Patent ID: 6261763
Filing Date: 2001-07-17
Classification: A61K,C07K,C12N,G01N

Abstract:
A method for determining whether an agent is capable of specifically inhibiting (A) the fusion of a macrophage-tropic primary isolate of HIV-1 to a CD4.sup.+ cell susceptible to infection by a macrophage-tropic HIV-1 or (B) the fusion of a T cell-tropic isolate of HIV-1 to a cell susceptible to infection by a T cell tropic HIV-1, but not both, which comprises:(a) contacting (i) a first appropriate CD4.sup.+ cell, which is labeled with a first dye, with (ii) a cell expressing the HIV-1 envelope glycoprotein of the macrophage-tropic primary isolate of HIV-1 on its surface, which is labeled with a second dye, in the presence of an excess of the agent under conditions which would normally permit the fusion of the CD4.sup.+ cell to the cell expressing the HIV-1 envelope glycoprotein on its surface in the absence of the agent, the first and second dyes being selected so as to allow resonance energy transfer between the dyes;(b) exposing the result of step (a) to conditions which would result in resonance energy transfer if fusion has occurred; and(c) determining whether there is a reduction of resonance energy transfer, when compared with the resonance energy transfer in the absence of the agent;(d) contacting (i) a second appropriate CD4.sup.+ cell, which is labeled with a first dye, with (ii) a cell expressing the HIV-1 envelope glycoprotein of a T cell-tropic isolate of HIV-1 on its surface, which is labeled with a second dye, in the presence of an excess of the agent under conditions which would normally permit the fusion of the CD4.sup.+ cell to the cell expressing the HIV-1 envelope glycoprotein on its surface in the absence of the agent, the first and second dyes being selected so as to allow resonance energy transfer between the dyes;(e) exposing the result of step (d) to conditions which would result in resonance energy transfer if fusion has occurred; and(f) determining whether there is a reduction of resonance energy transfer, when compared with the resonance energy transfer in the absence of the agent, wherein a decrease in transfer in step (c) but not step (f) indicates that the agent is capable of specifically inhibiting fusion of the macrophage-tropic primary isolate of HIV-1 to CD4.sup.+ cells and a decrease in transfer in step (f) but not step (c) indicates that the agent is capable of specifically inhibiting the fusion of a T cell-tropic isolate of HIV-1 to the CD4.sup.+ cells.