Ted Howard Hansen
Washington University
Project start date: 2004-03-01
Project end date: 2015-01-31
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to Ted Howard Hansen
MR1 BIOCHEMICAL FEATURES AND IMMUNOLOGICAL FUNCTIONS
Ted Howard Hansen, Professor Of Pathology And Immunolo
Washington University, Campus Box 1054, Saint Louis, Mo 63130-4899
Grant 5R01AI046553-08 from National Institute Of Allergy And Infectious Diseases
Abstract: Restricted repertoires of antigen specific receptors on B and T cells have been proposed to define discrete lymphocyte subpopulations at the frontier between innate and adaptive immunity. Notable examples of this are NK-T cells that use an invariant (TCR chain with a CDR3 of constant length and limited Vbeta segments. The activation and in vivo development of NK-T cells in mice is dependent upon the class Ib molecule, CDld. A remarkable story has recently emerged of a new alpha/beta T population termed mucosal-associated invariant T cells or MAlT cells. Interestingly, MAlT cells are predominantly expressed in the gut and are missing in germ-free mice. Furthermore, MAlT cells, like NK-T cells, have an invariant (TCR rearrangement of constant CDR3 length and limited Vbeta usage. And finally, activation and in vivo development of MAlT cells is dependent upon the newly characterized class Ib molecule, MR1. MR1 is highly conserved among mammals, and non-MHC encoded. We recently reported that MR1 has limited cell surface expression in transfected cell lines, is associated with the peptide-loading complex, and undergoes a ligand induced folding event similar to class la molecules. Furthermore, recombinant MR1 was obtained, but only in insect cells grown in highly supplemented media. These biochemical properties of MR1and the aforementioned analogies with CD1, raise the interesting possibility that MR1 presents a specific ligand from commensal flora to MAlT cells and thereby regulates mucosal immune responses. The proposed studies in this grant will define i) where endogenous MR1 is expressed, ii)the effector function of MAlT cells, iii) the nature of the putative MR1 ligand and whether it is bacteria-specific, and iv) how the MHC fold of MR1 functionally interacts with a putative ligand and the alpha/beta TCR of MAlT cells
Keywords: ATGN; Antigens; Bacteria; Biochemical; Cell Line; Cell Lines, Strains; Cell surface; CellLine; Cells; Chaperone; Complex; DNA Sequence Rearrangement; Development; Event; Genetics-Mutagenesis; Germ-Free; Grant; Heterogeneity; Immunity; Insecta; Insects; Invertebrates, Insects; Isoforms; Length; Ligand Binding; Ligands; Lymphocyte Subpopulations; Lymphocyte Subset; Malt Grain; Malts; Mammalia; Mammals; Mammals, General; Mammals, Mice; Mice; Molecular Biology, Mutagenesis; Molecular Chaperones; Mucosal Immune Responses; Murine; Mus; Mutagenesis; Nature; Peptides; Physiologic; Physiological; Population; Property; Property, LOINC Axis 2; Protein Isoforms; Rearrangement; Receptor Protein; Recombinants; Reporting; Surface; T-Cells; T-Lymphocyte; Thymus-Dependent Lymphocytes; Transgenic Organisms; cultured cell line; cytokine; frontier; immunogen; in vivo; interest; receptor; thymus derived lymphocyte; trafficking; transgenic
Project start date: 1999-12-01
Project end date: 2010-11-30
Budget start date: 1-DEC-2008
Budget end date: 30-NOV-2010
5R01AI046553-08 (2009): $355788
MHC-1 REGULATION BY HERPESVIRUS
Ted Howard Hansen, Professor Of Pathology And Immunolo
Washington University, Campus Box 1054, Saint Louis, Mo 63130-4899
Grant 5R01AI019687-27 from National Institute Of Allergy And Infectious Diseases
