Kaneko T, Fusauchi Y, Kakui Y, Masuda M, Akahoshi M, Teramura M, Motoji T, Okumura K, Mizoguchi H, Oshimi K
Department of Hematology, Tokyo Women's Medical College, Japan.
Blood. 1993 Mar 1;81(5):1333-41.
An anti-CD3 Fab' x anti-CD13 Fab' bispecific antibody (BsAb) was generated. This BsAb reacted with both CD3+ T cells and CD13+ acute myeloid leukemia (AML) cells. We investigated whether cytokine-stimulated peripheral blood mononuclear cells (PBMC) could lyse patient AML cells after addition of the BsAb. When interleukin-2 (IL-2)-stimulated PBMC were assayed for their cytotoxicity against 51Cr-labeled allogeneic and autologous CD13+ AML cells, their activity was markedly enhanced by the addition of the BsAb. PBMC stimulated with IL-2 plus anti-CD3 monoclonal antibody (MoAb) showed higher proliferative ability and higher cytotoxicity if this was expressed as lytic units per culture. IL-7-stimulated PBMC also exhibited enhanced cytotoxicity against CD13+ AML cells after addition of the BsAb. Ultrastructurally, CD13+ AML cells incubated with IL-2 plus anti-CD3 MoAb-stimulated PBMC and the BsAb showed apoptotic morphologic changes. A colony assay for AML blast progenitors showed that the colony formation of CD13+ AML cells was inhibited by the addition of autologous IL-2 plus anti-CD3 MoAb-stimulated PBMC, and that this inhibition was further enhanced by the addition of the BsAb. A colony assay for normal bone marrow progenitor cells showed that the addition of autologous IL-2 plus anti-CD3 MoAb-stimulated PBMC and the BsAb inhibited the formation of granulocyte-macrophage colonies and mixed-cell colonies. However, the degree of inhibition was smaller than that for the AML blast colonies. Taken together, these findings suggest that this BsAb may be useful for ex vivo purging of CD13+ AML cells in autologous bone marrow transplantation.
制备了一种抗CD3 Fab'×抗CD13 Fab'双特异性抗体（BsAb）。该BsAb可与CD3 + T细胞和CD13 +急性髓性白血病（AML）细胞发生反应。我们研究了在添加BsAb后，细胞因子刺激的外周血单个核细胞（PBMC）是否能够裂解患者的AML细胞。当检测白细胞介素-2（IL-2）刺激的PBMC对51Cr标记的同种异体和自体CD13 + AML细胞的细胞毒性时，添加BsAb可显著增强其活性。如果以每培养物的裂解单位表示，用IL-2加抗CD3单克隆抗体（MoAb）刺激的PBMC显示出更高的增殖能力和更高的细胞毒性。添加BsAb后，IL-7刺激的PBMC对CD13 + AML细胞也表现出增强的细胞毒性。在超微结构上，与IL-2加抗CD3 MoAb刺激的PBMC和BsAb一起孵育的CD13 + AML细胞显示出凋亡形态学变化。AML原始祖细胞的集落测定表明，添加自体IL-2加抗CD3 MoAb刺激的PBMC可抑制CD13 + AML细胞的集落形成，而添加BsAb可进一步增强这种抑制作用。正常骨髓祖细胞的集落测定表明，添加自体IL-2加抗CD3 MoAb刺激的PBMC和BsAb可抑制粒细胞-巨噬细胞集落和混合细胞集落的形成。然而，抑制程度小于AML原始集落。综上所述，这些发现表明该BsAb可能有助于自体骨髓移植中体外清除CD13 + AML细胞。
