Lentivirus-mediated Rna Interference Targeting Of Tnf-¦Á Treatment Of Mice With Collagen-induced Arthritis

OBSJECTIVE The intra-articular injection of lentivirus vectors has been proven to result in efficient expression of genes in synovium tissues.Systemic administration of TNF-αsiRNA has shown therapeutic effect in experiment model of rheumatoid arthritis(RA).In this study,we examined the effects of TNF-αgene knockdown in collagen-induced arthritis(CIA) model by systemic adminitration of lentiviral vector mediated TNF-αshort hairpin RNA(shRNA) gene.METHODS We first observed the suppression effect of treatment with siRNA on LPS-stimulated TNF-αsecretion in Raw264.7 macrophages.The lentivirus shRNA expression vector targeting TNF-αgene was constructed and packaged.The lentiviral vector carrying negative control shRNA gene was used as the control vector.After being immunized with typeⅡcollagen on day0 and 21,DBA1 mice received intravenouse injection of 1×10~7 transduction unite lentivirus-RNAi on day30 and 37.The articular index of CIA mice were evaluated.Serum samples were obteined in anethetized animals on day30, 37 and 45.Upon sacrifice on day45,hind paws were collected for radiography.The specimens were steined with hematoxylin/eosin in Paraffin section,and immunohistochemistry technique was also used.RESMLTS In vitro,TNF-αsiRNA efficiently and specifically modulated the expression of TNF-αat both the messenger RNA and protein levels.In vivo,significant reduction of articular index and TNF-αlevel in serum was detected in lentivirus-RNAi treated mice as compared with lentivirus-NC injected controls.However,the X-ray index showed no significant difference between the groups.CONCLUSIONS We demonstrated the efficiency of systemic delivery of lentiviral vector mediated TNF-αshRNA gene as a way to treat CIA.And lentiviral vector is an effective way to realise RNAi in vivo.