Human immune response to streptococcal inhibitor of complement, a serotype M1 group A Streptococcus extracellular protein involved in epidemics.
J Infect Dis
; 182(5): 1425-36, 2000 Nov.
Article
em En
| MEDLINE
| ID: mdl-11015234
ABSTRACT
Streptococcal inhibitor of complement (Sic) is a highly polymorphic extracellular protein made by serotype M1 group A Streptococcus strains that contributes to bacterial persistence in the mammalian upper respiratory tract. New variants of the Sic protein arise very rapidly by positive selection in human populations during M1 epidemics. The human antibody response to Sic was analyzed. Of 636 persons living in diverse localities, 43% had anti-Sic serum antibodies, but only 16.4% had anti-M1 protein serum antibody. Anti-Sic antibody was also present in nasal wash specimens in high frequency. Linear B cell epitope mapping showed that serum antibodies recognized epitopes located in structurally variable regions of Sic and the amino terminal hypervariable region of the M1 protein. Phage display analyses confirmed that the polymorphic regions of Sic are primary targets of host antibodies. These results support the hypothesis that selection of Sic variants occurs on mucosal surfaces by a mechanism that involves acquired host antibody.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Streptococcus pyogenes
/
Proteínas da Membrana Bacteriana Externa
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Proteínas de Bactérias
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Proteínas Inativadoras do Complemento
/
Antígenos de Bactérias
Limite:
Adolescent
/
Adult
/
Aged
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Aged80
/
Child
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Child, preschool
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Female
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Humans
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Infant
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Male
Idioma:
En
Revista:
J Infect Dis
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos