Ferrante A
Infect Immun. 1985 Aug;49(2):378-82. doi: 10.1128/iai.49.2.378-382.1985.
An examination of sera from a range of animals refractory to Trypanosoma lewisi showed that some contain trypanolytic activity and agglutinins for this trypanosome. Trypanolytic activity was demonstrated in bovine, sheep, and rabbit serum. These sera were shown to also contain agglutinins. The trypanolytic activity in all three sera was abolished by heat inactivation at 56 degrees C for 30 min. Studies with bovine serum showed that the lytic activity was totally inhibited by the addition of EDTA but was only partially inhibited by ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid-Mg2+, suggesting the involvement of both classical and alternate pathways of complement activation. Serum from the natural host, the rat but not mouse serum, was capable of inhibiting the trypanolytic activity of bovine serum. The agglutinins in bovine serum were specific, since they could be adsorbed out with T. lewisi but not T. musculi. They fractionated on gel filtration in the position expected for 19S antibodies. By using opsonization measuring techniques, it was found that mouse serum lacked opsonins to T. lewisi, although opsonic activity was detectable in human serum. The absence of agglutinins, trypanolysins, and opsonins in mouse serum suggests that other factors prevent the infection of mice by T. lewisi. From these findings, it would appear that the inability of T. lewisi to infect a range of mammals, with the exception of mice, could be due to the presence of antibodies, the ability to activate complement through the alternative pathway, or both. The absence of these recognition factors and the ability to evade the effects of alternative pathway activation may be important factors in the ability of this parasite to establish infections in rats.
对一系列对路氏锥虫具有抗性的动物血清进行检测发现，其中一些血清含有针对该锥虫的溶锥虫活性和凝集素。在牛、羊和兔血清中证实了溶锥虫活性。这些血清也被证明含有凝集素。所有这三种血清中的溶锥虫活性在56℃加热灭活30分钟后被消除。对牛血清的研究表明，添加乙二胺四乙酸（EDTA）可完全抑制其溶解活性，但乙二醇双（β-氨基乙基醚）-N,N-四乙酸镁（EGTA-Mg2+）仅部分抑制，这表明补体激活的经典途径和替代途径均参与其中。天然宿主大鼠的血清能够抑制牛血清的溶锥虫活性，而小鼠血清则不能。牛血清中的凝集素具有特异性，因为它们可以被路氏锥虫吸附去除，但不能被鼠锥虫吸附。它们在凝胶过滤中分离在19S抗体预期的位置。通过使用调理作用测量技术发现，小鼠血清缺乏针对路氏锥虫的调理素，尽管在人血清中可检测到调理活性。小鼠血清中缺乏凝集素、溶锥虫素和调理素表明，其他因素阻止了路氏锥虫感染小鼠。从这些发现来看，除小鼠外，路氏锥虫无法感染一系列哺乳动物可能是由于存在抗体、通过替代途径激活补体的能力或两者兼而有之。这些识别因子的缺失以及逃避替代途径激活影响的能力可能是该寄生虫在大鼠体内建立感染能力的重要因素。
