title: My4+/LeuM3- molecule and CD19 antigen are down-modulate by low affinity Fc gamma receptor II (CD32) stimulation on CD56-positive B-lymphoma cells.
abstract: My4+/LeuM3- molecule is recognized by My4, but not by LeuM3, both well known mAbs to CD14. In a previous study we showed that the My4+/LeuM3- molecule on a human monoblastic cell line, U937, is not CD14, but another cell surface antigen. The roles and functions of the My4+/LeuM3- molecule remained unknown. We now report that specific stimulation of Fc gammaR with aggregated IgG or anti-Fc gammaRII antibody down-modulated the My4+/LeuM3- molecules, as well as CD19, in a case of CD56-positive B cell lymphoma. Stimulation of Fc gammaR with anti-mu antibody, which induced concomitant stimulation of sIg, did not induce down-modulation of either molecule. Stimulation of CR2 (CD21), a protein which is functionally or physically associated with CD19, with anti-CR2 (CD21) mAbs also had no effect. The modulation occurred specifically on CD56-positive B-lymphoma cells, since My4+/LeuM3(-)-positive, CD56-negative B-lymphoma cells did not respond to the stimulation. These results suggest that CD19 and My4+/LeuM3- molecules are functionally or physically associated with Fc gammaR II on CD56 positive B-lymphoma cells defined as being at a terminal B cell differentiation stage.
authors.affiliation: Central Clinical Laboratory, Osaka Medical College, Takatsuki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ikemoto
authors.forename: T
authors.initials: T
authors.lastname: Nakagawa
authors.forename: M
authors.initials: M
authors.lastname: Hatanaka
authors.forename: M
authors.initials: M
authors.lastname: Hasegawa
authors.forename: T
authors.initials: T
authors.lastname: Kageyama
authors.forename: M
authors.initials: M
authors.lastname: Hirano
authors.forename: A
authors.initials: A
authors.lastname: Shimizu
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D018941:Antigens, CD19 / Q000187:drug effects / Q000502:physiology; D000951:Antigens, Neoplasm / Q000187:drug effects / Q000502:physiology*; D000954:Antigens, Surface / Q000187:drug effects / Q000502:physiology; D019002:CD56 Antigen / Q000378:metabolism; D015536:Down-Regulation; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism / Q000494:pharmacology; D016130:Immunophenotyping; D018950:Lipopolysaccharide Receptors / Q000502:physiology*; D016393:Lymphoma, B-Cell / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D017452:Receptors, IgG / Q000276:immunology / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000911:Antibodies, Monoclonal; D018941:Antigens, CD19; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D019002:CD56 Antigen; D007074:Immunoglobulin G; D018950:Lipopolysaccharide Receptors; D017452:Receptors, IgG