Two Novel Salmonella Bivalent Vaccines Confer Dual Protection against Two Salmonella Serovars in Mice.
Two Novel Salmonella Bivalent Vaccines Confer Dual Protection against Two Salmonella Serovars in Mice.
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两种新型沙门氏菌二价疫苗为小鼠提供针对两种沙门氏菌血清型的双重保护
DOI：
10.3389/fcimb.2017.00391
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发表时间：
2017
影响因子：
5.7
通讯作者：
Cheng A
中科院分区：
文献类型：
--
作者：
Zhao X;Dai Q;Jia R;Zhu D;Liu M;Wang M;Chen S;Sun K;Yang Q;Wu Y;Cheng A
非伤寒沙门氏菌包括数千种血清型，它们是全球食源性腹泻疾病的主要原因。本研究利用天冬氨酸半醛脱氢酶（Aspartate semialdehyde dehydrogenase，Asd）平衡致死载体-宿主系统构建了三种预防鼠伤寒沙门氏菌和纽波特沙门氏菌感染的双价疫苗。构建的Asd+质粒pCZ 11携带沙门氏菌纽波特O-抗原基因簇的一个亚组，包括wzx-wbaR-wbaL-wbaQ-wzy-wbaW-wbaZ基因，将其导入三种鼠伤寒沙门氏菌突变体中：当与阿拉伯糖一起生长时，具有光滑LPS表型的SLT 19（Δasd）、具有粗糙LPS表型的SLT 20（Δ asd ΔrfbN）和具有光滑LPS表型的SLT 22（Δasd ΔrfbN ΔpagL：：T araC PBAD rfbN）。免疫印迹证明，携带pCZ 11的SLT 19 [称为SLT 19（pCZ 11）]共表达同源和异源O-抗原; SLT 20（pCZ 11）仅表达异源O-抗原;当阿拉伯糖可用时，SLT 22（pCZ 11）表达两种类型的O-抗原，而在不存在阿拉伯糖的情况下，SLT 22（pCZ 11）仅表达异源O-抗原。在鼠伤寒沙门氏菌中排他性表达异源O抗原降低了细菌的游泳能力及其对多粘菌素B的敏感性。接着，为了减毒目的，从三个重组菌株中删除crp基因，分别产生三个二价疫苗菌株SLT 25（pCZ 11）、SLT 26（pCZ 11）和SLT 27（pCZ 11）。对各组BALB/c小鼠（12只小鼠/组）每4周间隔两次口服免疫109 CFU的每种疫苗株。与模拟免疫相比，用所有三种疫苗株免疫诱导针对鼠伤寒沙门氏菌和纽波特沙门氏菌LPS的显著血清IgG应答。鼠伤寒沙门氏菌或纽波特沙门氏菌致死攻毒后，三个疫苗株免疫组中小鼠组织中的细菌载量显著低于模拟组。三个疫苗免疫组中的所有小鼠在致命的鼠伤寒沙门氏菌攻击中存活。相反，SLT 26（pCZ 11）和SLT 27（pCZ 11）赋予针对致死沙门氏菌纽波特攻击的完全保护，但SLT 25（pCZ 11）仅提供50%的异源保护。因此，我们开发了两种新的沙门氏菌双价疫苗，SLT 26（pCZ 11）和SLT 27（pCZ 11），表明在减毒沙门氏菌菌株中递送异源O-抗原是开发具有广泛血清型覆盖的沙门氏菌疫苗的前瞻性方法。
Non-typhoidal Salmonella includes thousands of serovars that are leading causes of foodborne diarrheal illness worldwide. In this study, we constructed three bivalent vaccines for preventing both Salmonella Typhimurium and Salmonella Newport infections by using the aspartate semialdehyde dehydrogenase (Asd)-based balanced-lethal vector-host system. The constructed Asd+ plasmid pCZ11 carrying a subset of the Salmonella Newport O-antigen gene cluster including the wzx-wbaR-wbaL-wbaQ-wzy-wbaW-wbaZ genes was introduced into three Salmonella Typhimurium mutants: SLT19 (Δasd) with a smooth LPS phenotype, SLT20 (Δasd ΔrfbN) with a rough LPS phenotype, and SLT22 (Δasd ΔrfbN ΔpagL::T araC PBAD rfbN) with a smooth LPS phenotype when grown with arabinose. Immunoblotting demonstrated that SLT19 harboring pCZ11 [termed SLT19 (pCZ11)] co-expressed the homologous and heterologous O-antigens; SLT20 (pCZ11) exclusively expressed the heterologous O-antigen; and when arabinose was available, SLT22 (pCZ11) expressed both types of O-antigens, while in the absence of arabinose, SLT22 (pCZ11) expressed only the heterologous O-antigen. Exclusive expression of the heterologous O-antigen in Salmonella Typhimurium decreased the swimming ability of the bacterium and its susceptibility to polymyxin B. Next, the crp gene was deleted from the three recombinant strains for attenuation purposes, generating the three bivalent vaccine strains SLT25 (pCZ11), SLT26 (pCZ11), and SLT27 (pCZ11), respectively. Groups of BALB/c mice (12 mice/group) were orally immunized with 109 CFU of each vaccine strain twice at an interval of 4 weeks. Compared with a mock immunization, immunization with all three vaccine strains induced significant serum IgG responses against both Salmonella Typhimurium and Salmonella Newport LPS. The bacterial loads in the mouse tissues were significantly lower in the three vaccine-strain-immunized groups than in the mock group after either Salmonella Typhimurium or Salmonella Newport lethal challenge. All of the mice in the three vaccine-immunized groups survived the lethal Salmonella Typhimurium challenge. In contrast, SLT26 (pCZ11) and SLT27 (pCZ11) conferred full protection against lethal Salmonella Newport challenge, but SLT25 (pCZ11) provided only 50% heterologous protection. Thus, we developed two novel Salmonella bivalent vaccines, SLT26 (pCZ11) and SLT27 (pCZ11), suggesting that the delivery of a heterologous O-antigen in attenuated Salmonella strains is a prospective approach for developing Salmonella vaccines with broad serovar coverage.