Selective upregulation of a functional beta7 integrin on differentiating eosinophils.
BACKGROUND
The sequence of adhesion-molecule expression during eosinophil differentiation remains unclear.


METHODS
We analyzed the surface expression of alpha4, beta1, and beta7 integrins and compared it to established myeloid developmental markers, using the eosinophilic cell line HL-60 clone 15, as well as cord and peripheral blood differentiation assays.


RESULTS
Cells induced to eosinophil differentiation by treatment with butyric acid, IL-5, and GM-CSF showed a significant upregulation of beta7 integrin expression coincident with a marked upregulation of CD35 and attenuation of CD33 and beta1 integrin expression. In addition, adhesion of induced HL-60 clone 15 cells to fibronectin was attenuated by a beta7 integrin antibody.


CONCLUSIONS
Our data show that protein synthesis-dependent upregulation of the functional beta7 integrin occurs under conditions when beta4 and beta1 integrins are fully expressed, indicating a sequential appearance of specific adhesion molecules on differentiating eosinophil progenitors.
Lundahl
J
J
Department of Medicine, McMaster University, Hamilton, ON, Canada.
Sehmi
R
R
Hayes
L
L
Howie
K
K
Denburg
J A
JA
D015703:Antigens, CD / Q000378:metabolism; D002448:Cell Adhesion; D002454:Cell Differentiation; D004804:Eosinophils / Q000166:cytology* / Q000276:immunology*; D005353:Fibronectins / Q000378:metabolism; D005434:Flow Cytometry / Q000379:methods; D018922:HL-60 Cells; D006632:Histamine / Q000378:metabolism; D006801:Humans; D039441:Integrin alpha4; D039641:Integrin beta Chains; D019012:Integrin beta1 / Q000378:metabolism; D016023:Integrins / Q000378:metabolism*; D015854:Up-Regulation
D015703:Antigens, CD; D005353:Fibronectins; D039641:Integrin beta Chains; D019012:Integrin beta1; D016023:Integrins; C091368:integrin beta7; D039441:Integrin alpha4; D006632:Histamine