Systemic treatment with the bacterial flagellin protein, a Toll-like receptor 5 (TLR5) agonist, provides protection against high dose radiation through activation of nuclear factor-(B (NF-(B). NF-(B signaling induces multiple factors that contribute to cell survival and tissue regeneration, including apoptosis inhibitors, reactive oxygen species scavengers, and cytokines. We have engineered CBLB502, an optimized flagellin derivative with reduced immunogenicity, for development as a radioprotectant. While CBLB502 is currently in Phase 1 trials for biodefense applications, it is also expected to have a wide range of medical applications, including reduction of the adverse side effects of anti-cancer radio- and chemotherapy. However, repeated administration of CBLB502 could induce a neutralizing immune response that would limit its effectiveness. To develop alternative TLR5 agonists with reduced immunogenicity, we generated monoclonal anti-human-TLR5 antibodies that activate TLR5 upon binding. This proposal is focused on detailed functional and immunochemical characterization of the generated agonistic antibodies in order to select the candidates that most potently and specifically activate TLR5 in both epithelial and monocytic cells of human origin and also activate TLR5 from other species commonly used in pre-clinical drug evaluation. In the next phase of the project, the selected antibodies will be evaluated for radioprotective efficacy in vivo.
Public Health Relevance: Pharmacological activation of TLR5 with CBLB502, a derivative of the bacterial flagellin protein, is a powerful approach to protection of sensitive tissues from acute radiation exposure and other types of stress. However, prolonged treatment with CBLB502 for some medical applications (such as protection of normal tissues during anti-cancer radiotherapy) could induce undesirable immune responses. Alternative TLR5 agonists with reduced immunogenicity, such as the agonistic antibodies that are the subject of this proposal, would be ideal drugs for such applications, potentially leading to clinical impacts such as improvement of the therapeutic index of radiation therapy
Public Health Relevance Statement: Pharmacological activation of TLR5 with CBLB502, a derivative of the bacterial flagellin protein, is a powerful approach to protection of sensitive tissues from acute radiation exposure and other types of stress. However, prolonged treatment with CBLB502 for some medical applications (such as protection of normal tissues during anti-cancer radiotherapy) could induce undesirable immune responses. Alternative TLR5 agonists with reduced immunogenicity, such as the agonistic antibodies that are the subject of this proposal, would be ideal drugs for such applications, potentially leading to clinical impacts such as improvement of the therapeutic index of radiation therapy
Project Terms: 3-10C; AMCF-I; Active Oxygen; Acute; Adjuvant; Adverse effects; Agonist; Alimentary Canal; Animals; Antibodies; Apoptosis; Apoptosis Inhibitor; Apoptosis Pathway; Apoptotic; Attention; Benign; Binding; Binding (Molecular Function); Blood Cells; Blotting, Western; Body Tissues; C 3-5 Converting Enzyme; C3 Proactivator; C3PA; CVFBb; CXCL8; Cancer Patient; Cancer Radiotherapy; Cancer Treatment; Cancerous; Cell Communication and Signaling; Cell Death, Programmed; Cell Line; Cell Lines, Strains; Cell Protection; Cell Signaling; Cell Survival; Cell Viability; CellLine; Cells; Clinical; Clinical Trials, Phase I; Collection; Complement 3 Proactivator; Complement Factor B; Complement Factor B, Alternative Pathway; Complement Protein B; Complement Protein Factor B; Cytofluorometry, Flow; Cytokine Signal Transduction; Cytokine Signaling; Cytokines, Chemotactic; Cytoprotection; Data; Development; Digestive Tract; Dose; Drug Development, Preclinical; Drug Evaluation; Drug Testing/Development, Preclinical; Drug usage; Drugs; Early-Stage Clinical