再生多孔丝素膜创面局部运用激活不同部位T细胞的作用

Activation of T lymphocytes on local trauma after implantation of regenerated porus silk fibrion film

背景:丝素蛋白是从蚕丝中提取的天然高分子纤维蛋白,其具有良好的理化特性及生物相容性。而目前国内外有关再生多孔丝素膜植入体内后对T淋巴细胞的激活作用研究未见报道。目的:观察再生多孔丝素膜植入大鼠局部创面后对外周血单个核细胞、脾脏及胸腺中T淋巴细胞的激活作用。方法:切除SD大鼠背部皮肤建立2cm×2cm创面,随机分为2组:实验组覆盖经预处理的再生多孔丝素膜,将已切除皮肤的表皮盖在丝素膜上进行缝合,对照组仅覆盖自身表皮层。于术后第3,14,28,56,90天观察创面愈合及丝素膜的残留情况,采用双色免疫荧光及流式细胞术分析大鼠外周血、脾脏及胸腺中CD3+CD25+/CD3+T细胞百分率。结果与结论:植入早期,两组均可见局部、轻微的炎症细胞浸润,主要为淋巴细胞;至28d后,炎症细胞逐渐减少,并且在整个动态观察过程中,两组结果一致。实验组外周血中活化T细胞在14d之前呈一过性升高,随后开始下降,至28d以后,活化T细胞水平趋于稳定,与对照组无明显差异(P>0.05);脾脏与胸腺T细胞均有少量活化,随后即开始下降并趋于稳定,胸腺中CD3+CD25+/CD3+T细胞的阳性率较脾脏微高,与对照组均无明显差异(P>0.05)。说明再生多孔丝素膜对T淋巴细胞的激发作用较小,引发机体细胞免疫应答的能力较弱。

BACKGROUND：Silk fibroin is extracted from the natural polymer fibrin,which has a good physical and chemical properties and biocompatibility.While there is no report addressing activation of T lymphocytes after implantation of regenerated porous silk fibroin film at home and abroad.OBJECTIVE：To investigate the activation of T lymphocytes in peripheral blood monouclear cells（PBMC）,spleen and thymus on local trauma after implantation of regenerated porus silk fibrion film.METHODS：Wound with an area of 2 cm×2 cm was established by removing SD rats＇ skin of back,and randomly divided into two groups：experimental group and control group.Pretreated regenerated porous silk fibroin film was covered in experimental group,and the epidermis of the excisional skin covered silk fibroin film to undergo suture.At 3,14,28,56,90 days after operation,would healing and residue of silk fibroin film were observed.Two-color immunofluorescence and flow cytometry technology were used to analyze CD3＋CD25＋/CD3＋T cell percentage of PBMC,spleen and thymus in rats.RESULTS AND CONCLUSION：At the early stage of implantation,local and slight inflammatory cell infiltration could be seen between experimental and control groups,mainly lymphocytes.After 28 days,inflammatory cells were gradually decreased;the results between two groups were the same in the whole dynamic observation.Activated T cell of PBMC was transiently increased before 14 days,and then decreased.After 28 days,the level of activated T cell was tending towards stability.There was no significant difference between experimental and control groups（P 0.05）.T cells in spleen and thymus had small amounts of activation,and then began to decline and tended toward stability.Positive rate of CD3＋CD25＋/CD3＋T cell in thymus was slightly higher than that in spleen,and there was no significant difference between experimental and control groups（P 0.05）.It is indicated that regenerated porus silk fibrion film plays a small part in activation of T lymphocyte,and causes a weaker ability of cellular immune response.