Revoltella R P, Laricchia Robbio L, Liberati A M, Reato G, Foa R, Funaro A, Vinante F, Pizzolo G
Institute of Mutagenesis and Differentiation, C.N.R., Via G. Moruzzi 1, Pisa, 56100, Italy.
Cell Immunol. 2000 Sep 15;204(2):114-27. doi: 10.1006/cimm.2000.1704.
We detected natural antibodies (auto-Abs) binding human granulocyte-macrophage colony stimulating factor (GM-CSF) in umbilical cord blood (CB) (23 of 94 samples screened) and peripheral blood of women at the end of pregnancy (6 of 42 samples tested). To demonstrate that Abs detected in CB were produced by the fetus, CB mononuclear cells were infected with Epstein-Barr virus in vitro. Ten cell lines producing constitutively anti-recombinant human GM-CSF (rhGM-CSF) Abs were isolated and characterized. These cells displayed a male karyotype, an early activated B cell phenotype, coexpressed surface IgM and IgD, and secreted only IgM with prevailing lambda clonal restriction. Specific cell surface binding of biotinylated rhGM-CSF and high-level anti-rhGM-CSF IgM Ab production were typical features of early cell cultures. In late cell passages the frequency of more undifferentiated B cells increased. Serum Abs of either maternal or fetal origin or Abs produced in culture did not affect the granulocyte and macrophage colony stimulating activity of rhGM-CSF from bone marrow progenitors in soft agar, suggesting that the Abs produced were nonneutralizing.
我们在脐带血（CB）（筛查的94个样本中有23个）和妊娠末期女性的外周血（检测的42个样本中有6个）中检测到了与人类粒细胞巨噬细胞集落刺激因子（GM-CSF）结合的天然抗体（自身抗体）。为了证明在脐带血中检测到的抗体是由胎儿产生的，体外将脐带血单个核细胞感染爱泼斯坦-巴尔病毒。分离并鉴定了10个持续产生抗重组人GM-CSF（rhGM-CSF）抗体的细胞系。这些细胞表现出男性核型，早期活化B细胞表型，共表达表面IgM和IgD，且仅分泌具有主要λ克隆限制性的IgM。生物素化rhGM-CSF的特异性细胞表面结合和高水平抗rhGM-CSF IgM抗体产生是早期细胞培养的典型特征。在后期细胞传代中，更多未分化B细胞的频率增加。来自母体或胎儿的血清抗体或培养物中产生的抗体均不影响软琼脂中骨髓祖细胞来源的rhGM-CSF的粒细胞和巨噬细胞集落刺激活性，这表明产生的抗体不具有中和作用。
