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Identification of IgG Fc receptor type II on human megakaryoblastic cell lines (MEG‐01 and UT‐7)
Author(s) -
Wu Zhanhe,
Chesterman Colin N.,
Chong Beng H.
Publication year - 1993
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1993.tb03053.x
Subject(s) - receptor , identification (biology) , immunology , medicine , microbiology and biotechnology , biology , botany
Summary. In this study, Fcγ receptors (FcγR) on the cells of human megakaryoblastic leukaemia cell lines (Meg‐01 and UT‐7) were investigated. Binding of the anti‐FcγRII monoclonal antibody (MoAb) IV. 3 but not anti‐FcγRI MoAb (32.2), anti‐FcγRIII MoAb (3G8) nor control murine IgGs to Meg‐01 and UT‐7 cells was demonstrated by immunocytochemical staining and flow cytometric analysis. There was specific and saturable binding of 125 I‐labelled IV.3 Fab fragments to the megakaryoblasts but no binding of 125 I‐labelled 32.2 Fab nor 3G8 Fab fragments. MoAb IV.3 immunoprecipitated a 40 kD protein (FcγRII) from detergent cell lysates of surface radio‐labelled Meg‐01 and UT‐7 cells. More importantly, IV.3 Fab almost completely inhibited the binding of 125 I‐labelled human aggregated IgG to the Meg‐01 cells. In contrast, neither 32.2 Fab, 3G8 Fab nor Fab fragments of the control murine IgGs were inhibitory. These results indicate that only FcγR Type II is expressed on megakaryoblasts in these two cell lines.