Regulation of inflammatory response by an inhibitory cytokine in a mode of inhiditory cybemetics

我们研制了兔重组IL-1β和IL-1RA，以及针对这些细胞因子的抗体。利用这些材料和抗兔肿瘤坏死因子α，我们研究了IL-L和肿瘤坏死因子α在兔内毒素关节炎发病机制中的作用。在内毒素诱导的关节炎中，白细胞浸润在9小时达到高峰，钙质破坏在炎症24小时达到高峰。10µg IL-LRA与内毒素同时注射，可在整个观察期内对中性粒细胞的侵袭抑制70%，直至48小时，完全防止钙化的破坏。抗肿瘤坏死因子α(100mug)抗体还能抑制中性粒细胞的渗入达70%，并能完全阻止骨灰的破坏。这两种抑制物质联合使用，对中性粒细胞的渗透抑制达90%以上，并完全消除了钙化破坏。在内毒素关节炎模型中，IL-L的产生在6h达到高峰，其数量为196.7 pg/关节，产生的IL-L以β形式为主。肿瘤坏死因子α的产量在2小时达到高峰，为12.5 ng/个关节。为了研究中性粒细胞在去除钙酸盐中的作用，我们用氮芥静注制作了中性粒细胞减少的兔模型。脂多糖对中性粒细胞减少的兔无钙化破坏作用，不产生IL-1β，而产生的肿瘤坏死因子α与非白细胞减少的兔相比无明显变化。白细胞减少兔注射IL-1β(187pg)不破坏钙化。因此，肿瘤坏死因子α和白介素1β都是诱导内毒素刺激的关节炎的关键介质。但是，这些细胞因子并不直接导致组织损伤。接下来，我们调查了一种可能参与钙化破坏的产物，我们发现中性粒细胞衍生的超氧阴离子和弹性蛋白酶在这种炎症中负责钙化的破坏。

We developed rabbit recombinant IL-lbeta and IL-lra, as well as antibodies against these cytokines. Using these materials and anti-rabbit TNFalpha, we investigated the role of IL-l and TNFalpha in the pathogenesis of LPS-arthritis in rabbits. In the LPS-induced arthritis leukocyte infiltration peaked at 9hrs while destruction of caltilagepeaked at 24 hrs of the inflammation. When 10mug of IL-lra was injected simultaneously with LPS,the resulting neutrophil infiltration was inhibited by 70%during a whole observation period until 48 hrs and destruction of caltilage was completely prevented. Anti-TNFalpha (100mug) antibody also inhibited neutrophil infiltration by 70% and completely preveted destruction of caltilage. A combination of these two inhibitory substances produced furher suppression of neutrophil-infiltration by more than 90% and complete abrogation of caltilage-destruction. In the LPS-arthritis, production of IL-l peaked at 6hr and its amount was 196.7 pg/joint and the most of the produced IL-l was beta in form. Production of TNFalpha peaked at 2hr and its amount was 12.5 ng/joints. To investigate the role of neutrophils in the desruction of caltilate, we made neutropenic rabbits using i.v.nitrogen mustard. LPS induced no caltilage destruction and no production of IL-lbeta in the neutropenic rabbits, while production of TNFalpha was unchanges in comparison with non-leukopenic rabbits. Injection of IL-lbeta (187 pg) into the leukopenic rabbits did not result in destruction of caltilage. Thus, both TNFalpha and IL-lbeta is the key mediators for induction of LPS-stimulated arthritis. But, these cytokines are not directly responsible for tissue damage. Next, we investigated a production which may involved in the destruction of caltilage and we found that neutrophil-derived superoxide anion and elastase is responsible for destruction of caltilage in this inflammation.