Monomeric IgE and lipopolysaccharide synergistically prevent mast-cell apoptosis.
The apoptosis of bone marrow-derived mast-cells (BMMCs) after growth factor withdrawal was significantly prevented by a high concentration of IgE in the absence of antigen, and further enhanced by the presence of Toll-like receptor4 (TLR4) ligand, lipopolysaccharide (LPS). The effect of LPS was mediated by TLR4, since TLR4-deficient BMMCs did not show synergistic effects with IgE. The neutralizing amount of anti-IL-3 did not reverse the anti-apoptotic effects of both IgE and combination with LPS. LPS treatment with monomeric IgE synergistically prevented the loss of mitochondrial membrane potentials and was associated with an enhanced expression of anti-apoptotic protein, Bcl-xL, or with a reduced expression of proapoptotic protein, Puma, and Bim, respectively. Altogether, these results suggest that LPS, in a TLR4-dependent manner, together with IgE, synergistically prevent mast-cell apoptosis and may contribute to regulate the tissue mast-cell number.
Jayawardana
Sumanasiri T M
ST
Atopy (Allergy) Research Center, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
Ushio
Hiroko
H
Niyonsaba
François
F
Gondokaryono
Srie Prihianti
SP
Takenaka
Hiroshi
H
Ikeda
Shigaku
S
Okumura
Ko
K
Ogawa
Hideoki
H
D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D000072224:Bcl-2-Like Protein 11; D004357:Drug Synergism; D007073:Immunoglobulin E / Q000494:pharmacology*; D007377:Interleukin-3 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology*; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D051336:Mitochondrial Membranes / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; D000072224:Bcl-2-Like Protein 11; C494812:Bcl2l1 protein, mouse; C000606776:Bcl2l11 protein, mouse; D007377:Interleukin-3; D008070:Lipopolysaccharides; D008565:Membrane Proteins; C488588:PUMA protein, mouse; D011518:Proto-Oncogene Proteins; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D025521:Tumor Suppressor Proteins; D051020:bcl-X Protein; D007073:Immunoglobulin E