Jangpatarapongsa Kulachart, Sirichaisinthop Jeeraphat, Sattabongkot Jetsumon, Cui Liwang, Montgomery Scott M, Looareesuwan Sornchai, Troye-Blomberg Marita, Udomsangpetch Rachanee
Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
Microbes Infect. 2006 Mar;8(3):680-6. doi: 10.1016/j.micinf.2005.09.003. Epub 2006 Jan 11.
Immunity induced by Plasmodium vivax infection leads to memory T cell recruitment activated during "relapse" or "re-infection". This study aims to characterise memory T cells in patients with acute or convalescent P. vivax infection. Lymphocytes were collected from patients infected by P. vivax, immune controls and naive controls. The proportion of immature memory T cells, expressing CD45RO(+)CD27(+), and mature cells lacking CD27 was assessed. A statistically significant increase in the median percentage of memory T cell subsets expressing CD4(+) was observed in material from patients with an acute infection compared with that from either naive or immune controls. The high percentage of memory T cells in infected patients was maintained until 60 days post treatment. The immune controls living in a malaria endemic area had a somewhat increased proportion of memory T cell subsets expressing CD8(+). An approximately three-fold increase of these cell types was shown in patients with an acute infection and the level persisted until 60 days post treatment. Phenotypic characterisation of the peripheral lymphocytes during acute infection revealed that a large fraction of the lymphocytes carried the gammadelta phenotypes suggesting a role for these cells in the early response against P. vivax. Very low levels of P. vivax specific antibody were found. This might suggest that cell-mediated immunity may play a greater role in the development of naturally acquired protection against P. vivax infection than humoral immunity. Our results provide further insight into the mechanism of cell-mediated immunity to P. vivax infection that could be important for the future development of a successful vaccine and anti-malarial drug designation.
间日疟原虫感染诱导的免疫会导致记忆T细胞募集，这些细胞在“复发”或“再次感染”期间被激活。本研究旨在对急性或恢复期间日疟原虫感染患者的记忆T细胞进行特征描述。从间日疟原虫感染患者、免疫对照和未感染对照中收集淋巴细胞。评估表达CD45RO(+)CD27(+)的未成熟记忆T细胞和缺乏CD27的成熟细胞的比例。与未感染或免疫对照相比，急性感染患者样本中表达CD4(+)的记忆T细胞亚群的中位数百分比有统计学显著增加。感染患者中记忆T细胞的高百分比一直维持到治疗后60天。生活在疟疾流行地区的免疫对照中，表达CD8(+)的记忆T细胞亚群比例有所增加。急性感染患者中这些细胞类型增加了约三倍，且该水平一直持续到治疗后60天。急性感染期间外周淋巴细胞的表型特征显示，很大一部分淋巴细胞具有γδ表型，表明这些细胞在针对间日疟原虫的早期反应中起作用。发现间日疟原虫特异性抗体水平非常低。这可能表明细胞介导的免疫在自然获得针对间日疟原虫感染的保护的发展中可能比体液免疫发挥更大作用。我们的结果为间日疟原虫感染的细胞介导免疫机制提供了进一步的见解，这对于未来成功开发疫苗和抗疟药物具有重要意义。
