Title:  Immunomodulation by genetic modification of dendritic cells and B cells

United States Patent:  6,284,742

Assignee:  UAB Research Foundation (Birmingham, AL)

Filed:  September 28, 1999

A gene delivery vector used to generate genetically modified dendritic cells and B-cells central to the immune system. As a result, genetic modification of cells bearing the CD40 target antigen on its surface can be used to modulate immunity. Previously, both dendritic cells and B-cells have been resistant to gene transfer. The present invention serves to mediate dramatic enhancements in gene transfer to these cell types. Simultaneous with gene transfer, the vector system described herein matures dendritic cells and B-cells to a more potent immunoregulatory status. This invention provides technology for genetic manipulation of dendritic cells and B-cells.

SUMMARY OF THE INVENTION

A bispecific antibody was generated through chemical conjugation of antibodies with affinities for the adenovirus fiber-knob and a dendritic cell receptor, CD40. The present invention shows that CD40 targeted adenovirus mediates dramatic enhancements in gene transfer to monocyte derived dendritic cells and that these enhancements can be attributed to a quantitative increase in the number of cells transduced. Additionally, the present invention shows that this enhancement is specific to the epitope recognized by the G28.5 antibody through successful blockade with the parent monoclonal, G28.5, and failure of the conjugate to mediate gene transfer on CD40 negative lines. Furthermore, an upregulation of several well documented dendritic cell maturational markers and enhanced allo-MLR by these cells was observed after infection with a retargeted vector. The dual role of CD40 in this scenario as both a surrogate adenovirus receptor and a powerful trigger of dendritic cell maturation may prove fortuitous as a retargeting strategy to this critical cell type of the immune system.

One object of the present invention is to provide a n adenovirus vector capable of targeting and transducing immune system cells, such as dendritic cells and B-cells, wherein transduction of B-cells results in maturation of the B-cells.

In an embodiment of the present invention, there is provided an immunomodulatory adenovirus, comprising: an adenoviral vector, and a bispecific antibody, comprising an antibody, or fragment thereof, recognizing a fiber-knob protein of said adenovirus conjugated to an antibody, or fragment thereof, recognizing a CD40 antigen, wherein said adenovirus is targeted to and transduces immune system cells resulting in modulation of said cells. Additionally, the bispecific antibody may be the product of a gene fusion.

In yet another embodiment, there is provided a n immunomodulatory adenovirus, comprising: a recombinant adenoviral vector, wherein the adenoviral gene encoding a fiber-knob protein has been replaced with a gene encoding an antibody, or fragment thereof, recognizing a CD40 antigen, or encoding the natural ligand of CD40, the trimeric CD40 ligand. When the adenovirus is targeted to and transduces immune system cells, the transduction results in modulation of the cells.

In yet another embodiment of the present invention, the adenoviral vector may express a therapeutic gene, selected from the group consisting of a gene encoding a tumor antigen, a gene encoding an antigen for an infectious agent, a gene encoding a cytotoxic agent and a gene encoding an immunomodulatory agent; the antibody recognizing the CD40 antigen is G28.5; the immune system cells are selected from the group consisting of dendritic cells and B-cells, as well as non-immune cells selected from the group consisting of vascular endothelium cells, epithelium cells, cells exhibiting chronic inflammation and cells and vessels of Karposi's sarcoma tumors; and maturation of the immune cells is indicative of modulation of the immune cells.

In yet another embodiment, there is provided a method of immunomodulation in an individual in need of such treatment, comprising the step of: administering to the individual a n immunomodulatory adenovirus, wherein the adenovirus modulates an immune response in the individual. This modulation is due to expression of a therapeutic gene by said adenovirus, and/or maturation of immune cells. The immune system cells are selected from the group consisting of dendritic cells and B-cells, as well as non-immune cells selected from the group consisting of vascular endothelium cells, epithelium cells, cells exhibiting chronic inflammation and cells and vessels of Karposi's sarcoma tumors. Generally, the method will be useful in treating an individual having a disease such as cancer, infectious diseases, allo transplant rejection, xeno transplant rejection and autoimmunity diseases. Additionally, administration of the immunomodulatory adenovirus is selected from the group consisting of systemic, intradermal and ex vivo.

Claim 1 of 6 Claims

What is claimed is:

1. A composition for delivery of a gene of interest to antigen presenting cells comprising:

(a) an adenovirus encoding a gene of interest

(b) a first antibody which specifically binds a fiber-knob protein on said adenovirus; and

(c) a second antibody which specifically binds the CD40 antigen on the surface of said antigen presenting cells, wherein said first antibody and said second antibody are genetically fused to form a bispecific antibody.

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