Azadi Yaghob, Ahmadpour Ehsan, Hamishehkar Hamed, Daryani Ahmad, Spotin Adel, Mahami-Oskouei Mahmoud, Barac Aleksandra, Rajabi Saba, Alizadeh Paria, Montazeri Mahbobeh
Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Department of Parasitology and Mycology, Tabriz University of Medical Sciences, Tabriz, Iran.
Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Comp Immunol Microbiol Infect Dis. 2018 Aug;59:52-56. doi: 10.1016/j.cimid.2018.09.012. Epub 2018 Sep 23.
Toxoplasmosis is an infectious disease caused by the intracellular parasite Toxoplasma gondii. Although almost 1/3 of the world's population are seropositive, there is no effective vaccine against toxoplasmosis. Therefore, the development of an effective vaccine for control of toxoplasmosis is one of major concerns in parasitology. The aim of this study was to evaluate the efficacy of nano-liposomal excretory-secretory antigens (NLESA) in BALB/c mice.
Excretory-secretory antigens (ESA) was obtained from tachyzoites, encapsulated in the liposome and studied by scanning electron microscope. BALB/c mice were immunized with NLESA and ESA, sterile phosphate-buffered saline (PBS). Immunization was performed three times at 14-day intervals and challenged with 1 × 10 tachyzoites of T. gondii RH strain four weeks later. The parasite load of mice blood, brain and spleen tissues were determined using quantitative PCR targeted at the repeated element (RE) gene.
The immunization with NLESA and ESA induced a significant increase of anti-Toxoplasma IgG antibody compared with PBS group (P < 0.05). After challenge with tachyzoites, qPCR analyses showed significant reduction of parasite load in NLESA and ESA immunized mice compared with control group (P < 0.05). Also, NLESAs were more effective than ESAs and showed significantly reduced parasite load in blood (P = 0.001) and brain tissue (P = 0.01).
The vaccination with NLESA showed more promising results comparing to ESA. Further studies are recommended in order to achieve effectiveness of the vaccine against T. gondii.
弓形虫病是一种由细胞内寄生虫刚地弓形虫引起的传染病。尽管全球近三分之一的人口血清学呈阳性，但尚无有效的弓形虫病疫苗。因此，开发一种有效的弓形虫病控制疫苗是寄生虫学的主要关注点之一。本研究的目的是评估纳米脂质体排泄分泌抗原（NLESA）在BALB/c小鼠中的疗效。
从速殖子中获得排泄分泌抗原（ESA），将其包裹在脂质体中，并通过扫描电子显微镜进行研究。用NLESA、ESA和无菌磷酸盐缓冲盐水（PBS）对BALB/c小鼠进行免疫。每隔14天免疫3次，4周后用1×10个刚地弓形虫RH株速殖子进行攻击。使用针对重复元件（RE）基因的定量PCR测定小鼠血液、脑和脾组织中的寄生虫载量。
与PBS组相比，用NLESA和ESA免疫可显著提高抗弓形虫IgG抗体水平（P<0.05）。用速殖子攻击后，qPCR分析显示，与对照组相比，NLESA和ESA免疫小鼠的寄生虫载量显著降低（P<0.05）。此外，NLESA比ESA更有效，血液（P=0.001）和脑组织（P=0.01）中的寄生虫载量显著降低。
与ESA相比，用NLESA进行疫苗接种显示出更有前景的结果。建议进一步研究以实现该疫苗对刚地弓形虫的有效性。
