Department of Cell Biology and Physiology, Vascular Physiology Group, University of New Mexico Health Sciences Center, Albuquerque, New Mexico.
Department of Internal Medicine, Bioinformatics Shared Resource Center, Division of Molecular Medicine, University of New Mexico Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico.
Am J Physiol Lung Cell Mol Physiol. 2020 Dec 1;319(6):L968-L980. doi: 10.1152/ajplung.00184.2020. Epub 2020 Sep 30.
Chronic hypoxia (CH)-induced pulmonary hypertension (PH) results, in part, from T helper-17 (T17) cell-mediated perivascular inflammation. However, the antigen(s) involved is unknown. Cellular immunity to collagen type V (col V) develops after ischemia-reperfusion injury during lung transplant and is mediated by naturally occurring (n)T17 cells. gene codifies for the α1-helix of col V, which is normally hidden from the immune system within type I collagen in the extracellular matrix. promoter analysis revealed nuclear factor of activated T cells, cytoplasmic 3 (NFATc3) binding sites. Therefore, we hypothesized that smooth muscle NFATc3 upregulates col V expression, leading to nT17 cell-mediated autoimmunity to col V in response to CH, representing an upstream mechanism in PH development. To test our hypothesis, we measured indexes of PH in inducible smooth muscle cell (SMC)-specific knockout (KO) mice exposed to either CH (380 mmHg) or normoxia and compared them with wild-type (WT) mice. KO mice did not develop PH. In addition, was one of the 1,792 genes differentially affected by both CH and SMC NFATc3 in isolated intrapulmonary arteries, which was confirmed by RT-PCR and immunostaining. Cellular immunity to col V was determined using a trans vivo delayed-type hypersensitivity assay (Tv-DTH). Tv-DTH response was evident only when splenocytes were used from control mice exposed to CH but not from KO mice, and mediated by nT17 cells. Our results suggest that SMC NFATc3 is important for CH-induced PH in adult mice, in part, by regulating the expression of the lung self-antigen COL5A1 protein contributing to col V-reactive nT17-mediated inflammation and hypertension.
慢性缺氧（CH）引起的肺动脉高压（PH）部分是由辅助性 T 细胞 17（T17）细胞介导的血管周围炎症引起的。然而，涉及的抗原尚不清楚。在肺移植过程中，缺血再灌注损伤后会产生针对胶原类型 V（col V）的细胞免疫，由天然存在的（n）T17 细胞介导。COL5A1 基因编码 col V 的α1-螺旋，该螺旋在细胞外基质中的 I 型胶原中通常对免疫系统隐藏。启动子分析显示，激活 T 细胞的核因子，细胞质 3（NFATc3）结合位点。因此，我们假设平滑肌 NFATc3 上调 col V 的表达，导致 nT17 细胞介导 col V 的自身免疫反应对 CH 的反应，代表 PH 发展的上游机制。为了验证我们的假设，我们测量了暴露于 CH（380 mmHg）或常氧的诱导型平滑肌细胞（SMC）特异性 NFATc3 敲除（KO）小鼠的 PH 指标，并将其与野生型（WT）小鼠进行了比较。KO 小鼠没有发展为 PH。此外，COL5A1 是在分离的肺内动脉中受 CH 和 SMC NFATc3 共同影响的 1792 个基因之一，这通过 RT-PCR 和免疫染色得到了证实。使用体内延迟型超敏反应试验（Tv-DTH）测定针对 col V 的细胞免疫。只有当来自暴露于 CH 的对照小鼠的脾细胞用于 Tv-DTH 反应时，才会出现 Tv-DTH 反应，而不是来自 KO 小鼠的反应，并且由 nT17 细胞介导。我们的结果表明，SMC NFATc3 通过调节肺自身抗原 COL5A1 蛋白的表达，对成年小鼠的 CH 诱导的 PH 很重要，该蛋白有助于 col V 反应性 nT17 介导的炎症和高血压。
