scholarly journals MHC Class I Molecules Exacerbate Viral Infection by Disrupting Type I Interferon Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Simo Xia ◽  
Yijie Tao ◽  
Likun Cui ◽  
Yizhi Yu ◽  
Sheng Xu
Keyword(s):  
Viral Infection ◽  
Mhc Class I ◽  
Class I ◽  
Type I ◽  
Type I Ifn ◽  
Mhc I ◽  
Cell Responses ◽  
Innate Antiviral Immunity ◽  
Mhc Class I Molecules

MHC class I molecules are key in the presentation of antigen and initiation of adaptive CD8+ T cell responses. In addition to its classical activity, MHC I may possess nonclassical functions. We have previously identified a regulatory role of MHC I in TLR signaling and antibacterial immunity. However, its role in innate antiviral immunity remains unknown. In this study, we found a reduced viral load in MHC I-deficient macrophages that was independent of type I IFN production. Mechanically, MHC I mediated viral suppression by inhibiting the type I IFN signaling pathway, which depends on SHP2. Cross-linking MHC I at the membrane increased SHP2 activation and further suppressed STAT1 phosphorylation. Therefore, our data revealed an inhibitory role of MHC I in type I IFN response to viral infection and expanded our understanding of MHC I and antigen presentation.

Ligand Design for Specific MHC Class I Molecules on the Cell Surface

2020 ◽  
Author(s):  
Xizheng Sun ◽  
Reika Tokunaga ◽  
Yoko Nagai ◽  
Ryo Miyahara ◽  
Akihiro Kishimura ◽  
...  
Keyword(s):  
Cell Surface ◽  
Mhc Class I ◽  
Targeted Delivery ◽  
Peptide Ligands ◽  
Class I ◽  
Class I Mhc ◽  
Mhc I ◽  
Histocompatibility Complex ◽  
High Binding Affinity ◽  
Mhc Class I Molecules

<p><a></a><a></a><a>We have validated that ligand peptides designed from antigen peptides could be used for targeting specific major histocompatibility complex class I (MHC-I)</a> molecules on cell surface. To design the ligand peptides, we used reported antigen peptides for each MHC-I molecule with high binding affinity. From the crystal structure of the peptide/MHC-I complexes, we determined a modifiable residue in the antigen peptides and replaced this residue with a lysine with an ε-amine group modified with functional molecules. The designed ligand peptides successfully bound to cells expressing the corresponding MHC-I molecules via exchange of peptides bound to the MHC-I. We demonstrated that the peptide ligands could be used to transport a protein or a liposome to cells expressing the corresponding MHC-I. The present strategy may be useful for targeted delivery to cells overexpressing MHC-I, which have been observed autoimmune diseases.</p>

scholarly journals Viral infection causes a shift in the self peptide repertoire presented by human MHC class I molecules

2015 ◽  
Vol 9 (11-12) ◽  
pp. 1035-1052 ◽  
Author(s):  
Charles T. Spencer ◽  
Jelena S. Bezbradica ◽  
Mireya G. Ramos ◽  
Chenoa D. Arico ◽  
Stephanie B. Conant ◽  
...  
Keyword(s):  
Viral Infection ◽  
Mhc Class I ◽  
The Self ◽  
Class I ◽  
Mhc Class I Molecules

scholarly journals The role of mutated SOD1 gene in synaptic stripping and MHC class I expression following nerve axotomy in ALS murine model

2018 ◽  
Author(s):  
Roman M. Kassa ◽  
Roberta Bonafede ◽  
Federico Boschi ◽  
Manuela Malatesta ◽  
Raffaella Mariotti
Keyword(s):  
Mhc Class I ◽  
Murine Model ◽  
Excitatory Input ◽  
Class I ◽  
Facial Motoneurons ◽  
Cellular Pathways ◽  
First Time ◽  
Lateral Sclerosis ◽  
Mhc Class I Molecules

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motoneuron death. Several cellular pathways have been described to be involved in ALS pathogenesis; however, the involvement of presynaptic stripping and the related MHC class I molecules in mutant SOD1 motoneurons remains to be clarified. To this purpose, we here investigated, for the first time, the motoneurons behavior, di per seand after facial axonal injury, in terms of synaptic stripping and MHC class I expression in wild-type (Wt) mice and in a murine model of ALS, the SOD1(G93A) mice, at the presymptomatic and symptomatic stage of the disease. Concerning Wt animals, we found a reduction in synaptophysin immunoreactivity and an increase of MHC class I molecules in facial motoneurons after axotomy. In uninjured motoneurons of SOD1(G93A) mice, an altered presynaptic framework was evident, and this phenomenon increased during the disease course. The alteration in the presynaptic input is related to excitatory fibers. Moreover, after injury, a further decrease of excitatory input was not associated to an upregulation of MHC class I molecules in motoneuron soma. This study demonstrates, for the first time, that the presence of mutated SOD1 protein affects the MHC class I molecules expression, altering the presynaptic input in motoneurons. Nevertheless, a positive MHC class I immunolabeling was evident in glial cells around facial injured motoneurons, underlying an involvement of these cells in synaptic stripping. This study contributes to better understand the involvement of the mutated SOD1 protein in the vulnerability of motoneurons after damage.

