Enucleated L929 cells support invasion, differentiation, and multiplication of Trypanosoma cruzi parasites
Enucleated L929 cells support invasion, differentiation, and multiplication of Trypanosoma cruzi parasites
复制标题
DOI：
10.1128/iai.00194-07
复制
发表时间：
2007-08-01
影响因子：
3.1
通讯作者：
Rabinovitch, Michel
中科院分区：
文献类型：
--
作者：
Coimbra, Vanessa C.;Yamamoto, Denise;Rabinovitch, Michel
克氏锥虫（锥虫病的病原体）的细胞感染开始于吞噬体内的感染性锥鞭毛体的摄取以及它们释放到细胞质中，在细胞质中它们转化成复制性无鞭毛体;后者继而分化成溶细胞释放的感染性锥鞭毛体。我们在这里问，如果T。Cruzi感染程序可在去核宿主细胞中发展。在细胞松弛素B存在下通过离心去核并保持在34 ℃以延长胞质体存活的单层L929细胞用CL菌株的寄生虫感染。在有核细胞和无核细胞中评价了感染百分比、形态、阶段特异性标志物和每个细胞的寄生虫数量，这两种细胞都存在于相同的制备物中。寄生虫的吸收，无鞭毛体的分化和增殖，epimastigote和锥鞭毛体样形式的发展，以及寄生虫的初始溶细胞释放都记录了细胞质和有核细胞。虽然倍增时间相似，但在48和72 μ l时，胞质中的寄生虫载量显著低于有核细胞。用对小鼠表现出低毒力的高毒力菌株Y以及菌株CL-14和G获得了类似的结果。去核后24或48 h，细胞质也可被CL菌株感染。因此，T. Cruzi可在去核宿主细胞中发生，即，在不存在染色体和核仁基因转录的调节以及核中RNA修饰和加工的情况下。
Cell infection with Trypanosoma cruzi, the agent of Chagas' disease, begins with the uptake of infective trypomastigotes within phagosomes and their release into the cytosol, where they transform into replicating amastigotes; the latter, in turn, differentiate into cytolytically released and infective trypomastigotes. We ask here if the T. cruzi infection program can develop in enucleated host cells. Monolayers of L929 cells, enucleated by centrifugation in the presence of cytochalasin B and kept at 34 degrees C to extend the survival of cytoplasts, were infected with parasites of the CL strain. Percent infection, morphology, stage-specific markers, and numbers of parasites per cell were evaluated in nucleated and enucleated cells, both of which were present in the same preparations. Parasite uptake, differentiation and multiplication of amastigotes, development of epimastigoteand trypomastigote-like forms, and initial cytolytic release of parasites were all documented for cytoplasts and nucleated cells. Although the doubling times were similar, parasite loads at 48 and 72 It were significantly lower in the cytoplasts than in nucleated cells. Similar results were obtained with the highly virulent strain Y as well as with strains CL-14 and G, which exhibit low virulence for mice. Cytoplasts could also be infected with the CL strain 24 or 48 h after enucleation. Thus, infection of cells by T. cruzi can take place in enucleated host cells, i.e., in the absence of modulation of chromosomal and nucleolar gene transcription and of RNA modification and processing in the nucleus.