Department of Clinical Immunology, Faculty of Medicine and University Hospital in Hradec Kralove, Charles University Prague, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.
Folia Microbiol (Praha). 2011 Mar;56(2):149-54. doi: 10.1007/s12223-011-0028-y. Epub 2011 Apr 8.
Francisella tularensis is capable to modulate immunobiological activities of the host cells. We focused on the expression of ICAM-1 (CD54) on J774.2 mouse macrophage cell line infected by F. tularensis live vaccine strain (LVS) in vitro as a putative marker of subsequent elimination of infection. J774.2 cell line cells were infected by F. tularensis LVS strain (multiplicity of infection, 1:100). Cell cultures were stimulated either 3 h before infection or 3 h after infection by either lipopolysaccharide (LPS) or interferon γ (IFN-γ). The expression of ICAM-1 was determined by flow cytometry 6 h after infection. The intensity of ICAM-1 expression after 6 h of J774.2 macrophage cells infection by F. tularensis is very sensitive indicator of the effective macrophages stimulation resulting in the elimination of F. tularensis infection. The mean fluorescence intensity MFI = 49.8 is set-up by our experiments as a reliable threshold of the effective elimination of F. tularensis experimental infection with 83.3% sensitivity and 96.7% specificity, respectively. Simultaneous stimulation of J774.2 macrophage cells by LPS and IFN-γ was essential to elicit the elimination of F. tularensis infection. The ICAM-1 expression determined by flow cytometry can be considered to be highly sensitive and specific approach to predict elimination of F. tularensis infection by J774.2 macrophages.
弗氏志贺菌能够调节宿主细胞的免疫生物学活性。我们专注于 J774.2 小鼠巨噬细胞系感染弗氏志贺菌活疫苗株（LVS）后细胞间黏附分子-1（ICAM-1，CD54）的表达，将其作为后续感染消除的潜在标志物。用弗氏志贺菌 LVS 株（感染复数，1:100）感染 J774.2 细胞系。在感染前 3 小时或感染后 3 小时，用脂多糖（LPS）或干扰素 γ（IFN-γ）刺激细胞培养物。感染后 6 小时通过流式细胞术测定 ICAM-1 的表达。J774.2 巨噬细胞感染弗氏志贺菌 6 小时后 ICAM-1 表达的强度是有效刺激巨噬细胞从而消除弗氏志贺菌感染的非常敏感的指标。实验中确定的平均荧光强度（MFI）=49.8 是有效消除弗氏志贺菌实验感染的可靠阈值，其敏感性分别为 83.3%，特异性为 96.7%。LPS 和 IFN-γ 同时刺激 J774.2 巨噬细胞对于引发弗氏志贺菌感染的消除至关重要。通过流式细胞术测定的 ICAM-1 表达可被视为预测 J774.2 巨噬细胞消除弗氏志贺菌感染的高度敏感和特异的方法。