Abstract: Research into the molecular interactions between viruses and their hosts has revealed that viruses manipulate a multitude of cellular pathways to facilitate their dissemination. This is certainly in evidence for the class I antigen presentation pathway. Virus-encoded molecules have been described that affect this pathway at essentially every step from peptide generation by the proteasome, early assembly events in the ER, trafficking through the secretory pathway, and cell surface half-life. The fact that viruses have evolved such diverse mechanisms to target this pathway highlights the importance of class I antigen presentation in the host defense against viruses. An effective mechanism of preventing antigen presentation is to target nascent, ER-resident class I molecules for rapid degradation in the cytosol. It is now clear that immune evasion proteins US2 and US11 of HCMV and mK3 of gammaHV68 co-opt and greatly expedite ERAD, a normal physiologic pathway for destruction of overexpressed, misfolded, or unassembled host proteins . The molecular mechanism of ERAD is the subject of intense investigation due to its fundamental role in regulating protein expression and in human disease. However the molecular mechanisms of ERAD are largely unknown or remain controversial particularly in mammals. For example salient questions remain unanswered including how misfolded proteins are recognized, how they are retro-translocated or dislocated from the ER, and how chaperones might direct these processes. Furthermore, substrate ubiquitination clearly plays a key role in ERAD, however its specific role in the detection of substrates in the ER lumen and their dislocation to the cytosol are unknown. In this grant proposal we have the unique ability to use the mK3 immune evasion protein to define how proteins implicated in the quality control of class I MHC expression elicit ERAD of misassemble MHC-I proteins. These investigations will also define the precise mechanism of substrate ubiquitination and its role in substrate dislocation and the kinetics of degradation
Keywords: 20S Catalytic Proteasome; 20S Core Proteasome; 20S Proteasome; 20S Proteosome; APF-1; ATP-Dependent Proteolysis Factor 1; Affect; Antigen Presentation; Antigen Presentation Pathway; Antigen Processing and Presentation; Applications Grants; Arts; Binding; Binding (Molecular Function); CMV; Cell Communication and Signaling; Cell Signaling; Cell surface; Cells; Chaperone; Class I Antigens; Class I Major Histocompatibility Antigens; Collaborations; Complex Class 1; Cytomegalovirus; Cytosol; Detection; Dislocations; Dissociation; E3 Ligase; E3 Ubiquitin Ligase; ER-associated degradation Pathway; ERAD; Endoplasmic Reticulum Degradation Pathway; Event; Generations; Genes, Class I; Genes, MHC Class I; Genetics-Mutagenesis; Goals; Grant Proposals; Grants, Applications; HCMV; HMG-20; Half-Life; Half-Lifes; Herpesviridae; Herpesviruses; High Mobility Protein 20; Histocompatibility Antigens Class I; Host Defense; Human cytomegalovirus US2 protein; Immune; Intracellular Communication and Signaling; Investigation; Investigators; Joint Dislocation; Kinetic; Kinetics; L-Lysine; Lysine; MHC Class I; MHC Class I Genes; MHC Class I Molecule; MHC Class I Protein; MHC class I antigen; Macropain; Macroxyproteinase; Major Histocompatibility Complex Class 1; Mammalia; Mammals; Mammals, General; Membrane; Modeling; Molecular; Molecular Biology, Mutagenesis; Molecular Chaperones; Molecular Interaction; Multicatalytic Proteinase; Mutagenesis; Pathway interactions; Peptides; Physiologic; Physiological; Play; Process; Programs (PT); Programs [Publication Type]; Prosome; Proteasome; Proteasome Endopeptidase Complex; Proteins; Proteomics; Proteosome; Quality Control; Recruitment Activity; Regulation; Reporting; Research; Research Personnel; Researchers; Role; Salivary Gland Viruses; Signal Transduction; Signal Transduction Systems; Signaling; Site; Testing; US2 protein, HCMV; US2 protein, Human cytomegalovirus; US2 protein, Human herpesvirus 5; Ubiquitilation; Ubiquitin; Ubiquitin-Protein Ligase E3; Ubiquitination; Ubiquitinoylation; Virus; Viruses, General; aberrant protein folding; abnormal protein folding; biological signal transduction; cytomegalovirus group; dimer; experiment; experimental research; experimental study; gene product; herpes virus; human cytomegalovirus; human disease; insight; membrane structure; multicatalytic endopeptidase complex; novel; overexpression; pathologic protein folding; pathway; prevent; preventing; programs; protein expression; protein mis-folding; protein misfolding; recruit; research study; social role; trafficking; ubiquination; ubiquitin conjugation; ubiquitin-protein ligase
