Lider O, Cahalon L, Gilat D, Hershkoviz R, Siegel D, Margalit R, Shoseyov O, Cohen I R
Department of Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
Proc Natl Acad Sci U S A. 1995 May 23;92(11):5037-41. doi: 10.1073/pnas.92.11.5037.
The activation of T cells by antigens or mitogens leads to the secretion of cytokines and enzymes that shape the inflammatory response. Among these molecular mediators of inflammation is a heparanase enzyme that degrades the heparan sulfate scaffold of the extracellular matrix (ECM). Activated T cells use heparanase to penetrate the ECM and gain access to the tissues. We now report that among the breakdown products of the ECM generated by heparanase is a trisulfated disaccharide that can inhibit delayed-type hypersensitivity (DTH) in mice. This inhibition of T-cell mediated inflammation in vivo was associated with an inhibitory effect of the disaccharide on the production of biologically active tumor necrosis factor alpha (TNF-alpha) by activated T cells in vitro; the trisulfated disaccharide did not affect T-cell viability or responsiveness generally. Both the in vivo and in vitro effects of the disaccharide manifested a bell-shaped dose-response curve. The inhibitory effects of the trisulfated disaccharide were lost if the sulfate groups were removed. Thus, the disaccharide, which may be a natural product of inflammation, can regulate the functional nature of the response by the T cell to activation. Such a feedback control mechanism could enable the T cell to assess the extent of tissue degradation and adjust its behavior accordingly.
抗原或有丝分裂原激活T细胞会导致细胞因子和酶的分泌,这些物质会影响炎症反应。在这些炎症分子介质中,有一种乙酰肝素酶,它能降解细胞外基质(ECM)的硫酸乙酰肝素支架。活化的T细胞利用乙酰肝素酶穿透ECM并进入组织。我们现在报告,乙酰肝素酶产生的ECM分解产物中有一种三硫酸化二糖,它可以抑制小鼠的迟发型超敏反应(DTH)。这种对体内T细胞介导的炎症的抑制作用与二糖在体外对活化T细胞产生生物活性肿瘤坏死因子α(TNF-α)的抑制作用有关;三硫酸化二糖一般不影响T细胞的活力或反应性。二糖的体内和体外作用均呈现钟形剂量反应曲线。如果去除硫酸基团,三硫酸化二糖的抑制作用就会消失。因此,这种可能是炎症天然产物的二糖可以调节T细胞对激活的反应功能性质。这种反馈控制机制可以使T细胞评估组织降解的程度,并相应地调整其行为。