Establishment of new system to prevent oral infectious diseases relating to oral biofilm

变形链球菌表面蛋白抗原（Pac）中富含丙氨酸的重复区（A区）作为龋病疫苗的抗原成分受到广泛关注。A区的Pac（残基361-386）肽段具有与多种HLA-DR分子结合的多重结合基序（L-V-K-A）和可被S.变种人本研究探讨了Pac（361-386）肽是否是诱导人产生抑制性抗体的有效抗原，以及与唾液中抗体诱导的相关性。从151名健康人受试者（年龄：36.6±12.6）收集刺激的唾液样品。用NOD-scid小鼠移植人外周血单个核细胞（PBMC），检测Pac（361-386）肽的免疫原性。用酶联免疫吸附试验测定人唾液和移植鼠血清中抗Pac（361-386）肽的Hu-伊加和IgG抗体滴度。人唾液中抗Pac（361-386）肽伊加抗体滴度（a）随年龄增长而显著降低。高抗体组（3<a）的MS和mS/ tS比值低于无抗体组（0.1>a）和中等抗体组（3 <a>1）。Allel DRB 1 ^*1501和DRB 1 ^*0406与抗体的高诱导显著相关，并且也倾向于减少乳酸杆菌和S.变种人此外，在表达各种DRB 1基因型的移植NOD-scid小鼠中证实了肽的免疫原性。肽免疫诱导的单克隆抗体（SH_2、KH_5）对S.变形菌在大鼠牙齿表面的定植。因此，Pac（361-386）肽具有很强的免疫原性，能在人体口腔中诱导抑制性抗体，其诱导受年龄、HLA-DRB 1基因型和细胞因子的调节。这些结果可能有助于利用口腔药物递送系统（3DS）清除口腔生物膜系统，预防口腔疾病。

Alanine-rich repeating region (A-region) in surface protein antigen (Pac) of Streptococcus mutans has been given much attention as an antigenic component for dental caries vaccines. The Pac (residue 361-386) peptide in A-region possesses a multiple binding motif (L--V-K-A) to various HLA-DR molecules and the B-cell core epitope (Y---L--Y) recognizing by the inhibiting antibody to S. mutans. In this study, we investigated whether Pac (361-386) peptide was effective antigen for induction of the inhibiting antibody in human, and what correlate with the antibody induction in saliva. Stimulated saliva samples were collected from 151 healthy human subjects (age : 36.6±12.6). NOD-scid mice grafted with human peripheral blood mononuclear cells (PBMC)were used to examine immunogenicity of Pac (361-386) peptide. Hu- IgA and IgG antibody titers to Pac (361-386) peptide in the human saliva and sera from the grafted mice were analyzed by enzyme-linked immuno sorbent assay. Anti-Pac(361-386) peptide IgA antibody titer (a) in human saliva decreased significantly in age-dependent mannaer. MS and mS/ tS ratio were lower in high antibody group (3<a) than no antibody (0.1>a) and moderate group (3≧a>1). Allel DRB1^*1501 and DRB1^*0406 were significantly correlated with high induction of the antibodies and also tended to reduce Lactobacilli and S. mutans. Moreover, the peptide immunogenicities were confirmed in the grafted NOD-scid mice expressing various DRB1 genotypes. The monoclonal antibody induced by the peptide immunization (SH2, KH5) inhibited S. mutans colonization on the tooth surfaces in rats. Therefore, the Pac(361-386) peptide has strong immunogenicity and induce the inhibiting antibody in human oral cavity, and the induction are regulated by aging, HLA-DRB1 genotype and cytokine. These results may be helpful in removing system of oral biofilm using Dental Drug delivary system(3DS) with the human monoclonal antibody to prevent dental diseases.