Department of Preventive and Community Dentistry, Graduate School of Dentistry, Osaka Dental University, 1-8 Kuzuha Hanazono-Cho, Hirakata-Shi, Osaka, 573-1121, Japan.
Department of Oral Health Science and Social Welfare, Graduate School of Oral Sciences, Tokushima University, 3-18-15 Kuramoto-Cho, Tokushima-Shi, Tokushima, 770-8504, Japan.
BMC Oral Health. 2023 Feb 24;23(1):123. doi: 10.1186/s12903-023-02821-6.
We previously showed that fimbriae-bore from Poryphyromonas gingivalis (Pg), one of the putative periodontopathogenic bacteria specifically bound to a peptide domain (stat23, prp21) shared on statherin or acidic proline-rich protein 1 (PRP1) molecule of human salivary proteins (HSPs). Here, we investigated whether the nasal administration of DNA plasmid expressing Flt3 ligand (pFL) and CpG oligodeoxynucleotide 1826 as double DNA adjuvant (dDA) with stat23 and prpr21 induces antigen (Ag)-specific salivary secretory IgA (SIgA) antibodies (Abs) in mice. Further, we examined that stat23- and prpr21-specific salivary SIgA Abs induced by dDA have an impact on Pg-binding to human whole saliva-coated hydroxyapatite beads (wsHAPs).
C57BL/6N mice were nasally immunized with dDA plus sta23 or/and prp21 peptide as Ag four times at weekly intervals. Saliva was collected one week after the final immunization and was subjected to Ag-specific ELISA. To examine the functional applicability of Ag-specific SIgA Abs, SIgA-enriched saliva samples were subjected to Pg binding inhibition assay to wsHAPs.
Significantly elevated levels of salivary SIgA Ab to stat23 or prp21 were seen in mice given nasal stat23 or prp21 with dDA compared to those in mice given Ag alone. Of interest, mice nasally given the mixture of stat23 and prp21 as double Ags plus dDA, resulted in both stat23- and prp21-specific salivary SIgA Ab responses, which are mediated through significantly increased numbers of CD11c dendritic cell populations and markedly elevated Th1 and Th2 cytokines production by CD4 T cells in the mucosal inductive and effector tissues. The SIgA Ab-enriched saliva showed significantly reduced numbers of live Pg cells binding to wsHAPs as compared with those in mice given double Ags without dDA or naïve mice. Additionally, saliva from IgA-deficient mice given nasal double Ags plus dDA indicated no decrease of live Pg binding to wsHAPs.
These findings show that HSP-derived peptides-specific salivary SIgA Abs induced by nasal administration of stat23 and prp21 peptides plus dDA, play an essential role in preventing Pg attachment and colonization on the surface of teeth, suggesting a potency that the SIgA may interrupt and mask fimbriae-binding domains in HSPs on the teeth.
我们之前表明，牙龈卟啉单胞菌（Pg）的菌毛孔可特异性结合人唾液蛋白（HSP）中的一个肽段（stat23、prp21），该肽段存在于牙骨质蛋白或酸性富含脯氨酸蛋白 1（PRP1）分子上。在这里，我们研究了鼻内给予表达 Flt3 配体（pFL）和 CpG 寡脱氧核苷酸 1826 的 DNA 质粒作为双 DNA 佐剂（dDA）与 stat23 和 prpr21 联合使用是否会诱导小鼠的抗原（Ag）特异性唾液分泌型免疫球蛋白 A（SIgA）抗体。此外，我们还研究了 dDA 诱导的 stat23 和 prpr21 特异性唾液 SIgA 抗体是否会影响 Pg 与人类全唾液包被羟基磷灰石珠（wsHAPs）的结合。
C57BL/6N 小鼠每周经鼻内免疫 dDA 加 stat23 或/和 prp21 肽作为 Ag 共 4 次。最后一次免疫后一周收集唾液，并进行 Ag 特异性 ELISA。为了研究 Ag 特异性 SIgA 抗体的功能适用性，将富含 SIgA 的唾液样本用于 Pg 与 wsHAPs 的结合抑制测定。
与单独给予 Ag 的小鼠相比，经鼻给予 dDA 加 stat23 或 prp21 的小鼠，唾液中针对 stat23 或 prp21 的 SIgA Ab 水平显著升高。有趣的是，经鼻给予混合 stat23 和 prp21 作为双 Ag 加 dDA 的小鼠，导致了 both stat23-和 prp21-特异性唾液 SIgA Ab 反应，这是通过粘膜诱导和效应组织中 CD4 T 细胞中显著增加的 CD11c 树突状细胞群体和明显升高的 Th1 和 Th2 细胞因子产生介导的。与未给予双 Ag 和 dDA 的小鼠或未致敏小鼠相比，富含 SIgA 的唾液显示出 live Pg 细胞与 wsHAPs 的结合数量显著减少。此外，给予鼻内双 Ag 加 dDA 的 IgA 缺陷型小鼠的唾液表明，live Pg 与 wsHAPs 的结合没有减少。
这些发现表明，由鼻内给予 stat23 和 prp21 肽加 dDA 诱导的 HSP 衍生肽特异性唾液 SIgA Ab ，在防止 Pg 附着和定植于牙齿表面方面发挥重要作用，这表明 SIgA 可能中断并掩盖牙齿上 HSP 中的菌毛结合域。
