Ontogeny of the humoral response to group A streptococcal carbohydrate: Class and IgG subclass composition of antibodies in children

Abstract

We determined isotypes of natural antibodies to streptococcal group A carbohydrate (A-CHO) in sera from 101 children between 1 and 16 years of age, using a calibrated enzyme-linked immunosorbent assay system. Anti-A-CHO IgM could be detected in all but one sera. Median levels increased with age and were highest between 8 and 12 years. IgG antibodies were present at low concentrations up to the age of 4 years, and consisted predominantly of the IgG1 subclass. Between 4 and 8 years, concentrations of anti-A-CHO IgG markedly increased and median levels continued to increase through age 12-16. Anti-A-CHO IgG1 levels closely followed the pattern of IgG antibody concentrations. The number of IgG2 antibody positive sera was low in young children, as expected. In the 8-12 year age group and later, anti-A-CHO IgG2 was present in more than half of the samples, and in children between 12 and 16, medians of IgG2 and IgG1 antibodies were similar. Sera containing anti-A-CHO IgG3 were rare in children up to 4 years of age, but in the group of 4-8-year-old children, this subclass was detectable in 36% and later in up to 77% of the sera. Thus, the IgG response to A-CHO showed a clear maturation during childhood, involving the subclasses IgG1, IgG2 and IgG3. There were no significant differences in A-CHO levels between boys and girls.

Avidity and titer of immunoglobulin G subclasses to Porphymmonas gingivalis in adult periodontitis patients

“…Also, IgG2 demonstrates lower Fey receptor binding than IgGl and IgG3 to various leukocyte subpopulations (17), When IgGl was examined in our study, no significant differences in relative avidity were seen wheti P. gingivalis, streptokinase and tetanus toxoid were compared. It is notable that there was no detectable IgGl antibody reactive with LPS, confirming previous reports that indicate that LPS and other carbohydrate antigens tend to stimulate IgG2 rather than IgGl (26,29,34,35). If, instead of ELI-SA units, we examined endpoint titers obtained during the ELISA titrations, the levels of antibody to P. gingivaliswhole cell were very low in the IgGl class (data not shown), suggesting that the actual contribution of anti-P. gingivalis antibodies of the IgG 1 subclass to the total hutnoral response (IgGl^) was quite minitnal.…”

A Temporal Model of Human IgE and IgG Antibody Function

“…This could help explain reports that IgG2 dominates the antibody response to carbohydrates response (42). In fact similar concentrations of IgG1 and IgG2 antibodies have often been reported in response to carbohydrate antigens (43–45), and IgG2 antibodies are also a conspicuous part of the response to many protein antigens (46). It is clear that the chemistry of carbohydrate antigens cannot explain the IgG2 response.…”

Analysis of the Ontogeny of the Murine Humoral Response toNeisseria meningitidisB Capsular Polysaccharide Reveals Levels of ComplexityRelevant to Vaccine Development

“…In 5-7-week-old mice, the anti-CpsB IgG subclass distribution was IgG3 (and IgG1), which differed from that in mice with mature anti-CpsB responses, in which IgG2a and IgG2b predominate. Similar changes from IgG1 and IgG3 in children to IgG2 in adults have been described in human responses to polysaccharides [30][31][32]. The shift in IgG profile could reflect a shift in the quality or quantity of cytokine-dependent and other forms of ancillary help delivered to the B cell, or, more likely, it could reflect the maturation of mechanisms that allow B cells to use these signals.…”