Effect of transcription factor GATA-2 on phagocytic activity of alveolar macrophages from Pneumocystis carinii-infected hosts
Effect of transcription factor GATA-2 on phagocytic activity of alveolar macrophages from Pneumocystis carinii-infected hosts
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DOI：
10.1128/iai.71.9.4943-4952.2003
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发表时间：
2003-09-01
影响因子：
3.1
通讯作者：
Lee, CH
中科院分区：
文献类型：
--
作者：
Lasbury, ME;Tang, X;Lee, CH
来自卡氏肺囊虫感染的宿主的肺泡巨噬细胞在吞噬作用方面存在缺陷（W. Chen、J. W. Mills 和 A. G. Harmsen, Int. J. Exp. Pathol. 73:709-720, 1992 ；H. Koziel 等人，J. Clin. Investig. 1992）。 102：1332-1344，1998）。进行实验以确定该缺陷是否是卡氏疟原虫生物体所特有的。结果表明，这些巨噬细胞无法吞噬卡氏疟原虫生物体和异硫氰酸荧光素（FITC）缀合的乳胶珠，表明来自卡氏疟原虫感染宿主的肺泡巨噬细胞普遍存在吞噬功能缺陷。为了确定这种缺陷是否与最近发现的卡氏疟原虫感染期间 GATA-2 转录因子基因的下调相关，用抗 GATA-2 寡核苷酸处理来自地塞米松抑制或健康大鼠的肺泡巨噬细胞，然后测定吞噬作用。还用有义寡核苷酸处理肺泡巨噬细胞的等分试样作为对照。与用有义寡核苷酸处理的细胞相比，用反义寡核苷酸处理的细胞对卡氏疟原虫生物体的吞噬作用降低了 46%，对 FITC 乳胶珠的吞噬作用降低了 65%。为了确定是否可以通过 GATA-2 的过表达来纠正卡氏疟原虫感染宿主的肺泡巨噬细胞的吞噬功能缺陷，将含有由巨细胞病毒 (CMV) 启动子驱动的有义方向的大鼠 GATA-2 基因的质粒引入卡氏疟原虫感染的大鼠的肺泡巨噬细胞中。用相对于 CMV 启动子呈反义方向的含有 GATA-2 的质粒转染的相同细胞的等份作为对照。与接受反义 GATA-2 构建体的肺泡巨噬细胞相比，用有义 GATA-2 表达构建体处理的肺泡巨噬细胞对卡氏疟原虫生物体的吞噬活性增加了 66%，对 FITC-乳胶珠的吞噬活性增加了 280%。本研究结果表明，GATA-2在卡氏疟原虫感染过程中肺泡巨噬细胞的吞噬作用调节中发挥着重要作用。
Alveolar macrophages from Pneumocystis carinii-infected hosts are defective in phagocytosis (W. Chen, J. W. Mills, and A. G. Harmsen, Int. J. Exp. Pathol. 73:709-720, 1992; H. Koziel et al., J. Clin. Investig. 102:1332-1344,,1998). Experiments were performed to determine whether this defect is specific for P. carinii organisms. The results showed that these macrophages were unable to phagocytose both P. carinii organisms and fluorescein isothiocyanate (FITC)-conjugated latex beads, indicating that alveolar macrophages from P. carinii-infected hosts have a general defect in phagocytosis. To determine whether this defect correlates with the recently discovered down-regulation of the GATA-2 transcription factor gene during P. carinii infection, alveolar macrophages from dexamethasone-suppressed or healthy rats were treated with anti-GATA-2 oligonucleotides and then assayed for phagocytosis. Aliquots of the alveolar macrophages were also treated with the sense oligonucleotides as the control. Cells treated with the antisense oligonucleotides were found to have a 46% reduction in phagocytosis of P. carinii organisms and a 65% reduction in phagocytosis of FITC-latex beads compared to those treated with the sense oligonucleotides. To determine whether the defect in phagocytosis in alveolar macrophages from P. carinii-infected hosts can be corrected by overexpression of GATA-2, a plasmid containing the rat GATA-2 gene in the sense orientation driven by the cytomegalovirus (CMV) promoter was introduced into alveolar macrophages from P. carinii-infected rats. Aliquots of the same cells transfected with a plasmid containing GATA-2 in the antisense orientation relative to the CMV promoter served as the control. Alveolar macrophages treated with the sense GATA-2 expression construct were found to increase their phagocytic activity by 66% in phagocytosis of P. carinii organisms and by 280% in phagocytosis of FITC-latex beads compared to those that received the antisense GATA-2 construct. The results of this study indicate that GATA-2 plays an important role in the regulation of phagocytosis in alveolar macrophages during P. carinii infection.