1
|
Cloutier M, Fortin JS, Thibodeau J. The transmembrane domain and luminal C-terminal region independently support invariant chain trimerization and assembly with MHCII into nonamers. BMC Immunol 2021; 22:56. [PMID: 34384367 PMCID: PMC8362237 DOI: 10.1186/s12865-021-00444-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 07/20/2021] [Indexed: 05/31/2023] Open
Abstract
Background Invariant chain (CD74, Ii) is a multifunctional protein expressed in antigen presenting cells. It assists the ER exit of various cargos and serves as a receptor for the macrophage migration inhibitory factor. The newly translated Ii chains trimerize, a structural feature that is not readily understood in the context of its MHCII chaperoning function. Two segments of Ii, the luminal C-terminal region (TRIM) and the transmembrane domain (TM), have been shown to participate in the trimerization process but their relative importance and impact on the assembly with MHCII molecules remains debated. Here, we addressed the requirement of these domains in the trimerization of human Ii as well as in the oligomerization with MHCII molecules. We used site-directed mutagenesis to generate series of Ii and DR mutants. These were transiently transfected in HEK293T cells to test their cell surface expression and analyse their interactions by co-immunoprecipitations. Results Our results showed that the TRIM domain is not essential for Ii trimerization nor for intracellular trafficking with MHCII molecules. We also gathered evidence that in the absence of TM, TRIM allows the formation of multi-subunit complexes with HLA-DR. Similarly, in the absence of TRIM, Ii can assemble into high-order structures with MHCII molecules. Conclusions Altogether, our data show that trimerization of Ii through either TM or TRIM sustains nonameric complex formation with MHCII molecules. Supplementary Information The online version contains supplementary material available at 10.1186/s12865-021-00444-6.
Collapse
Affiliation(s)
- Maryse Cloutier
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Succ Centre-Ville, CP 6128, Montréal, QC, H3C 3J7, Canada
| | - Jean-Simon Fortin
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Succ Centre-Ville, CP 6128, Montréal, QC, H3C 3J7, Canada
| | - Jacques Thibodeau
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Succ Centre-Ville, CP 6128, Montréal, QC, H3C 3J7, Canada.
| |
Collapse
|
2
|
Chen BM, Al-Aghbar MA, Lee CH, Chang TC, Su YC, Li YC, Chang SE, Chen CC, Chung TH, Liao YC, Lee CH, Roffler SR. The Affinity of Elongated Membrane-Tethered Ligands Determines Potency of T Cell Receptor Triggering. Front Immunol 2017; 8:793. [PMID: 28740495 PMCID: PMC5502409 DOI: 10.3389/fimmu.2017.00793] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/22/2017] [Indexed: 01/17/2023] Open
Abstract
T lymphocytes are important mediators of adoptive immunity but the mechanism of T cell receptor (TCR) triggering remains uncertain. The interspatial distance between engaged T cells and antigen-presenting cells (APCs) is believed to be important for topological rearrangement of membrane tyrosine phosphatases and initiation of TCR signaling. We investigated the relationship between ligand topology and affinity by generating a series of artificial APCs that express membrane-tethered anti-CD3 scFv with different affinities (OKT3, BC3, and 2C11) in addition to recombinant class I and II pMHC molecules. The dimensions of membrane-tethered anti-CD3 and pMHC molecules were progressively increased by insertion of different extracellular domains. In agreement with previous studies, elongation of pMHC molecules or low-affinity anti-CD3 scFv caused progressive loss of T cell activation. However, elongation of high-affinity ligands (BC3 and OKT3 scFv) did not abolish TCR phosphorylation and T cell activation. Mutation of key amino acids in OKT3 to reduce binding affinity to CD3 resulted in restoration of topological dependence on T cell activation. Our results show that high-affinity TCR ligands can effectively induce TCR triggering even at large interspatial distances between T cells and APCs.
