Abstract: Betulin and dihydrobetulin acyl derivatives according to the present invention have been found to have potent anti-HIV activity. The compounds of the present invention have Formula I as described herein, or pharmaceutically acceptable salts thereof, wherein R1 is a C2-C20 substituted or unsubstituted carboxyacyl, R2 is hydrogen, chloro, bromo, or hydroxy, R4 is hydrogen or C(C6H5)3; wherein the dashed line represents an optional double bond between C20 and C29.

Abstract: The invention is directed to methods for identifying compounds that decrease the ability of a virus, such as HIV-1, to infect previously uninfected cells by inducing conformational changes in viral envelope proteins, and the compounds discovered by such methods.

Abstract: This invention provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention also provides an immunoconjugate which comprises 1) a gamma radiation-emitting radionuclide of low to moderate cytotoxicity and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention further provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a heterotetramer comprising two heavy chains and two light chains, both heavy chains being either a) IgG2 heavy chains or b) chimeric CD4-IgG2 heavy chains, and both light chains being either a) kappa light chains or b) chimeric CD4-kappa light chains.

Abstract: This invention provides a polypeptide comprising a fragment of a chemokine receptor capable of inhibiting HIV-1 infection. In an embodiment, the chemokine receptor is C—C CKR-5. In another embodiment, the fragment comprises at least one extracellular domain of the chemokine receptor C—C CKR-5. This invention further provides different uses of the chemokine receptor for inhibiting HIV-1 infection.

Abstract: The invention is directed to a methods for identifying compounds that inhibit or prevent infection of cells by enveloped viruses such as HIV-1 by preventing or disrupting conformational changes in the viral transmembrane protein that are required for virus fusion with those cells, and the compounds discovered by such methods. The invention also includes using these assays as diagnostic assays to detect antibodies in virus infected individuals that inhibit the viral entry processes.

Abstract: This invention provides: agents determined to be capable of specifically inhibiting the fusion of a macrophage-tropic primary isolate of HIV-1 to a CD4+ cell, but not a T cell-tropic isolate of HIV-1 to a CD4+ cell; and agents determined to be capable of specifically inhibiting the fusion of a T cell-tropic isolate of HIV-1 to a CD4+ cell, but not a macrophage-tropic primary isolate of HIV-1 to a CD4+ cell. This invention also provides: agents capable of specifically inhibiting the fusion of a macrophage tropic primary isolate of HIV-1 with a CD+ cell susceptible to infection by a macrophage-tropic primary isolate of HIV-1; and agents capable of specifically inhibiting the fusion of a T cell-tropic isolate of HIV-1 with a CD4+ cell susceptible to infection by a T cell-tropic isolate of HIV-1. The agents include but are not limited to antibodies.

Abstract: 3′,4′-di-O-camphanoyl-(+)-cis-khellactone analogs according to the present invention have been found to have anti-HIV activity.

Abstract: This invention provides methods for inhibiting fusion of HIV-1 to CD4+ cells which comprise contacting CD4+ cells with a non-chemokine agent capable of binding to a chemokine receptor in an amount and under conditions such that fusion of HIV-1 to the CD4+ cells is inhibited. This invention also provides methods for inhibiting HIV-1 infection of CD4+ cells which comprise contacting CD4+ cells with a non-chemokine agent capable of binding to a chemokine receptor in an amount and under conditions such that fusion of HIV-1 to the CD4+ cells is inhibited, thereby inhibiting the HIV-1 infection. This invention provides non-chemokine agents capable of binding to the chemokine receptor and inhibiting fusion of HIV-1 to CD4+ cells.

Abstract: The invention is directed to a methods for identifying compounds that inhibit or prevent infection of cells by enveloped viruses such as HIV-1 by preventing or disrupting conformational changes in the viral transmembrane protein that are required for virus fusion with those cells, and the compounds discovered by such methods. The invention also includes using these assays as diagnostic assays to detect antibodies in virus infected individuals that inhibit the viral entry processes.

Abstract: This invention provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention also provides an immunoconjugate which comprises 1) a gamma radiation-emitting radionuclide of low to moderate cytotoxicity and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention further provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a heterotetramer comprising two heavy chains and two light chains, both heavy chains being either a) IgG2 heavy chains or b) chimeric CD4-IgG2 heavy chains, and both light chains being either a) kappa light chains or b) chimeric CD4-kappa light chains.

Abstract: This invention provides agents determined to be capable of inhibiting the fusion of a macrophage-tropic primary isolate of HIV-1 to a CD4+cell and agents determined to be capable of inhibiting the fusion of a T cell-tropic isolate of HIV-1 to a CD4+cell. This invention also provides methods to identify such agents. This invention further provides methods of inhibiting fusion of a macrophage-tropic primary isolate of HIV-1 with a CD+ cell and methods of inhibiting fusion of a T cell-tropic isolate of HIV-1 with a CD4+cell susceptible to infection by a T cell-tropic isolate of HIV-1.

