Zhao Wenting, Liu Jianwen, Xu Ruixue, Zhang Cui, Pang Qin, Chen Xin, Liu Shengfa, Hong Lingxian, Yuan Jing, Li Xiaotong, Chen Yixin, Li Jian, Su Xin-Zhuan
State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, Fujian, 361005, P. R. China.
State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, Fujian, 361005, P. R. China; National Institute of Diagnostics and Vaccine Development in Infectious Diseases, School of Public Health, Xiamen University, Xiamen, Fujian, 361005, P. R. China.
PLoS One. 2015 Jul 28;10(7):e0133478. doi: 10.1371/journal.pone.0133478. eCollection 2015.
Leucocytozoon parasites infect a large number of avian hosts, including domestic chicken, and cause significant economical loss to the poultry industry. Although the transmission stages of the parasites were observed in avian blood cells more than a century ago, the specific host cell type(s) that the gametocytes infect remain uncertain. Because all the avian blood cells, including red blood cells (RBCs), are nucleated, and the developing parasites dramatically change the morphology of the infected host cells, it has been difficult to identify Leucocytozoon infected host cell(s). Here we use cell-type specific antibodies to investigate the identities of the host cells infected by Leucocytozoon sabrazesi gametocytes. Anti-RBC antibodies stained RBCs membrane strongly, but not the parasite-infected cells, ruling out the possibility of RBCs being the infected host cells. Antibodies recognizing various leukocytes including heterophils, monocytes, lymphocytes, and macrophages did not stain the infected cells either. Antisera raised against a peptide of the parasite cytochrome B (CYTB) stained parasite-infected cells and some leukocytes, particularly cells with a single round nucleus as well as clear/pale cytoplasm suggestive of thrombocytes. Finally, a monoclonal antibody known to specifically bind chicken thrombocytes also stained the infected cells, confirming that L. sabrazesi gametocytes develop within chicken thrombocytes. The identification of L. sabrazesi infected host cell solves a long unresolved puzzle and provides important information for studying parasite invasion of host cells and for developing reagents to interrupt parasite transmission.
白细胞虫寄生虫感染包括家鸡在内的大量禽类宿主，给家禽业造成重大经济损失。尽管一个多世纪前就在禽类血细胞中观察到了该寄生虫的传播阶段，但配子体感染的具体宿主细胞类型仍不确定。由于所有禽类血细胞，包括红细胞（RBC）都有细胞核，且发育中的寄生虫会显著改变被感染宿主细胞的形态，因此很难识别被白细胞虫感染的宿主细胞。在此，我们使用细胞类型特异性抗体来研究被萨氏白细胞虫配子体感染的宿主细胞的身份。抗红细胞抗体强烈染色红细胞膜，但不染色被寄生虫感染的细胞，排除了红细胞是被感染宿主细胞的可能性。识别包括嗜异性粒细胞、单核细胞、淋巴细胞和巨噬细胞在内的各种白细胞的抗体也未对被感染细胞染色。针对该寄生虫细胞色素B（CYTB）的一段肽产生的抗血清染色被寄生虫感染的细胞和一些白细胞，特别是具有单个圆形细胞核以及清晰/浅色细胞质提示为血小板的细胞。最后，一种已知特异性结合鸡血小板的单克隆抗体也对被感染细胞染色，证实萨氏白细胞虫配子体在鸡血小板内发育。萨氏白细胞虫感染宿主细胞的鉴定解决了一个长期未解决的难题，并为研究寄生虫对宿主细胞的入侵以及开发阻断寄生虫传播的试剂提供了重要信息。
