TY - JOUR
T1 - Heterogeneity of antibodies reactive with the dominant antigen of Actinobacillus actinomycetemcomitans
AU - Nakashima, Keisuke
AU - Schenkein, Harvey A.
AU - Califano, Joseph V.
AU - Tew, John G.
PY - 1997/9
Y1 - 1997/9
N2 - The serotype b-specific carbohydrate antigen (SbAg) of Actinobacillus actinomycetemcomitans Y4 is reported to be the O antigen of lipopolysaccharide, and the highest titers of serum antibody reactive with A. actinomycetemcomitans in early-onset periodontitis (EOP) patients bind SbAg. These high titers of serum antibody reactive with SbAg are associated with a lesser extent and severity of periodontal disease. The aim of this study was to determine if a limited number of genes code for anti-SbAg antibodies as has been shown for immunoglobulin G (IgG) reactive with the type b polysaccharide from Haemophilus influenzae. Serum IgG reactive with the SbAg was prepared from 20 high-titer EOP patients by affinity chromatography. The IgG subclass concentrations were determined, and heterogeneity was analyzed by isoelectric focusing (IEF). IgG2 was the dominant subclass (83% of total IgG) in the anti-SbAg IgG fraction and represented an average of 1.33% of total serum IgG2. The IgG2 reactive with SbAg was isolated from the affinity-purified IgG fraction by affinity chromatography with protein A and subclass-specific monoclonal antibodies. On IEF gels, only 4 to 20 bands were observed in the anti-SbAg IgG fractions, indicating limited heterogeneity. N- terminal amino acid sequence analysis of eight representative anti- SbAg IgG2 preparations indicated that variable heavy and light chains consisted largely of V(H)III and V(K)II, respectively. However, a significant fraction of anti-SbAg may use V(H) and V(k) genes with blocked N termini. In short, these findings indicate that IgG reactive with SbAg is very much like the antibody reactive with H. influenzae type b polysaccharide. Similarities include IgG2 dominance, limited bands on IEF gels, supporting an oligoclonal response, and use of genes from V(H)III and V(k)II regions.
AB - The serotype b-specific carbohydrate antigen (SbAg) of Actinobacillus actinomycetemcomitans Y4 is reported to be the O antigen of lipopolysaccharide, and the highest titers of serum antibody reactive with A. actinomycetemcomitans in early-onset periodontitis (EOP) patients bind SbAg. These high titers of serum antibody reactive with SbAg are associated with a lesser extent and severity of periodontal disease. The aim of this study was to determine if a limited number of genes code for anti-SbAg antibodies as has been shown for immunoglobulin G (IgG) reactive with the type b polysaccharide from Haemophilus influenzae. Serum IgG reactive with the SbAg was prepared from 20 high-titer EOP patients by affinity chromatography. The IgG subclass concentrations were determined, and heterogeneity was analyzed by isoelectric focusing (IEF). IgG2 was the dominant subclass (83% of total IgG) in the anti-SbAg IgG fraction and represented an average of 1.33% of total serum IgG2. The IgG2 reactive with SbAg was isolated from the affinity-purified IgG fraction by affinity chromatography with protein A and subclass-specific monoclonal antibodies. On IEF gels, only 4 to 20 bands were observed in the anti-SbAg IgG fractions, indicating limited heterogeneity. N- terminal amino acid sequence analysis of eight representative anti- SbAg IgG2 preparations indicated that variable heavy and light chains consisted largely of V(H)III and V(K)II, respectively. However, a significant fraction of anti-SbAg may use V(H) and V(k) genes with blocked N termini. In short, these findings indicate that IgG reactive with SbAg is very much like the antibody reactive with H. influenzae type b polysaccharide. Similarities include IgG2 dominance, limited bands on IEF gels, supporting an oligoclonal response, and use of genes from V(H)III and V(k)II regions.
UR - http://www.scopus.com/inward/record.url?scp=0030930696&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030930696&partnerID=8YFLogxK
U2 - 10.1128/iai.65.9.3794-3798.1997
DO - 10.1128/iai.65.9.3794-3798.1997
M3 - Article
C2 - 9284154
AN - SCOPUS:0030930696
SN - 0019-9567
VL - 65
SP - 3794
EP - 3798
JO - Infection and Immunity
JF - Infection and Immunity
IS - 9
ER -