Abstract: This invention provides methods for inhibiting fusion of HIV-1 to CD4+ cells which comprise contacting CD4+ cells with a non-chemokine agent capable of binding to a chemokine receptor in an amount and under conditions such that fusion of HIV-1 to the CD4+ cells is inhibited. This invention also provides methods for inhibiting HIV-1 infection of CD4+ cells which comprise contacting CD4+ cells with a non-chemokine agent capable of binding to a chemokine receptor in an amount and under conditions such that fusion of HIV-1 to the CD4+ cells is inhibited, thereby inhibiting the HIV-1 infection. This invention provides non-chemokine agents capable of binding to the chemokine receptor and inhibiting fusion of HIV-1 to CD4+ cells.

Abstract: This invention provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention also provides an immunoconjugate which comprises 1) a gamma radiation-emitting radionuclide of low to moderate cytotoxicity and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention further provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a heterotetramer comprising two heavy chains and two light chains, both heavy chains being either 1) IgG2 heavy chains or b) chimeric CD4-IgG2 heavy chains, and both light chains being either a) kappa light chains or b) chimeric CD4-kappa light chains.

Abstract: The current invention relates to methods of generating immunogens that elicit broadly neutralizing antibodies which target regions of viral envelope proteins such as the gp 120/gp41 complex of HIV-1. More specifically, the current invention involves using stabilizing peptides modeling the &agr;-helical regions of the ectodomain of the HIV-1 transmembrane protein to stabilize fusion-active intermediate structures which can be used as vaccine immunogens.

Abstract: This invention provides an antibody capable of specifically inhibiting the fusion of an HIV-1 envelope glycoprotein cell with an appropriate CD4+ cell without cross reacting with the HIV-1 envelope glycoprotein or CD4 and capable of inhibiting infection by one or more strains so HIV-1. This antibody is then used to identify a molecule which is important for HIV infection. Different uses of the antibody and the molecule are described.

Abstract: Previous studies of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein-mediated membrane fusion have focused on laboratory-adapted T-lymphotropic strains of the virus. The goal of this application was to develop a novel screening assay to characterize membrane fusion mediated by a primary HIV-1 isolate in comparison with a laboratory-adapted strain. To this end, a novel fusion assay was developed on the basis of the principle of resonance energy transfer, using HeLa cells stably transfected with gp120/gp41 from the T-lymphotropic isolate HIV-1LA1 or the macrophage-tropic primary isolate HIV-1JR-FL. These cells fused with CD4+ target cell lines with a tropism mirroring that of infection by the two viruses. Of particular note, HeLa cells expressing HIV-1JR-FL gp120/gp41 fused only with PM1 cells, a clonal derivative of HUT 78, and not with other T-cell or macrophage cell lines.

Abstract: This invention provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention also provides an immunoconjugate which comprises 1) a gamma radiation-emitting radionuclide of low to moderate cytotoxicity and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention further provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a heterotetramer comprising two heavy chains and two light chains, both heavy chains being either a) IgG2 heavy chains or b) chimeric CD4-IgG2 heavy chains, and both light chains being either a) kappa light chains or b) chimeric CD4-kappa light chains.

Abstract: This invention provides methods for inhibiting fusion of HIV-1 to CD4.sup.+ cells which comprise contacting CD4.sup.+ cells with a non-chemokine agent capable of binding to a chemokine receptor in an amount and under conditions such that fusion of HIV-1 to the CD4.sup.+ cells is inhibited. This invention also provides methods for inhibiting HIV-1 infection of CD4.sup.+ cells which comprise contacting CD4.sup.+ cells with a non-chemokine agent capable of binding to a chemokine receptor in an amount and under conditions such that fusion of HIV-1 to the CD4.sup.+ cells is inhibited, thereby inhibiting the HIV-1 infection. This invention provides non-chemokine agents capable of binding to the chemokine receptor and inhibiting fusion of HIV-1 to CD4.sup.+ cells. This invention also provides pharmaceutical compositions comprising an amount of the non-chemokine agent capable of binding to the chemokine receptor and inhibiting fusion of HIV-1 to CD4.sup.+ cells effective to prevent fusion of HIV-1 to CD4.sup.

Abstract: An immunoconjugate which consists of a cytotoxic radionuclide and a homodimer comprising two heavy chains, the cytotoxic radionuclide being linked to the heavy chains dirctly or using a bifunctional chelator and a composition which comprises the immunoconjugate and an acceptable carrier.

Abstract: This invention provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention also provides an immunoconjugate which comprises 1) a gamma radiation-emitting radionuclide of low to moderate cytotoxicity and 2) a CD4-gamma2 chimeric heavy chain homodimer linked thereto. This invention further provides an immunoconjugate which comprises 1) a non-peptidyl toxin and 2) a heterotetramer comprising two heavy chains and two light chains, both heavy chains being either a) IgG2 heavy chains or b) chimeric CD4-IgG2 heavy chains, and both light chains being either a) kappa light chains or b) chimeric CD4-kappa light chains.