Brombacher Frank, Kastelein Robert A, Alber Gottfried
University of Cape Town, Division of Immunology, Groote Schuur Hospital, 7925 Cape Town, South Africa.
Trends Immunol. 2003 Apr;24(4):207-12. doi: 10.1016/s1471-4906(03)00067-x.
Interleukin-12 (IL-12), which is composed of a p35 and a p40 subunit, is a proinflammatory natural-killer (NK) cell-stimulating, Th1-inducing and Th1-maintaining cytokine, which promotes cell-mediated immunity. On activation, heterodimeric IL-12 is found in small amounts, whereas free p40 is produced in excess. Besides IL-12, other p40-dependent molecules exist that orchestrate Th1 responses. Homodimeric p40 can act as an IL-12 antagonist by competing for its receptor. Recent data also reveal potential immunostimulatory functions of p40. In addition, p40 can be covalently linked to a p35-related protein p19. This heterodimer is known as IL-23 and has activities on memory T cells. Finally, IL-27, the latest addition to this family, is a heterodimer composed of the p40-related protein EBI3 (Epstein-Barr virus-induced gene 3) and the p35-related protein p28. IL-27 is involved in early Th1 initiation.
白细胞介素-12（IL-12）由一个p35亚基和一个p40亚基组成，是一种促炎性细胞因子，可刺激自然杀伤（NK）细胞、诱导Th1细胞并维持其功能，促进细胞介导的免疫。激活后，可发现少量的异二聚体IL-12，而游离的p40则过量产生。除IL-12外，还存在其他协调Th1反应的p40依赖性分子。同二聚体p40可通过竞争其受体而作为IL-12拮抗剂。最近的数据还揭示了p40潜在的免疫刺激功能。此外，p40可与一种p35相关蛋白p19共价连接。这种异二聚体被称为IL-23，对记忆T细胞有活性。最后，IL-27是该家族的最新成员，是一种由p40相关蛋白EBI3（爱泼斯坦-巴尔病毒诱导基因3）和p35相关蛋白p28组成的异二聚体。IL-27参与早期Th1启动。
