Brown T A, Byres L, Gardner M, Van Dyke T E
Department of Oral Biology, University of Florida, Gainesville 32610.
Infect Immun. 1991 Mar;59(3):1126-30. doi: 10.1128/iai.59.3.1126-1130.1991.
Patients with juvenile periodontitis frequently have elevated levels of serum immunoglobulin A (IgA) antibodies to antigens of Actinobacillus actinomycetemcomitans. IgA occurs in two subclasses, IgA1 and IgA2, and in monomeric and polymeric forms. Because IgA1 is susceptible to cleavage by IgA1 proteases produced by microorganisms found at mucosal sites and in the gingival crevice, we wished to determine the IgA subclass distribution of antibodies to antigens of A. actinomycetemcomitans. The molecular form was examined because it may indicate the origin of the IgA and because the form differs in acute and chronic infections. There is also evidence that monomeric and polymeric IgA have different biological functions. Serum was taken from patients with juvenile periodontitis before and at intervals during and after initiation of therapy. IgA subclass distribution was determined against a sonic extracts of A. actinomycetemcomitans ATCC 2952a (serotype b) by using monoclonal anti-subclass reagents in an enzyme-linked immunosorbent assay. To determine the molecular form of the antibodies, sera were separated by high-performance liquid chromatography on a size-exclusion column. Fractions were assayed for antibody activity by the enzyme-linked immunosorbent assay, and described above. The results of the subclass analysis of the sera indicated that while both IgA1 and IgA2 antibodies to A. actinomycetemcomitans sonic extract are often found before, during, and after treatment, IgA1 antibodies dominated the response. There was a predominance of monomeric IgA1 antibodies to A. actinomycetemcomitans sonic extracts in most samples before, during, and after treatment. The monomeric form is consistent with what is seen in other chronic infections. The predominance of IgA1 antibodies implies that any protective effects of the IgA response to A. actinomycetemcomitans could be compromised by microbial IgA1 proteases.
青少年牙周炎患者血清中抗伴放线放线杆菌抗原的免疫球蛋白A（IgA）抗体水平常常升高。IgA有两个亚类，即IgA1和IgA2，且有单体和多聚体形式。由于IgA1易被黏膜部位及牙龈沟中发现的微生物产生的IgA1蛋白酶裂解，我们希望确定抗伴放线放线杆菌抗原抗体的IgA亚类分布情况。之所以检测分子形式，是因为它可能提示IgA的来源，还因为其形式在急性和慢性感染中有所不同。也有证据表明单体和多聚体IgA具有不同的生物学功能。在治疗开始前、治疗期间及治疗后，间隔一定时间采集青少年牙周炎患者的血清。通过酶联免疫吸附测定法，使用单克隆抗亚类试剂，针对伴放线放线杆菌ATCC 2952a（血清型b）的超声提取物，测定IgA亚类分布。为确定抗体的分子形式，血清在排阻色谱柱上通过高效液相色谱法进行分离。各组分通过上述酶联免疫吸附测定法检测抗体活性。血清亚类分析结果表明，虽然在治疗前、治疗期间及治疗后，常常能检测到抗伴放线放线杆菌超声提取物的IgA1和IgA2抗体，但IgA1抗体在反应中占主导。在大多数样本的治疗前、治疗期间及治疗后，抗伴放线放线杆菌超声提取物的单体IgA1抗体占优势。单体形式与其他慢性感染中的情况一致。IgA1抗体占优势意味着IgA对伴放线放线杆菌反应的任何保护作用可能会被微生物IgA1蛋白酶削弱。
