotD protects mice against systemic infection with Streptococcus pneumoniae.
The human pathogen Streptococcus pneumoniae contains genes for a putative polyamine ABC transporter which are organized in an operon and designated potABCD. Polyamine transport protein D (PotD) is an extracellular protein which binds polyamines and possibly other structurally related molecules. PotD has been shown to contribute to virulence in both a murine sepsis model and a pneumonia model with capsular type 3 pneumococci. The protective efficacy of recombinant PotD was evaluated by active immunization and intravenous challenge with capsular type 3 pneumococci in CBA/N mice. Immunized mice had 91.7% survival following lethal pneumococcal challenge, compared with 100% mortality in the control group. Immunized animals had high-titer anti-PotD antibodies following three immunizations with alum. Protection in a sepsis model was also seen after passive administration of rabbit antiserum raised against PotD (P < 0.004). These results suggest that antibodies to PotD confer protection against invasive pneumococcal disease and that this protein should be studied further as a potential vaccine candidate for protection against invasive pneumococcal infections.
Shah
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Research Service (151), Veterans Affairs Medical Center, 1500 Woodrow Wilson Drive, Jackson, MS 39216, USA.
Swiatlo
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D018528:ATP-Binding Cassette Transporters / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D000818:Animals; D000907:Antibodies, Bacterial / Q000008:administration & dosage / Q000276:immunology; D007116:Immunization, Passive; D051379:Mice; D008808:Mice, Inbred CBA; D011008:Pneumococcal Infections / Q000517:prevention & control*; D011073:Polyamines / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D013296:Streptococcus pneumoniae / Q000276:immunology*; D014611:Vaccination
D018528:ATP-Binding Cassette Transporters; D000907:Antibodies, Bacterial; D011073:Polyamines; D011994:Recombinant Proteins