02183nas a2200325   4500000000100000008004100001260001300042653001200055653002500067653005300092653001100145653001900156653001200175653004100187653001600228653000900244653002400253653001400277653002500291653001800316100001300334700001200347700001500359700001200374245009700386300000900483490000600492520134500498022001401843       2007                            d  c2007 Jan10aAnimals10aCell Differentiation10aGranulocyte-Macrophage Colony-Stimulating Factor10aHumans10aInterleukin-1010aleprosy10aMacrophage Colony-Stimulating Factor10aMacrophages10aMice10aMice, Inbred BALB C10aMonocytes10aMycobacterium leprae10aT-Lymphocytes1 aMakino M1 aMaeda Y1 aFukutomi Y1 aMukai T00aContribution of GM-CSF on the enhancement of the T cell-stimulating activity of macrophages.  a70-70 v93 a<p>Mycobacterium leprae is an intracellular parasitic organism that multiplies in macrophages (MØ). It inhibits the fusion of mycobacterial phagosome with lysosome and induces interleukin (IL)-10 production from macrophages. However, macrophages are heterogenous in various aspects. We examined macrophages that differentiated from monocytes using either recombinant (r) granulocyte-MØ colony-stimulating factor (GM-CSF) (these MØ are named as GM-MØ) or rMØ colony-stimulating factor (M-CSF) (cells named as M-MØ) in terms of the T cell-stimulating activity. Although both macrophages phagocytosed the mycobacteria equally, GM-MØ infected with M. leprae and subsequently treated with IFN-gamma- and CD40 ligand (L) stimulated T cells to produce interferon-gamma (IFN-gamma), but M-MØ lacked the ability to stimulate T cells. While M-MØ mounted a massive IL-10 production, GM-MØ did not produce the cytokine on infection with M. leprae. M. leprae-infected, IFN-gamma- and CD40L-treated GM-MØ expressed a higher level of HLA-DR and CD86 Ags than those of M-MØ, and expressed one of the dominant antigenic molecules of M. leprae, Major Membrane Protein-II on their surface. These results indicate that GM-CSF, but not M-CSF, contributes to the up-regulation of the T cell-stimulating activity of M. leprae-infected macrophages.</p>  a1286-4579