ABSTRACT
BACKGROUND: Nearly half of all infiltrating leukocytes in rejecting human allografts are macrophages, yet, in comparison with T cells, much less is known about the contribution of this cell type to rejection. Our laboratory has previously described models of rejection of human skin or artery grafts in immunodeficient mouse hosts mediated by adoptively transferred allogeneic T cells. However, mature human monocyte/macrophages have consistently failed to engraft in these animals. Here, we describe the introduction of human CD68+ macrophages into irradiated immunodeficient mice by transplantation of enriched CD34+ hematopoietic stem-cells isolated from peripheral blood of G-colony-stimulating factor pretreated adults. METHODS: We investigated strains of immunodeficient mice bearing human tissue grafts (skin and artery) inoculated with 1 x 10(6) human CD34+ adult hematopoietic stem cells, peripheral blood monuclear cells autologous to the CD34 donor, or both for human cell engraftment. RESULTS: In the absence of T cells, CD68+ CD14+ macrophages infiltrate allogeneic human skin but produce little injury or thrombosis. Both responses are enhanced when combined with adoptive transfer of T cells autologous to the hematopoietic stem cells as exemplified by the induction of the macrophage activation marker CD163. CD68+ macrophages also infiltrate allogeneic arterial interposition grafts, producing intimal expansion and calcification in the absence of T cells. CONCLUSIONS: These new models may be used to study the role of human macrophages in transplant rejection and other pathologies in vivo.
Subject(s)
Adult Stem Cells/immunology , Arteries/immunology , Arteries/transplantation , Graft Rejection/immunology , Hematopoietic Stem Cell Transplantation , Hematopoietic Stem Cells/immunology , Macrophages/immunology , Skin Transplantation/immunology , Skin/immunology , Adoptive Transfer , Animals , Antigens, CD/analysis , Antigens, CD34/analysis , Antigens, Differentiation, Myelomonocytic/analysis , Arteries/pathology , Disease Models, Animal , Graft Rejection/pathology , Humans , Interleukin Receptor Common gamma Subunit/genetics , Interleukin Receptor Common gamma Subunit/immunology , Lipopolysaccharide Receptors/analysis , Mice , Mice, Inbred NOD , Mice, Knockout , Mice, SCID , Receptors, Cell Surface/analysis , Skin/pathology , T-Lymphocytes/immunology , T-Lymphocytes/transplantation , Transplantation, Homologous , Whole-Body IrradiationABSTRACT
In this study, a recombinant truncated West Nile virus envelope protein antigen (rWNV-E) was produced in serum-free cultures of the expresSF+ insect cell line via baculovirus infection. This production system was selected based on its use in the production of candidate human and animal vaccine antigens. A defined fermentation and purification process for the rWNV-E antigen was established to control for purity and immunogenicity of each protein batch. The material formulated with aluminum hydroxide was stable for greater than 8months at 4 degrees C. The recombinant vaccine candidate was evaluated for immunogenicity and protective efficacy in several animal models. In mouse and hamster WNV challenge models, the vaccine candidate induced viral protection that correlated with anti-rWNV-E immunogenicity and WNV neutralizing antibody titers. The rWNV-E vaccine candidate was used to boost horses previously immunized with the Fort Dodge inactivated WNV vaccine and also to induce WNV neutralizing titers in naïve foals that were at least 14weeks of age. Furthermore, the vaccine candidate was found safe when high doses were injected into rats, with no detectable treatment-related clinical adverse effects. These observations demonstrate that baculovirus-produced rWNV-E can be formulated with aluminum hydroxide to produce a stable and safe vaccine which induces humoral immunity that can protect against WNV infection.
