| Project/Area Number |
16590358
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Bacteriology (including Mycology)
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| Research Institution | Shimane University |
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Principal Investigator |
TOMIOKA Haruaki Shimane University, Microbiology and Immunology, Professor, 医学部, 教授 (40034045)
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| Co-Investigator(Kenkyū-buntansha) |
SANO Chiaki Shimane University, Microbiology and Immunology, Lecturer, 医学部, 講師 (70325059)
SHIMIZU Toshiaki Shimane University, Microbiology and Immunology, Instructor, 医学部, 助手 (60284030)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2005: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2004: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | phospholipase A_2 / mycobacteria / macrophage / phosphorylated protein / phagosome / phospholipase A_2 |
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| Research Abstract |
The purpose of the present study is to investigate the profiles of intracellular translocation and phosphorylation of cytosolic phospholipase A_2(cPLA_2) in macrophage (Mφ) infected with Mycobacterium tuberculosis (MTB) or Mycobacterium avium complex (MAC). We also examined the mode of intramacrophage signal transduction related to the cPLA_2 translocation and phosphorylation. The present study gave the following findings, (1)ATP significantly potentiated Mφ anti-MTB or anti-MAC bactericidal activity. This effects of ATP was specifically blocked by a cPLA_2 inhibitor, arachidonyl trifluoromethylketone (a-TFMK). (2)Intramacrophage translocation of membranous arachidonic acid (AA) molecules to MAC-containing phagosomes was also specifically blocked by a-TFMK. (3)By confocal microscopic observation of MAC-infected Mφs, it was found that ATP enhanced intracellular translocation of cPLA_2 into MAC-containing phagosomes. (4)This cPLA_2 translocation was found to coincide with infection-induced Mφ apoptosis. (5)When CHO cells and CD36^+CHO cells transfected with GFP tagged cPLA_2 (GFP-cPLA_2) were infected with MAC, intracellular GFP-cPLA_2 was observed to translocate to the MAC-containing phagosomes. Since cellular cPLA_2 activities and translocation are tightly regulated by phosphorylation of certain serine residues of cPLA_2 molecules, it is of interest to examine the roles of cPLA_2's serine residues, including Ser505,Ser515 and Ser727,in intracellular translocation and activation cPLA_2 in MAC-infected Mφs. In this context, we are currently attempting to generate vectors encoding the cDNAs of GFP-tagged cPLA_2 with appropriate phosphorylation site mutations.
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