Rittipornlertrak Amarin, Nambooppha Boondarika, Muenthaisong Anucha, Punyapornwithaya Veerasak, Tiwananthagorn Saruda, Chung Yang-Tsung, Tuvshintulga Bumduuren, Sivakumar Thillaiampalam, Yokoyama Naoaki, Sthitmatee Nattawooti
Graduate School of Veterinary Sciences, Chiang Mai University, Muang, Chiang Mai, Thailand.
Department of Food Animal Clinic, Faculty of Veterinary Medicine, Chiang Mai University, Muang, Chiang Mai, Thailand.
PeerJ. 2021 Jul 16;9:e11765. doi: 10.7717/peerj.11765. eCollection 2021.
Bovine babesiosis caused by s) has had a significant effect on the mobility and mortality rates of the cattle industry worldwide. Live-attenuated vaccines are currently being used in many endemic countries, but their wide use has been limited for a number of reasons. Although recombinant vaccines have been proposed as an alternative to live vaccines, such vaccines are not commercially available to date. Apical membrane antigen-1 (AMA-1) is one of the leading candidates in the development of a vaccine against diseases caused by apicomplexan parasite species. In () AMA-1 (PfAMA-1), several antibodies against epitopes in the plasminogen, apple, and nematode (PAN) motif of PfAMA-1 domain I significantly inhibited parasite growth. Therefore, the purpose of this study was to predict an epitope from the PAN motif of domain I in the AMA-1 (BbAMA-1) using a combination of linear and conformational B-cell epitope prediction software. The selected epitope was then bioinformatically analyzed, synthesized as a peptide (sBbAMA-1), and then used to immunize a rabbit. Subsequently, growth- and the invasion-inhibitory effects of the rabbit antiserum were immunologically characterized.
Our results demonstrated that the predicted BbAMA-1 epitope was located on the surface-exposed α-helix of the PAN motif in domain I at the apex area between residues 181 and 230 with six polymorphic sites. Subsequently, sBbAMA-1 elicited antibodies capable of recognizing the native BbAMA-1 in immunoassays. Furthermore, anti-serum against sBbAMA-1 was immunologically evaluated for its growth- and invasion-inhibitory effects on merozoites . Our results demonstrated that the rabbit anti-sBbAMA-1 serum at a dilution of 1:5 significantly inhibited ( < 0.05) the growth of merozoites by approximately 50-70% on days 3 and 4 of cultivation, along with the invasion of merozoites by approximately 60% within 4 h of incubation when compared to the control groups.
Our results indicate that the epitope predicted from the PAN motif of BbAMA-1 domain I is neutralization-sensitive and may serve as a target antigen for vaccine development against bovine babesiosis caused by .
由[具体病原体名称未给出]引起的牛巴贝斯虫病对全球养牛业的流动性和死亡率产生了重大影响。减毒活疫苗目前在许多流行国家使用，但其广泛应用因多种原因受到限制。尽管重组疫苗已被提议作为活疫苗的替代品，但此类疫苗至今尚未商业化。顶膜抗原-1（AMA-1）是开发针对由顶复门寄生虫引起疾病的疫苗的主要候选抗原之一。在[具体研究内容未给出]中，几种针对恶性疟原虫AMA-1（PfAMA-1）结构域I中纤溶酶原、苹果和线虫（PAN）基序表位的抗体显著抑制了寄生虫生长。因此，本研究的目的是使用线性和构象性B细胞表位预测软件相结合的方法，从双芽巴贝斯虫AMA-1（BbAMA-1）结构域I的PAN基序中预测一个表位。然后对所选表位进行生物信息学分析，合成为一种肽（sBbAMA-1），接着用于免疫兔子。随后，对兔抗血清的生长抑制和侵袭抑制作用进行免疫学表征。
我们的结果表明，预测的BbAMA-1表位位于结构域I中PAN基序的表面暴露α螺旋上，在181至230位残基之间的顶端区域，有六个多态性位点。随后，sBbAMA-1在免疫测定中诱导出能够识别天然BbAMA-1的抗体。此外，对针对sBbAMA-1的抗血清在对双芽巴贝斯虫裂殖子的生长抑制和侵袭抑制作用方面进行了免疫学评估。我们的结果表明，稀释度为1:5的兔抗sBbAMA-1血清在培养的第3天和第4天显著抑制（P<0.05）双芽巴贝斯虫裂殖子的生长约50 - 70%，与对照组相比，在孵育4小时内裂殖子的侵袭也受到约60%的抑制。
我们的结果表明，从BbAMA-1结构域I的PAN基序预测的表位对中和敏感，可能作为针对由[具体病原体名称未给出]引起的牛巴贝斯虫病疫苗开发的靶抗原。
