Recent evidence demonstrates an essential role for cellular cathepsins in viral glycoprotein processing and cellular entry for the highly pathogenic viruses Ebola, SARS, coronavirus and Nipah/Hendra. Cathepsin L appears to be important for SARS CoV and Nipah virus glycoprotein activation while Ebola requires both cathepsins L and B for viral entry. Inhibitors of these enzymes effectively block viral entry and replication in cell culture. This proposal will build upon these new findings and will develop cathepsin inhibitors as therapeutics for these diverse viral agents. To accomplish this goal we propose the following aims:
Specific Aim 1) Utilize high throughput screening of diverse libraries to identify cathepsin inhibitors.
Specific Aim 2) Test the candidate compounds for inhibition of viral entry using a rapid, quantitative and safe assay employing viral pseudotypes carrying the glycoproteins of Ebola, SARS CoV, or Hendra virus. Confirm the inhibitory effect on replication of SARS CoV and a model coronavirus, mouse hepatitis virus (MHV).
Specific Aim 3) Test the cathepsin inhibitors identified in Aims 1 and 2 in animal model systems using SARS CoV and MHV. In conclusion, the proposed work will produce candidate molecules for treatment of infection by viruses such as Ebola, SARS CoV and Hendra. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project--Cooperative Agreements (U01)
Project #
5U01AI070369-02
Application #
7291059
Study Section
Special Emphasis Panel (ZAI1-GSM-M (M1))
Program Officer
Cassels, Frederick J
Project Start
2006-09-27
Project End
2009-08-31
Budget Start
2007-09-01
Budget End
2008-08-31
Support Year
2
Fiscal Year
2007
Total Cost
$575,911
Indirect Cost
Name
University of Pennsylvania
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
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Shah, Parag P; Wang, Tianhua; Kaletsky, Rachel L et al. (2010) A small-molecule oxocarbazate inhibitor of human cathepsin L blocks severe acute respiratory syndrome and ebola pseudotype virus infection into human embryonic kidney 293T cells. Mol Pharmacol 78:319-24
Kaletsky, Rachel L; Francica, Joseph R; Agrawal-Gamse, Caroline et al. (2009) Tetherin-mediated restriction of filovirus budding is antagonized by the Ebola glycoprotein. Proc Natl Acad Sci U S A 106:2886-91