Spinella S, Liegeard P, Hontebeyrie-Joskowicz M
Unité d'Immunoparasitologie, Institut Pasteur, Paris, France.
Exp Parasitol. 1992 Feb;74(1):46-56. doi: 10.1016/0014-4894(92)90138-z.
The kinetic and isotypic pattern of hypergammaglobulinemia has been investigated in C3H/HeJ infected with Trypanosoma cruzi. Hypergammaglobulinemia appeared 14 days postinfection, increased until Day 28 postinfection, and persisted throughout the chronic phase (greater than 60 days of infection). The main isotype secreted was IgG2a, reaching 10-fold the control level. High titers of autoantibodies were found of IgM and IgG subclasses. Isotypic characterization of antibodies against myosin, myelin, and keratin, was performed and determined to be IgG2a subclass in the chronic stage of infection. Specific responses against T. cruzi took place 2 weeks postinfection when the parasitemia was high. Interestingly, parasite-specific response was maximal after 4 weeks of infection and plateaued during the chronic phase when parasites were rare. In contrast to the humoral polyclonal response in the chronic stage, showing a preferential IgG2a pattern, the anti-T. cruzi response consisted of all the different isotypes: IgM, IgG1, IgG3, IgG2a, and IgG2b, throughout the infection. Identical patterns of parasite antigens were recognized by IgG2a and IgG2b antibodies. Few different antigens were identified by the IgG3. Some antigens were recognized by several isotypes, others by only one isotype. With regard to the existence of antigenic cross-reactivities between host and parasite, we designed absorption experiments on parasite-specific immunoadsorbent showing that specific antibodies eluted from the column failed to recognize the natural antigens. These studies suggest that nonspecific and antiparasite-specific responses may be maintained by different regulatory pathways.
对感染克氏锥虫的C3H/HeJ小鼠的高丙种球蛋白血症的动力学和同型模式进行了研究。高丙种球蛋白血症在感染后14天出现，在感染后第28天之前升高，并在整个慢性期（感染超过60天）持续存在。分泌的主要同型是IgG2a，达到对照水平的10倍。发现IgM和IgG亚类的自身抗体滴度很高。对肌球蛋白、髓磷脂和角蛋白的抗体进行了同型特征分析，并确定在感染的慢性期为IgG2a亚类。感染后2周，当寄生虫血症很高时，对克氏锥虫发生了特异性反应。有趣的是，寄生虫特异性反应在感染4周后最大，并在慢性期寄生虫稀少时达到平稳状态。与慢性期显示优先IgG2a模式的体液多克隆反应相反，在整个感染过程中，抗克氏锥虫反应由所有不同的同型组成：IgM、IgG1、IgG3、IgG2a和IgG2b。IgG2a和IgG2b抗体识别相同模式的寄生虫抗原。IgG3识别的不同抗原很少。一些抗原被几种同型识别，另一些仅被一种同型识别。关于宿主和寄生虫之间抗原交叉反应的存在，我们在寄生虫特异性免疫吸附剂上设计了吸收实验，结果表明从柱上洗脱的特异性抗体无法识别天然抗原。这些研究表明，非特异性和抗寄生虫特异性反应可能由不同的调节途径维持。
