Sialoadhesin-related compositions and methods

Abstract

Methods of delivering a cargo moiety to a cell is provided according to embodiments of the invention which includes contacting a cell expressing sialoadhesin with a conjugate including a sialoadhesin binding moiety and a cargo moiety. The sialoadhesin binding moiety binds to the sialoadhesin expressed by the cell and is internalized along with the cargo, delivering the cargo moiety to the cell. Particular methods provided by the invention include induction or enhancement of sialoadhesin expression in a cell which naturally produces little or no sialoadhesin. Induction or enhancement of sialoadhesin expression includes transfection of a sialoadhesin expression construct and/or administration of an agent effective to induce or enhance sialoadhesin expression. Methods and compositions for stimulating an immune response in a subject are detailed. Particular methods and compositions for stimulating an immune response to a virus are provided by the invention.

1 . A method of delivering a cargo moiety to a cell, the method comprising:
 contacting a cell expressing sialoadhesin with a conjugate, the conjugate comprising a sialoadhesin binding moiety and a cargo moiety, wherein the sialoadhesin binding moiety binds to the sialoadhesin expressed by the cell, thereby delivering the cargo moiety to the cell.   
     
     
         2 . The method of  claim 1  wherein the cell is a macrophage. 
     
     
         3 . The method of  claim 1  wherein the sialoadhesin binding moiety is an antibody. 
     
     
         4 . The method of  claim 1  wherein the sialoadhesin binding moiety is a sialoadhesin ligand. 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1  wherein the response is an immune response. 
     
     
         7 . The method of  claim 1  wherein the cargo moiety is an antigen. 
     
     
         8 . The method of  claim 1  wherein the cargo moiety is an inhibitor of the cell. 
     
     
         9 . The method of  claim 1  wherein the cargo moiety is a cytotoxic agent. 
     
     
         10 . The method of  claim 9  wherein the cytotoxic agent is a ribosome inactivating protein. 
     
     
         11 . The method of  claim 9  wherein the cytotoxic agent is saporin. 
     
     
         12 . (canceled) 
     
     
         13 . The method of  claim 1  wherein the cargo moiety is an antimicrobial agent effective to inhibit a microbe selected from the group consisting of: a bacterium, a virus, a fungus, a protozoan, and a combination thereof. 
     
     
         14 . The method of  claim 1 , wherein the cargo moiety comprises a nucleic acid. 
     
     
         15 . The method of  claim 7  wherein the antigen is selected from the group consisting of: a protein, a peptide, a glycoprotein and a glycopeptide. 
     
     
         16 . (canceled) 
     
     
         17 . The method of  claim 7  wherein the antigen is an influenza virus haemagglutinin or an antigenic portion thereof. 
     
     
         18 . The method of  claim 17  wherein the antigenic portion of an influenza virus haemagglutinin is encoded by SEQ ID NO:3 or a homologue thereof. 
     
     
         19 . The method of  claim 1  wherein the cell is in vitro. 
     
     
         20 . The method of  claim 1  wherein the cell is in vivo. 
     
     
         21 . The method of  claim 1  further comprising treating the cell with a cytokine effective to induce or enhance expression of sialoadhesin. 
     
     
         22 . The method of  claim 21  wherein the cell is selected from the group consisting of: a monocyte, a monocyte cell line, a macrophage and a macrophage cell line. 
     
     
         23 . The method of  claim 22  wherein the cell is selected from the group consisting of: a human cell and a human-derived cell line. 
     
     
         24 . The method of  claim 23  wherein the human-derived cell line is human monocyte cell line THP-1. 
     
     
         25 . The method of  claim 21  wherein the cytokine is interferon-alpha. 
     
     
         26 . The method of  claim 1  wherein the cell is transfected with an expression construct encoding sialoadhesin. 
     
     
         27 .- 36 . (canceled) 
     
     
         37 . The method of  claim 2  wherein the cargo moiety is an antimicrobial agent effective to inhibit a microbe selected from the group consisting of: a bacterium, a virus, a fungus, a protozoan, and a combination thereof. 
     
     
         38 . The method of  claim 2  wherein the cargo moiety is a cytokine. 
     
     
         39 .- 51 . (canceled) 
     
     
         52 . A method of stimulating an immune response to an antigen in a subject, the method comprising:
 administering a composition comprising a sialoadhesin binding moiety conjugated to an antigen to the subject whereby to stimulate an immune response therein.   
     
     
         53 .- 56 . (canceled) 
     
     
         57 . The method of  claim 52  wherein the antigen is influenza virus haemagglutinin isolated from an influenza virus. 
     
     
         58 . The method of  claim 52  wherein the antigen is recombinant influenza virus haemagglutinin. 
     
     
         59 . The method of  claim 58  wherein the recombinant influenza virus protein is an extracellular portion of an influenza virus haemagglutinin encoded by the nucleic acid sequence of SEQ ID NO:3 or a homologue thereof. 
     
     
         60 . The method of  claim 52  wherein the antigen is influenza virus haemagglutinin identified by SEQ ID NO:4 or a homologue thereof. 
     
     
         61 . (canceled) 
     
     
         62 . The method of  claim 52  wherein the sialoadhesin binding moiety is an antibody. 
     
     
         63 . The method of  claim 62  wherein the sialoadhesin binding moiety is selected from the group consisting of: monoclonal antibody 41D3, monoclonal antibody 7D2 and monoclonal antibody MCA2316. 
     
     
         64 . The method of  claim 62  wherein the sialoadhesin binding moiety is a sialoadhesin ligand. 
     
     
         65 .- 69 . (canceled) 
     
     
         70 . A method of transfecting a cell, the method comprising:
 administering a sialoadhesin binding moiety conjugated to an expression construct to a cell expressing sialoadhesin.   
     
     
         71 . The method of  claim 70 , wherein the cell expressing sialoadhesin is a cell transfected with a sialoadhesin expression construct. 
     
     
         72 . The method of  claim 71  wherein the cell is a cell line stably expressing sialoadhesin. 
     
     
         73 . The method of  claim 70  wherein the cell is treated with a cytokine to induce or enhance sialoadhesin expression. 
     
     
         74 .- 78 . (canceled) 
     
     
         79 . A method of treating a pathological condition in a subject, the method comprising:
 administering a therapeutically effective amount of a sialoadhesin binding moiety conjugated to a therapeutic cargo moiety to the subject,   wherein the therapeutic cargo moiety is delivered to a sialoadhesin expressing cell in the subject, thereby treating the pathological condition.   
     
     
         80 . The method of  claim 79  wherein the therapeutic cargo moiety is an inhibitor of the cell. 
     
     
         81 . The method of  claim 80  wherein the inhibitor is a cytotoxic agent. 
     
     
         82 . The method of  claim 81  wherein the inhibitor is saporin. 
     
     
         83 . The method of  claim 79  wherein the pathological condition is characterized by presence of a pathogen in the cell. 
     
     
         84 . The method of  claim 79  wherein the pathological condition is an autoimmune disease. 
     
     
         85 . The method of  claim 79  wherein the cargo moiety is an inhibitor of macrophage activation and/or inflammation. 
     
     
         86 . The method of  claim 86  wherein the inhibitor of macrophage activation and/or inflammation is selected from the group consisting of: IL-10, TGF-beta, 6-(methylsulfinyl)hexyl isothiocyanate, a sesquiterpene chromones, and a combination thereof. 
     
     
         87 . The method of  claim 79  wherein the pathological condition is cancer. 
     
     
         88 .- 95 . (canceled)