Methods for increasing a cytotoxic T lymphocyte response in vivo

Abstract

The invention provides methods for T helper-independent activation of an antigen-specific cytotoxic T lymphocyte response in an individual. The methods generally involve administering to an individual an immunostimulatory nucleic acid molecule in an amount effective to increase an antigen-specific CTL response in the individual. The invention further provides methods for increasing chemokine secretion, which can block HIV infection.

What is claimed is:  
     
         1 . A method of increasing antigen-specific cytotoxic T lymphocyte (CTL) activity in a CD4 +  T cell-deficient individual, comprising administering an immunostimulatory nucleic acid molecule in an amount effective to increase antigen-specific CTL activity.  
     
     
         2 . The method of  claim 1 , wherein said immunostimulatory nucleic acid molecule comprises a nucleotide sequence selected from the group consisting of 5′-purine-purine-cytosine-guanine-pyrimidine-pyrimidine-3′; 5′-purine-TCG-pyrimidine-pyrimidine-3′; and 5′-(TGC) n -3′, where n≧1.  
     
     
         3 . The method of  claim 1 , wherein the formulation further comprises an antigen or an antigenic fragment selected from the group consisting of an antigen associated with an intracellular pathogen or an antigenic fragment thereof, a tumor-associated antigen, and a tumor-specific antigen, or an antigenic fragment thereof.  
     
     
         4 . The method of  claim 3 , wherein the immunostimulatory nucleic acid molecule is chemically linked to the antigen.  
     
     
         5 . The method of  claim 1 , wherein the individual has a reduced number of CD4 +  T lymphocytes due to a primary immunodeficiency.  
     
     
         6 . The method of  claim 1 , wherein the individual has a reduced number of CD4 +  T lymphocytes due to an acquired immunodeficiency.  
     
     
         7 . The method of  claim 6 , wherein the acquired immunodeficiency is a temporary immunodeficiency due to a treatment selected from the group consisting of radiation therapy to treat a cancer, chemotherapy to treat a cancer, immunosuppression following bone marrow transplantation, immunosuppression caused by treatment for an autoimmune disease, and immunosuppression following organ transplantation.  
     
     
         8 . The method of  claim 6 , wherein the acquired immunodeficiency is acquired immunodeficiency syndrome.  
     
     
         9 . The method of  claim 1 , wherein said immunostimulatory nucleic acid molecule is administered to a mucosal tissue.  
     
     
         10 . The method of  claim 1 , wherein said immunostimulatory nucleic acid molecule is administered systemically.  
     
     
         11 . A method of decreasing tumor load in a CD4 +  T cell-deficient individual, comprising administering a formulation comprising an immunostimulatory nucleic acid molecule selected from the group consisting of 5′-purine-purine-cytosine-guanine-pyrimidine-pyrimidine-3′; 5′-purine-TCG-pyrimidine-pyrimidine-3′; and 5′-(TGC) n -3′, where n≧1.  
     
     
         12 . The method of  claim 11 , wherein the formulation further comprises a tumor-associated antigen, a tumor-specific antigen, or antigenic epitope thereof.  
     
     
         13 . The method of  claim 11 , wherein the immunostimulatory nucleic acid molecule is chemically linked to the tumor-associated antigen, tumor-specific antigen, or antigenic epitope thereof.  
     
     
         14 . A method of treating an infectious disease in a CD4 +  T cell-deficient individual, comprising administering a formulation comprising an immunostimulatory nucleic acid molecule comprising a nucleotide sequence selected from the group consisting of 5′-purine-purine-cytosine-guanine-pyrimidine-pyrimidine-3′; 5′-purine-TCG-pyrimidine-pyrimidine-3′; and 5′-(TGC) n -3′, where n≧1.  
     
     
         15 . The method of  claim 14 , wherein the infectious disease is caused by an intracellular pathogen.  
     
     
         16 . The method of  claim 14 , wherein the infectious disease is caused by an opportunistic infection.  
     
     
         17 . The method of  claim 14 , wherein the infectious disease is caused by a pathogen selected from the group consisting of cytomegalovirus,  Mycobacterium tuberculosis, Mycobacterium avium,  Epstein-Barr virus,  Toxoplasma gondii,  a fungus, a yeast, and varicella zoster virus.  
     
     
         18 . The method of  claim 14 , wherein the individual has a reduced number of CD4 +  T lymphocytes due to a primary immunodeficiency.  
     
     
         19 . The method of  claim 14 , wherein the individual has a reduced number of CD4 +  T lymphocytes due to an acquired immunodeficiency.  
     
     
         20 . The method of  claim 19 , wherein the acquired immunodeficiency is acquired immunodeficiency syndrome.  
     
     
         21 . The method of  claim 14 , wherein the infectious disease is caused by human immunodeficiency virus.  
     
     
         22 . A method for treating an individual at risk for becoming CD4 +  T cell deficient, comprising administering a formulation comprising an immunostimulatory nucleic acid molecule comprising a nucleotide sequence selected from the group consisting of 5′-purine-purine-cytosine-guanine-pyrimidine-pyrimidine-3′; 5′-purine-TCG-pyrimidine-pyrimidine-3′; and 5′-(TGC) n -3′, where n≧1.  
     
     
         23 . The method of  claim 22 , wherein the individual is at risk for recurrence of a cancer.  
     
     
         24 . The method of  claim 22 , wherein the individual is at risk for developing an acquired immunodeficiency.  
     
