Medicine and Health Sciences Commons^™

Development And Characterization Of A Severe Acute Respiratory Syndrome-Associated Coronavirus-Neutralizing Human Monoclonal Antibody That Provides Effective Immunoprophylaxis In Mice, Thomas Greenough, Gregory Babcock, Anjeanette Roberts, Hector Hernandez, William Thomas, Jennifer Coccia, Robert Graziano, Mohan Srinivasan, Israel Lowy, Robert Finberg, Kanta Subbarao, Leatrice Vogel, Mohan Somasundaran, Katherine Luzuriaga, John Sullivan, Donna Ambrosino

William D Thomas Jr

BACKGROUND: Severe acute respiratory syndrome (SARS) remains a significant public health concern after the epidemic in 2003. Human monoclonal antibodies (MAbs) that neutralize SARS-associated coronavirus (SARS-CoV) could provide protection for exposed individuals. METHODS: Transgenic mice with human immunoglobulin genes were immunized with the recombinant major surface (S) glycoprotein ectodomain of SARS-CoV. Epitopes of 2 neutralizing MAbs derived from these mice were mapped and evaluated in a murine model of SARS-CoV infection. RESULTS: Both MAbs bound to S glycoprotein expressed on transfected cells but differed in their ability to block binding of S glycoprotein to Vero E6 cells. Immunoprecipitation analysis revealed …

Human Monoclonal Antibodies Directed Against Toxins A And B Prevent Clostridium Difficile-Induced Mortality In Hamsters, Gregory Babcock, Teresa Broering, Hector Hernandez, Robert Mandell, Katherine Donahue, Naomi Boatright, Anne Stack, Israel Lowy, Robert Graziano, Deborah Molrine, Donna Ambrosino, William Thomas

William D Thomas Jr

Clostridium difficile is the leading cause of nosocomial antibiotic-associated diarrhea, and recent outbreaks of strains with increased virulence underscore the importance of identifying novel approaches to treat and prevent relapse of Clostridium difficile-associated diarrhea (CDAD). CDAD pathology is induced by two exotoxins, toxin A and toxin B, which have been shown to be cytotoxic and, in the case of toxin A, enterotoxic. In this report we describe fully human monoclonal antibodies (HuMAbs) that neutralize these toxins and prevent disease in hamsters. Transgenic mice carrying human immunoglobulin genes were used to isolate HuMAbs that neutralize the cytotoxic effects of either toxin …

Amino Acids 270 To 510 Of The Severe Acute Respiratory Syndrome Coronavirus Spike Protein Are Required For Interaction With Receptor, Gregory Babcock, Diana Esshaki, William Thomas, Donna Ambrosino

William D Thomas Jr

A novel coronavirus, severe acute respiratory syndrome coronavirus (SARS-CoV), has recently been identified as the causative agent of severe acute respiratory syndrome (SARS). SARS-CoV appears similar to other coronaviruses in both virion structure and genome organization. It is known for other coronaviruses that the spike (S) glycoprotein is required for both viral attachment to permissive cells and for fusion of the viral envelope with the host cell membrane. Here we describe the construction and expression of a soluble codon-optimized SARS-CoV S glycoprotein comprising the first 1,190 amino acids of the native S glycoprotein (S(1190)). The codon-optimized and native S glycoproteins …

Therapy With A Severe Acute Respiratory Syndrome-Associated Coronavirus-Neutralizing Human Monoclonal Antibody Reduces Disease Severity And Viral Burden In Golden Syrian Hamsters, Anjeanette Roberts, William Thomas, Jeannette Guarner, Elaine Lamirande, Gregory Babcock, Thomas Greenough, Leatrice Vogel, Norman Hayes, John Sullivan, Sherif Zaki, Kanta Subbarao, Donna Ambrosino

