Zijlstra M, Vasmel W L, Voormanns M, de Goede R E, Schoenmakers H J, Nieland J, Slater R M, Melief C J
J Exp Med. 1986 May 1;163(5):1213-26. doi: 10.1084/jem.163.5.1213.
To study the role of class II MHC expression in mouse lymphomagenesis, we examined the cell surface expression of I-A/E antigens on 24 spontaneous or murine leukemia virus (MuLV)-induced mouse B10.A (I-Ak, I-Ek) B cell lymphomas. Two primary B10.A B cell lymphomas were observed with strong I-Ek expression but with only minimal cell surface I-Ak expression. Both tumors are readily transplantable in syngeneic mice, with maintenance of their I-A-, I-E+ phenotype. Strikingly, one I-A-, I-E+ B cell lymphoma contains a (11; 17) translocation with a breakpoint on chromosome 17 that is localized within or very close to the H-2 complex. DNA of both tumors contains normal restriction enzyme fragments of the A alpha and A beta genes. Northern blot analyses indicated that one I-A-, I-E+ tumor strongly expressed A alpha, E alpha, and E beta mRNAs but possessed only a weak expression of A beta mRNA. The other B cell lymphoma showed A beta, E alpha, and E beta mRNA expression but only minimal A alpha mRNA expression. In 11 primary B10.A B cell lymphomas with a normal I-A+, I-E+ phenotype, no imbalances in A alpha/A beta mRNA levels were observed. The implications of these findings for the role of class II MHC expression in mouse B cell lymphoma-genesis are discussed.
为了研究II类主要组织相容性复合体（MHC）表达在小鼠淋巴瘤发生中的作用，我们检测了24例自发或鼠白血病病毒（MuLV）诱导的小鼠B10.A（I-Ak，I-Ek）B细胞淋巴瘤细胞表面I-A/E抗原的表达情况。观察到两例原发性B10.A B细胞淋巴瘤有强I-Ek表达，但细胞表面I-Ak表达极少。这两种肿瘤均可在同基因小鼠中轻易移植，并维持其I-A-、I-E+表型。引人注目的是，一例I-A-、I-E+ B细胞淋巴瘤存在（11；17）易位，17号染色体上的断裂点位于H-2复合体内或非常靠近该复合体。两种肿瘤的DNA均含有Aα和Aβ基因的正常限制性酶切片段。Northern印迹分析表明，一例I-A-、I-E+肿瘤强烈表达Aα、Eα和Eβ mRNA，但Aβ mRNA表达较弱。另一例B细胞淋巴瘤显示Aβ、Eα和Eβ mRNA表达，但Aα mRNA表达极少。在11例具有正常I-A+、I-E+表型的原发性B10.A B细胞淋巴瘤中，未观察到Aα/Aβ mRNA水平的失衡。本文讨论了这些发现对于II类MHC表达在小鼠B细胞淋巴瘤发生中作用的意义。
