J Med Microbiol 57 (2008), 273-278; DOI: 10.1099/jmm.0.47661-0
© 2008 Society for General Microbiology
ISSN 1473-5644
Recognition of pneumococcal isolates by antisera raised against PspA fragments from different clades
Michelle Darrieux1,
,
Adriana T. Moreno1,
,
Daniela M. Ferreira1,
Fabiana C. Pimenta2,
Ana Lúcia S. S. de Andrade2,
Alexandre P. Y. Lopes1,
Luciana C. C. Leite1 and
Eliane N. Miyaji1
1 Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil, 1500, 05509-900, São Paulo, SP, Brazil
2 Instituto de Patologia Tropical e Saude Publica, Universidade Federal de Goias, Goiania, Brazil
Correspondence
Eliane N. Miyaji
enmiyaji{at}butantan.gov.br
Received 28 September 2007
Accepted 7 November 2007
Pneumococcal surface protein A (PspA) is an important vaccine candidate against pneumococcal infections, capable of inducing protection in different animal models. Based on its structural diversity, it has been suggested that a PspA-based vaccine should contain at least one fragment from each of the two major families (family 1, comprising clades 1 and 2, and family 2, comprising clades 3, 4 and 5) in order to elicit broad protection. This study analysed the recognition of a panel of 35 pneumococcal isolates bearing different PspAs by antisera raised against the N-terminal regions of PspA clades 1 to 5. The antiserum to PspA clade 4 was found to show the broadest cross-reactivity, being able to recognize pneumococcal strains containing PspAs of all clades in both families. The cross-reactivity of antibodies elicited against a PspA hybrid including the N-terminal region of clade 1 fused to a shorter and more divergent fragment (clade-defining region, or CDR) of clade 4 (PspA1–4) was also tested, and revealed a strong recognition of isolates containing clades 1, 4 and 5, and weaker reactions with clades 2 and 3. The analysis of serum reactivity against different PspA regions further revealed that the complete N-terminal region rather than just the CDR should be included in an anti-pneumococcal vaccine. A PspA-based vaccine is thus proposed to be composed of the whole N-terminal region of clades 1 and 4, which could also be expressed as a hybrid protein.
Abbreviations: CDR, clade-defining region.
Both authors contributed equally to this work.
Copyright © 2008 Society for General Microbiology.