IL-12R beta 2  (白介素-12 受体 β2)

IL-12 受体是一种 I 型细胞因子受体，与 IL-12 结合。IL-12 受体主要在 NK 和 T 细胞上表达，由 beta 1和 beta 2 亚基组成，是 gp130 细胞因子受体超家族的成员。IL-12R beta 2 (简称 IL-12R2 或 IL-12Rβ2) 是 IL-12 受体的一个亚基，IL-12RB2 是其人类基因的名称。IL-12Rβ2 蛋白和 IL-12Rβ1 蛋白共表达，可以导致高亲和力 IL-12 结合位点的形成以及 IL-12 依赖性信号传导的重建。IL-12 与 IL-12 受体结合后，与 IL-12Rβ1 直接相互作用的细胞质蛋白 TYK2 和与 IL-12Rβ2 相互作用的 JAK2 被酪氨酸磷酸化。磷酸化的 TYK2 和 JAK2 是随后酪氨酸磷酸化和激活与 IL-12Rβ2 结合的 STAT4 所必需的。STAT4 是一种转录因子，随后发生同二聚体化、易位至细胞核并与其靶 DNA 结合以激活 IFN-γ 和其他靶基因的转录^[1]。IL-12Rβ2 链的表达被认为是控制 T 细胞发育和功能的关键因素。在 Th1 细胞分化中起重要作用，缺失会导致 Th1 分化失败，Th1 效应分子产生功能障碍。该基因的上调被发现与许多传染病有关，例如克罗恩病和麻风病，被认为有助于炎症反应和宿主防御^[2]。

IL-12 receptor is a type I cytokine receptor that binds to IL-12. IL-12 receptor is expressed primarily on NK and T cells and consists of beta 1 and beta 2 subunits and is a member of the gp130 cytokine receptor superfamily. IL-12R beta 2 (abbreviated IL-12R2 or IL-12Rβ2) is a subunit of the IL-12 receptor, and IL-12Rβ2 is its human gene name. Co-expression of IL-12Rβ2 protein and IL-12Rβ1 protein can lead to the formation of high-affinity IL-12 binding sites and the reconstitution of IL-12-dependent signaling. Upon IL-12 binding to the IL-12 receptor, the cytoplasmic protein TYK2, which interacts directly with IL-12Rβ1, and JAK2, which interacts with IL-12Rβ2, are tyrosine phosphorylated. Phosphorylated TYK2 and JAK2 are required for subsequent tyrosine phosphorylation and activation of STAT4 that binds to IL-12Rβ2. STAT4 is a transcription factor that subsequently homodimerizes, translocates to the nucleus and binds to its target DNA to activate transcription of IFN-γ and other target genes^[1].
Expression of the IL-12Rβ2 chain is thought to be a key factor in controlling T cell development and function. It plays an important role in Th1 cell differentiation and deletion results in failure of Th1 differentiation and dysfunctional production of Th1 effector molecules. Up-regulation of this gene has been found to be associated with many infectious diseases, such as Crohn's disease and leprosy, which are thought to contribute to the inflammatory response and host defense^[2].

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