ABSTRACT
Objective Receptor was screened to find out the interaction between outer membrane protein 25 of Brucella(OMP25) and Brucella infected macrophages.Methods Recombinant OMP25 protein was expressed and purified.The 7 peptide was screened out with OMP25 protein by phage display technology.OMP25-7 peptide interactions were further confirmed by enzyme linked immunosorbent assay(ELISA) after candidate peptides were predicted with bioinformatics software.Four potential 7 peptides were synthetized.Their functions were estimated after Brucella abortus 2308 infected murine macrophages RAW264.7.Results Forty-two cyclic 7 peptides were screened out based on purified OMP25 by the M13 Phage Library Kit.Four peptides,named as ST-7,MT-7,TF-7 and SN-7,were confirmed with ELISA.Colony forming unit(CFU) result demonstrated ST-7,MT-7,TF-7 and SN-7 showed some function for inhibition of intracellular parasite.ST-7 inhibition ratio was 14.4％-51.8％ for Brucella abortus 2308; MT-7 inhibition ratio was 49.6％-69.5％ for Brucella abortus 2308; TF-7 inhibition ratio was 43.2％-74.4％ for Brucella abortus 2308; SN-7 inhibition ratio was 57.5％-82.2％ for 2308.ELISA result showed,that compared to control group,tumor necrosis factor α(TNF-α)increased no statistical significance in each time point of ST-7,MT-7 experiment groups (all P ＞ 0.05).There was no statistical significance in 8 h ago of TF-7,SN-7 experiment groups (all P ＞ 0.05),but there was statistical significance in 12,24 h (all P ＜ 0.05).Conclusions We have obtained four effective OMP25 receptors through phage display technology; TF-7 and SN-7 have inhibited Brucella abortus 2308 invasion and intracellular survival in murine macrophage cells,while ST-7 and MT-7 have only prevented the invasion against Brucella abortus 2308.