Project start date: 1983-09-01
Project end date: 2011-05-31
Budget start date: 1-JUN-2010
Budget end date: 31-MAY-2011
5R01AI019687-27 (2010): $322515
5R01AI019687-26 (2009): $325772
MR1 BIOCHEMICAL FEATURES AND IMMUNOLOGICAL FUNCTIONS
Ted Howard Hansen, Professor Of Pathology And Immunolo
Washington University, Campus Box 1054, Saint Louis, Mo 63130-4899
Grant 2R01AI046553-09A1 from National Institute Of Allergy And Infectious Diseases
Abstract: Elimination of pathogen-infected cells requires their sequential recognition by cells in the innate and acquired immune systems. A unique category of T cells collectively referred to as ´innate T cells´ kinetically bridge the innate and acquired immune responses. Interestingly, the activation of innate T cells can be restricted by the expression of MHC-like molecules or class Ib molecules. The ability of innate T cells to respond rapidly stems from their lack of dependence on clonal expansion, resulting from less discriminating receptor-ligand interactions. By comparison, classical MHC molecules restrict conventional CD4 and CD8 T cells in the acquired immune response, and they require 10-14 days to clonally expand to sufficient numbers due to highly specific receptor-ligand interactions. The experiments in this grant will characterize the novel class Ib molecule MR1 that is evolutionarily conserved in mammals and restricts the development of mucosal-associated invariant T cells or MAIT cells in a manner dependent upon the commensal flora and B cells. MAIT cells have several features consistent with their function as innate T cells including i) invariant T cell receptor alpha chains, ii) the ability to rapidly release cytokines, and iii) apparent recognition of an evolutionarily conserved ligand. However, the nature of the MR1 ligand is unknown as is the physiological role of MAIT cells. In this application we will test whether MAIT cells detect Mycobacterium tuberculosis-infected cells and are critical components of host resistance to this pathogen. In addition, we will elucidate the nature of the MR1 ligand, the pathway by which it is presented, and the crystal structure of a ligand/MR1 complex. Cellular, molecular and structural dissection of MR1 antigen presentation to MAIT cells will critically define the mechanism and importance of this pathway in protective immunity to bacteria. Mucosal immune responses provide a front line defense against infection. In this grant we will study how a unique subset of T cells associated with mucosal tissues potentially control early immunity to Mycobacterium tuberculosis. Our findings will define the mechanism of bacteria recognition by these mucosal T cells and their function in controlling disease
Relevance: Mucosal immune responses provide a front line defense against infection. In this grant we will study how a unique subset of T cells associated with mucosal tissues potentially control early immunity to Mycobacterium tuberculosis. Our findings will define the mechanism of bacteria recognition by these mucosal T cells and their function in controlling disease
Project start date: 2000-09-30
Project end date: 2015-04-30
Budget start date: 1-MAY-2010
Budget end date: 30-APR-2011
PFA/PA: PA-07-070
2R01AI046553-09A1 (2010): $380000
SCT PROBES FOR PATHOGEN IMMUNITY
Ted Howard Hansen, Professor Of Pathology And Immunolo
Washington University, Campus Box 1054, Saint Louis, Mo 63130-4899
Grant 2R01AI055849-06A1 from National Institute Of Allergy And Infectious Diseases
