Control of CD8+ T cells through interference of Cytomegalovirus with the "peptide loading complex" (PLC)

通过巨细胞病毒与“肽负载复合物”(PLC) 的干扰来控制 CD8 T 细胞

• 批准号: 37394995
• 负责人: Professor Dr. Hartmut Hengel
• 金额: --
• 依托单位: Institut für Virologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/37394995?language=en
• 关键词: Control; CD8+; cells; through; interference

MHC I antigen presentation to CD8+ T-cells is a major mechanism of immune defense against virally infected cells. The endogenous antigens are loaded onto MHC I in the ER by the peptide loading complex (PLC), consisting of MHC I, the peptide transporter TAP, and chaperones including tapasin. Tapasin brings MHC I and TAP in close vicinity and together with the oxidoreductase ERp57 the peptide-receptive state of the MHC peptide-binding groove is regulated. HCMV can cause severe disease in immunocompromised persons, reflecting the delicate balance between the immune system reacting on the infection and the evasion of it by the virus itself. To cope with MHC I antigen presentation HCMV encodes for several post-translational strategies which have been extensively studied in transfected cells. We have analysed the PLC in naturally HCMV-infected cells and monitored the composition of the PLC throughout HCMV replication. Metabolic labeling experiments have revealed not only the absence of MHC I incorporation into the PLC during early time points of infection, but also lack of tapasin starting at early but being most pronounced at late times of infection. In contrast, Western blot analysis demonstrated only a slow decline of tapasin steady state levels in infected cells, suggesting a blocked synthesis rather than degradation. We found, after an initial induction at 8 hrs p.i., a strong inhibition of tapasin transcription at 24 hrs p.i. that persisted throughout the replication cycle. Furthermore, also reduction of TAP1 and TAP2 transcription was observed contrasting the elevated levels of MHC I transcripts. The project now follows two further objectives. First, the molecular basis of tapasin dissociation from MHC class I during HCMV infection will be analysed. This effect precedes the repression of tapasin transcription and occurs independently from the known HCMV inhibitors of the MHC class I pathway of antigen presentation, US2, US3 and US6. The goal is to identify the responsible HCMV gene that is supposed to exert a key function in the disruption of the PLC during HCMV infection. Identification of PLC regulating factors will allow for the second objective which is the analysis of MHC I presented antigens during HCMV infection after repairing PLC assembly and function. This will be informative for the evaluation of the actual escape of CD8+ T cell recognition of HCMV antigens and HCMV vaccine design.

MHC I抗原呈递给CD8+ T细胞是针对病毒感染细胞的免疫防御的主要机制。内源性抗原通过肽加载复合物（PLC）加载到ER中的MHC I上，所述肽加载复合物由MHC I、肽转运蛋白TAP和包括tapasin的分子伴侣组成。Tapasin使MHC I和TAP紧密靠近，并与氧化还原酶ERp57一起调节MHC肽结合沟的肽接受状态。HCMV可以在免疫功能低下的人中引起严重的疾病，这反映了免疫系统对感染的反应和病毒本身对其的逃避之间的微妙平衡。为了科普MHC I抗原呈递，HCMV编码几种翻译后策略，其在转染细胞中已被广泛研究。我们分析了PLC在自然HCMV感染的细胞和监测整个HCMV复制的PLC的组成。代谢标记实验不仅揭示了在感染的早期时间点期间没有MHC I掺入PLC中，而且还缺乏在早期开始但在感染的晚期最明显的tapasin。相比之下，Western印迹分析证明在感染的细胞中tapasin稳态水平仅缓慢下降，表明合成受阻而不是降解。我们发现，在感染后8小时的初始诱导后，在感染后24小时对tapasin转录的强烈抑制。在整个复制周期中持续存在。此外，还观察到TAP 1和TAP 2转录的减少，与MHC I转录物的升高水平形成对比。该项目现在有两个进一步的目标。首先，将分析在HCMV感染期间tapasin从MHC I类解离的分子基础。这种作用先于tapasin转录的抑制，并且独立于抗原呈递的MHC I类途径的已知HCMV抑制剂US2、US3和US6而发生。我们的目标是确定负责HCMV基因，应该发挥关键功能，在破坏PLC在HCMV感染。PLC调节因子的鉴定将允许第二个目标，即在修复PLC组装和功能后分析HCMV感染期间MHC I呈递的抗原。这将为评估HCMV抗原的CD8+ T细胞识别的实际逃逸和HCMV疫苗设计提供信息。

项目成果

Inhibition of mouse TAP by immune evasion molecules encoded by non-murine herpesviruses.

非鼠疱疹病毒编码的免疫逃避分子对小鼠 TAP 的抑制

• DOI: 10.1016/j.molimm.2010.12.008
• 发表时间: 2010
• 期刊: Molecular immunology
• 影响因子: 3.6
• 作者: Verweij MC;Knetsch W;Quinten E;Halenius A;van Bel N;Drijfhout JW;Ressing ME;Hengel H;van Hall T;Wiertz E
• 通讯作者: Wiertz E

The Efficiency of Human Cytomegalovirus pp65495–503 CD8+ T Cell Epitope Generation Is Determined by the Balanced Activities of Cytosolic and Endoplasmic Reticulum-Resident Peptidases

• DOI: 10.4049/jimmunol.1101886
• 发表时间: 2012-07
• 期刊: The Journal of Immunology
• 作者: S. Urban;K. Textoris-Taube;B. Reimann;K. Janek;Tanja Dannenberg;F. Ebstein;Christin Seifert;F. Zhao;J. Kessler;A. Halenius;P. Henklein;J. Paschke;S. Cadel;H. Bernhard;F. Ossendorp;T. Foulon;D. Schadendorf;A. Paschen;U. Seifert

Loss-of-function mutations within the IL-2 inducible kinase ITK in patients with EBV-associated lymphoproliferative diseases

• DOI: 10.1038/leu.2011.371
• 发表时间: 2012-05-01
• 期刊: LEUKEMIA
• 影响因子: 11.4
• 作者: Linka, R. M.;Risse, S. L.;Borkhardt, A.
• 通讯作者: Borkhardt, A.

Host immune system gene targeting by a viral miRNA

• DOI: 10.1126/science.1140956
• 发表时间: 2007-07-20
• 期刊: SCIENCE
• 影响因子: 56.9
• 作者: Stern-Ginossar, Noam;Elefant, Naama;Mandelboim, Ofer
• 通讯作者: Mandelboim, Ofer

Gamma Interferon-Induced Interferon Regulatory Factor 1-Dependent Antiviral Response Inhibits Vaccinia Virus Replication in Mouse but Not Human Fibroblasts

• DOI: 10.1128/jvi.02042-08
• 发表时间: 2009-02
• 期刊: Journal of Virology
• 影响因子: 5.4
• 作者: M. Trilling;Vu Thuy Khanh Le;A. Zimmermann;H. Ludwig;K. Pfeffer;G. Sutter;Geoffrey L. Smith;H. Hengel