Lu H, Califano J V, Schenkein H A, Tew J G
Clinical Research Center for Periodontal Diseases, School of Dentistry, Medical College of Virginia, Richmond 23298.
Infect Immun. 1993 Jun;61(6):2400-7. doi: 10.1128/iai.61.6.2400-2407.1993.
The aims of this study were to determine the immunodominant antigens of Actinobacillus actinomycetemcomitans serotype b (Aab) for the different immunoglobulin (Ig) classes and subclasses and to determine the relative levels of these different Igs in serum. Seropositive early-onset periodontitis patients were sampled, and the Ig classes IgG, IgA, and IgM and subclasses IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2 were studied. Reactivity with Aab antigens was assessed by using the Western blot (immunoblot) in limiting dilution analysis and radioimmunoassay with sera from 13 early-onset periodontitis subjects. A smeared antigen in the upper portion of the immunoblots, typical of high-molecular-weight LPS, was immunodominant for IgG, IgA, IgM, IgG1, IgG2, IgG3, IgA1, and IgA2. This smeared antigen was present in every patient for all of these Igs at the endpoint. A few additional antigens were also present at the endpoint in some patients, but none were present in more than half of the subjects. The distribution of antibody titers by Ig classes reactive with the Aab immunodominant antigen was IgG > IgA > IgM. The distribution of antibody titers by IgG subclass was IgG2 > IgG1 approximately IgG3. Further quantitation by radioimmunoassay revealed that the mean concentration of IgG2 (65.7 micrograms/ml) was significantly greater than that of IgG1 (8.8 micrograms/ml). The IgA subclass distribution was IgA1 >> IgA2, with IgA1 apparently being second only to IgG2. Therefore, the Aab antigen eliciting the highest antibody level in virtually all Ig classes and subclasses appeared to be lipopolysaccharide, and IgG2 was markedly elevated over all other serum Ig classes or subclasses reactive with Aab.
本研究的目的是确定伴放线放线杆菌b血清型（Aab）针对不同免疫球蛋白（Ig）类别和亚类的免疫显性抗原，并确定血清中这些不同Ig的相对水平。对血清反应阳性的早发性牙周炎患者进行采样，研究Ig类别IgG、IgA和IgM以及亚类IgG1、IgG2、IgG3、IgG4、IgA1和IgA2。通过蛋白质印迹法（免疫印迹法）在有限稀释分析中以及用13名早发性牙周炎受试者的血清进行放射免疫测定来评估与Aab抗原的反应性。免疫印迹上部的一种涂抹状抗原，是高分子量脂多糖的典型特征，对IgG、IgA、IgM、IgG1、IgG2、IgG3、IgA1和IgA2具有免疫显性。在终点时，所有这些Ig的每个患者中都存在这种涂抹状抗原。在终点时，一些患者中还存在一些其他抗原，但超过半数受试者中不存在任何一种。与Aab免疫显性抗原反应的Ig类别中抗体滴度的分布为IgG>IgA>IgM。IgG亚类的抗体滴度分布为IgG2>IgG1≈IgG3。通过放射免疫测定进一步定量显示，IgG2的平均浓度（65.7微克/毫升）显著高于IgG1（8.8微克/毫升）。IgA亚类分布为IgA1>>IgA2，IgA1显然仅次于IgG2。因此，几乎在所有Ig类别和亚类中引发最高抗体水平的Aab抗原似乎是脂多糖，并且与Aab反应的所有其他血清Ig类别或亚类相比，IgG2明显升高。
