Virus-specific Early Antigen Expressed in the Nucleus of Cowpox Virus-infected Cells Kitamoto, N. and Hiroi, K. and Miyamoto, K. and Tanaka, T. and Miyamoto, H.,, 71, 235-240 (1990), doi = https://doi.org/10.1099/0022-1317-71-1-235, publicationName = Microbiology Society, issn = 0022-1317, abstract= Two monoclonal antibodies (MAbs) were obtained from BALB/c mice immunized with cowpox virus (CPV)-infected cells cultured in the presence of cytosine-l-β-d-arabinofuranosyl-HCl (Ara C). In the immunofluorescence test, the specific antigen reacting with these MAbs was restricted almost entirely to the nucleus in CPV-infected cells in the presence of Ara C at any time. On the other hand, in CPV-infected cells in the absence of Ara C, the antigen was first detectable within the nucleus 2 h after infection and migrated to the cytoplasm as the infection proceeded. On immuno- blotting, only one component with an M r of 27K was detected 2 to 24 h after infection of cells with CPV in either the presence or absence of Ara C. The antigen was also detected in vaccinia virus-infected cells, but not in any mock-infected cells nor in any virions purified from infected cells. These results suggest that the antigen reacting with the MAbs is virus-specific and a non-structural early antigen., language=, type=