Detection of novel CD antigens on the surface of human mast cells and basophils

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.

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.

Primary MC were found to react with mAbs against KIT (CD117), the signal regulatory protein SIRP-alpha (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-alpha. The HMC-1 cell line was recognized by mAbs against SIRP-alpha, 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.

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.