Title:  Human monoclonal antibodies to the CD4-binding domain of HIV, uses thereof and synergistic neutralization of HIV

United States Patent:  6,241,986

Assignee:  New York University (New York, NY)

Filed:  March 21, 1994

Human monoclonal antibodies specific for the CD4-binding domain of HIV gp120 are useful in the neutralization of HIV and in the prevention of HIV infection and the treatment of a subject infected with HIV. Such antibodies and heterohybridomas producing them are disclosed. Synergistic mixtures of at least two human monoclonal antibodies specific for two different epitopes of gp120 are used to neutralize HIV, to prevent HIV infection and to treat a subject infected with HIV. In this synergistic mixture, one antibody has broad HIV group specificity, and is preferably specific for the CD4-binding domain. The other antibody is preferably specific for the V3 loop and has a range of neutralizing activity such that it neutralizes virus of the MN strain, MN-like families, and widely divergent HIV-1 isolates which are members of various V3 lop classes.

SUMMARY OF THE INVENTION

The present inventors have produced and analyzed several novel human mAbs reactive with the CD4-binding domain of gp120. The present inventors used gp120 from one particular strain of HIV-1, HTLV-IIIB, as a screening antigen, and started with cells from naturally infected patients as their approach to assure the selection of mAbs with broad group reactivity. The discoveries detailed herein demonstrate that the CD4-binding domain is immunogenic, as three of the four mAbs of the present invention described herein, were reactive with this region. Furthermore, the results suggest that most, if not all antibodies to the CD4-binding domain in naturally infected hosts are neutralizing antibodies, since three mAbs specific for this region had potent virus neutralizing activity.

In addition, the present inventors have discovered that appropriate combinations of antibodies specific for two different gp120 epitopes, the CD4-binding domain and the V3 loop, interact synergistically to result in greater than expected virus neutralization and enhanced host range of specificity.

The present invention is directed to an antibody specific for an epitope of the CD4-binding domain of gp120, the antibody being a human monoclonal antibody which is group-specific, neutralizing, and capable of binding to gp120 when the gp120 is bound to an immobilized anti-V3 loop antibody.

The present invention is also directed to a human monoclonal antibody specific for an epitope of the CD4-binding domain of gp120, wherein the antibody is selected from the group consisting of human monoclonal antibody 448-D, 559/64-D, 588-D and an antibody which blocks the binding of human monoclonal antibody 448-D, 559/64-D or 588-D to gp120.

In one embodiment, the antibody is the human monoclonal antibody 448-D or an antibody which blocks the binding of human monoclonal antibody 448-D to gp120. In another embodiment, the antibody is the human monoclonal antibody 559/64-D or an antibody which blocks the binding of human monoclonal antibody 559/64-D to gp120. In yet another embodiment, the antibody is the human monoclonal antibody 588-D or an antibody which blocks the binding of human monoclonal antibody 588-D to gp120.

The present invention is further directed to a cell line producing any of the above human monoclonal antibodies. Preferably, the cell line is a human-mouse heterohybridoma. Preferred cell lines are 448-D (ATCC #HB 10895), 559/64-D (ATCC #HB 10893) or 588-D (ATCC #HB 10894).

The present invention also includes a method for neutralizing HIV comprising contacting the HIV with an effective amount of the above antibody.

Also provided is a method for preventing infection by HIV in a subject or treating a subject infected with HIV, comprising administering to the subject an effective amount of the above antibody.

The present invention is also directed to a composition useful for neutralizing HIV, for preventing infection by HIV-1, or for treating a subject infected with HIV, comprising an effective amount of a mixture of at least a first and a second antibody specific for different epitopes of the HIV gp120 protein, wherein

(a) the first antibody is group-specific; and

(b) the second antibody is specific for the V3 region of gp120, and has a range of neutralizing activity such that it neutralizes MN, MN-like families, and widely divergent HIV-1 isolates which are members of various V3 loop classes, including RF and IIIB,

and wherein the neutralizing activity of the mixture is greater than the sum of the neutralizing activity of each antibody alone. In a preferred embodiment, the second antibody neutralizes both the MN and RF strains or both the MN and IIIB strains of HIV-1.

Preferably, in the above composition, the first and the second antibody are monoclonal antibodies, more preferably, human monoclonal antibodies. A preferred first antibody is specific for the CD4-binding domain of gp120, and a preferred second antibody is specific for the V3 domain of gp120. Preferably, the first antibody of this composition is a human monoclonal antibody which is group-specific, neutralizing, and capable of binding to gp120 when the gp120 is bound to an immobilized anti-V3 loop antibody. More preferably, (1) the first antibody is selected from the group consisting of 448-D, 559/64-D, 588-D and an antibody which blocks the binding of 448-D, 559/64-D or 588-D to gp120, and (2) the second antibody is the human monoclonal antibody 447-52D (referred to below also as 447-D).

Also provided is a method for neutralizing HIV comprising providing to the HIV the composition described above, thereby neutralizing the virus.

In another embodiment, the invention provides a method for preventing HIV infection in a subject or treating a subject infected with HIV, comprising administering to the subject an effective amount of the composition described above, thereby preventing the infection or treating the subject.

The present invention is directed to a pharmaceutical composition comprising an antibody specific for an epitope of the CD4-binding domain of the gp120, the antibody being a human monoclonal antibody which is group-specific, neutralizing, and capable of binding to gp120 when the gp120 is bound to an immobilized anti-V3 loop antibody, and a pharmaceutically acceptable excipient. Preferably, in this pharmaceutical composition, the antibody is selected from the group consisting of human monoclonal antibody 448-D, 559/64-D, 588-D and an antibody which blocks the binding of human monoclonal antibody 448-D, 559/64-D or 588-D to gp120.

Another pharmaceutical composition of the present invention comprises the composition described above having at least a first and a second antibody, and a pharmaceutically acceptable excipient.

Claim 1 of 42 Claims

What is claimed is:

1. A molecule capable of binding to an epitope of the CD4-binding domain of HIV-1 gp120, comprising:

(a) a human monoclonal antibody specific for an epitope of the CD4-binding domain of HIV-1 gp120, which antibody is group-specific, neutralizing, and capable of binding to gp120 when the gp120 is bound to an immobilized anti-V3 loop antibody, wherein said antibody has all the antigen binding characteristics of the human monoclonal antibody designated 448-D produced by the cell line having ATCC No. HB 10895, or

(b) an antigen binding fragment of said human monoclonal antibody.

____________________________________________
If you want to learn more about this patent, please go directly to the U.S. Patent and Trademark Office Web site to access the full patent.