口服重组植物乳杆菌表达旋毛虫无机焦磷酸酶疫苗诱导 BALB/c 小鼠保护性免疫。

Oral vaccination with recombinant Lactobacillus plantarum encoding Trichinella spiralis inorganic pyrophosphatase elicited a protective immunity in BALB/c mice.

机构信息

Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China.

出版信息

PLoS Negl Trop Dis. 2021 Oct 26;15(10):e0009865. doi: 10.1371/journal.pntd.0009865. eCollection 2021 Oct.

BACKGROUND

Trichinellosis is a serious zoonotic disease distributed around the world. It is needed to develop a safe, effective and feasible anti-Trichinella vaccine for prevention and control of trichinellosis. The aim of this study was to construct a recombinant Lactobacillus plantarum encoding Trichinella spiralis inorganic pyrophosphatase (TsPPase) and investigate its immune protective effects against T. spiralis infection.

METHODOLOGY/PRINCIPAL FINDINGS: The growth of recombinant L. plantarum was not affected by TsPPase/pSIP409-pgsA' plasmid, and the recombinant plasmid was inherited stably in bacteria. Western blot and immunofluorescence assay (IFA) indicated that the rTsPPase was expressed on the surface of recombinant L. plantarum. Oral vaccination with rTsPPase induced higher levels of specific serum IgG, IgG1, IgG2a and mucosal secretory IgA (sIgA) in BALB/c mice. ELISA analysis revealed that the levels of IFN-γ and IL-4 released from spleen, mesenteric lymph nodes and Peyer's patches were evidently increased at 2-4 weeks following vaccination, compared to MRS (De Man, Rogosa, Sharpe) medium control group (P < 0.05). Immunization of mice with rTsPPase exhibited a 67.18, 54.78 and 51.91% reduction of intestinal infective larvae, adult worms and muscle larvae at 24 hours post infection (hpi), 6 days post infection (dpi) and 35 dpi, respectively (P < 0.05), and the larval molting and development was significantly inhibited by 45.45% at 24 hpi, compared to the MRS group.

CONCLUSIONS

TsPPase plays a crucial role in T. spiralis molting and development, oral vaccination with rTsPPase induced a significant local mucosal sIgA response and systemic Th1/Th2 immune response, and immune protection against T. spiralis infection in BALB/c mice.

背景

旋毛虫病是一种分布于世界各地的严重人畜共患疾病。为了预防和控制旋毛虫病，需要开发一种安全、有效、可行的抗旋毛虫疫苗。本研究旨在构建编码旋毛虫无机焦磷酸酶（TsPPase）的重组植物乳杆菌，并研究其对旋毛虫感染的免疫保护作用。

方法/主要发现：TsPPase/pSIP409-pgsA'质粒的生长不受重组植物乳杆菌的影响，重组质粒在细菌中稳定遗传。Western blot 和免疫荧光分析（IFA）表明 rTsPPase 表达在重组植物乳杆菌的表面。口服 rTsPPase 疫苗可诱导 BALB/c 小鼠产生更高水平的特异性血清 IgG、IgG1、IgG2a 和黏膜分泌型 IgA（sIgA）。ELISA 分析显示，与 MRS（De Man、Rogosa、Sharpe）培养基对照组相比，接种后 2-4 周，脾、肠系膜淋巴结和派尔集合淋巴结释放的 IFN-γ和 IL-4 水平明显升高（P < 0.05）。rTsPPase 免疫的小鼠在感染后 24 小时（hpi）、6 天（dpi）和 35 天（dpi）时，肠道感染性幼虫、成虫和肌肉幼虫的减少分别为 67.18%、54.78%和 51.91%（P < 0.05），在感染后 24 小时时，幼虫蜕皮和发育受到显著抑制，为 45.45%，与 MRS 组相比。