〔Abstract〕 Objective To construct a stable synovial cell line MH7A from rheumatoid arthritis(RA) patients using lentiviral vectors that interfere with the expression of tumor necrosis factor receptor associated factor 2(TRAF2), and to study the role of TNF-α-TRAF2 signaling in MH7A abnormal proliferation. Methods Based on the design principles of human TRAF2 gene sequence and shRNA sequence, three pairs of TRAF2 shRNA interference sequences were designed and synthesized. The primers were annealed by PCR, and a linear vector was obtained by double enzyme digestion PLKO.1-puro. The linearized vector was connected to the annealed primers through Solution I, and the connected products were introduced into receptive cells. The plates were coated, and positive colonies were selected for sequencing. Three different recombinant plasmids of PLKO.1-TRAF2-shRNA lentivirus were constructed, and lentivirus packaging plasmids was used to package logarithmic growth phase HEK 293T cells. Virus solution was collected to infect MH7A cells. At the same time, puromycin was used to screen MH7A stable transgenic strains with low TRAF2 expression. CCK-8 method, Western blot, and qPCR were used to detect the proliferation function of MH7A induced by TNF-α and low expression of TRAF2, as well as downstream signal TRAF2, P65 protein expression and mRNA levels. Results PLKO.1-TRAF2-shRNA(1), PLKO.1-TRAF2-shRNA(2), and PLKO.1-TRAF2-shRNA(3) lentivirus vector plasmids and control group lentivirus vector plasmids PLKO.1-puro were successfully constructed. The three TRAF2-shRNA lentivirus vector plasmids and control group lentivirus vector plasmids PLKO.1-puro were respectively introduced into the lentivirus packaging plasmid of HEK 293T to obtain virus solution. After infecting MH7A cells with the virus solution, they were treated with puromycin(2.00 μ G/mL) screening and obtaining MH7A stable transgenic plants after 2 days. Through qPCR and Western blot results, it was found that the expression of TRAF2 mRNA and protein in PLKO.1-TRAF2-shRNA(1) MH7A stably transfected cells was significantly reduced compared to the negative control group. The results of CCK-8 and Western blot showed that after knocking down TRAF2 in MH7A, the proliferation of MH7A cells with low TRAF2 expression induced by TNF-α and the phosphorylation level of P65 were significantly reduced. Conclusion A stable transgenic strain of PLKO.1-TRAF2-shRNA(1) MH7A cells was successfully constructed to investigate the role of TNF-α-TRAF2 signal activation in mediating abnormal proliferation of RA synovial cells.