Verity EE, Williams LA, Haddad DN, Choy V, O'Loughlin C, Chatfield C, Saksena NK, Cunningham A, Gelder F, McPhee DA. Broad neutralization and complement-mediated lysis of HIV-1 by PEHRG214, a novel caprine anti-HIV-1 polyclonal antibody.
AIDS 2006;
20:505-15. [PMID:
16470114 DOI:
10.1097/01.aids.0000210604.78385.95]
[Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVES
To assess the potency, breadth of action, and mechanism of action of the polyclonal goat anti-HIV antibody, PEHRG214.
DESIGN
Typical human antibody responses to HIV-1 infection are unable to neutralize virus efficiently, clear the infection, or prevent disease progression. However, more potent neutralizing antibodies may be capable of playing a pivotal role in controlling HIV replication in vivo. PEHRG214 is a polyclonal caprine antibody raised against purified HIV-associated proteins, such that epitopes that are immunologically silent in humans may potentially be recognized in another species. It has been administered safely to HIV-infected individuals in Phase I clinical trials.
METHODS
The anti-HIV activity of PEHRG214 was assessed using neutralization and virion lysis assays. The target proteins for PEHRG214 activity were investigated using flow cytometry and by adsorption of anti-cell antibodies from the antibody cocktail.
RESULTS
PEHRG214 strongly neutralized a diverse range of primary HIV-1 isolates, encompassing subtypes A to E and both CCR5 and CXCR4 phenotypes. Neutralization was enhanced by the presence of complement. PEHRG214 also induced complement-mediated lysis of all HIV-1 isolates tested, and recognized or cross-reacted with a number of host cell proteins. Lysis was abrogated by adsorption with T and/or B cells expressing GPI-linked proteins, but not by GPI-deficient B cells or red blood cells.
CONCLUSIONS
PEHRG214 was found to potently neutralize and lyse HIV-1 particles. By targeting host cell proteins present in the viral envelope, which are conserved among all strains tested, PEHRG214 potentially opens up a highly novel means of eliminating circulating virus in infected individuals.
Collapse