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Identification of human CD93 as the phagocytic C1q receptor (C1qRp) by expression cloning
Author(s) -
Steinberger Peter,
Szekeres Andreas,
Wille Stefan,
Stöckl Johannes,
Selenko Nicole,
Prager Elisabeth,
Staffler Günther,
Madic Otto,
Stockinger Hannes,
Knapp Walter
Publication year - 2002
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.71.1.133
Subject(s) - biology , microbiology and biotechnology , phagocytosis , haematopoiesis , receptor , complementary dna , macrophage , cloning (programming) , in vitro , gene , stem cell , biochemistry , computer science , programming language
CD93 is a ∼120 kDa O ‐sialoglycoprotein that within the hematopoietic system is selectively expressed on cells of the myeloid lineage. So far, its primary structure and function were unknown. We used retroviral‐expression cloning to isolate the CD93 cDNA. Sequence analysis revealed that CD93 is identical to a protein on human phagocytes termed C1q receptor (C1qRp). C1qRp was shown previously to mediate enhancement of phagocytosis in monocytes and was suggested to be a receptor of C1q and two other structurally related molecules. When studying CD93 transductants and control cells, we found that cells expressing CD93 have enhanced capacity to bind C1q. Furthermore, we show that immature dendritic cells (DC) express CD93/C1qRp, and mature DC, known to have reduced capacity for antigen uptake and to have lost the ability to phagocytose, show weak‐to‐negative CD93/C1qRp expression.