Influence of Mycobacterium tuberculosis 19 kDa lipoprotein upon the expression and distribution of Toll-like receptor-2 on the surface of macrophages / 中国人兽共患病学报

ABSTRACT

To observe the effect of Mycobacterium tuberculosis 19 kDa lipoprotein (Mtb P19) upon the expression and distribution of Toll-like receptor-2 (TLR-2) on the surface of macrophages, Mtb P19 was prepared from the cultured M.tuberculosis H37 Ra strain , and phorbol myristatye acetate (PMA)-differentiated THP-1 cells were co-cultivated with Mtb P19 at concentration of 10 g/mL and at 37 ℃ temperature and a condition containing 5% CO_2.for 6 hours.. The distribution of TLP-2 on the surface of macrophages was investigated by immuno-cellular chemical method (ICC) while the effect of Mtb P19 upon the expression of TLR on the surface of macrophages was assayed by fluorescent antibody staining. In addition,the changes of TLR-2 expression before and after the effect of Mtb P19 were investigated by flow cytometry analysis and change of TLR-2 arrangement after stimulation with Mth P19 was determined by co-focal microscopy. It was found that the TLR-2 molecules were evenly distributed on the surface of macrophages as demonstrated by ICC. The mean fluorescent intensity increased significantly after stimulation with Mtb P19 for 6 hours in comparison with that of the control group, and the patchy surface with fluorescent staining positive zones could be detected on the surface of macrophages. Nevertheless , the distribution of TLR-2 molecule in the control group appeared to be randomly dynamic. It is evident that the Mth P19 not only can induce the surface expression of TLR-2 molecules, but also cause a functional aggregation of this receptor.