Batista Milene Tavares, Souza Renata D, Ferreira Ewerton L, Robinette Rebekah, Crowley Paula J, Rodrigues Juliana F, Brady L Jeannine, Ferreira Luís C S, Ferreira Rita C C
Vaccine Development Laboratory, Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
Department of Oral Biology, University of Florida, College of Dentistry, Gainesville, Florida, USA.
Infect Immun. 2014 Dec;82(12):4978-88. doi: 10.1128/IAI.02074-14. Epub 2014 Sep 15.
Streptococcus mutans is a major etiologic agent of dental caries, a prevalent worldwide infectious disease and a serious public health concern. The surface-localized S. mutans P1 adhesin contributes to tooth colonization and caries formation. P1 is a large (185-kDa) and complex multidomain protein considered a promising target antigen for anticaries vaccines. Previous observations showed that a recombinant P1 fragment (P1(39-512)), produced in Bacillus subtilis and encompassing a functional domain, induces antibodies that recognize the native protein and interfere with S. mutans adhesion in vitro. In the present study, we further investigated the immunological features of P1(39-512) in combination with the following different adjuvants after parenteral administration to mice: alum, a derivative of the heat-labile toxin (LT), and the phase 1 flagellin of S. Typhimurium LT2 (FliCi). Our results demonstrated that recombinant P1(39-512) preserves relevant conformational epitopes as well as salivary agglutinin (SAG)-binding activity. Coadministration of adjuvants enhanced anti-P1 serum antibody responses and affected both epitope specificity and immunoglobulin subclass switching. Importantly, P1(39-512)-specific antibodies raised in mice immunized with adjuvants showed significantly increased inhibition of S. mutans adhesion to SAG, with less of an effect on SAG-mediated bacterial aggregation, an innate defense mechanism. Oral colonization of mice by S. mutans was impaired in the presence of anti-P1(39-512) antibodies, particularly those raised in combination with adjuvants. In conclusion, our results confirm the utility of P1(39-512) as a potential candidate for the development of anticaries vaccines and as a tool for functional studies of S. mutans P1.
变形链球菌是龋齿的主要病原体，龋齿是一种在全球范围内普遍存在的传染病，也是一个严重的公共卫生问题。位于表面的变形链球菌P1黏附素有助于在牙齿上定植并形成龋齿。P1是一种大型（185 kDa）复杂的多结构域蛋白，被认为是抗龋齿疫苗的一个有前景的靶抗原。先前的观察表明，在枯草芽孢杆菌中产生的包含一个功能结构域的重组P1片段（P1(39 - 512)）可诱导识别天然蛋白并在体外干扰变形链球菌黏附的抗体。在本研究中，我们进一步研究了在给小鼠经肠胃外给药后，P1(39 - 512)与以下不同佐剂联合使用时的免疫学特征：明矾、热不稳定毒素（LT）的衍生物以及鼠伤寒沙门氏菌LT2的1期鞭毛蛋白（FliCi）。我们的结果表明，重组P1(39 - 512)保留了相关的构象表位以及唾液凝集素（SAG）结合活性。佐剂的共同给药增强了抗P1血清抗体反应，并影响了表位特异性和免疫球蛋白亚类转换。重要的是，在用佐剂免疫的小鼠中产生的P1(39 - 512)特异性抗体对变形链球菌与SAG黏附的抑制作用显著增强，而对SAG介导的细菌聚集（一种天然防御机制）的影响较小。在存在抗P1(39 - 512)抗体，特别是与佐剂联合产生的抗体时，变形链球菌对小鼠的口腔定植受到损害。总之，我们的结果证实了P1(39 - 512)作为抗龋齿疫苗开发的潜在候选物以及作为变形链球菌P1功能研究工具的实用性。
