Laurenti M D, Gidlund M, Ura D M, Sinhorini I L, Corbett C E, Goto H
Departamento de Patologia, Instituto de Medicina Tropical de São Paulo (LIM/38), Faculdade de Medicina, Universidade de São Paulo, Brasil.
Braz J Med Biol Res. 1999 Mar;32(3):323-5. doi: 10.1590/s0100-879x1999000300012.
In order to study the role of natural killer (NK) cells during the early period of Leishmania infection, BALB/c mice were selectively and permanently depleted of NK cells by injection with 90Sr and subsequently infected with Leishmania (Leishmania) amazonensis (HSJD-1 strain). 90Sr is known to selectively deplete NK cells, leaving an intact T- and B-cell compartment and preserving the ability to produce both interferon alpha and IL-2. This method of depletion has advantages when compared with depletion using anti-NK cell monoclonal antibodies because the effect is permanent and neither activates complement nor provokes massive cell death. In the present study, after one month of treatment with 90Sr, the depletion of NK cells was shown by a more than ten-fold reduction in the cytotoxic activity of these cells: 2 x 10(6) spleen cells from NK-depleted animals were required to reach the same specific lysis of target cells effected by 0.15 x 10(6) spleen cells from normal control animals. The histopathology of the skin lesion at 7 days after Leishmania infection showed more parasites in the NK cell-depleted group. This observation further strengthens a direct role of NK cells during the early period of Leishmania infection.
为了研究自然杀伤（NK）细胞在利什曼原虫感染早期的作用，通过注射90Sr对BALB/c小鼠进行选择性和永久性NK细胞清除，随后用亚马逊利什曼原虫（HSJD - 1株）感染。已知90Sr可选择性清除NK细胞，使T细胞和B细胞区室保持完整，并保留产生α干扰素和白细胞介素 - 2的能力。与使用抗NK细胞单克隆抗体进行清除相比，这种清除方法具有优势，因为其效果是永久性的，既不激活补体也不引发大量细胞死亡。在本研究中，用90Sr治疗一个月后，这些细胞的细胞毒性活性降低了十多倍，表明NK细胞被清除：来自NK细胞清除动物的2×10⁶个脾细胞才能达到与来自正常对照动物的0.15×10⁶个脾细胞对靶细胞相同的特异性裂解。利什曼原虫感染7天后皮肤病变的组织病理学显示，NK细胞清除组中有更多寄生虫。这一观察结果进一步强化了NK细胞在利什曼原虫感染早期的直接作用。
