Kwon Eun-Young, Cha Gil Sun, Joo Ji-Young, Lee Ju-Youn, Choi Jeomil
Department of Periodontology, Pusan National University School of Dentistry, Yangsan, Korea.
Biomedical Research Institute, Pusan National University Hospital, Busan, Korea.
J Periodontal Implant Sci. 2017 Jun;47(3):174-181. doi: 10.5051/jpis.2017.47.3.174. Epub 2017 Jun 28.
Epitope spreading is a phenomenon in which distinct subdominant epitopes become major targets of the immune response. Heat shock protein (HSP) 60 from (PgHSP60) and peptide 19 from PgHSP60 (Pep19) are immunodominant epitopes in autoimmune disease patients, including those with periodontitis. It remains unclear whether Pep19 is a dominant epitope in subjects without periodontitis or autoimmune disease. The purpose of this study was to determine the epitope spreading pattern and verify Pep19 as an immunodominant epitope in healthy teenagers using dot immunoblot analysis. The patterns of epitope spreading in age-matched patients with type 1 diabetes mellitus (type 1 DM) and healthy 20- to 29-year old subjects were compared with those of healthy teenagers.
Peptide from PgHSP60, HSP60 (MtHSP60), and HSP60 (CpHSP60) was synthesized for comparative recognition by sera from healthy subjects and patients with autoimmune disease (type 1 DM). Dot immunoblot analysis against a panel of peptides of PgHSP60 and human HSP60 (HuHSP60) was performed to identify epitope spreading, and a densitometric image analysis was conducted.
Of the peptide from PgHSP60, MtHSP60, and CpHSP60, PgHSP60 was the predominant epitope and was most consistently recognized by the serum samples of healthy teenagers. Most sera from healthy subjects and patients with type 1 DM reacted more strongly with PgHSP60 and Pep19 than the other peptides. The relative intensity of antibody reactivity to Pep19 was higher in the type 1 DM group than in the healthy groups.
Pep19 is an immunodominant epitope, not only in autoimmune disease patients, but also in healthy young subjects, as evidenced by their robust immunoreactivity. This result suggests that the Pep19-specific immune response may be an initiator that triggers autoimmune diseases.
表位扩展是一种现象，即不同的亚优势表位成为免疫反应的主要靶点。牙龈卟啉单胞菌热休克蛋白（PgHSP60）中的热休克蛋白60和PgHSP60中的肽19（Pep19）是自身免疫性疾病患者（包括牙周炎患者）中的免疫显性表位。尚不清楚Pep19在无牙周炎或自身免疫性疾病的受试者中是否为显性表位。本研究的目的是使用斑点免疫印迹分析确定表位扩展模式，并验证Pep19在健康青少年中作为免疫显性表位。将年龄匹配的1型糖尿病（1型DM）患者和健康的20至29岁受试者的表位扩展模式与健康青少年的进行比较。
合成来自PgHSP60、结核分枝杆菌热休克蛋白60（MtHSP60）和嗜肺军团菌热休克蛋白60（CpHSP60）的肽，用于健康受试者和自身免疫性疾病（1型DM）患者血清的比较识别。针对一组PgHSP60和人热休克蛋白60（HuHSP60）肽进行斑点免疫印迹分析以识别表位扩展，并进行光密度图像分析。
在来自PgHSP60、MtHSP60和CpHSP60的肽中，PgHSP60是主要表位，并且最一致地被健康青少年的血清样本识别。大多数健康受试者和1型DM患者的血清与PgHSP60和Pep19的反应比其他肽更强。1型DM组中抗体对Pep19反应性的相对强度高于健康组。
Pep19是一种免疫显性表位，不仅在自身免疫性疾病患者中，而且在健康的年轻受试者中也是如此，这通过他们强大的免疫反应性得到证明。该结果表明，Pep19特异性免疫反应可能是引发自身免疫性疾病的启动因素。
