Detection of Novel CD Antigens on the Surface of Human Mast Cells and Basophils

Background: Mast cells (MC) and basophils are effector cells of allergic reactions. Growth and function of these cells are regulated by a network of cytokines, other ligands, and respective cell surface membrane receptors. Methods: In the present study, we examined the expression of novel CD antigens on human lung MC, skin MC, blood basophils, the MC line HMC-1, and the basophil cell line KU-812. Expression of surface antigens was analyzed by monoclonal antibodies (mAbs) and indirect immunofluorescence staining techniques. Results: Primary MC were found to react with mAbs against KIT (CD117), the signal regulatory protein SIRP-α (CD172a), and the ectoenzyme E-NPP3 (CD203c). Human basophils were found to express large amounts of E-NPP3 and lower levels of Siglec-5 (CD170), CXCR4 (CD184) and SIRP-α. The HMC-1 cell line was recognized by mAbs against SIRP-α, CXCR4, endothelial protein C receptor (CD201) and E-NPP3. KU-812 cells were found to react with mAbs against E-NPP3, CXCR4 and glycophorin C (CD236R), but did not react with mAb against endothelial protein C receptor. Most of the other CD antigens tested disclosed negative results. Conclusions: In summary, our data provide further evidence that MC and basophils express a unique composition of surface antigens. The use of novel CD antibodies may help to isolate MC and basophils and to study their functional properties.