Cytomegalovirus Surface Protein Complex For Use in Vaccines and as a Drug Target

Abstract

Immunogenic compositions and prophylactic or therapeutic vaccines for use in protecting and treating against human cytomegalovirus (CMV) are disclosed. Subunit vaccines comprising a human CMV protein complex comprising pUL128 or pUL130, and nucleic acid vaccines comprising at least one nucleic acid encoding a CMV protein complex comprising pUL128 or pUL130 are described. Also disclosed are therapeutic antibodies reactive against a CMV protein complex comprising pULl28or pUL130, as well as methods for screening compounds that inhibit CMV infection of epithelial and endothelial cells, methods for immunizing a subject against CMV infection, methods for determining the capability of neutralizing antibodies to inhibit CMV infection of cell types other than fibroblasts, and methods of diminishing an CMV infection.

What is claimed: 
     
         1 . An immunogenic composition comprising a pharmaceutically acceptable carrier and a complex of cytomegalovirus (CMV) proteins comprising pUL128 or pUL130 and, optionally, at least one other virus or cellular constituent of a CMV virion complex. 
     
     
         2 . The composition of  claim 1 , wherein the other virus or cellular constituent of the virion complex is one or more of pUL131, gH, gL, or gB. 
     
     
         3 . The composition of  claim 1 , wherein multiple fragments of one or more of pUL128, pUL130, pUL131, gH, gL or gB are linked into one polypeptide chain. 
     
     
         4 . The composition of  claim 3 , wherein the complex is produced by expression of a CMV genome encoding an attenuated CMV, wherein the attenuation does not affect formation of the complex. 
     
     
         5 . A subunit vaccine comprising a pharmaceutically acceptable carrier and at least one cytomegalovirus (CMV) protein or fragment thereof, selected from pUL128, pUL130, or a complex that includes pUL128 or pUL130, and, optionally, at least one other virus or cellular constituent of a CMV virion complex, wherein the vaccine induces an immune response against CMV in a recipient. 
     
     
         6 . The subunit vaccine of  claim 5 , wherein at least one protein of the complex is coupled to a carrier protein. 
     
     
         7 . The subunit vaccine of  claim 5 , wherein the protein, protein fragment or complex is expressed on the surface of an attenuated CMV virus particle. 
     
     
         8 . The subunit vaccine of  claim 5 , wherein the protein or fragment thereof is fused to one or more other proteins or fragments thereof present on the surface of the CMV virus particle. 
     
     
         9 . A nucleic acid vaccine comprising a pharmaceutically acceptable carrier and a vector comprising at least one nucleic acid molecule encoding a CMV protein or fragment thereof, selected from pUL128, pUL130, or a complex that includes pUL128 or pUL130, wherein the at least one nucleic acid molecule is expressed in a vaccine recipient, and wherein the expression product induces an immune response against CMV in the recipient. 
     
     
         10 . The nucleic acid vaccine of  claim 9 , comprising a non-CMV vector that expresses one or more of pUL128, pUL130, pUL131, gH, gL, or gB, or a fragment thereof. 
     
     
         11 . The nucleic acid vaccine of  claim 10 , wherein two or more of the fragments are expressed on a single polypeptide. 
     
     
         12 . Antibodies or epitope-binding fragments thereof, which specifically bind to a virus-coded protein from a CMV virion complex that includes pUL128 or pUL130, wherein the antibodies or epitope-binding fragments thereof inhibit binding of the CMV virion complex to a cellular receptor, or CMV infection of a cell, or both. 
     
     
         13 . The antibodies of  claim 12 , which specifically bind to pUL128. 
     
     
         14 . The antibodies of  claim 13 , which are polyclonal antibodies of antiserum having ATCC Accession No. [______]. 
     
     
         15 . The antibodies of  claim 13 , which compete for binding to an epitope on pUL128 recognized by monoclonal antibodies produced by a hybridoma cell line having ATCC Accession No. [______]. 
     
     
         16 . The antibodies of  claim 13 , which are monoclonal antibodies produced by a hybridoma cell line having ATCC Accession No. [______]. 
     
     
         17 . A neutralizing binding partner of a CMV virion complex comprising pUL128, which comprises one or more virion binding sequences having 70% or greater identity to one or more complementarity determining regions (CDR) present in the monoclonal antibodies of  claim 16 . 
     
     
         18 . The antibodies of  claim 12 , which specifically bind to pUL130. 
     
     
         19 . The antibodies of  claim 18 , which compete for binding to an epitope on pUL130 recognized by monoclonal antibodies produced by a hybridoma cell line having ATCC Accession No. [______]. 
     
     
         20 . The antibodies of  claim 18 , which are monoclonal antibodies produced by a hybridoma cell line having ATCC Accession No. [______]. 
     
