Müllbacher A, Lobigs M, Yewdell J W, Bennink J R, Tha Hla R, Blanden R V
Division of Immunology and Cell Biology, John Curtin School of Medical Research, Australian National University, Canberra, A.C.T. 2601, Australia.
Scand J Immunol. 1999 Oct;50(4):420-6. doi: 10.1046/j.1365-3083.1999.00619.x.
Cytotoxic T (Tc)-cell responses against influenza virus infection in BALB/c (H-2d) mice are dominated by Tc clones reactive to the viral nucleoprotein (NP). Here, we report investigations using recombinant vaccinia viruses (VV) encoding major histocompatibility complex (MHC) class I H-2Kd molecules differing by a single amino acid from glutamine (wild-type, Kdw) to histidine (mutant, Kdm) at position 114 located in the floor of the peptide-binding groove. Influenza-infected target cells expressing Kdw were strongly lysed by Kd-restricted Tc cells against A/WSN influenza virus or the immunodominant peptide of viral NP (NPP147-155), whereas infected Kdm-expressing targets gave little or no lysis, respectively, thus showing the immunodominance of NPP147-155. Kdm-expressing target cells saturated with synthetic NPP147-155 (10-5 M) were lysed similarly to Kdw-expressing targets by NPP147-155-specific Tc cells. Thus the defect in influenza-infected Kdm-expressing targets was quantitative; insufficient Kdm-peptide complexes were expressed. Tc-cell responses against four other viruses or alloantigens showed no effect of Kdm. When peptide transport-defective cells were infected with VV-Kdw or VV-Kdm and co-infected with a recombinant VV encoding an endoplasmic reticulum-targeted viral peptide, two influenza haemaglutinin peptides caused higher expression of Kdw than NPP147-155 indicating their higher affinity for Kdw. These results are inconsistent with the hypothesis that immunodominance in the anti-influenza response reflects high affinity of the immunodominant peptide, but are consistent with skewing of the Tc-cell receptor repertoire.
在BALB/c（H-2d）小鼠中，针对流感病毒感染的细胞毒性T（Tc）细胞反应主要由对病毒核蛋白（NP）有反应的Tc克隆主导。在此，我们报告了使用重组痘苗病毒（VV）进行的研究，这些重组痘苗病毒编码主要组织相容性复合体（MHC）I类H-2Kd分子，其位于肽结合槽底部的第114位氨基酸从谷氨酰胺（野生型，Kdw）到组氨酸（突变型，Kdm）有一个氨基酸差异。表达Kdw的流感感染靶细胞被针对A/WSN流感病毒或病毒NP免疫显性肽（NPP147-155）的Kd限制性Tc细胞强烈裂解，而表达Kdm的感染靶细胞分别几乎没有或没有裂解，从而显示了NPP147-155的免疫显性。用合成的NPP147-155（10-5 M）饱和的表达Kdm的靶细胞被NPP147-155特异性Tc细胞裂解的情况与表达Kdw的靶细胞相似。因此，流感感染的表达Kdm的靶细胞中的缺陷是定量的；表达的Kdm-肽复合物不足。针对其他四种病毒或同种异体抗原的Tc细胞反应未显示Kdm有影响。当肽转运缺陷细胞用VV-Kdw或VV-Kdm感染并与编码内质网靶向病毒肽的重组VV共同感染时，两种流感血凝素肽导致Kdw的表达高于NPP147-155，表明它们对Kdw的亲和力更高。这些结果与抗流感反应中的免疫显性反映免疫显性肽的高亲和力这一假设不一致，但与Tc细胞受体库的偏向一致。
