Previous Article | Next Article ![]()
Infection and Immunity, October 1998, p. 4588-4592, Vol. 66, No. 10
W. W. Karakawa Microbial Pathogenesis
Laboratory, Nabi, Rockville, Maryland
Received 23 March 1998/Returned for modification 27 May
1998/Accepted 10 July 1998
Bacterial capsular polysaccharides (CP) are carbohydrate polymers
comprised of repeating saccharide units. Several of these CP have side
chains attached to their backbone structures. The side chains may
include O-acetyl, phosphate, sialic acid, and other moieties. Those
moieties represent the immunodominant epitopes and the most functional
ones. The clinically significant Staphylococcus aureus type
5 CP (CP 5) and type 8 CP (CP 8) are comprised of a trisaccharide
repeat unit with one O-acetyl group attached to each repeat unit. The
immunogenicity of these CP and the functionality of antibodies to the
backbone and the O-acetyl moieties were investigated. Immunization with
the native CP conjugates (CP with 75% O-acetylation) elicited a high
proportion of antibodies directed against the O-acetyl moiety.
Nonetheless, all of the vaccinees produced antibodies to the backbone
moieties as well. Conjugate vaccines made of de-O-acetylated CP
elicited backbone antibodies only. Antibodies to both backbone and
O-acetyl groups were found to be opsonic against S. aureus strains which varied in their O-acetyl content. Absorption studies with
O-acetylated and de-O-acetylated CP showed that (i) native CP
conjugates generated antibodies to both backbone and O-acetyl groups
and (ii) O-acetylated isolates were opsonized by both populations of
antibodies while the non-O-acetylated strains were predominantly opsonized by the backbone antibodies. These results suggest that S. aureus CP conjugate vaccines elicit multiple populations
of antibodies with diverse specificities. Moreover, the antibodies of
different specificities (backbone or O-acetyl) are all functional and
efficient against the variations in bacterial CP that may occur among
clinically significant S. aureus pathogenic isolates.
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Antigenic Determinants of Staphylococcus
aureus Type 5 and Type 8 Capsular Polysaccharide
Vaccines
*
Corresponding author. Mailing address: Nabi, 12280 Wilkins Ave., Rockville, MD 20852. Phone: (301) 255-6970. Fax: (301)
770-2014. E-mail address: afattom{at}nabi.com.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|