Collapse
Affiliation(s)
- Bing-Mae Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Mohammad Ameen Al-Aghbar
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.,Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan.,Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan
| | - Chien-Hsin Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Tien-Ching Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.,Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan.,Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan
| | - Yu-Cheng Su
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ya-Chen Li
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Shih-En Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chin-Chuan Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Tsai-Hua Chung
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yuan-Chun Liao
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chau-Hwang Lee
- Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan.,Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan.,Department of Physics, National Taiwan University, Taipei, Taiwan
| | - Steve R Roffler
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.,Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| |
Collapse
|
3
|
Fortin JS, Genève L, Gauthier C, Shoukry NH, Azar GA, Younes S, Yassine-Diab B, Sékaly RP, Fremont DH, Thibodeau J. MMTV superantigens coerce an unconventional topology between the TCR and MHC class II. THE JOURNAL OF IMMUNOLOGY 2014; 192:1896-906. [PMID: 24453254 DOI: 10.4049/jimmunol.1203130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mouse mammary tumor virus superantigens (vSAGs) are notorious for defying structural characterization, and a consensus has yet to be reached regarding their ability to bridge the TCR to MHC class II (MHCII). In this study, we determined the topology of the T cell signaling complex by examining the respective relation of vSAG7 with the MHCII molecule, MHCII-associated peptide, and TCR. We used covalently linked peptide/MHCII complexes to demonstrate that vSAG presentation is tolerant to variation in the protruding side chains of the peptide, but can be sensitive to the nature of the protruding N-terminal extension. An original approach in which vSAG was covalently linked to either MHCII chain confirmed that vSAG binds outside the peptide binding groove. Also, whereas the C-terminal vSAG segment binds to the MHCII α-chain in a conformation-sensitive manner, the membrane-proximal N-terminal domain binds the β-chain. Because both moieties of the mature vSAG remain noncovalently associated after processing, our results suggest that vSAG crosslinks MHCII molecules. Comparing different T cell hybridomas, we identified key residues on the MHCII α-chain that are differentially recognized by the CDR3β when engaged by vSAG. Finally, we show that the highly conserved tyrosine residue found in the vSAg TGXY motif is required for T cell activation. Our results reveal a novel SAG/MHCII/TCR architecture in which vSAGs coerce a near-canonical docking between MHCII and TCR that allows eschewing of traditional CDR3 binding with the associated peptide in favor of MHCII α-chain binding. Our findings highlight the plasticity of the TCR CDRs.
Collapse
Affiliation(s)
- Jean-Simon Fortin
- Laboratoire d'Immunologie Moléculaire, Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec HC3 3J7, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
A novel one-step strategy for the preparation of HLA/HBc18–27 and HLA/CEA694–702 complexes with ion exchange chromatography. Biotechnol Lett 2010; 32:1803-8. [DOI: 10.1007/s10529-010-0374-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2010] [Accepted: 07/28/2010] [Indexed: 11/26/2022]
|
5
|
Justesen S, Harndahl M, Lamberth K, Nielsen LLB, Buus S. Functional recombinant MHC class II molecules and high-throughput peptide-binding assays. Immunome Res 2009; 5:2. [PMID: 19416502 PMCID: PMC2690590 DOI: 10.1186/1745-7580-5-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Accepted: 05/05/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Molecules of the class II major histocompability complex (MHC-II) specifically bind and present exogenously derived peptide epitopes to CD4+ T helper cells. The extreme polymorphism of the MHC-II hampers the complete analysis of peptide binding. It is also a significant hurdle in the generation of MHC-II molecules as reagents to study and manipulate specific T helper cell responses. Methods to generate functional MHC-II molecules recombinantly, and measure their interaction with peptides, would be highly desirable; however, no consensus methodology has yet emerged. RESULTS We generated alpha and beta MHC-II chain constructs, where the membrane-spanning regions were replaced by dimerization motifs, and the C-terminal of the beta chains was fused to a biotinylation signal peptide (BSP) allowing for in vivo biotinylation. These chains were produced separately as inclusion bodies in E. coli , extracted into urea, and purified under denaturing and non-reducing conditions using conventional column chromatography. Subsequently, diluting the two chains into a folding reaction with appropriate peptide resulted in efficient peptide-MHC-II complex formation. Several different formats of peptide-binding assay were developed including a homogeneous, non-radioactive, high-throughput (HTS) binding assay. Binding isotherms were generated allowing the affinities of interaction to be determined. The affinities of the best binders were found to be in the low nanomolar range. Recombinant MHC-II molecules and accompanying HTS peptide-binding assay were successfully developed for nine different MHC-II molecules including the DPA1*0103/DPB1*0401 (DP401) and DQA1*0501/DQB1*0201, where both alpha and beta chains are polymorphic, illustrating the advantages of producing the two chains separately. CONCLUSION We have successfully developed versatile MHC-II resources, which may assist in the generation of MHC class II -wide reagents, data, and tools.
Collapse
Affiliation(s)
- Sune Justesen
- Laboratory of Experimental Immunology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
| | | | | | | | | |
Collapse
|
6
|
Abstract
Secreted and intracellular proteins including antibodies, cytokines, major histocompatibility complex molecules, antigens, and enzymes can be redirected to and anchored on the surface of mammalian cells to reveal novel functions and properties such as reducing systemic toxicity, altering the in vivo distribution of drugs and extending the range of useful drugs, creating novel, specific signaling receptors and reshaping protein immunogenicity. The present review highlights progress in designing vectors to target and retain chimeric proteins on the surface of mammalian cells. Comparison of chimeric proteins indicates that selection of the proper cytoplasmic domain and introduction of oligiosaccharides near the cell surface can dramatically enhance surface expression, especially for single-chain antibodies. We also describe progress and limitations of employing surface-tethered proteins for preferential activation of prodrugs at cancer cells, imaging gene expression in living animals, performing high-throughput screening, selectively activating immune cells in tumors, producing new adhesion molecules, creating local immune privileged sites, limiting the distribution of soluble factors such as cytokines, and enhancing polypeptide immunogenicity. Surface-anchored chimeric proteins represent a rich source for developing new techniques and creating novel therapeutics.
