Wallengren Marie Louise Lundin
Department of Cariology, Faculty of Odontology, Malmö University, Malmö, Sweden, 2004.
Swed Dent J Suppl. 2004(166):1-67.
The aim of the present studies was to investigate a possible relationship between the human leukocyte antigen (HLA) complex, colonization of mutans streptococci and salivary immunoglobulin A (IgA) antibodies against mutans streptococcal antigens. In the first study a strong inverse relationship between HLA-DR4 and levels of mutans streptococci was observed for a group of renal transplant patients (I). In a group with healthy blood-donors a similar trend was observed (I). This tendency was also seen for a selected population investigated in the second study (II). Since the HLA molecules regulate the production of antibodies in saliva, the salivary IgA activity to three oral streptococci in a population of HLA-DR4-positive and DR4-negative subjects was investigated in the following study (III). It was found that the HLA-DR4-positive subjects, especially the DRB10401 and DRB10404 subgroups, showed a weaker IgA activity, in particular to Streptococcus mutans, as compared to the HLA-DR4-negative. However, immune response patterns revealed by Western blotting are often complex and for further studies with larger study populations it was crucial to unravel the nature of the detected antigens. In the fourth study (IV), untreated saliva, as well as saliva, in which cell-surface reactive IgA had been absorbed with whole bacteria cells, were analysed in Western blot against different oral streptococci. The high molecular bands, that were absent after absorption, likely represented cell-surface antigens and were thus of interest as they might be involved in adhesion mechanisms and available for blocking in vivo. In the next study (V), the salivary IgA activity to cell-surface antigens of three oral streptococci in relation to different HLA-DRB14 alleles was studied in a larger population. The immunoblots were analysed in a computer program and intensity graphs revealed that the DRB10401 and 0404 subgroups, compared to other DRB104 types, showed fewer as well as less intense immunoblot bands to antigens from S. mutans, S. sobrinus and streptococcal antigen (SA) I/II, but not S. parasanguis. The main conclusion from this thesis is that the HLA profile of the individual seems to influence the salivary IgA response to mutans streptococcal antigens and might thus also affect the conditions for the bacteria in the oral cavity.
本研究的目的是调查人类白细胞抗原（HLA）复合体、变形链球菌定植与唾液中抗变形链球菌抗原的免疫球蛋白A（IgA）抗体之间可能存在的关系。在第一项研究中，观察到一组肾移植患者中HLA-DR4与变形链球菌水平之间存在强烈的负相关关系（I）。在一组健康献血者中也观察到了类似的趋势（I）。在第二项研究中对选定人群进行调查时也发现了这种趋势（II）。由于HLA分子调节唾液中抗体的产生，因此在接下来的研究（III）中，对HLA-DR4阳性和DR4阴性人群中针对三种口腔链球菌的唾液IgA活性进行了研究。结果发现，与HLA-DR4阴性人群相比，HLA-DR4阳性人群，尤其是DRB10401和DRB10404亚组，表现出较弱的IgA活性，特别是针对变形链球菌。然而，蛋白质印迹法揭示的免疫反应模式通常很复杂，对于更大规模研究人群的进一步研究来说，弄清单个细菌细胞吸收细胞表面反应性IgA后的唾液中检测到的抗原的性质至关重要。在第四项研究（IV）中，对未经处理的唾液以及用全细菌细胞吸收了细胞表面反应性IgA的唾液进行了针对不同口腔链球菌的蛋白质印迹分析。吸收后消失的高分子条带可能代表细胞表面抗原，因此很受关注，因为它们可能参与黏附机制并且可用于体内阻断。在接下来的研究（V）中，在更大规模人群中研究了针对三种口腔链球菌细胞表面抗原的唾液IgA活性与不同HLA-DRB14等位基因的关系。在计算机程序中对免疫印迹进行了分析，强度图显示，与其他DRB104类型相比，DRB10401和0404亚组对变形链球菌、远缘链球菌和链球菌抗原（SA）I/II的抗原的免疫印迹条带数量更少且强度更低，但对血链球菌则不然。本论文的主要结论是，个体的HLA谱似乎会影响唾液中针对变形链球菌抗原的IgA反应，因此也可能影响口腔中细菌的生存条件。
