Determination of cytokines involved in initiation of acute inflammation.

了解炎症发生发展过程中的细胞因子。我们建立了兔消减基因文库，并检测到在炎症过程中特异表达的几种候选细胞因子，即肿瘤坏死因子α(TNFα)、IL-8、IL-1β和IL-1ra。然后，我们制备了这些基因产物的重组体和抗体，并研究了这些细胞因子在脂多糖诱导的兔急性炎症发病机制中的意义。我们得出以下结论：1.在炎症的早期阶段(2小时内)产生了肿瘤坏死因子α和IL-8。这些细胞因子的产生是相互独立的，即抑制其中一种并不会抑制另一种细胞因子的产生。中性粒细胞的减少并不会导致产量的减少。免疫组织化学染色显示驻留细胞表达这两种细胞因子，但不表达中性粒细胞。IL-1β在后期产生(6h达高峰)。IL-1β的产生是由肿瘤坏死因子α和IL-8共同诱导的，即抑制这两种细胞因子会导致IL-1β的产生减少。重组人肿瘤坏死因子α或IL-8可诱导IL-1β的产生。IL-1ra由浸润性中性粒细胞和巨噬细胞产生，并通过抑制肿瘤坏死因子α和IL-8而被抑制。重组IL-1ra可抑制中性粒细胞的浸润。抑制IL-1ra可促进中性粒细胞浸润和组织破坏。抑制肿瘤坏死因子α或IL-8可部分抑制炎症早期(2小时)中性粒细胞的浸润，但不能抑制炎症后期(9小时)的中性粒细胞浸润。抑制IL-1可导致炎症后期中性粒细胞浸润减少。由此我们得出结论：肿瘤坏死因子α和IL-8都是炎症的始动因子，而IL-1β在急性炎症反应中起放大作用。

To know the cytokines involved in the development of inflammation. We developed a subtraction gene library of rabbit and detected several candidate cytokines which are specifically expressed during the course of inflammation, i.e.TNFalpha), IL-8, IL-1beta and IL-1ra. Then, we made recombinants and antibodies of these gene products and investigated the significance of these cytokines in the pathogenesis of LPS-induced acute inflammation in rabbits.We conclude the followings :1. TNFalpha and IL-8 were produced during the initial stage (within 2 hrs). The production of these cytokines were mutually independent, namely inhibition of one of these did not suppressed the production of the other. The production was not reduced by depletion of neutrophils. Immunostaining revealed that resident cells were positive for these two cytokines, but not neutrophils.2. IL-1beta was produced during a later stage (peaked at 6 hrs). Production of IL-1beta was induced by both TNFalpha and IL-8 ; namely, inhibition of the two cytokines resulted in reduced production of IL-1beta. Recombinant TNFalpha or IL-8 induced the strong production of IL-1beta.3. IL-1 ra was produced by infiltrated neutrophils and macrophages and suppressed by inhibition of TNFalpha and IL-8. Recombinant IL-1ra suppressed the infiltration of neutrophils. Inhibition of IL-1ra produced enhanced neutrophil infiltration and tissue destruction.4. Inhibition of TNFalpha or IL-8 resulted in a partial inhibition of neutrophil infiltration at an early stage (2 hrs) of inflammation, but not those in a later stage (9 hrs).5. Inhibition of IL-1 resulted in reduced neutrophil infiltration at the later stage of inflammation. Then, we reached a conclusion that both TNFalpha and IL-8 act as initiation of inflammation and IL-1beta play a role in the amplification of acute inflammation.