     
         21 . A neutralizing binding partner of a CMV virion complex comprising pUL130, which comprises one or more virion binding sequences having 70% or greater identity to a complementarity determining regions (CDR) present in the monoclonal antibodies of  claim 20 . 
     
     
         22 . A method of inhibiting CMV infection of endothelial or epithelial cells, comprising inhibiting binding of a CMV virion complex comprising pUL128 or pUL130 to the cells, thereby inhibiting the CMV infection. 
     
     
         23 . The method of  claim 22 , wherein the inhibiting of binding is accomplished by treating the cells with an antibody immunospecific for pUL128 or pUL130. 
     
     
         24 . A method for screening compounds for the ability to inhibit entry of CMV into host cells, the method comprising:
 a) exposing host cells, in the presence or absence of a test compound, to or one or more cellular receptors of host cells to CMV virions or a component thereof selected from (i) pUL128 or a fragment thereof, (ii) pUL130 or fragment thereof, or (iii) a complex that includes pUL128 or pUL130, and, optionally, at least one other virus or cellular constituent of a CMV virion complex; and   b) determining if the test compound interferes with binding of the CMV virions or component thereof to the host cells or cellular receptors, wherein the interfering of the binding is indicative that the test compound is capable of inhibiting the entry of the CMV into the host cells.   
     
     
         25 . The method of  claim 24 , wherein the host cells are epithelial cells or endothelial cells. 
     
     
         26 . The method of  claim 24 , wherein the CMV virions are produced by expressing a virion encoding polynucleotide in cells transfected with a vector containing the polynucleotide. 
     
     
         27 . The method of  claim 26 , wherein the vector is BADrUL131. 
     
     
         28 . The method of  claim 24 , wherein a selected test compound capable of interfering with the binding of CMV or components thereof to the host cells or cellular receptors is subjected to a secondary screen comprising:
 a) exposing the host cells to CMV virions in the presence or absence of the selected test compound; and   b) determining if the selected test compound inhibits one or more of (i) production of CMV proteins within the host cells; (ii) a cytopathic effect of CMV infection; or (iii) spread of virus proteins from cell to cell, the inhibition being further indicative that the test compound is capable of inhibiting the CMV infection.   
     
     
         29 . A method of screening compounds for their ability to neutralize human CMV infectivity of endothelial or epithelial cells, the method comprising:
 a) exposing the epithelial or endothelial cells to CMV virions comprising a virion complex that includes pUL128 or pUL130, in the presence or absence of a test compound; and   b) determining if the test compound inhibits entry of the CMV into the host cells, the inhibition being indicative that the test compound is able to neutralize human CMV infectivity of the endothelial or epithelial cells.   
     
     
         30 . The method of  claim 29 , wherein the test compound is an antibody or epitope-binding fragment thereof, or a neutralizing binding partner of a CMV virion complex comprising pUL130 or pUL128. 
     
     
         31 . The method of  claim 29 , wherein the CMV virions are produced by expressing a virion encoding polynucleotide in cells transfected with a vector containing s a genome of a Clinical isolate of CMV or of a laboratory strain of CMV that comprises, or that has been engineered to comprise a functional UL131-128 locus. 
     
     
         32 . The method of  claim 31 , wherein the vector is BADrUL131. 
     
     
         33 . A method of immunizing a patient against CMV infection by administering to the patient a substance that is:
 a) an immunogenic composition comprising a pharmaceutically acceptable carrier and a complex of cytomegalovirus (CMV) proteins comprising pUL128 or pUL130 and, optionally, at least one other virus or cellular constituent of a CMV virion complex;   b) a subunit vaccine comprising a pharmaceutically acceptable carrier and at least one cytomegalovirus (CMV) protein or fragment thereof, selected from pUL128, pUL130, or a complex that includes pUL128 or pUL130, and, optionally, at least one other virus or cellular constituent of a CMV virion complex; or   c) a nucleic acid vaccine comprising a pharmaceutically acceptable carrier and a vector comprising at least one nucleic acid molecule encoding a CMV protein or fragment thereof, selected from pUL128, pUL130, or a complex that includes pUL128 or pUL130, wherein the at least one nucleic acid molecule is expressed in the patient;   
       under conditions permitting the patient to develop an immune response to the substance or the proteins encoded by the substance. 
     
     
         34 . A method of diminishing a CMV infection in a patient, comprising administering to the patient antibodies or epitope-binding fragments thereof, which specifically bind to a virus-coded protein in a CMV virion complex that includes pUL128 or pUL130, wherein the antibodies or epitope-binding fragments thereof inhibit binding of the human CMV virion complex to a cellular receptor, or CMV infection of a cell, or both, thereby diminishing the CMV infection in the patient.