牛坏死杆菌43K OMP对鼠乳腺上皮细胞分泌炎性因子的影响OA

To investigate the effects of 43 kDa outer membrane protein(43K OMP)derived from Fusobacterium necrophorum on the secretion of inflammatory factors in mouse mammary epithelial cells(MMECs),and to clarify the immune mechanism of Fusob-acterium necrophorum by detecting inflammation-related cytokines after recombinant 43K OMP stimulation of MMECs.The CCK-8 assay was used to screen the cell inhibition rates of MMECs treated with 43K OMP at concentrations of 10,20 and 40 μg·mL-1 for different durations.MMECs were stimulated with the optimal concentration of 43K OMP,and samples were collected at 6,12,18,and 24 h post-treatment.The mRNA relative expression of inflammatory cytokines IL-6,IL-1β and TNF-α was determined via qRT-PCR,while the secretion levels of these cytokines in cell supernatants were quantified by ELISA.These results showed that the optimal stimulation condition was 20 μg·mL-1 43K OMP with a treatment duration of 24 h.When MMECs were incubated with 20 μg·mL-1 43K OMP for 18 h and 24 h,the relative mRNA expression of IL-6,IL-1β and TNF-α increased extremely significantly(P＜0.01).After 24 h of stimulation,the contents of IgG,IL-6,IL-1β,IL-8 and TNF-α in cell supernatants were significantly elevated(P＜0.05),and varying degrees of increasing trends were observed at other time points.In conclusion,43K OMP of F.necrophorum can accelerate the secretion of IL-6,IL-1β and TNF-α in MMECs and induce the production of multiple pro-inflammatory cytokines,which participates in host immune defense against F.necrophorum infection.