Abstract: Antigen presentation by MHC class I molecules to CD8 T cells is a major pathway by which the acquired immune system detects and eliminates virus infected cells. All nucleated cells express MHC class I molecules and are thus potentially capable of direct antigen presentation to CD8 T cells upon infection. However, several, but not all, recent studies suggest that predominantly DCs (or a specific subset of DCs) are uniquely required for in vivo priming of CD8 T cells to virus. Because pathogens may not directly infect these requisite DCs, cross presentation pathways have been proposed; in essence, the infected cell may not be the primary antigen presenting cell. Additionally, for many arthropod-transmitted viruses, virus-specific antigens may require transfer from migratory DCs in the skin to lymph node resident DCs to efficiently prime CD8 T cells. However, the mechanism by which pathogen-specific antigens are shuttled from the infected cells to DCs or between DC subsets is unknown. Not surprisingly, these same issues of direct presentation vs. cross-presentation also apply to CD8 T cell responses to tumors or following DNA vaccination. As a novel strategy to elicit pathogen immunity, we have engineered preprocessed and preloaded MHC class I molecules as single chains of peptide, beta-2 microglobulin and class I heavy chain. We have termed these complexes single chain trimers or SCTs. SCTs are very stably expressed at the cell surface and we and others have demonstrated that SCTs elicit a robust CD8 T cell response. In this grant we will test whether SCTs confer protective immunity against viruses and bacteria, and probe the cellular and molecular basis of vivo priming of CD8 T cells following SCT vaccination. Our hypothesis is that SCT vaccine efficacy results from crosspresentation by CD81 DCs using a novel mechanism involving intercellular membrane exchange. Protective immunity to several pathogens requires that MHCI molecules bind antigenic peptides for presentation to CD8 T cells. However, to bind MHCI molecules, pathogen-derived peptides must compete with an extensive pool of endogenous peptides of the host. We have engineered MHCI molecules so that they can be pre-loaded with pathogen-derived peptides. In this grant, we will test the efficacy and mechanism of using these pre-loaded MHCI as vaccines
Keywords: APC; ATGN; Affinity; Antigen Presentation; Antigen-Presenting Cells; Antigens; Arthropoda; Arthropods; Bacteria; Binding; Binding (Molecular Function); CD8; CD81; CD81 gene; CD8B; CD8B1; CD8B1 gene; Cell surface; Cells; Class I Antigens; Class I Major Histocompatibility Antigens; Complex; Complex Class 1; Cross Presentation; DNA; DNA Vaccines; Deoxyribonucleic Acid; Disease; Disorder; Disulfides; Engineering; Engineerings; Grant; Histocompatibility Antigens Class I; Immune system; Immunity; Immunologic Accessory Cells; Infection; LYT3; Lymph node proper; MHC Class I Molecule; MHC Class I Protein; MHC class I antigen; Major Histocompatibility Complex Class 1; Mammals, Mice; Membrane; Mice; Molecular; Molecular Interaction; Monocytes / Macrophages / APC; Murine; Mus; Naked DNA Vaccines; Pathway interactions; Peptides; Reticuloendothelial System, Lymph Node; Role; Secure; Skin; T-Cells; T-Lymphocyte; TAPA-1; TAPA1; TSPAN28; Testing; Thymotaxin; Thymus-Dependent Lymphocytes; Vaccination; Vaccines; Vaccines, DNA; Vaccines, Recombinant DNA; Virus; Viruses, General; accessory cell; base; beta-2 Microglobulin; body system, allergic/immunologic; design; designing; disease/disorder; efficacy testing; immunogen; in vivo; lymph gland; lymph nodes; membrane structure; new approaches; novel; novel approaches; novel strategies; novel strategy; organ system, allergic/immunologic; pathogen; pathway; public health relevance; response; social role; thymus derived lymphocyte; tumor; vaccine efficacy
Relevance: Protective immunity to several pathogens requires that MHCI molecules bind antigenic peptides for presentation to CD8 T cells. However, to bind MHCI molecules, pathogen-derived peptides must compete with an extensive pool of endogenous peptides of the host. We have engineered MHCI molecules so that they can be pre-loaded with pathogen-derived peptides. In this grant, we will test the efficacy and mechanism of using these pre-loaded MHCI as vaccines
Project start date: 2004-03-01
Project end date: 2015-01-31
Budget start date: 1-FEB-2010
Budget end date: 31-JAN-2011
PFA/PA: PA-07-070
2R01AI055849-06A1 (2010): $158334