Igarashi M, Kano F, Tamekuni K, Machado R Z, Navarro I T, Vidotto O, Vidotto M C, Garcia J L
Protozoology Laboratory, Departamento de Medicina Veterinária Preventiva, Universidade Estadual de Londrina, Postal Box 6001, 86050-970 Londrina, PR, Brazil.
Exp Parasitol. 2008 Mar;118(3):386-92. doi: 10.1016/j.exppara.2007.10.002. Epub 2007 Oct 11.
The purpose of this work was to evaluate protective activity against brain cyst formation in BALB/c mice intranasally vaccinated with recombinant proteins from Toxoplasma gondii. The recombinant proteins rROP2, rGRA5 and rGRA7 were used in vaccine preparation. Thirty-three female mice were divided into three groups, these animals received two doses by intranasal route at days 0 and 21 as follows; group 1 (G1, n=11) received 12.5 microg of each recombinant protein plus 0.5 microg of cholera toxin, group 2 (G2, n=11) received phosphate buffer saline (PBS) plus 0.5 microg of cholera toxin, and group 3 (G3, n=11) received PBS only. At challenge day (day 33) three animals from each group were euthanatized for IgA measure from intestine. Mice were infected orally with 50 cysts from the VEG strain at day 33. At challenge day the G1 animals had high immunoglobulin A levels, however, they only showed IgG antibody titers against rROP2 and rGRA7. Animals from G1 also exhibited strong resistance to cyst formation compared with the control group (G3, P<0.05). However, we did not observe differences in protection against brain cyst formation between G1 and G2 (P>0.1). These results indicate that intranasal immunization in BALB/c mice with recombinant proteins rROP2, rGRA5 and rGRA7 associated with cholera toxin induced partial protection, when compared with G3, against tissue cyst formation after oral infection with tissue cysts from T. gondii.
本研究旨在评估用刚地弓形虫重组蛋白经鼻内接种BALB/c小鼠后对脑囊肿形成的保护作用。疫苗制备中使用了重组蛋白rROP2、rGRA5和rGRA7。33只雌性小鼠分为三组，这些动物在第0天和第21天经鼻内途径接受两剂接种，具体如下：第1组（G1，n = 11）接受12.5微克每种重组蛋白加0.5微克霍乱毒素，第2组（G2，n = 11）接受磷酸盐缓冲盐水（PBS）加0.5微克霍乱毒素，第3组（G3，n = 11）仅接受PBS。在攻毒日（第33天），每组处死三只动物以测量肠道中的IgA。在第33天，小鼠经口感染来自VEG株的50个囊肿。在攻毒日，G1组动物的免疫球蛋白A水平较高，然而，它们仅显示出针对rROP2和rGRA7的IgG抗体滴度。与对照组（G3，P<0.05）相比，G1组动物对囊肿形成也表现出较强的抵抗力。然而，我们未观察到G1组和G2组在预防脑囊肿形成方面存在差异（P>0.1）。这些结果表明，与G3组相比，用重组蛋白rROP2、rGRA5和rGRA7联合霍乱毒素经鼻内免疫BALB/c小鼠，在经口感染刚地弓形虫组织囊肿后可诱导部分保护作用，防止组织囊肿形成。
