Interleukin-3 promotes the expression of E-NPP3/CD203C on human blood basophils in healthy subjects and in patients with birch pollen allergy.
We recently identified the ectoenzyme CD203c as a novel basophil activation antigen that is upregulated in response to FcepsilonRI cross-linkage. We investigated the effects of various interleukins (ILs) on expression of CD203c on blood basophils using an antibody against CD203c and flow cytometry. Of all cytokines tested, only IL-3 was found to upregulate expression of CD203c on basophils above baseline levels. The effects of IL-3 were dose- and time-dependent (EC(50): 0.1-1 ng/ml) without differences observed between healthy and allergic donors. Whereas anti-IgE induced maximum upregulation of CD203c within 15 minutes, the IL-3-induced upregulation showed a maximum after 180 minutes. IgE-receptor cross-linking resulted in enhanced expression of both CD63 and CD203c, whereas IL-3 enhanced the levels of CD203c without promoting expression of CD63. The IL-3-induced upregulation of CD203c was also observed in highly enriched basophils and was counteracted by a blocking antibody against the alpha chain of the IL-3 receptor (CD123). The IL-3-induced upregulation of CD203c was also found to depend on the presence of calcium. To analyze signaling pathways involved in IL-3-induced upregulation of CD203c, pharmacologic inhibitors were applied. The PI3-kinase inhibitors, wortmannin and LY294002 counteracted the IL-3-induced expression of CD203c, whereas MEK- and PKC inhibitors showed no effects. In conclusion, IL-3 upregulates expression of CD203c on basophils through a specific receptor and via a PI3-kinase-dependent signaling-pathway. Compared to FcepsilonRI-mediated cell activation, IL-3-induced upregulation of CD203c is a late(r) event and is not accompanied by upregulation of CD63.
Hauswirth
A W
AW
Department of Internal Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Austria.
Sonneck
K
K
Florian
S
S
Krauth
M T
MT
Bohm
A
A
Sperr
W R
WR
Valenta
R
R
Schernthaner
G H
GH
Printz
D
D
Fritsch
G
G
Buhring
H J
HJ
Valent
P
P
D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics; D001491:Basophils / Q000276:immunology* / Q000378:metabolism*; D029662:Betula / Q000276:immunology*; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D007377:Interleukin-3 / Q000502:physiology*; D010727:Phosphoric Diester Hydrolases / Q000096:biosynthesis / Q000235:genetics*; D010980:Platelet Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D011058:Pollen / Q000276:immunology*; D011755:Pyrophosphatases / Q000096:biosynthesis / Q000235:genetics*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology*; D060149:Tetraspanin 30
D015703:Antigens, CD; C554586:CD63 protein, human; C427944:ENPP3 protein, human; D007377:Interleukin-3; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases