[Comparative proteomics research on THP-1 cells infected with Brucella].

ABSTRACT

Brucella is a facultative intracellular pathogen that survives and multiplies inside host macrophages to cause brucellosis. The response of macrophage plays an essential role in the initiation of immune process following Brucella challenge. Nowadays, proteome approaches have been widely used in many different systems to investigate host-microbe interactions. The effect of pathogen-specific virulence mechanism can now be dissected using bacterial mutants and comparing different species. Attenuated vaccine strain 104M is defective in multification in host macrophage and is cleared relatively rapidly from tissues of the host, whereas virulent strains Brucella abortus 544A can produce chronic infection and cause brucellosis. In order to understand the underlying mechanisms of virulent Brucella intracellular survival, and detect the different-expressed proteins of THP-1 cells after infection with attenuated and virulent strains of Brucella abortus, a comparative proteomics research was conducted. Whole cellular protein profiling of THP-1 cells was presented by two dimensional (2D) electrophoresis and Coomassie Blue staining. After in-gel protein digestion, the different-expressed spots were detected by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS). All the peptide mass fingerprints (PMFs) were searched by the program Mascot developed by Matrix Science Ltd. For identifying proteins, database of hemo sapiens was used. A total of 38 proteins with changed expression level were found. These proteins can be grouped into two familes (1) the expression level increased after infection with 544A; (2) the expression level increased after infection with 104M. Out of the 38 proteins, 10 were mainly in the field of signal transduction, 6 were cytoskeletal proteins, 8 were substance metabolism related proteins and 3 were cell stress and defense associated proteins. Functions of the remaining proteins were unknown. These results provide insight into the changed global protein patterns of THP-1 cells after infection as well as a comprehensive foundation to further study of host-bacterial interaction.