Enhancement of the antibody-dependent tumoricidal activity of human monocytes by human monocytic colony-stimulating factor.
Human monocytic colony-stimulating factor (hM-CSF) stimulates mature cells as well as progenitor cells of human monocyte lineage. In the present study, we investigated the effect of completely purified native hM-CSF on the tumoricidal activity of human monocytes against Raji (Burkitt lymphoma-derived cell line) using a chromium release assay. Preincubation of human peripheral blood monocytes with hM-CSF for 48 h markedly enhanced their antibody-dependent cellular cytotoxicity (ADCC). This enhancing effect was dependent on the concentration of hM-CSF, and maximal enhancement was achieved at the concentration of 66 ng/ml. The number of receptor sites on monocytes against the Fc portion of immunoglobulin G increased 2- to 4-fold during 48 h incubation with hM-CSF. These results suggest that hM-CSF stimulates monocyte-ADCC by increasing the number of Fc receptor sites on human monocytes.
Suzu
S
S
Biochemical Research Laboratory, Morinaga Milk Industry Co., Ltd., Kanagawa.
Yanai
N
N
Saito
M
M
Kawashima
T
T
Kasahara
T
T
Saito
M
M
Takaku
F
F
Motoyoshi
K
K
D000920:Antibody-Dependent Cell Cytotoxicity; D002051:Burkitt Lymphoma / Q000276:immunology*; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D016173:Macrophage Colony-Stimulating Factor; D009000:Monocytes / Q000276:immunology*; D011961:Receptors, Fc / Q000276:immunology / Q000378:metabolism; D012397:Rosette Formation; D014407:Tumor Cells, Cultured
D003115:Colony-Stimulating Factors; D007074:Immunoglobulin G; D011961:Receptors, Fc; D016173:Macrophage Colony-Stimulating Factor