Theander T G, Pedersen B K, Bygbjerg I C, Jepsen S, Larsen P B, Kharazmi A
Department of Infectious Diseases, State University Hospital, Copenhagen, Denmark.
Acta Trop. 1987 Dec;44(4):415-22.
Mononuclear cells (MNC) isolated from malaria immune donors and from donors never exposed to malaria were stimulated in vitro with soluble purified Plasmodium falciparum antigens (SPag) or PPD. After 7 days of culture the proliferative response and the cytotoxic activity against the natural killer cell (NK cell) sensitive cell line, K562, were measured. It was found that SPag stimulation enhanced cytotoxic activity of MNC from donors whose lymphocytes exhibited a strong proliferative response to the antigen. MNC with low proliferative responsiveness showed increased cytotoxic activity if the MNC were preincubated with interleukin 2 (IL-2) for one hour before the start of the cytotoxic assay. SPag activation did not enhance the cytotoxic activity of MNC which did not respond to the antigen in the proliferation assay, and preincubation of these cells with IL-2 did not increase the activity. PPD stimulation enhanced the cytotoxic activity and induced strong proliferative responses in all MNC preparations. The role of NK cells in the protection against malaria is unknown, but they play a role in the protection against virus infection and in the immune surveillance against cancer. Our findings indicate that malaria antigens either directly or through the activation of immunoregulatory cells enhance the NK cell activity.
从疟疾免疫供体和从未接触过疟疾的供体中分离出的单核细胞（MNC），在体外分别用可溶性纯化恶性疟原虫抗原（SPag）或结核菌素纯蛋白衍生物（PPD）进行刺激。培养7天后，检测其增殖反应以及对自然杀伤细胞（NK细胞）敏感细胞系K562的细胞毒性活性。结果发现，SPag刺激增强了来自淋巴细胞对该抗原表现出强烈增殖反应的供体的MNC的细胞毒性活性。如果在细胞毒性试验开始前将增殖反应性低的MNC与白细胞介素2（IL-2）预孵育1小时，则其细胞毒性活性会增加。SPag激活并未增强在增殖试验中对该抗原无反应的MNC的细胞毒性活性，并且将这些细胞与IL-2预孵育也不会增加其活性。PPD刺激增强了所有MNC制剂的细胞毒性活性并诱导了强烈的增殖反应。NK细胞在抵抗疟疾中的作用尚不清楚，但它们在抵抗病毒感染和对癌症的免疫监视中发挥作用。我们的研究结果表明，疟疾抗原要么直接，要么通过激活免疫调节细胞来增强NK细胞活性。
