Frøyland Marianne, Thompson Keith M, Thorpe Susan J, Sahota Surinder S, Gedde-Dahl Tobias, Bogen Bjarne
Institute of Immunology, University of Oslo and Rikshospitalet-Radiumhospitalet Medical Center, Oslo, Norway.
Haematologica. 2007 May;92(5):690-3. doi: 10.3324/haematol.10850.
It has been suggested that VH4-34 gene segment expression is counter-selected in multiple myeloma (MM) due to a self-tolerance mechanism. We cloned and sequenced a VH4-34 gene segment from bone marrow mononuclear cells of a stage III MM patient. We show that VH4-34 was expressed by the serum IgA myeloma (M)-protein, as demonstrated by reactivity with the VH4-34 specific 9G4 mAb and mass spectrometry (MS). The M-protein had weak reactivity with nuclei. These results demonstrate that VH4-34 may be expressed in secreted IgA M-protein with weak autoreactivity. Thus, counter-selection of VH4-34 is pronounced but not absolute in MM. Mechanisms of how VH4-34 can occasionally be expressed in MM and clinical implications are discussed.
有人提出，由于自身耐受机制，VH4-34基因片段的表达在多发性骨髓瘤（MM）中受到反向选择。我们从一名III期MM患者的骨髓单个核细胞中克隆并测序了一个VH4-34基因片段。我们发现，血清IgA骨髓瘤（M）蛋白表达了VH4-34，这通过与VH4-34特异性9G4单克隆抗体的反应性和质谱（MS）得以证明。M蛋白与细胞核的反应性较弱。这些结果表明，VH4-34可能在具有弱自身反应性的分泌型IgA M蛋白中表达。因此，VH4-34的反向选择在MM中很明显，但不是绝对的。本文讨论了VH4-34在MM中偶尔表达的机制及其临床意义。