Trials; Effectiveness; Engineering; Engineerings; Epithelial; Ethics; Evaluation Studies, Drug; Evolution; Factor B; Family member; Flagellin; Flow Cytofluorometries; Flow Cytometry; Flow Microfluorimetry; Future; GCP-1; GCP1; GI Tract; Gastrointestinal Tract; Gastrointestinal tract structure; Gene Expression; Generations; Goals; Hematologic Body System; Hematopoietic Body System; Hematopoietic System; Homologous Chemotactic Cytokines; Host Defense Mechanism; Human; Human, General; Hybridomas; IL-8; IL8; IL8 gene; INFLM; Idiopathic Parkinson Disease; Immune Precipitation; Immune response; Immunity; Immunity, Innate; Immunity, Native; Immunity, Natural; Immunity, Non-Specific; Immunomodulators; Immunoprecipitation; In Vitro; Inflammation; Inflammatory; Injection of therapeutic agent; Injections; Intercrines; Intestinal; Intestines; Intracellular Communication and Signaling; K60; LECT; LUCT; LYNAP; Lewy Body Parkinson Disease; Ligands; Lymphocytes, Null; MDNCF; MONAP; Macaca mulatta; Malignant Cell; Malignant Neoplasm Therapy; Malignant Neoplasm Treatment; Mammals, Mice; Man (Taxonomy); Man, Modern; Mass Spectrum; Mass Spectrum Analysis; Measures; Mediating; Medical; Medication; Mice; Microbe; Microfluorometry, Flow; Microorganisms, General; Moab, Clinical Treatment; Molecular; Molecular Interaction; Monoclonal Antibodies; Mononuclear; Murine; Mus; NAF; Natural Immunity; Normal Cell; Normal Tissue; Normal tissue morphology; Nuclear; Null Cells; Null Lymphocytes; Organ System, Hematologic; Outcome; Oxygen Radicals; Paralysis Agitans; Parkinson; Parkinson Disease; Parkinson's; Parkinson's disease; Parkinsons disease; Pattern; Peripheral Blood Cell; Pharmaceutic Preparations; Pharmaceutical Preparations; Phase; Phase 1 Clinical Trials; Phase I Clinical Trials; Phase I Study; Photometry/Spectrum Analysis, Mass; Preclinical Drug Development; Primary Parkinsonism; Pro-Oxidants; Process; Programs (PT); Programs [Publication Type]; Properdin Factor B; Property; Property, LOINC Axis 2; Proteins; Radiation; Radiation Syndromes; Radiation therapy; Radiotherapeutics; Radiotherapy; Reactive Oxygen Species; Receptor Signaling; Recombinants; Reporter; Reporter Genes; Resistance; Rhesus; Rhesus Macaque; Rhesus Monkey; SCYB8; SIS cytokines; Salmonella; Screening procedure; Signal Pathway; Signal Transduction; Signal Transduction Systems; Signaling; Specificity; Spectrometry, Mass; Spectroscopy, Mass; Spectrum Analyses, Mass; Spectrum Analysis, Mass; Stress; TIL3; TLR protein; TLR4; TLR4 gene; TLR5; TLR5 receptor; TOLL; TSG-1; Testing; Therapeutic; Therapeutic Index; Therapeutic Studies; Therapy Research; Tissues; Toll-Like Receptor 5; Toll-like receptors; Toll/Interleukin-1 Receptor-Like Protein 3; Toxic effect; Toxicities; Treatment Side Effects; Vaccination; Variant; Variation; Western Blotting; Western Blottings; Western Immunoblotting; alimentary tract; animal efficacy; anti-microbial; anticancer therapy; antimicrobial; b-ENAP; base; biodefense; biological signal transduction; bowel; cancer cell; cancer radiation therapy; cancer therapy; cell type; chemoattractant cytokine; chemokine; chemotherapy; comparative efficacy; cross reactivity; cultured cell line; cytokine; digestive canal; drug development; drug efficacy; drug use; drug/agent; efficacy trial; experiment; experimental research; experimental study; flow cytophotometry; gene product; hToll; host response; immunogenic; immunogenicity; immunoresponse; improved; in vivo; interest; irradiation; microorganism; non-human primate; nonhuman primate; phase 1 study; phase 1 trial; phase I trial; polypeptide; pre-clinical; preclinical; preclinical study; programs; protein blotting; protocol, phase I; public health relevance; radiation adverse effect; ray (radiation); regenerate new tissue; regenerating damaged tissue; research study; resistant; response; screening; screenings; side effect; therapy adverse effect; tissue regeneration; toll-5 receptor; treatment adverse effect
