Identification of a widely distributed 90-kDa glycoprotein that is homologous to the Hermes-1 human lymphocyte homing receptor.
Homing of recirculating lymphocytes from the blood into the lymphoid tissues is mediated by 90-kDa homing receptors on the lymphocyte cell surface, allowing selective binding to specialized endothelium lining high endothelial venules. This study describes two novel mAb, NKI-P1 and NKI-P2, directed against functional epitopes of a human lymphocyte homing receptor, gp90. Biochemical studies demonstrated that these antibodies recognize a 90-kDa glycoprotein which is similar to the Ag recognized by the mAb Hermes-1. This notion was confirmed by immunohistochemical studies showing identical reaction patterns. Furthermore, it was observed that NKI-P1 and NKI-P2 blocked adhesion of lymphocytes to high endothelial venules. Immunohistochemical, immunofluorescence, and immunoprecipitation studies revealed that gp90 is widely expressed on hemopoietic cells including lymphocytes, macrophages/dendritic cells, myeloid cells, and erythrocytes. The gp90 is also expressed on a number of nonhemopoietic cells such as endothelial cells, certain epithelial cells, and fibroblasts. In addition to its expression on normal cells, gp90 is present on a spectrum of tumor cell lines of lymphoid, monocytic, epithelial, glial, and melanocytic origin. In addition to the 90-kDa product, the antibodies immunoprecipitate several polypeptides in the range of 120 to 200 kDa. Interestingly, it was observed that certain mamma tumor cell-line cells lack the 90-kDa polypeptide indicating the heterogeneous expression of the molecules recognized by the antibodies. These results indicate that the 90-kDa glycoprotein homologues of the Hermes-1 human lymphocyte homing receptor are expressed on hemopoietic tissues as well as on a number of nonhemopoietic tissues and tumor cell lines. Although the function of these molecules in nonlymphoid cells is presently unknown, they might play a role in cell-cell or cell-matrix adhesion.
Pals
S T
ST
Department of Pathology, Free University, Amsterdam, The Netherlands.
Hogervorst
F
F
Keizer
G D
GD
Thepen
T
T
Horst
E
E
Figdor
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CC
D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D000954:Antigens, Surface / Q000276:immunology / Q000302:isolation & purification*; D001402:B-Lymphocytes / Q000502:physiology; D002449:Cell Aggregation; D002460:Cell Line; D006023:Glycoproteins / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D008562:Membrane Glycoproteins / Q000276:immunology / Q000302:isolation & purification*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D011233:Precipitin Tests; D011971:Receptors, Immunologic / Q000276:immunology / Q000302:isolation & purification*; D016201:Receptors, Lymphocyte Homing; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D016201:Receptors, Lymphocyte Homing