Pitzurra L, Marconi P, Bistoni F, Blasi E
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Italy.
Infect Immun. 1989 Aug;57(8):2452-6. doi: 10.1128/iai.57.8.2452-2456.1989.
This study was designed to evaluate the effects of tetanus toxin (TT) on lysozyme (LZM) activity by the GG2EE macrophage cell line. GG2EE cells spontaneously produced low amounts of LZM, which were mostly secreted into the culture medium. Upon treatment with various cytokines, GG2EE cells exhibited altered LZM activity. In particular, exposure of GG2EE cells to alpha/beta interferon (IFN-alpha/beta) reduced LZM activity, as opposed to treatment with gamma interferon (IFN-gamma) or colony-stimulating factor 1, which potentiated LZM activity. Spontaneous LZM activity of GG2EE cells was not susceptible to TT action; in contrast, when IFN-gamma- or colony-stimulating factor 1-susceptible cells were treated with TT, a significant reduction on LZM activity was observed. The TT inhibitory effect was dose dependent and manifested only after a 6-h incubation of GG2EE cells with TT. Treatment of GG2EE cells with heat-inactivated TT as well as Ibc- and B-IIb-TT-derived fragments was found to be ineffective, while pretreatment with B-IIb- but not with Ibc-TT-derived fragment abrogated the TT effect. Overall, these data indicate the existence of a specific TT-GG2EE cell interaction, leading to selective inhibition of cytokine-induced LZM activity.
本研究旨在通过GG2EE巨噬细胞系评估破伤风毒素（TT）对溶菌酶（LZM）活性的影响。GG2EE细胞自发产生少量LZM，这些LZM大多分泌到培养基中。在用各种细胞因子处理后，GG2EE细胞的LZM活性发生改变。特别是，GG2EE细胞暴露于α/β干扰素（IFN-α/β）会降低LZM活性，而用γ干扰素（IFN-γ）或集落刺激因子1处理则会增强LZM活性。GG2EE细胞的自发LZM活性对TT作用不敏感；相反，当对IFN-γ或集落刺激因子1敏感的细胞用TT处理时，观察到LZM活性显著降低。TT的抑制作用呈剂量依赖性，且仅在GG2EE细胞与TT孵育6小时后才表现出来。发现用热灭活的TT以及Ibc-和B-IIb-TT衍生片段处理GG2EE细胞无效，而用B-IIb-而非Ibc-TT衍生片段预处理可消除TT的作用。总体而言，这些数据表明存在特定的TT-GG2EE细胞相互作用，导致对细胞因子诱导的LZM活性的选择性抑制。