Collapse
Affiliation(s)
- Tian-Lu Cheng
- Faculty of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | | |
Collapse
|
7
|
Hung CF, Tsai YC, He L, Wu TC. DNA vaccines encoding Ii-PADRE generates potent PADRE-specific CD4+ T-cell immune responses and enhances vaccine potency. Mol Ther 2007; 15:1211-9. [PMID: 17356542 PMCID: PMC3171992 DOI: 10.1038/sj.mt.6300121] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
It is now clear that CD4+ T cells play a crucial role in the generation of CD8+ T effector and memory T-cell immune responses. In this study, we enhanced the CD4+ T-cell immune responses in mice by constructing a DNA vaccine encoding an invariant (Ii) chain in which the class II-associated Ii peptide (CLIP) region is replaced with a CD4+ T-helper epitope, PADRE (Ii-PADRE) (invariant Pan HLA-DR reactive epitope). C57BL/6 mice vaccinated with DNA encoding Ii-PADRE showed significantly greater PADRE-specific CD4+ T-cell immune responses than mice vaccinated with DNA encoding the Ii chain alone (Ii DNA). More important, administration of DNA encoding human papillomavirus (HPV) E6 or E7 antigen with DNA encoding Ii-PADRE led to significantly stronger E6- or E7-specific CD8+ T-cell immune responses and more potent protective and therapeutic anti-tumor effects against an E6/E7-expressing tumor model in mice than administration of E6 or E7 DNA with Ii DNA. Overall, our data indicate that administration of DNA vaccines with Ii-PADRE DNA represents an effective approach to enhancing the generation of CD4+ T cells and eliciting stronger antigen-specific CD8+ T-cell immune responses. Therefore, this strategy may be expected to have significant potential for clinical translation.
Collapse
MESH Headings
- Animals
- CD4-Positive T-Lymphocytes/cytology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- Cell Line, Transformed
- Cell Line, Tumor
- Cytokines/analysis
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Flow Cytometry
- Interferon-gamma/analysis
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Mice
- Mice, Inbred C57BL
- Neoplasms, Experimental/immunology
- Neoplasms, Experimental/pathology
- Neoplasms, Experimental/prevention & control
- Peptides/immunology
- Vaccination/methods
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Viral Vaccines/administration & dosage
- Viral Vaccines/genetics
- Viral Vaccines/immunology
Collapse
Affiliation(s)
- Chien-Fu Hung
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
| | | | | | | |
Collapse
|
8
|
Reed-Loisel LM, Sullivan BA, Laur O, Jensen PE. An MHC Class Ib-Restricted TCR That Cross-Reacts with an MHC Class Ia Molecule. THE JOURNAL OF IMMUNOLOGY 2005; 174:7746-52. [PMID: 15944277 DOI: 10.4049/jimmunol.174.12.7746] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TCR transgenic 6C5 T cells recognize an insulin B chain epitope presented by the nonclassical class I MHC molecule, Qa-1(b). Positive selection of these T cells was shown previously to require Qa-1(b). Despite dedicated specificity for Qa-1(b), evidence presented in the current study indicates that 6C5 T cells can cross-recognize a classical class I molecule. Clonal deletion was observed unexpectedly in 6C5.H-2(bxq) mice, which do not express I-E MHC class II molecules and thus should not be subject to superantigen-mediated negative selection. 6C5 T cells were observed to respond in vivo and in vitro to spleen cells from allogeneic H-2(q) mice, and specificity was mapped to D(q). Evidence was obtained for direct recognition of D(q), rather than indirect presentation of a D(q)-derived peptide presented by Qa-1(b). Polyclonal CD8(+) T cells from class Ia-deficient K(b)D(b-/-) mice reacted in vitro to allogeneic spleen cells with an apparent frequency comparable to conventional class Ia-restricted T cells. Our results provide a clear example of a Qa-1-specific TCR that can cross-react with a class Ia molecule and evidence supporting the idea that this may be a common property of T cells selected by class Ib molecules.
Collapse
MESH Headings
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Line, Transformed
- Cell Line, Tumor
- Cell Lineage/genetics
- Cell Lineage/immunology
- Clonal Deletion
- Crosses, Genetic
- H-2 Antigens/genetics
- H-2 Antigens/immunology
- H-2 Antigens/metabolism
- Histocompatibility Antigens Class I/genetics
- Histocompatibility Antigens Class I/immunology
- Histocompatibility Antigens Class I/metabolism
- Mammary Tumor Virus, Mouse/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Superantigens/genetics
- Superantigens/immunology
- Superantigens/metabolism
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
Collapse
Affiliation(s)
- Lisa M Reed-Loisel
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | | | |
Collapse
|