William D Thomas Jr

BACKGROUND: Immunotherapy with monoclonal antibodies (MAbs) offers safe interventions for the prevention of infection in patients after organ transplantation and for the treatment of cancers and autoimmune diseases. MAb 201 is a severe acute respiratory syndrome-associated coronavirus (SARS-CoV)-specific MAb that prevents establishment of viral replication in vitro and prevents viral replication in vivo when administered prophylactically. The efficacy of MAb 201 in the treatment of SARS was evaluated in golden Syrian hamsters, an animal model that supports SARS-CoV replication to high levels and displays severe pathological changes associated with infection, including pneumonitis and pulmonary consolidation. METHODS: Golden Syrian hamsters that …

Lineage-Specific T-Cell Responses To Cancer Mucosa Antigen Oppose Systemic Metastases Without Mucosal Inflammatory Disease., Adam Snook, Peng Li, Benjamin J Stafford, Elizabeth J Faul, Lan Huang, Ruth C Birbe, Alessandro Bombonati, Stephanie Schulz, Matthias Schnell, Laurence Eisenlohr, Scott Waldman

Adam E Snook

Cancer mucosa antigens are emerging as a new category of self-antigens expressed normally in immunologically privileged mucosal compartments and universally by their derivative tumors. These antigens leverage the established immunologic partitioning of systemic and mucosal compartments, limiting tolerance opposing systemic antitumor efficacy. An unresolved issue surrounding self-antigens as immunotherapeutic targets is autoimmunity following systemic immunization. In the context of cancer mucosa antigens, immune effectors to self-antigens risk amplifying mucosal inflammatory disease promoting carcinogenesis. Here, we examined the relationship between immunotherapy for systemic colon cancer metastases targeting the intestinal cancer mucosa antigen guanylyl cyclase C (GCC) and its effect on inflammatory …

Mast Cell Stabilization Decreases Cardiomyocyte And Lv Function In Dogs With Isolated Mitral Regurgitation., Betty Pat, Cheryl Killingsworth, Yuanwen Chen, James D Gladden, Greg Walcott, Pamela C Powell, Thomas Denney, Himanshu Gupta, Ravi Desai, Michael Tillson, A Ray Dillon, Louis J Dell'italia

Ravi V Desai MD

BACKGROUND: Mast cells are increased in isolated mitral regurgitation (MR) in the dog and may mediate extracellular matrix loss and left ventricular (LV) dilatation. We tested the hypothesis that mast cell stabilization would attenuate LV remodeling and improve function in the MR dog.

METHODS AND RESULTS: MR was induced in adult dogs randomized to no treatment (MR, n = 5) or to the mast cell stabilizer, ketotifen (MR + MCS, n = 4) for 4 months. LV hemodynamics were obtained at baseline and after 4 months of MR and magnetic resonance imaging (MRI) was performed at sacrifice. MRI-derived, serial, short-axis …

Chymase Inhibition Prevents Fibronectin And Myofibrillar Loss And Improves Cardiomyocyte Function And Lv Torsion Angle In Dogs With Isolated Mitral Regurgitation., Betty Pat, Yuanwen Chen, Cheryl Killingsworth, James D Gladden, Ke Shi, Junying Zheng, Pamela C Powell, Greg Walcott, Mustafa I Ahmed, Himanshu Gupta, Ravi Desai, Chih-Chang Wei, Naoki Hase, Tsunefumi Kobayashi, Abdelkarim Sabri, Henk Granzier, Thomas Denney, Michael Tillson, A Ray Dillon, Ahsan Husain, Louis J Dell'italia

Ravi V Desai MD

BACKGROUND: The left ventricular (LV) dilatation of isolated mitral regurgitation (MR) is associated with an increase in chymase and a decrease in interstitial collagen and extracellular matrix. In addition to profibrotic effects, chymase has significant antifibrotic actions because it activates matrix metalloproteinases and kallikrein and degrades fibronectin. Thus, we hypothesize that chymase inhibitor (CI) will attenuate extracellular matrix loss and LV remodeling in MR.

METHODS AND RESULTS: We studied dogs with 4 months of untreated MR (MR; n=9) or MR treated with CI (MR+CI; n=8). Cine MRI demonstrated a >40% increase in LV end-diastolic volume in both groups, consistent with …