     
         25 . The method of  claim 24 , wherein said immunostimulatory nucleic acid molecule is administered to a mucosal tissue.  
     
     
         26 . A method of increasing production of IFNγ in a CD4 +  T cell-deficient individual, comprising administering an immunostimulatory nucleic acid molecule in an amount effective to increase IFNγ production in the individual.  
     
     
         27 . The method of  claim 26 , wherein the immunostimulatory nucleic acid molecule is conjugated to an antigen, and IFNγ production is increased in an antigen-specific manner.  
     
     
         28 . A method for increasing secretion of a chemokine ligand for a chemokine receptor in vivo, comprising administering to an individual an immunostimulatory nucleic acid molecule in an amount sufficient to increase secretion of a chemokine ligand for a chemokine receptor.  
     
     
         29 . The method of  claim 28 , wherein the chemokine receptor is CCR5.  
     
     
         30 . The method of  claim 28 , wherein the chemokine ligand is selected from the group consisting of MIP-1α, MIP-1β, and RANTES.  
     
     
         31 . The method of  claim 28 , wherein the cell is selected from the group consisting of a macrophage, a monocyte, and a T lymphocyte.  
     
     
         32 . The method of  claim 28 , wherein the immunostimulatory nucleic acid molecule comprises the sequence 5′-purine-purine-C-G-pyrimidine-pyrimidine-3′.  
     
     
         33 . The method of  claim 28 , wherein the immunostimulatory nucleic acid molecule comprises the sequence 5′-purine-T-C-G-pyrimidine-pyrimidine-3′.  
     
     
         34 . The method of  claim 28 , wherein the immunostimulatory nucleic acid molecule comprises the sequence 5′-(TCG)n-3′, wherein n is any integer that is 1 or greater.  
     
     
         35 . The method of  claim 28 , wherein the immunostimulatory nucleic acid molecule comprises the sequence 5′-purine-purine-C-G-pyrimidine-pyrimidine-C-G-3′.  
     
     
         36 . A method for increasing antigen-specific secretion of a chemokine ligand for a chemokine receptor in vivo, comprising administering to an individual a composition comprising an immunostimulatory nucleic acid molecule and an antigen associated with a pathogenic organism, wherein the immunostimulatory nucleic acid molecule is present in the formulation in an amount sufficient to increase secretion of a chemokine ligand for a chemokine receptor in response to the antigen.  
     
     
         37 . The method of  claim 36 , wherein the immunostimulatory nucleic acid molecule and the antigen are admixed.  
     
     
         38 . The method of  claim 36 , wherein the immunostimulatory nucleic acid molecule and the antigen are in proximate association.  
     
     
         39 . The method of  claim 38 , wherein the immunostimulatory nucleic acid molecule and the antigen are conjugated.  
     
     
         40 . The method of  claim 36 , wherein the antigen is associated with human immunodeficiency virus.  
     
     
         41 . The method of  claim 38 , wherein the antigen is gp120, or an immunogenic fragment thereof.  
     
     
         42 . A method for inhibiting entry of an immunodeficiency virus into a cell in vivo, comprising administering to an individual an immunostimulatory nucleic acid molecule in an amount sufficient to increase secretion of a chemokine ligand for a chemokine receptor and inhibit binding of the immunodeficiency virus to the chemokine receptor.  
     
     
         43 . The method of  claim 42 , wherein the immunodeficiency virus is a human immunodeficiency virus.  
     
     
         44 . The method of  claim 42 , wherein chemokine receptor is CCR5.  
     
     
         45 . The method of  claim 42 , wherein the immunostimulatory nucleic acid molecule comprises the sequence 5′-purine-purine-C-G-pyrimidine-pyrimidine-3′.  
     
     
         46 . The method of  claim 42 , wherein the immunostimulatory nucleic acid molecule comprises the sequence 5′-purine-T-C-G-pyrimidine-pyrimidine-3′.  
     
     
         47 . The method of  claim 42 , wherein the immunostimulatory nucleic acid molecule comprises the sequence 5′-(TCG) n -3′, wherein n is any integer that is 1 or greater.  
     
     
         48 . The method of  claim 42 , wherein the immunostimulatory nucleic acid molecule is administered in a formulation comprising the immunostimulatory nucleic acid molecule and an antigen associated with the immunodeficiency virus.  
     
     
         49 . The method of  claim 48 , wherein the antigen is gp120.  
     
     
         50 . The method of  claim 49 , wherein the immunostimulatory nucleic acid molecule and gp120 are in proximate association.  
     
     
         51 . A method for inhibiting entry of a human immunodeficiency virus into a cell in vivo, comprising administering to an individual an immunostimulatory nucleic acid molecule in an amount sufficient to increase secretion of a chemokine ligand for a CCR5 chemokine receptor and inhibit binding of the immunodeficiency virus to the chemokine receptor.  
     
     
         52 . A method of inducing a cytotoxic T lymphocyte (CTL) response to a soluble exogenous antigen, comprising administering to an individual an immunostimulatory nucleic acid molecule and a soluble exogenous antigen in an amount effective to increase CTL activity specific to the soluble exogenous antigen.  
     
     
         53 . The method of  claim 52 , wherein said immunostimulatory nucleic acid molecule comprises a nucleotide sequence selected from the group consisting of 5′-purine-purine-cytosine-guanine-pyrimidine-pyrimidine-3′; 5′-purine-TCG-pyrimidine-pyrimidine-3′; and 5′-(TGC) n -3′, where n≧1.