Yang Isaac, Kremen Thomas J, Giovannone Adrian J, Paik Elena, Odesa Sylvia K, Prins Robert M, Liau Linda M
UCLA Division of Neurosurgery, University of California at Los Angeles School of Medicine, Los Angeles, California 90095-6901, USA.
J Neurosurg. 2004 Feb;100(2):310-9. doi: 10.3171/jns.2004.100.2.0310.
Little is known about the quantitative modulation of major histocompatibility complex (MHC) Class I expression on human gliomas that is effected by interferons; even less is known about the immunogenic peptides that are accommodated in the peptide-binding motifs of MHC Class I alleles in these brain tumors. In this article the authors investigated the ability of interferon (IFN)alpha and IFNgamma to upregulate MHC Class I expression and to modulate acid-eluted Class I-bound peptides on human glioblastoma multiforme (GBM) cells in vitro.
Early-passage primary human GBM cell cultures and U87MG GBM cells were incubated with varying doses of INFalpha or IFNgamma ranging between 0 and 2000 U/ml. Upregulation of MHC Class I expression was assayed by immunocytochemical analysis, flow cytometry, and Western blot analysis. Modulation of acid-eluted MHC Class I-bound peptides from the IFN-treated GBM cells was examined with the aid of mass spectroscopy. The in vitro expression of the MHC Class I molecule was upregulated by both IFNalpha and IFNgamma in a dose-dependent manner. Interferon-gamma exhibited a more potent effect on MHC Class I upregulation, peaking at 10 U/ml; whereas the effect of IFNalpha was less marked, reaching a plateau at 500 U/ml. In addition, a native peptide eluted from MHC Class I molecules of human GBM cells was identified and found to be consistently upregulated by IFN treatment.
Interferon-alpha and IFN-gamma can significantly upregulate the MHC Class I molecules that are expressed on the cell surface of human GBM cells as well as the potentially immunogenic peptides bound to the MHC. These results may help explain the molecular basis for increased immunogenicity with IFN treatment of human GBMs and might provide added insight into the design of future antitumor vaccines for human brain tumors.
关于干扰素对人胶质瘤上主要组织相容性复合体（MHC）I类分子表达的定量调节作用，人们了解甚少；对于这些脑肿瘤中MHC I类等位基因的肽结合基序中所容纳的免疫原性肽，了解更少。在本文中，作者研究了α干扰素（IFN）和γ干扰素在体外上调人多形性胶质母细胞瘤（GBM）细胞上MHC I类分子表达以及调节酸洗脱的与MHC I类分子结合的肽的能力。
将早期传代的原代人GBM细胞培养物和U87MG GBM细胞与0至2000 U/ml不同剂量的INFα或INFγ孵育。通过免疫细胞化学分析、流式细胞术和蛋白质印迹分析来检测MHC I类分子表达的上调情况。借助质谱法检测经IFN处理的GBM细胞中酸洗脱的与MHC I类分子结合的肽的调节情况。IFNα和IFNγ均以剂量依赖性方式上调MHC I类分子的体外表达。γ干扰素对MHC I类分子上调的作用更强，在10 U/ml时达到峰值；而IFNα的作用则不太明显，在500 U/ml时达到平台期。此外，还鉴定出一种从人GBM细胞的MHC I类分子上洗脱的天然肽，并发现其经IFN处理后持续上调。
α干扰素和γ干扰素可显著上调人GBM细胞表面表达的MHC I类分子以及与MHC结合的潜在免疫原性肽。这些结果可能有助于解释IFN治疗人GBM时免疫原性增加的分子基础，并可能为未来人脑肿瘤抗肿瘤疫苗的设计提供更多见解。
