TEST is a novel taxonomy of knowledge representations based on three distinct hierarchically organized representational features: Tropism, Embodiment, and Situatedness. Tropic representational features reflect constraints of the physical world on the agent's ability to form, reactivate, and enrich embodied (i.e., resulting from the agent's bodily constraints) conceptual representations embedded...

Among HIV-infected individuals, co-infection with Mycobacterium tuberculosis is associated with faster progression to AIDS. We investigated the hypothesis that M. bovis BCG and M. tuberculosis (Mtb complex) could enhance susceptibility of CD4+ cells to HIV infection. Peripheral blood mononuclear cells (PBMCs) collected from healthy donors were stimulated with M. bovis BCG, M. tuberculosis CDC15...

The murine Fv1 gene restricts infection by N- or B-tropic murine leukemia viruses at a postentry, preintegration stage. The Fv1-sensitive viruses previously used for the study of Fv1 encode an ecotropic envelope gene and thus only infect rodent cells. Consequently, the study of Fv1 restriction has been carried out solely in mice and murine cell lines. By infection with retroviral vectors contai...

The chemokine receptor, CXCR4, serves as the primary coreceptor for entry of T-cell tropic human immunodeficiency virus (HIV). Binding of either the CXC-chemokine, stromal-derived factor 1 alpha (SDF-1 alpha), or a CXCR4 antagonist, AMD3100, to CXCR4 inhibits infection of CD4(+) T cells by T-tropic HIV-1, although only SDF-1 alpha triggers T-cell signaling cascades. We have previously demonstra...

Macrophages contribute to HIV-1 pathogenesis by forming a viral reservoir and mediating neurological disorders. Cell-free HIV-1 infection of macrophages is inefficient, in part due to low plasma membrane expression of viral entry receptors. We find that macrophages selectively capture and engulf HIV-1-infected CD4+ T cells leading to efficient macrophage infection. Infected T cells, both health...

The CC chemokines MIP-1alpha, MIP-1beta, and RANTES suppress replication of certain HIV-1 strains in cultured PBMC and T cell lines by blocking interaction of gp120 with CC chemokine receptor 5 (CCR5). However, the same chemokines can enhance HIV-1 replication in cultured macrophages. The net effect of chemokines on HIV-1 infection in intact lymphoid tissue, the major reservoir of HIV-1 in vivo...

Human immunodeficiency virus type-1 is highly variable and utilizes two independent pathways, one via the CCR5 coreceptor and the other via CXCR4 to enter CD4+ cells. Both virus types can simultaneously be found in HIV-1-infected patients and the shift to a majority of CXCR4-tropic viruses is an indication for the development of AIDS-related symptoms. It is thought that each virus type will inf...

A late-passage derivative of SC-1 cells with stable relative resistance to N- and B-tropic viruses but with retained sensitivity to NB-tropic viruses has been identified. Dual resistance was seen with the XC plaque assay, as well as reverse transcriptase assay and radioimmunoassay for viral p30. Evidence was found for resistance in clonal derivatives. These findings suggest a possible instabili...

Model transformation languages are crucial for the success of Model-Driven Engineering (MDE), being comparable to the importance of compilers for high-level programming languages. The support of large transformation scenarios, however, is still in its infancy since the development of transformations currently takes place on a low-level of abstraction, lacking appropriate reuse mechanisms. We pr...

The chemokine receptors CCR5 and CXCR4 are coreceptors for the human immunodeficiency virus (HIV) and determine the cell tropism of different HIV strains. Previous studies on their regulation were performed under conditions of unspecific T-lymphocyte stimulation and provided conflicting results. To mimic physiologic conditions, highly purified primary Staphylococcus enterotoxin B (SEB)-reactive...