Role of the polypeptide region of a 33kDa mycobacterial lipoprotein for efficient IL-12 production.
Mycobacterium leprae lipoprotein, LpK, induced IL-12 production from human monocytes. To determine the components essential for cytokine production and the relative role of lipidation in the activation process, we produced lipidated and non-lipidated truncated forms of LpK. While 0.5nM of lipidated LpK-a having N-terminal 60 amino acids of LpK produced more than 700pg/ml IL-12 p40, the non-lipidated LpK-b having the same amino acids as that of LpK-a required more than 20nM of the protein to produce an equivalent dose of cytokine. Truncated protein having the C-terminal 192 amino acids of LpK did not induce any cytokine production. Fifty nanomolar of the synthetic lipopeptide of LpK produced only about 200pg/ml IL-12. Among the truncated LpK, only LpK-a and lipopeptide stimulated NF-kB-dependent reporter activity in TLR-2 transfectant. However, when monocytes were stimulated with lipopeptide in the presence of non-lipidated protein, they produced IL-12 synergistically. Therefore, both peptide regions of LpK and lipid residues are necessary for efficient IL-12 production.
Department of Microbiology, Leprosy Research Center,National Institute of Infectious Diseases, 4-2-1 Aobacho,Higashimurayama, Tokyo 189-0002, Japan.
Yasuko
Y
Yamashita
Yumi
Y
Maeda
Fumihiko
F
Takeshita
Patrick J
PJ
Brennan
Masahiko
M
Makino
D001426:Bacterial Proteins / Q000378:metabolism*; D006801:Humans; D018664:Interleukin-12 / Q000096:biosynthesis*; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D009166:Mycobacterium leprae / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors
D001426:Bacterial Proteins; C464640:LpK protein, Mycobacterium leprae; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors; D018664:Interleukin-12