诱导性共刺激分子靶点用于小鼠佐剂诱导型关节炎模型的可行性

目的 观察诱导性共刺激分子(ICOS)靶点用于小鼠佐剂诱导型关节炎(AIA)模型的可行性。方法 选取20只BALB/c小鼠,于右后爪分别注射等剂量完全弗氏佐剂(AIA组,n=10)或磷酸盐缓冲液(对照组,n=10),之后经尾静脉分别注射ICOS-IRD680 mAb探针(AIA组)或IgG-IRD680 mAb探针对照组,比较24及48 h后2组近红外荧光成像右爪与左爪荧光强度比值;提取小鼠总RNA行转录组测序,筛选并分析差异表达基因。针对对照组提取脾脏原代T细胞并分选磁珠阴性T细胞,以佛波酯/离子霉素刺激、诱导活化T细胞形成,检测其表面ICOS蛋白表达水平,并进行安全性评价。结果 相比对照组,AIA组ICOS基因表达显著上调、T细胞占比增高,FoxP3+调节性T细胞、CD8+T细胞及CD4+T细胞中ICOS分布较多。对照组分选磁珠阴性T细胞前、后CD3+T细胞纯度分别为65.31%和90.14%;其中,ICOS蛋白阳性小鼠CD4+T细胞在活化前、后占比分别为7.14%及31.20%,且活化CD4+T细胞ICOS蛋白平均荧光强度(586±25)显著高于未活化者(161±31)(t=25.390,P<0.001)。注射探针后24及48 h,AIA组右爪/左爪荧光强度比值均高于对照组(t=34.600、P<0.001;t=23.380、P<0.001)。相比对照组,AIA组小鼠心、肝、肾组织未见明显病理改变,且组间血清谷丙转氨酶、谷草转氨酶及肌酐无明显差异(P均>0.05)。结论 ICOS靶点用于小鼠AIA模型安全、可行。

Feasibility of inducible costimulatory target in mice adjuvant-induced arthritis models

Objective To observe the feasibility of inducible costimulatory (ICOS) target in mice adjuvant-induced arthritis (AIA) models. Methods Twenty BALB/c mice were injected with equal dose of complete Freund''s adjuvant (AIA group, n=10) or phosphate buffered saline (control group, n=10) into the right back paws. The second day after injection, ICOS-IRD680 mAb probes were injected in AIA group, while IgG-IRD680 mAb probes were injected in control group through tail vein, respectively. The fluorescent intensity ratio of the right and left paw based on near-infrared fluorescence imaging 24 and 48 h later were compared between groups. The total RNA of mice were extracted for transcriptome sequencing, and differentially expressed genes (DEG) were screened and analyzed. Primary T cells were extracted from the spleen of mice in control group, then magnetic negative T cells were sorted. Activated T cells were stimulated and induced using phoboxylate/ionomycin, the expression level of ICOS protein on the surface of activated T cells were detected, and the safety of probe was also evaluated. Results The expression of ICOS gene in AIA group was significantly up-regulated, and the proportion of T cells was higher than that in control group. ICOS tented to distribute in FoxP3+ regulatory T cells, CD8+T cells and CD4+T cells. The purity of CD3+T cells before and after magnetic negative T cells was 65.31% and 90.14%, respectively. The proportion of CD4+T cells before and after activated was 7.14% and 31.20%, respectively, and the mean fluorescent intensity of ICOS protein in activated CD4+T cells (586±25) was significantly higher than that in non-activated CD4+ T cells (161±31) (t=25.390, P<0.001). Twenty-four and 48 h after probe injection, the fluorescent intensity ratio of the right paw/left paw in AIA group was higher than that in control group (t=34.600, P<0.001; t=23.380, P<0.001). Compared with control group, no significant pathological change of heart, liver nor kidney tissues of mice in AIA group was detected, while no significant difference of glutamic-pyruvic transaminase, glutamic-oxaloacetic transaminase nor creatinine was found between groups (all P>0.05). Conclusion ICOS target was safe and feasible for mice AIA models.