Myelodysplasia in 2 pig-tailed macaques (Macaca nemestrina) associated with retroviral vector-mediated insertional mutagenesis and overexpression of HOXB4.

Gammaretroviral vectors are an efficient means to effect gene therapy. However, genotoxicity from insertion at nonrandom sites can confer a competitive advantage to transduced cells, resulting in clonal proliferation or neoplasia. Six pig-tailed macaques (Macaca nemestrina) underwent total body irradiation and reconstitution with autologous stem cells genetically modified by a gammaretroviral vector overexpressing HOXB4. Two animals were euthanized owing to irradiation- or transplantation-associated toxicity, whereas the other 4 had successful reconstitution. Of the 4 macaques with successful reconstitution, 1 has no long-term follow-up information; 1 was euthanized owing to infection with simian varicella virus infection 18 months post-total body irradiation; and the 2 others are described herein as case Nos. 1 and 2. After being stable for 3 years, case No. 1 developed pancytopenia and petechiation, and after 2 years of stability case No. 2 developed anemia and thrombocytopenia. Despite therapy, the animals deteriorated and were euthanized. Gross findings included emaciation; case No. 1 also had hemorrhage, peritonitis, and cholecystitis. Histologically, bone marrow was hypercellular with predominately blast cells of all hematopoietic lineages, though with myeloid predominance, and with maturation arrest and blast cell dysplasia (myelodysplasia). Myelodysplasia was likely from a combination of insertional mutagenesis by the retroviral vector and overexpression of HOXB4. Consequences of myelodysplasia included the blood dyscrasias and, in case No. 1, hemorrhage, bacterial cholecystitis, hepatitis, and peritonitis.

Integrated molecular signature of disease: analysis of influenza virus-infected macaques through functional genomics and proteomics.

Recent outbreaks of avian influenza in humans have stressed the need for an improved nonhuman primate model of influenza pathogenesis. In order to further develop a macaque model, we expanded our previous in vivo genomics experiments with influenza virus-infected macaques by focusing on the innate immune response at day 2 postinoculation and on gene expression in affected lung tissue with viral genetic material present. Finally, we sought to identify signature genes for early infection in whole blood. For these purposes, we infected six pigtailed macaques (Macaca nemestrina) with reconstructed influenza A/Texas/36/91 virus and three control animals with a sham inoculate. We sacrificed one control and two experimental animals at days 2, 4, and 7 postinfection. Lung tissue was harvested for pathology, gene expression profiling, and proteomics. Blood was collected for genomics every other day from each animal until the experimental endpoint. Gross and microscopic pathology, immunohistochemistry, viral gene expression by arrays, and/or quantitative real-time reverse transcription-PCR confirmed successful yet mild infections in all experimental animals. Genomic experiments were performed using macaque-specific oligonucleotide arrays, and high-throughput proteomics revealed the host response to infection at the mRNA and protein levels. Our data showed dramatic differences in gene expression within regions in influenza virus-induced lesions based on the presence or absence of viral mRNA. We also identified genes tightly coregulated in peripheral white blood cells and in lung tissue at day 2 postinoculation. This latter finding opens the possibility of using gene expression arrays on whole blood to detect infection after exposure but prior to onset of symptoms or shedding.