抗CD44抗体对激活的T淋巴细胞介导的白血病细胞的细胞毒作用的影响

目的　研究抗CD4 4抗体对正常人T淋巴细胞增殖及对T淋巴细胞介导的急性髓性白血病细胞的细胞毒作用的影响。方法　利用 3H]TdR掺入法检测T淋巴细胞的DNA合成 ;利用双染色 流式细胞仪法检测T淋巴细胞介导的白血病细胞的细胞毒作用。结果　单独抗CD4 4抗体对IL 2激活的T淋巴细胞的DNA合成无明显影响 ,但协同抗CD2 抗体后明显增强了抗CD2 抗体对IL 2激活的T淋巴细胞DNA合成的抑制。单独抗CD4 4抗体即可抑制IL 2激活的T淋巴细胞介导的白血病细胞的细胞毒作用 ,协同抗CD2 抗体后对IL 2激活的T淋巴细胞介导的白血病细胞的细胞毒作用的抑制更加明显。结论　CD4 4的交联所导致的阴性信号传入而引起的T淋巴细胞增殖的抑制可能是通过CD2 交联而诱导的。抗CD4 4抗体和抗CD2 抗体对T淋巴细胞所介导的白血病细胞的细胞毒作用的抑制可能与其部分地封闭了CD4 4分子和CD2 分子的表达以及与干扰了Fas FasL的结合有关

Effects of anti-CD44 antibody on the cytotoxicity of leukemic cells mediated by activated T lymphocyte

Objective To study the effect of anti CD 44 antibody alone or combined anti CD 44 with anti CD 2 antibodies on the normal T lymphocyte proliferation and on the cytotoxicity of acute myelogenous leukemic cell mediated by T lymphocyte. Methods The authors pretreated the normal T lymphocyte activated by IL 2 with the anti CD 44 antibody alone, or combined with anti CD 2 antibodies with different concentrations DNA synthesis and the cytotoxicity of leukemic cell line MML 1 mediated by T lymphocyte were respectively detected with 3H] TdR incorporation method and double staining flow cytometry. Results Anti CD 44 antibody alone could not induce the proliferation of T lymphocyte activated by IL 2, and showed no influence on the DNA synthesis of T lymphocyte activated by IL 2. However, the combination of anti CD 44 with anti CD 2 antibodies could significantly increase the inhibitory effect of anti CD 2 antibody on the IL 2 activated T lymphocyte proliferation and the DNA synthesis. Anti CD 44 or anti CD 2 antibody alone could inhibit the cytotoxicity of leukemic cell line MML 1 mediated by the IL 2 activated T lymphocyte, and then the PKH2 PI double staining leukemic cells decreased. The combinatory effect of anti CD 44 with anti CD 2 antibodies obviously increased the inhibitory on the cytotoxicity of the activated T lymphocyte. Conclusion The inhibit effect of T lymphocyte proliferation induced by the negative signal transduction resulted from the CD 44 molecule cross ligated with CD 44 antibody might associate with the CD 2 molecule cross ligation. The inhibitory effect of anti CD 44 and anti CD 2 antibody on the cytotoxicity of leukemic cell line MML 1 mediated by the IL 2 activated T lymphocyte might be due to the partial block of the expressions of CD 44 and CD 2 molecules, which might interfere with the Fas FasL ligation.