PD-1在弥漫大B细胞淋巴瘤的表达及对CD8+T细胞功能影响的研究

目的 研究程序性细胞死亡受体1(PD-1)在弥漫大B细胞淋巴瘤(DLBCL)组织中的表达情况及对T细胞功能的影响.方法 收集临床上诊断为DLBCL的患者经手术切除的标本54例:根据国际预后指数(IPI)分类,IPI<2分的31例,IPI>2分的23例,瘤周正常淋巴组织14例,利用Western Blot技术分析DLBCL组织和正常淋巴组织中PD-1表达水平的差异;通过流式细胞仪对比分析上述两种组织中PD-1+CD8+T比例及IFN-γ/IL-2双阳性的水平.结果 Western Blot显示DLBCL组织及正常淋巴组织均表达PD-1,而肿瘤组织中PD-1的表达水平高;正常淋巴组织PD-1+CD8+T细胞比例低于肿瘤组织(P<0.01),IPI<2 DLBCL组织中PD-1+CD8+T细胞比例较IPI>2分的DLBCL组织低(P<0.01);正常淋巴组织中PD-1+CD8+T细胞和PD-1-CD8+T细胞中IFN-γ/IL-2双阳性的表达未见明显差异(P>0.05);DLBCL组织中PD-1+CD8+T细胞较PD-1-CD8+T细胞中IFN-γ/IL-2双阳性比例低(P<0.01),且IPI>2分的DLBCL组织中PD-1+CD8+T细胞比IPI<2分PD-1+CD8+T细胞中IFN-γ/IL-2双阳性比例低(P<0.01).结论 DLBCL组织中PD-1表达增多,且IFN-γ/IL-2双阳性比例减少,且随着IPI增加,上述现象更加明显.

Objective To analyze the expression of PD-1 on surface of infiltrating T cell in Diffuse Large B Cell Lymphoma(DLBCL), and the impact functions of the T Cells. Methods 1. 54 human DLBCL tumor tissues(IPI<2 points had 31 cases and IPI>2 points had 23 cases) and 14 peritumoral normal tissues. It was analyzed through following methods:1. Western Blot was used to investigate expression of PD-1 in DLBCL and its adjacent normal tissues. 2. The expression of the PD-1 molecules on the surface of CD8+T cell was compared and the functions of the CD8+T Cells on the secretion of IFN-γ and IL-2 in human DLBCL and its adjacent normal tissue were analyzed. Results Data of Western Blot indicated that PD-1 molecule could be detected in all patients with DLBCL and expression level was significantly higher in DLBCL than in its adjacent normal lymphatic tissues. The results of flow cytometry showed that the proportion of PD-1+CD8+T cell in peritumoral normal lymphatic tissue was significantly lower than DLBCL tissue of IPI<2 points,P<0.01. It was significantly decreased in DLBCL of IPI<2 points than DLBCL IPI>2 points tissue,P<0.01. In peritumoral normal lymphatic tissues,there were no difference between percentage of IFN-γ+IL-2+PD-1+CD8+T cells and IFN-γ+/IL-2+PD-1-CD8+T cells,P>0.05. The percentage of IFN-γ+/IL-2+PD-1+CD8+T cell in DLBCL tissues was significantly lower than IFN-γ+/IL-2+PD-1-CD8+T cell,P<0.01. The percentage of IFN-γ+/IL-2+PD-1+CD8+T cell in DLBCL tissues of IPI>2 points was significantly lower than percentage of IPI<2 points tissues,P<0.01. Conclusion DLBCL expresses more PD-1 molecule,and CD8+T cells secretes less anti-tumor cytokines.