Summary The metacestode stage of the tapeworm Mesocestoides vogae (M. vogae) has the ability of asexual growth in the peritoneal cavity of rodents and other intermediate hosts without restriction. Early immunological events have decisive role in the establishment of infection. In the present study we investigated the kinetic of myeloid and lymphoid cell populations and the proportions of cells undergoing apoptosis in peritoneal cavities of mice within the first month after oral infection with M. vogae larvae. Proportions of cell phenotypes and apoptotic cells were examined by flow cytometry and by microscopical analysis of cells following May/Grünwald staining and fluorescent stain Hoechst 33234, respectively. Total numbers of peritoneal cells increased and their distribution changed towards accumulation of myelo-monocytic cell lineage in the account of reduced proportions of lymphoid cells. CD4+ T cell subpopulations were more abundant than CD8+ and their proportions elevated within two weeks post infection (p.i.) which was followed by a significant decline. Expression level of CD11c marker on myelo-monocytic cells revealed phenotype heterogeneity and proportions of cells with low and medium expression elevated from day 14 p.i. along with concurrent very low presence of CD11chigh phenotype. Lymphoid cell population was highly resistant to apoptosis but elevated proportions of myeloid cells were in early/late stage of apoptosis. Apoptosis was detected in a higher number of adherent cells from day 14 p.i. onwards as evidenced by nuclear fluorescent staining. By contrast, cells adherent to larvae, mostly macrophages and eosinophils, did not have fragmented nuclei. Our data demonstrated that apoptosis did not account for diminished population of peritoneal lymphoid cells and substantial proportions of myeloid cells seem to be more susceptible to apoptotic turnover in peritoneal cavity of mice with ongoing M. vogae infection, suggesting their important role in the host-parasite interactions.

中文翻译：

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小鼠模型幼虫 Mesocestoides vogae 感染小鼠腹腔内髓细胞和淋巴细胞群对凋亡的敏感性差异

小结 绦虫 Mesocestoides vogae (M. vogae) 的后绦虫阶段具有在啮齿动物和其他中间宿主的腹腔中不受限制地无性生长的能力。早期免疫事件对感染的建立起决定性作用。在本研究中，我们调查了骨髓和淋巴样细胞群的动力学以及在口服 M. vogae 幼虫后第一个月内小鼠腹腔中发生凋亡的细胞比例。通过流式细胞术和分别在 May/Grünwald 染色和荧光染色 Hoechst 33234 后对细胞进行显微镜分析，检查细胞表型和凋亡细胞的比例。由于淋巴细胞比例减少，腹膜细胞总数增加，并且它们的分布朝着骨髓-单核细胞谱系的积累而变化。CD4+ T 细胞亚群比 CD8+ 更丰富，它们的比例在感染后 (pi) 两周内升高，随后显着下降。骨髓单核细胞上 CD11c 标记物的表达水平显示表型异质性和低和中表达的细胞比例从接种后第 14 天升高，同时 CD11chigh 表型的存在非常低。淋巴样细胞群对细胞凋亡具有高度抵抗力，但升高的髓细胞比例处于细胞凋亡的早期/晚期。从接种后第 14 天开始，在更多贴壁细胞中检测到细胞凋亡 核荧光染色证明。相比之下，附着在幼虫上的细胞，主要是巨噬细胞和嗜酸性粒细胞，没有破碎的细胞核。我们的数据表明，细胞凋亡并不能解释腹膜淋巴细胞数量减少的原因，而且相当大比例的骨髓细胞似乎更容易受到持续感染 M. vogae 的小鼠腹腔中细胞凋亡周转的影响，表明它们在宿主寄生虫中的重要作用相互作用。