The peptide-loading complex – antigen translocation and MHC class I loading

2009 ◽  
Vol 390 (8) ◽  
Author(s):  
Christian Schölz ◽  
Robert Tampé
Keyword(s):  
Mhc Class I ◽  
Antigen Processing ◽  
Surface Display ◽  
Class I ◽  
Antigenic Peptides ◽  
Mhc I ◽  
Protein Fragments ◽  
Long Term Stability ◽  
Peptide Loading ◽  
Mhc Class I Molecules

Abstract A large and dynamic membrane-associated machinery orchestrates the translocation of antigenic peptides into the endoplasmic reticulum (ER) lumen for subsequent loading onto major histocompatibility complex (MHC) class I molecules. The peptide-loading complex ensures that only high-affinity peptides, which guarantee long-term stability of MHC I complexes, are presented to T-lymphocytes. Adaptive immunity is dependent on surface display of the cellular proteome in the form of protein fragments, thus allowing efficient recognition of infected or malignant transformed cells. In this review, we summarize recent findings of antigen translocation by the transporter associated with antigen processing and loading of MHC class I molecules in the ER, focusing on the mechanisms involved in this process.

scholarly journals Role of non-classical MHC class I molecules in cancer immunosuppression

2013 ◽  
Vol 2 (11) ◽  
pp. e26491 ◽  
Author(s):  
Grazyna Kochan ◽  
David Escors ◽  
Karine Breckpot ◽  
David Guerrero-Setas
Keyword(s):  
Mhc Class I ◽  
Class I ◽  
Cancer Immunosuppression ◽  
Mhc Class I Molecules

scholarly journals Recent advances in Major Histocompatibility Complex (MHC) class I antigen presentation: Plastic MHC molecules and TAPBPR-mediated quality control

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 158 ◽  
Author(s):  
Andy van Hateren ◽  
Alistair Bailey ◽  
Tim Elliott
Keyword(s):  
Quality Control ◽  
Major Histocompatibility Complex ◽  
Antigen Presentation ◽  
Mhc Class I ◽  
Class I ◽  
Major Histocompatibility ◽  
Mhc I ◽  
Histocompatibility Complex ◽  
Peptide Loading ◽  
Mhc Class I Molecules

We have known since the late 1980s that the function of classical major histocompatibility complex (MHC) class I molecules is to bind peptides and display them at the cell surface to cytotoxic T cells. Recognition by these sentinels of the immune system can lead to the destruction of the presenting cell, thus protecting the host from pathogens and cancer. Classical MHC class I molecules (MHC I hereafter) are co-dominantly expressed, polygenic, and exceptionally polymorphic and have significant sequence diversity. Thus, in most species, there are many different MHC I allotypes expressed, each with different peptide-binding specificity, which can have a dramatic effect on disease outcome. Although MHC allotypes vary in their primary sequence, they share common tertiary and quaternary structures. Here, we review the evidence that, despite this commonality, polymorphic amino acid differences between allotypes alter the ability of MHC I molecules to change shape (that is, their conformational plasticity). We discuss how the peptide loading co-factor tapasin might modify this plasticity to augment peptide loading. Lastly, we consider recent findings concerning the functions of the non-classical MHC I molecule HLA-E as well as the tapasin-related protein TAPBPR (transporter associated with antigen presentation binding protein-related), which has been shown to act as a second quality-control stage in MHC I antigen presentation.

scholarly journals The first step of peptide selection in antigen presentation by MHC class I molecules

2015 ◽  
Vol 112 (5) ◽  
pp. 1505-1510 ◽  
Author(s):  
Malgorzata A. Garstka ◽  
Alexander Fish ◽  
Patrick H. N. Celie ◽  
Robbie P. Joosten ◽  
George M. C. Janssen ◽  
...  
Keyword(s):  
Mhc Class I ◽  
Peptide Pool ◽  
Class I ◽  
Second Step ◽  
Temperature Sensitive ◽  
Antigenic Peptides ◽  
Mhc I ◽  
Wide Range ◽  
Peptide Complexes ◽  
Mhc Class I Molecules

MHC class I molecules present a variable but limited repertoire of antigenic peptides for T-cell recognition. Understanding how peptide selection is achieved requires mechanistic insights into the interactions between the MHC I and candidate peptides. We find that, at first encounter, MHC I H-2Kb considers a wide range of peptides, including those with expanded N termini and unfitting anchor residues. Discrimination occurs in the second step, when noncanonical peptides dissociate with faster exchange rates. This second step exhibits remarkable temperature sensitivity, as illustrated by numerous noncanonical peptides presented by H-2Kb in cells cultured at 26 °C relative to 37 °C. Crystallographic analyses of H-2Kb–peptide complexes suggest that a conformational adaptation of H-2Kb drives the decisive step in peptide selection. We propose that MHC class I molecules consider initially a large peptide pool, subsequently refined by a temperature-sensitive induced-fit mechanism to retain the canonical peptide repertoire.

Sign in / Sign up

Export Citation Format

Share Document