[Rearrangement and altered expression of actin in macrophages induced by Mycobacterium tuberculosis].
OBJECTIVE
To investigate the effect of M. tuberculosis infection on actin in host-cells.


METHODS
The form and distribution of fibrous actin and changes of actin expression were observed by confocal microscopy and Western blot analysis in macrophages infected with either M. tuberculosis H(37)R(a) or H(37)R(v) at 6 h, 12 h and 24 h after infection. Non-infected macrophages or macrophages treated with dead M. tuberculosis H(37)R(v) served as controls.


RESULTS
F-actin aggregated and the actin expression was suppressed in macrophages infected with H(37)R(a) or H(37)R(v), and the effect appeared earlier in cells infected by the virulent H(37)R(v) strain than in cells infected by the avirulent H(37)R(a) strain. In macrophages treated with the dead H(37)R(v), actin was not affected.


CONCLUSIONS
The results suggest that in the process of infection, M. tuberculosis evades the bactericidal mechanisms possibly by secretion of certain proteins or factors which affect the host-cell actin.
Xu
Yong-zhong
YZ
Institute of Genetics, Fudan University, Shanghai 200433, China.
Bai
Hai-tao
HT
Hu
Zhong-yi
ZY
Chen
Jian-ping
JP
Chunyu
Li-juan
LJ
Wei
Yi
Y
Wang
Hong-hai
HH
D000199:Actins / Q000378:metabolism*; D006801:Humans; D008264:Macrophages / Q000378:metabolism* / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000502:physiology*; D020298:U937 Cells
D000199:Actins