Department of Biochemistry and Molecular Biology II, CIBERehd, School of Pharmacy, Instituto de Investigación Biosanitaria ibs.GRANADA, University of Granada, Granada, Spain.
Department of Pharmacology, CIBERehd, School of Pharmacy, Instituto de Investigación Biosanitaria ibs.GRANADA, University of Granada, Granada, Spain.
J Crohns Colitis. 2017 Jul 1;11(7):857-870. doi: 10.1093/ecco-jcc/jjw222.
Two alkaline phosphatase isoforms, intestinal [IAP] and tissue non-specific alkaline phosphatase [TNAP], are coexpressed in mouse colon, with the latter predominating in colitis. We aimed to examine the role of TNAP in T lymphocytes, using heterozygous TNAP+/- mice [as TNAP-/- mice are non-viable].
In vitro primary cultures and in vivo T cell models using TNAP+/- mice were used.
Stimulated splenocytes [lipopolysaccharide and concanavalin A] and T lymphocytes [concanavalin A and a-CD3/a-CD28] showed a decreased cytokine production and expression when compared with wild-type [WT] cells. Decreased T cell activation was reproduced by the TNAP inhibitors levamisole, theophylline, and phenylalanine in WT cells. Intraperitoneal administration of anti-CD3 in vivo resulted in reduced plasma cytokine levels, and decreased activation of splenocytes and T cells ex vivo in TNAP+/- mice. We further tested the hypothesis that TNAP expressed in T lymphocytes is involved in T cell activation and inflammation, using the lymphocyte transfer model of colitis. Rag1-/- mice were transferred with T naïve cells [CD4+ CD62L+] from TNAP+/- or WT mice and developed colitis, which was attenuated in the group receiving TNAP+/- cells. Compared with WT, T cells from TNAP+/- mice showed a decreased capacity for proliferation, with no change in differentiation.
Our results offer clear evidence that TNAP modulates T lymphocyte function and specifically T cell-dependent colitis. This was associated with distinct changes in the type of TNAP expressed, probably because of changes in glycosylation.
两种碱性磷酸酶同工酶，肠型[IAP]和组织非特异性碱性磷酸酶[TNAP]，在小鼠结肠中共同表达，后者在结肠炎中占优势。我们旨在研究 TNAP 在 T 淋巴细胞中的作用，使用杂合子 TNAP+/- 小鼠[因为 TNAP-/- 小鼠不能存活]。
使用 TNAP+/- 小鼠进行体外原代培养和体内 T 细胞模型。
与野生型[WT]细胞相比，刺激的脾细胞[脂多糖和伴刀豆球蛋白 A]和 T 淋巴细胞[伴刀豆球蛋白 A 和 a-CD3/a-CD28]显示细胞因子产生和表达减少。WT 细胞中 TNAP 抑制剂左旋咪唑、茶碱和苯丙氨酸可再现 T 细胞激活减少。体内抗 CD3 腹腔内给药导致血浆细胞因子水平降低，并减少 TNAP+/- 小鼠体内脾细胞和 T 细胞的体外激活。我们进一步测试了 TNAP 在 T 淋巴细胞中表达的假设，该假设涉及 T 细胞激活和炎症，使用结肠炎的淋巴细胞转移模型。Rag1-/- 小鼠接受来自 TNAP+/-或 WT 小鼠的幼稚 T 细胞[CD4+ CD62L+]转移，并发生结肠炎，而接受 TNAP+/- 细胞的组结肠炎减轻。与 WT 相比，TNAP+/- 小鼠的 T 细胞增殖能力降低，而分化无变化。
我们的结果提供了明确的证据，表明 TNAP 调节 T 淋巴细胞功能，特别是 T 细胞依赖性结肠炎。这与所表达的 TNAP 类型的明显变化有关，可能是由于糖基化的变化。
