摘要目的 观察胞壁酰二肽与抗CD10单克隆抗体偶联物(MDP-Ab)对急性白血病患儿树突状细胞(DC)活性的影响.方法 采用本课题组新合成的MDP-Ab作用于急性淋巴细胞性白血病患儿分离培养所得的DC.分为6组:对照组、未偶联的抗 CD10抗体组、未偶联的 MDP组、MDP-Ab组、脂多糖(LPS)组及MDP-Ab+LPS组,培养8 d,收集各组DC,检测细胞免疫表型、内吞作用及细胞上清液中白细胞介素12(IL-12)水平.采用活细胞荧光剂羧基荧光素二醋酸盐琥珀酰亚胺酯(CFSE)染色法检测各组作用的淋巴细胞增殖情况,酶联免疫吸附法检测上清液干扰素-γ(IFN-γ)水平.结果 1.DC细胞免疫表型:MDP-Ab促进白血病患儿外周血DC表达人白细胞(位点)DR抗原(HLA-DR)、共刺激分子(CD80、CD86)及成熟分子(CD83)的阳性细胞均明显高于对照组、未偶联的抗 CD10抗体组及未偶联的 MDP组,但低于 LPS组及 MDP-Ab +LPS组(F =629.62,P=0.000).2.IL-12水平:MDP-Ab组、LPS组及MDP-Ab+LPS组均明显高于对照组、未偶联的抗CD10抗体组及未偶联的MDP组(F=857.87,P=0.000).MDP-Ab组与LPS组、MDP-Ab+LPS组相比,亦有显著性差异(P<0.05).3.DC吞噬功能:对照组(即未成熟DC)为(81.3 ± 10.1)%,明显高于未偶联的抗CD10抗体组、未偶联的MDP组、MDP-Ab组、LPS及MDP-Ab+LPS组(F=383.04,P=0.000).4.混合淋巴细胞反应及IFN-γ水平:与对照组、未偶联的抗CD10抗体组及未偶联的MDP组相比,MDP-Ab组、LPS组及MDP-Ab+LPS组CFSE阳性细胞及IFN-γ水平明显增高,以MDP-Ab+LPS组为最高(F=393.36,P=0.000;F=2497.18, P=0.000).结论 新合成的免疫偶联物MDP-Ab能促进白血病患儿外周血DC成熟.

abstractsObjective To study the effect of a new immunomodulator composed of muramyl dipeptide(MDP) and anti-CD10monoclonal antibody(MDP-Ab)on the dendritic cells(DC)of children with acute leukemia. Methods DC was adopted to divide the children with acute lymphoblastic leukemia into 6 groups,including the control group,unconjugated anti-CD10alone,unconjugated MDP alone,MDP-Ab alone,lipopolysaccharide(LPS)alone and MDP-Ab + LPS.The immunophenotypes,the endocytosis interleukin-12(IL-12)were detected.The stimulation index of autologous lymphocytes was assayed by adopting 5-(and 6)-carboxyfluorescein diacetate,succinimidyl es-ter(CFSE)-staining method.The supernatants of DC and autologous lymphocytes were used to detect the level of in-terferon-γ(IFN-γ)by using enzyme-linked immunosorbent assay.Results (1)DC immunophenotype:The ex-pressions of human leukocyte antigen-DR(HLA-DR),mature molecule(CD83)and co-stimulatory molecules (CD80and CD86)were increased significantly upon DC triggered with MDP-Ab,compared with the control group,un-conjugated anti-CD10group,and unconjugated MDP group,but lower than those in LPS and combination of MDP-Ab with LPS(F=629.62,P=0.000).(2)The level of IL-12:a significant increase in IL-12 level was detected in MDP-Ab group,LPS group,and combination of MDP-Ab with LPS group,compared with the control group,uncon-jugated anti-CD10group,and unconjugated MDP group(F=857.87,P=0.000). There were significant differences among the first three groups.(3)Endocytosis assay:The uptake of DCs stimulated by unconjugated anti-CD10,un-conjugated MDP,MDP-Ab immunoconjugate,LPS or combination was lower than that of immature DC in the control group which was(81.3 ± 10.1)%.(4)Mixed lymphocyte reaction and IFN-γ level:DC,treated with MDP-Ab, LPS and combination,stimulated more CFSE positive cells and higher level of IFN-γ secretion than the control group and unconjugated anti-CD10group,unconjugated MDP group. The most significance was observed in combination of MDP-Ab with LPS(F=393.36,P=0.000;F=2 497.18,P=0.000).Conclusion It is concluded that MDP-Ab could promote the proliferation and maturation of DC derived from blood of children with acute leukemia.