Effect of T cell immunoglobulin domain and mucin domain protein-3 gene interfered by short hairpin RNA on helper T lymphocytes 17 differentiation and proinflammatory capacity in asthmatic mice

Abstract

Objective To investigate the effect of down-regulating of T cell immunoglobulin domain and mucin domain protein-3(Tim-3) gene in asthmatic mouse model by short hairpin RNA(shRNA) and explore the role of Tim-3 on the differentiation of helper T lymphocytes 17(Th17), airway inflammation, as well as airway hyperresponsiveness in pathogenesis of asthma. Methods An asthmatic murine model was established by way of ovalbumin(OVA) sensitization and challenge.Treating Tim-3 gene was intranasally administered with Tim-3-specific shRNA.Invasive pulmonary impedance method was adopted to detect mice airway resistance.Flow cytometry analysis was performed to determine the levels of Th17; enzyme linked immunosorbent assay was performed to determine the concentrations of IL-17 and transforming growth factor-beta(TGF-β) in supernatant. Results Asthmatic mice model was successfully established.By using Tim-3 shRNA silencing Tim-3, airway inflammation was reduced and airway hyperresponsiveness was declined in asthmatic group; the levels of Th17 cells in asthmatic group [(6.43±1.01)%] were significantly increased compared with normal controls[(1.75±0.02)%]. After using Tim-3 shRNA silencing Tim-3, the levels of Th17 cells [(2.36±0.28)%]were decreased (F=40.05, P<0.05); the level of IL-17 in asthmatic group[(118.8±16.5)ng/L] was significantly increased compared with normal controls[(72.5±13.6)ng/L], after using Tim-3 shRNA silencing Tim-3, the level of IL-17 [(73.6±12.5)ng/L]was decreased (F=32.80, P<0.05), while the expression of TGF-β did not change. Conclusions Down regulation of Tim-3 gene can decrease airway inflammation and airway hyperresponsiveness, which may be related to the change of Th17 cell differentiation. Key words: Asthma; T cell immunoglobulin domain and mucin domain protein-3; RNA interference; T hel-per cell