Ashman L K, Cambareri A C, Eglinton J M
Department of Microbiology and Immunology, University of Adelaide, South Australia.
Leuk Res. 1990;14(7):637-44. doi: 10.1016/0145-2126(90)90019-6.
Monoclonal antibody YB5.B8 was previously shown to inhibit haemopoietic colony formation in response to a complex growth factor supplement in vitro (Cambareri A. C., Ashman L. K., Cole S. R. & Lyons A. B. (1988), Leukemia Res. 12, 929). We now report studies of the effect of the antibody on colony formation by normal human bone marrow cells in response to recombinant human colony-stimulating factors GM-CSF, G-CSF and IL-3. MAb YB5.B8 significantly reduced the yield of colonies of all types examined (granulocyte-macrophage, granulocyte, macrophage and eosinophil) in response to GM-CSF but not to IL-3 or G-CSF. However, MAb YB5.B8 failed to influence the proliferation of the myelomonocytic leukaemia cell line RC-2A in response to GM-CSF, G-CSF or IL-3. Direct binding studies demonstrated the presence of low numbers of receptors for GM-CSF on RC-2A cells, however, the binding of this cytokine was not influenced by co- and/or pre-incubation with MAb YB5.B8. Therefore the antigen identified by YB5.B8 is probably not a receptor for GM-CSF and may indirectly influence the response of normal haemopoietic progenitors to this cytokine.
单克隆抗体YB5.B8先前已被证明可在体外抑制对复合生长因子补充剂产生反应的造血集落形成（Cambareri A.C., Ashman L.K., Cole S.R. & Lyons A.B. (1988), Leukemia Res. 12, 929）。我们现在报告该抗体对正常人骨髓细胞在重组人集落刺激因子GM-CSF、G-CSF和IL-3作用下集落形成的影响研究。单克隆抗体YB5.B8显著降低了对GM-CSF产生反应的所有检测类型集落（粒细胞-巨噬细胞、粒细胞、巨噬细胞和嗜酸性粒细胞）的产量，但对IL-3或G-CSF无此作用。然而，单克隆抗体YB5.B8未能影响髓单核细胞白血病细胞系RC-2A在GM-CSF、G-CSF或IL-3作用下的增殖。直接结合研究表明RC-2A细胞上存在少量GM-CSF受体，然而，该细胞因子的结合不受与单克隆抗体YB5.B8共同孵育和/或预孵育的影响。因此，YB5.B8识别的抗原可能不是GM-CSF的受体，可能间接影响正常造血祖细胞对该细胞因子的反应。
