Koga Tomohiro, Mizui Masayuki, Yoshida Nobuya, Otomo Kotaro, Lieberman Linda A, Crispín José C, Tsokos George C
Division of Rheumatology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School , Boston, MA , USA.
Autoimmunity. 2014 Nov;47(7):445-50. doi: 10.3109/08916934.2014.915954. Epub 2014 May 15.
Foxp3(+) regulatory T cells (Treg) are pivotal for the maintenance of peripheral tolerance and prevent development of autoimmune diseases. We have reported that calcium/calmodulin-dependent protein kinase IV (CaMK4) deficient MRL/lpr mice display less disease activity by promoting IL-2 production and increasing the activity of Treg cells. To further define the mechanism of CaMK4 on Treg cells in systemic lupus erythematosus (SLE), we used the Foxp3-GFP reporter mice and treated them with KN-93, an inhibitor of CaMK4.
We generated MRL/lpr Foxp3-GFP mice to record Treg cells; stimulated naïve CD4(+) T cells from MRL/lpr Foxp3-GFP mice under Treg polarizing conditions in the absence or presence of KN-93; evaluated the number of GFP positive cells in lymphoid organs and examined skin and kidney pathology at 16 weeks of age. We also examined the infiltration of cells and recruitment of Treg cells in the kidney.
We show that culture of MRL/lpr Foxp3-GFP T cells in the presence of KN-93 promotes Treg differentiation in a dose-dependent manner. Treatment of MRL/lpr Foxp3-GFP mice with KN-93 results in a significant induction of Treg cells in the spleen, peripheral lymph nodes and peripheral blood and this is accompanied by decreased skin and kidney damage. Notably, KN-93 clearly diminishes the accumulation of inflammatory cells along with reciprocally increased Treg cells in target organ.
Our results indicate that KN-93 treatment enhances the generation of Treg cells in vitro and in vivo highlighting its potential therapeutic use for the treatment of human autoimmune diseases.
Foxp3(+)调节性T细胞（Treg）对于维持外周免疫耐受及预防自身免疫性疾病的发生至关重要。我们曾报道，钙/钙调蛋白依赖性蛋白激酶IV（CaMK4）缺陷的MRL/lpr小鼠通过促进白细胞介素-2（IL-2）的产生及增强Treg细胞活性而表现出较低的疾病活性。为进一步明确CaMK4在系统性红斑狼疮（SLE）中对Treg细胞的作用机制，我们使用了Foxp3-GFP报告基因小鼠并用CaMK4抑制剂KN-93对其进行处理。
我们培育了MRL/lpr Foxp3-GFP小鼠以记录Treg细胞；在有无KN-93的情况下，于Treg极化条件下刺激来自MRL/lpr Foxp3-GFP小鼠的初始CD4(+) T细胞；评估16周龄时淋巴器官中GFP阳性细胞的数量，并检查皮肤和肾脏病理情况。我们还检测了肾脏中的细胞浸润及Treg细胞募集情况。
我们发现，在KN-93存在的情况下培养MRL/lpr Foxp3-GFP T细胞可呈剂量依赖性地促进Treg分化。用KN-93处理MRL/lpr Foxp3-GFP小鼠可导致脾脏、外周淋巴结和外周血中Treg细胞显著诱导增加，同时皮肤和肾脏损伤减轻。值得注意的是，KN-93明显减少了炎症细胞的积聚，同时相应增加了靶器官中的Treg细胞。
我们的结果表明，KN-93处理可在体外和体内增强Treg细胞的生成，突出了其在治疗人类自身免疫性疾病方面的潜在治疗用途。
