TY - JOUR
T1 - CD11b/CD18 (Mac-1) is required for degranulation of human eosinophils induced by human recombinant granulocyte-macrophage colony-stimulating factor and platelet-activating factor
AU - Horie, Shiro
AU - Kita, Hirohito
PY - 1994/6/1
Y1 - 1994/6/1
N2 - Recent evidence suggests adhesion molecules play an important role in the function of leukocytes. Because human eosinophils are known to express β2 integrins, we hypothesized that these adhesion molecules mediate the effector function of eosinophils. Normal human eosinophils incubated in albumin- coated polystyrene plates released granule protein and produced superoxide anion when stimulated with human recombinant granulocyte-macrophage CSF (rGM- CSF), platelet-activating factor (PAF), or PMA. Simultaneous monitoring of eosinophil adhesion and degranulation showed that degranulation was always preceded by cellular adhesion regardless of stimuli. Furthermore, eosinophil degranulation induced by human rGM-CSF and PAF was abolished in suspension culture of the cells when the cell suspensions were gently stirred. To identify the molecules involved in this adhesion-dependent degranulation, we have investigated the effects of mAbs (mAb) against β integrins. mAb reactive with CD18 markedly inhibited the eosinophil adhesion and degranulation induced by PAF and human rGM-CSF. mAb reactive with CD11b also moderately inhibited the adhesion and degranulation. In contrast, mAb reactive with CD11a slightly enhanced or showed no effect on the adhesion and degranulation by human rGM-CSF or PAF. Superoxide production induced by human rGM-CSF and PAF was also abolished by the treatment of cells with anti-CD18 mAb. mAb against CD11b and CD18 had little effect on degranulation and superoxide production induced by PMA. These results indicate that CD11b/CD18 (Mac-1)-dependent cellular adhesion plays an important role in the degranulation and superoxide production of eosinophils induced by human rGM- CSF and PAF, and that these mechanisms may be employed in vivo where eosinophils contact with stromal cells and/or proteins.
AB - Recent evidence suggests adhesion molecules play an important role in the function of leukocytes. Because human eosinophils are known to express β2 integrins, we hypothesized that these adhesion molecules mediate the effector function of eosinophils. Normal human eosinophils incubated in albumin- coated polystyrene plates released granule protein and produced superoxide anion when stimulated with human recombinant granulocyte-macrophage CSF (rGM- CSF), platelet-activating factor (PAF), or PMA. Simultaneous monitoring of eosinophil adhesion and degranulation showed that degranulation was always preceded by cellular adhesion regardless of stimuli. Furthermore, eosinophil degranulation induced by human rGM-CSF and PAF was abolished in suspension culture of the cells when the cell suspensions were gently stirred. To identify the molecules involved in this adhesion-dependent degranulation, we have investigated the effects of mAbs (mAb) against β integrins. mAb reactive with CD18 markedly inhibited the eosinophil adhesion and degranulation induced by PAF and human rGM-CSF. mAb reactive with CD11b also moderately inhibited the adhesion and degranulation. In contrast, mAb reactive with CD11a slightly enhanced or showed no effect on the adhesion and degranulation by human rGM-CSF or PAF. Superoxide production induced by human rGM-CSF and PAF was also abolished by the treatment of cells with anti-CD18 mAb. mAb against CD11b and CD18 had little effect on degranulation and superoxide production induced by PMA. These results indicate that CD11b/CD18 (Mac-1)-dependent cellular adhesion plays an important role in the degranulation and superoxide production of eosinophils induced by human rGM- CSF and PAF, and that these mechanisms may be employed in vivo where eosinophils contact with stromal cells and/or proteins.
UR - http://www.scopus.com/inward/record.url?scp=0028332666&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028332666&partnerID=8YFLogxK
M3 - Article
C2 - 7514638
AN - SCOPUS:0028332666
SN - 0022-1767
VL - 152
SP - 5457
EP - 5467
JO - Journal of Immunology
JF - Journal of Immunology
IS - 11
ER -