Advancing the health and well-being of animals and people


Principal Investigator: Gary Whittaker

Department of Microbiology & Immunology
Email: grw7@cornell.edu; Phone: 607-253-4019
Sponsor: Feline Health Center
Grant Number: N/A
Title: Single Particle Studies of Coronavirus Fusion for the Development of Anti-fusogenic Antibodies as Potential FIP Therapeutics
Annual Direct Cost: $49,902
Project Period: 08/01/2013-07/31/2014

Description (Provided by applicant): Feline infectious peritonitis (FIP) is a dangerous systemic infection caused by feline coronaviruses (FCoVs) and is a leading cause of mortality in cats. This virus is clinically one of the most important pathogens of cats, because there is no reliable diagnosis, vaccine, or treatment for the FIP disease. FCoVs exist in two major serotypes (types 1 and 2) and normally infect the intestinal tract, causing minimal clinical signs. A recent model suggests that an “internal mutation” is responsible for the conversion of the benign enteric virus (feline enteric coronavirus, FECV) to a pathogenic form (feline infectious peritonitis virus, FIPV) that causes FIP. Two well-established type 2 FCoV isolates (FECV-1683 and FIPV-1146) are known to cause mild GI disease or FIP respectively. Pathogenic differences between FECV-1683 and FIPV-1146 have been mapped to the S2 (fusion) domain of the spike protein, indicating that virus entry is a critical factor in determining pathogenesis. We have recently developed a microfluidic-based, single particle tracking (SPT) assay that offers exquisite control over the sequence of triggers FCoVs use to induce membrane fusion, enabling the quantitative study the membrane fusion process. Importantly, this assay incorporates the proteinaceous receptor for FCoVs, which until now, was a major obstacle to carrying out single particle fusion studies of coronaviruses. The overall goal of this proposal is to employ this assay to study how the sequence of triggers (which, in nature, varies depending on the host cell) impacts the fusion pathway and fusion kinetics of both FECV and FIPV. These studies will provide important insight into tissue tropism of this virus. Once the fusion pathways have been characterized for these viruses, we propose to develop monoclonal antibodies that target the conserved fusion peptide of FCoVs and use the SPT assay to identify the MAbs that result in the most anti-fusogenic activity. Our studies are likely to have great clinical impact in the treatment of this disease in the cat and can be directly applied to both the development of anti-viral therapeutics and diagnostic tests.

The project represents the concerted efforts of two experienced PIs within the veterinary and engineering colleges at Cornell, who will apply their combined expertise to advance our understanding of feline coronavirus infection with the goal of identifying new reagents for FIP therapy.