An open reading frame (ORF) with homology to interleukin-10 (IL-10) has been identified in rhesus cytomegalovirus (RhCMV). The IL-10-like protein is generated from a multispliced, polyadenylated early gene transcript encompassing part of the corresponding UL111A ORF of human CMV (HCMV). Immunological analyses confirm expression of the IL-10-like protein both in tissue culture and in RhCMV-infected rhesus macaques. Conserved ORFs were subsequently identified in human, baboon, and African green monkey CMV, and a fully processed transcript has been mapped in fibroblasts infected with the Towne strain of HCMV. The conservation of this previously unrecognized ORF suggests that the protein may play an essential role in primate CMV persistence and pathogenesis.

Pathogenicity of human cytomegalovirus (HCMV) correlates with the immune status of infected individuals. In fully immunocompetent individuals, host antiviral immune responses contain virus replication. In contrast, HCMV can be a serious cause of morbidity and mortality in individuals without an intact immune system (Ho, 1991). Greater understanding of both host antiviral immune responses and mechanisms of viral pathogenesis is required to design strategies which effectively limit HCMV disease. Infection of rhesus macaques (Macacca mulatta) with rhesus CMV

Objectives: The ovarian tumor marker CA125 is expressed on human MUC16, a cell surface bound mucin that is also shed by proteolytic cleavage. Human MUC16 is overexpressed by ovarian cancer cells. MUC16 facilitates the binding of ovarian tumor cells to mesothelial cells lining the peritoneal cavity. Additionally, MUC16 also is a potent inhibitor of natural killer cell mediated anti-tumor cytotoxic responses. Extensive studies using human as well as murine ovarian tumor cell models are required to clearly define the function of MUC16 in the progression of ovarian tumors. The major objective of this study was to determine if the murine ovarian tumor cells, MOVCAR, express Muc16 and to characterize antibodies that recognize this mucin. Methods:RT-PCR analysis was used for detecting the Muc16 message and size exclusion column chromatography for isolating Muc16 produced by MOVCAR cells. Soluble and cell-associated murine Muc16 were analyzed, respectively, by Western blotting and flow cytometry assays using a new panel of antibodies. The presence of N-linked oligosaccharides on murine Muc16 was determined by ConA chromatography. Results:We demonstrate that murine Muc16 is expressed by mouse ovarian cancer cells as an ~250 kDa glycoprotein that carries both O-linked and N-linked oligosaccharides. In contrast to human MUC16, the murine ortholog is primarily released from the cells and cannot be detected on the cell surface. Since the released murine Muc16 is not detected by conventional anti-CA125 assays, we have for the first time identified a panel of anti-human MUC16 antibodies that also recognizes the murine counterpart. Conclusion:The antibodies identified in this study can be used in future purification of murine Muc16 and exhaustive study of its properties. Furthermore, the initial identification and characterization of murine Muc16 is a vital preliminary step in the development of effective murine models of human ovarian cancer. These models will aid in the further elucidation of the role that human MUC16 plays in the etiology and progression of ovarian tumors.

The aim of this study was to characterize the expression of the rhesus HLA-E ortholog Mamu-E, particularly at the maternal-fetal interface. Mamu-E expression was confirmed by locus-specific RT-PCR in the placenta as well as in peripheral blood mononuclear cells (PBMC) and other organs. We evaluated the utility of antibodies recognizing HLA-E (MEM-E/06 against native HLA-E, MEM-E/02 against denatured HLA-E) to detect Mamu-E by flow cytometry/immunofluorescence, Western blot, and immunohistochemistry (IHC). Western blot analysis of cells and selected transfectants confirmed the recognition of Mamu-E but not Mamu-AG by antibodies MEM-E/06 and HC10 but not MEM-E/02. Immunohistochemical staining of frozen sections of rhesus placenta with the MEM-E/06 antibody demonstrated expression in most populations of rhesus monkey trophoblast cells, including villous cytotrophoblasts (strong positive staining), apical membrane of syncytiotrophoblasts (light to moderate staining) and extravillous cytotrophoblasts (moderate to strong staining, especially endovascular trophoblasts in early pregnancy). Expression was not trophoblast cell-specific, especially at term, when endothelial cells in both the chorionic plate and placental villi showed strong staining for Mamu-E. Staining of rhesus extravillous trophoblast cells suggested the co-expression of Mamu-E and Mamu-AG (the rhesus HLA-G homolog) on these cells. MEM-E/06 was shown also to react with differentiating rhesus placental syncytiotrophoblasts in primary culture, detecting intracellular and weak surface expression of Mamu-E. We conclude that the gestation-dependent co-expression of Mamu-E with Mamu-AG in villous and extravillous trophoblast cells suggests important and perhaps complementary but distinct roles of these two non-classical MHC class I loci in pregnancy at the maternal-fetal interface. In addition, the MEM-E/06 antibody will be useful for the detection of Mamu-E at the maternal-fetal interface in the rhesus monkey.

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