Original Paper Int Arch Allergy Immunol 2002;127:299–307 Detection of Novel CD Antigens on the Surface of Human Mast Cells and Basophils Minoo Ghannadan a Alexander W. Hauswirth a Gerit-Holger Schernthaner a Michael R. Müller b Walter Klepetko b Georg Schatzl c Wolfgang R. Sperr a Hans-Jörg Bühring d Peter Valent a a Department of Internal Medicine I, Division of Hematology and Hemostaseology, b Department of Surgery, c Department of Urology, University of Vienna, Austria; d Department of Internal Medicine II, University of Tübingen, Germany Received: May 21, 2001 Accepted after revision: November 2, 2001 Correspondence to: Prof. Dr. Peter Valent Department of Internal Medicine I Division of Hematology and Hemostaseology Währinger Gürtel 18–20, A–1090 Vienna (Austria) Tel. +43 1 40400 6085, Fax +43 1 402 6930, E-Mail peter.valent@akh-wien.ac.at ABC Fax + 41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 2002 S. Karger AG, Basel 1018–2438/02/1274–0299$18.50/0 Accessible online at: www.karger.com/journals/iaa Key Words Basophils W Mast cells W SIRP-· W E-NPP3 Abstract 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 recep- tors. M ethods: 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 baso- phil cell line KU-812. Expression of surface antigens was analyzed by monoclonal antibodies (mAbs) and indirect immunofluorescence staining techniques. Results: Pri- mary MC were found to react with mAbs against KIT (CD117), the signal regulatory protein SIRP-· (CD172a), and the ectoenzyme E-NPP3 (CD203c). Human basophils were found to express large amounts of E-NPP3 and low- er levels of Siglec-5 (CD170), CXCR4 (CD184) and SIRP-·. The HMC-1 cell line was recognized by mAbs against SIRP-·, 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 pro- vide further evidence that MC and basophils express a unique composition of surface antigens. The use of nov- el CD antibodies may help to isolate MC and basophils and to study their functional properties. Copyright © 2002 S. Karger AG, Basel Introduction Mast cells (MC) and basophils are effector cells of aller- gic reactions [1, 2]. Both cell types produce and store a number of mediators of allergy [1–4]. They also express high-affinity IgE-binding sites [5, 6], adhesion receptors [7, 8], virus- and complement-binding sites [9–13], surface membrane enzymes [9–12] and cytokine receptors [11, 12, 14–19]. Most of these surface structures are associated with distinct functional properties including proliferation, adhesion or mediator secretion [5, 12–14, 18–23]. During the past decade, the cell surface membrane phe- notype of human MC and human blood basophils has been established using antibodies against defined CD antigens [7–13]. Using these reagents, MC and basophils were found to differ in several aspects. Likewise, MC, but not basophils, express substantial amounts of CD117 (KIT) [11, 12, 19]. In contrast, basophils, but not tissue MC, express significant levels of CD18, CD31, and CD123 [in- terleukin (IL)-3R·] [11, 12, 14, 24]. In the present study,