Quantitative determination of immunoglobulin G specific for group B streptococcal beta C protein in human maternal serum.
The beta C protein of group B streptococci (GBS) elicits antibody that is protective against GBS challenge in animals and is considered to be a potential component of a GBS conjugate vaccine. We developed a quantitative enzyme-linked immunosorbent assay to measure beta-specific serum immunoglobulin G (IgG) levels and used it to compare beta-specific IgG in a group of mothers of neonates with invasive type Ib/beta GBS disease and a group of mothers colonized with Ib/beta strains whose neonates remained well. beta-Specific IgG concentrations from these 2 groups were similar. To investigate differences in beta-specific antibody in animals and humans, protein fragments were generated that corresponded to major regions within the beta C protein. A single major region was predominantly recognized in human and rabbit serum samples. Thus, in contrast to immunized animals, no relationship was seen between levels of naturally acquired human beta-specific IgG and protection from neonatal disease. This difference was not explained by a major difference in epitope specificity.
Lachenauer
Catherine S
CS
Channing Laboratory and Division of Infectious Diseases, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. clachenauer@channing.harvard.edu
Baker
Carol J
CJ
Baron
Miriam J
MJ
Kasper
Dennis L
DL
Gravekamp
Claudia
C
Madoff
Lawrence C
LC
D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood*; D007231:Infant, Newborn; D010587:Phagocytosis; D011247:Pregnancy / Q000276:immunology*; D013292:Streptococcus agalactiae / Q000276:immunology*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; C070010:streptococcal beta antigen