Novel Compound Inhibitors of HIV-1<sub>NL4-3</sub> Vpu
Carolyn A. Robinson,
Terri D. Lyddon,
Hwi Min Gil,
David T. Evans,
Yury V. Kuzmichev,
Jonathan Richard,
Andrés Finzi,
Sarah Welbourn,
Lynn Rasmussen,
N. Miranda Nebane,
Vandana V. Gupta,
Sam Ananthan,
Zhaohui Cai,
Elizabeth R. Wonderlich,
Corinne E. Augelli-Szafran,
Robert Bostwick,
Roger G. Ptak,
Susan M. Schader,
Marc C. Johnson
Affiliations
Carolyn A. Robinson
Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine and the Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
Terri D. Lyddon
Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine and the Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
Hwi Min Gil
Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA
David T. Evans
Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA
Yury V. Kuzmichev
Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA
Jonathan Richard
Centre de Recherche du CHUM, Montréal, QC HX2 0A9, Canada
Andrés Finzi
Centre de Recherche du CHUM, Montréal, QC HX2 0A9, Canada
Sarah Welbourn
Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine and the Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
Lynn Rasmussen
High-Throughput Screening Center, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA
N. Miranda Nebane
High-Throughput Screening Center, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA
Vandana V. Gupta
Department of Chemistry, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA
Sam Ananthan
Department of Chemistry, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA
Zhaohui Cai
Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA
Elizabeth R. Wonderlich
Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA
Corinne E. Augelli-Szafran
Department of Chemistry, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA
Robert Bostwick
High-Throughput Screening Center, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA
Roger G. Ptak
Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA
Susan M. Schader
Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA
Marc C. Johnson
Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine and the Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
HIV-1 Vpu targets the host cell proteins CD4 and BST-2/Tetherin for degradation, ultimately resulting in enhanced virus spread and host immune evasion. The discovery and characterization of small molecules that antagonize Vpu would further elucidate the contribution of Vpu to pathogenesis and lay the foundation for the study of a new class of novel HIV-1 therapeutics. To identify novel compounds that block Vpu activity, we have developed a cell-based ‘gain of function’ assay that produces a positive signal in response to Vpu inhibition. To develop this assay, we took advantage of the viral glycoprotein, GaLV Env. In the presence of Vpu, GaLV Env is not incorporated into viral particles, resulting in non-infectious virions. Vpu inhibition restores infectious particle production. Using this assay, a high throughput screen of >650,000 compounds was performed to identify inhibitors that block the biological activity of Vpu. From this screen, we identified several positive hits but focused on two compounds from one structural family, SRI-41897 and SRI-42371. We developed independent counter-screens for off target interactions of the compounds and found no off target interactions. Additionally, these compounds block Vpu-mediated modulation of CD4, BST-2/Tetherin and antibody dependent cell-mediated toxicity (ADCC). Unfortunately, both SRI-41897 and SRI-42371 were shown to be specific to the N-terminal region of NL4-3 Vpu and did not function against other, more clinically relevant, strains of Vpu; however, this assay may be slightly modified to include more significant Vpu strains in the future.