Immunologically significant herpes simplex virus antigens and methods for using same

#The invention relates to molecules, compositions and methods that can be used for the treatment and prevention of HSV infection. More particularly, the invention identifies epitopes of HSV proteins that can be used for methods, molecules and compositions having the antigenic specificity of HSV-specific T cells, and in particular, of CD8+ as well as CD4+ T cells.

#Cellular immune responses are required to limit the severity of recurrent HSV infection in humans. Initial genital HSV-2 infections are prolonged and severe, while recurrences are less severe and more frequently asymptomatic. Resolution of primary HSV-2 infection is associated with infiltration of antigen-specific T cells, including CD8+ cytotoxic T lymphocytes (CTLs). Serial lesion biopsy studies of recurrent HSV-2 infection in humans has shown a shift to CD8+ predominance as lesions mature and correlation of local CTL activity with virus clearance (Koelle, D M et al., J. Clin. Invest. 1998, 101:1500-1508; Cunningham, Ala. et al., J. Clin. Invest. 1985, 75:226-233). Thus, HSV antigens recognized by CD8+ CTL can be used for novel therapies and vaccines.

#The complete DNA sequence of herpes simplex virus (HSV) is approximately 150 kb and encodes about 85 known genes, each of which encodes a protein in the range of 50-1000 amino acids in length. Unknown are the immunogenic epitopes within these proteins, each epitope approximately 9-12 amino acids in length, that are capable of eliciting an effective T cell immune response to viral infection.

#FIG. 1A is a schematic representing organization of the HSV genome in the region of 0.67-0.73 map units. Boundaries are approximate. HSV-1×HSV-2 intertypic recombinant viruses (IRV) are also shown. HSV-2 DNA is indicated by a solid line; HSV-1 DNA by a dashed line, and indeterminate regions by a multiple line. The HSV-2 BamH I w fragment used for expression cloning is also shown.

#FIG. 1B is a bar graph showing proliferative responses of T-cell clones (TCC) to the indicated IRV. Data are delta CPM [3H] thymidine incorporation compared to media alone, which was less than 500 cpm in each case.

#FIG. 2 is an immunoblot showing determination of the HSV viral phenotype of the UL49 gene product (VP22) of IRV DX32. Lysates of mock-infected cells and cells infected with the viral strains DX32, HSV-1 or HSV-2 were separated by SDS-PAGE, blotted, and probed with VP22-specific mAb. The molecular weights (kD) of marker proteins are shown at right.

#The invention provides HSV antigens that are useful for the prevention and treatment of HSV infection. Disclosed herein are antigens and/or their constituent epitopes confirmed to be recognized by T-cells derived from herpetic lesions. In some embodiments, T-cells having specificity for antigens of the invention have demonstrated cytotoxic activity against virally infected cells. The identification of immunogenic antigens responsible for T-cell specificity facilitates the development of improved anti-viral therapeutic and prophylactic strategies. Compositions containing antigens or polynucleotides encoding antigens of the invention provide effectively targeted vaccines for prevention and treatment of HSV infection.

#Definitions

#All scientific and technical terms used in this application have meanings commonly used in the art unless otherwise specified. As used in this application, the following words or phrases have the meanings specified.