PD-L2基因敲除小鼠胶原抗体诱导的关节炎模型建立与评价OA

Objective:To establish a collagen antibody-induced arthritis(CAIA)model of PD-L2 knockout mice and to evalu-ate immune status of mice.Methods:CAIA model of wild-type(WT)and PD-L2 gene knockout(PD-L2-/-)mice were established.Mouse body weight and hind paw thickness were measured and joint scores were performed.HE,Masson and modified saffron-O and fast green staining were used to evaluate inflammation of mouse joint tissues.Flow cytometry was used to detect difference of propor-tions of T cells,B cells,NK cells and monocytes in spleen of two groups,and inflammatory factors IFN-γ,IL-4 and IL-17 secreted by CD4+T cells,CD11b+cells and NK cells were detected by permeabilization flow cytometry.Results:CAIA model of mice in both WT group and PD-L2-/-group were successfully established.After modeling,body weight of WT-CAIA group and PD-L2-/--CAIA group were decreased,thickness of hind paws was increased,and joint score was increased.Joint swelling score,synovial thickening score,inflammatory cell infiltration score and cartilage erosion score in PD-L2-/--CAIA group were lower than WT-CAIA group,but there was no significant difference(P>0.05).Proportions of CD4+T cells,CD8+T cells,CD8+central memory T cells and NK cells in PD-L2-/--CAIA group were lower than WT-CAIA group(P<0.05).Secretion of IFN-γ and IL-17 by CD4+T cells in PD-L2-/--CAIA group were lower than WT-CAIA group(P<0.05),secretion of IFN-γ,IL-4 and IL-17 by CD11b+cells were lower than WT-CAIA group(P<0.05),and secretion of IFN-γ and IL-17 by NK cells were lower than WT-CAIA group(P<0.05).Conclusion:PD-L2 knockout can still induce onset of arthritis of mice,but degree of inflammation of joint tissue is lower than WT group.