Study on the pattern recognition and response effect of mast cell to B.suis in vitro

【摘要】：Brucellosis is an important zoonotic disease caused by Brucella,and there is no effective control measures.Recent studies show that mast cell(MC)is not only a major effector cell of allergic reactions,but also play an important role in the body against pathogens.In this study,we mainly compare the changes of cytokine production and TLR of MC after infected by B.suis S_2 and B.suis WboA~-S_2.Objective:To investigate the pattern recognition and immune response of MCs to brucella.Methods:P815 were infected by B.suis S_2,B.suis WboA~-S_2 and escherichia coli,nomal P815 acted as the control group.The levels of IL-6,TNF-α,LT,histamine in serum were detected by ELISA;The mRNA expression of TLR4,8 and 9 of p815 were detected by RT-PCR.Results:The levels of IL-6,LT and histamine were obviously higher than the nomal group(P0.05)at 1h,12h and24h after infected by B.suis S_2,B.suis WboA~-S_2 and escherichia coli,and the levels of IL-6 in the same infection groups increased gradually,but the levels of LT had no changed.The level of TNF-a had no statistical significance compared with the nomal group(P0.05)at 1h,and it was higher than the nomal group(P0.05)at 12h,24h.There had no statistical significance with the levels of IL-6,LT and TNF-αbetween B.suis S_2 and B.suis WboA~-S_2 groups(P0.05).The levels of histamine of B.suis S_2 groups were lower than the B.suis WboA~-S_2 groups at 24h(P0.05).Normal p815expressed TLR4,8 and 9.The mRNA expression of TLR4 enhanced gradually and TLR9 grew at 12h,but weakened at 24h after infected by B.suis S_2.The mRNA expression of TLR4 weakened at 12h,and both of TLR4 and TLR9were enhanced at 24h after infected by B.suis WboA~-S_2.The mRNA expression of TLR4 enhanced at 12h and weakened at 24h after infected by escherichia coli,however,TLR9 weakened at 12h and enhanced at 24h.The mRNA expression of TLR8 had no significant changes at different time points after infected by these three Bacterias.Conclusion:Both of the B.suis S_2and B.suis WboA~-S_2 can activate p815 and induce p815 to secrete large number of cytokine,besides,the production of WboA gene maybe is the main pattern ligand of stimulating MC release histamine,TLR4 and TLR9 of p815 participate in recognizing Brucella.