One well-characterized in vitro function of Nef is its ability to remove CD4, the human immunodeficiency virus (HIV) receptor, from the cell surface. Nef accomplishes this by accelerating the internalization and degradation of CD4. Current models propose that Nef promotes CD4 internalization via an increased association of CD4 with clathrin-coated pits (CCP). Here, we investigated the effect of...

Human immunodeficiency virus (HIV)-infected individuals develop an acquired immune deficiency syndrome (AIDS) due to loss in their lymphocyte numbers and cellular defects in T cells and antigen-presenting cells (APC). HIV infection of the thymus results in deficient replenishment of the peripheral naive T-cell pool. The HIV nef gene was shown to be important for progression towards AIDS and cel...

Although successful attempts to inhibit HIV-1 replication in T cells using RNAi have been reported, the effect of HIV-specific RNAi on macrophages is not well known. Macrophages are key targets for anti-HIV-1 therapy because they are able to survive long after the initial infection with HIV and can spread the virus to T cells. In this study, we identified a putative RNAi target of HIV, consisti...

BACKGROUND Plants may represent excellent alternatives to classical heterologous protein expression systems, especially for the production of biopharmaceuticals and vaccine components. Modern vaccines are becoming increasingly complex, with the incorporation of multiple antigens. Approaches towards developing an HIV vaccine appear to confirm this, with a combination of candidate antigens. Among...

Running title: Nef induces MHC II and MVB accumulations ABSTRACT Nef alters the cell surface expression of several immunoreceptors, which may contribute to viral escape. We show that Nef modifies MHC II intracellular trafficking and thereby its function. In the presence of Nef, mature, peptide loaded MHC II were down-modulated at the cell surface and accumulated intracellularly, while immature ...

Human immunodeficiency virus (HIV)-infected individuals develop an acquired immune deficiency syndrome (AIDS) due to loss in their lymphocyte numbers and cellular defects in T cells and antigen-presenting cells (APC). HIV infection of the thymus results in deficient replenishment of the peripheral naive T-cell pool. The HIV nef gene was shown to be important for progression towards AIDS and cel...

Human immunodeficiency virus 1 (HIV-1) Nef downregulates surface expression of CD4, an integral component of the functional HIV receptor complex, through accelerated endocytosis of surface receptors and diminished transport of CD4 from the Golgi network to the plasma membrane. HIV-1 Nef also diminishes surface expression of major histocompatibility complex (MHC) class I antigens. In the case of...

Monocytes/macrophages play a predominant role in the immunologic network by secreting and reacting to a wide range of soluble factors. Human immunodeficiency virus (HIV) infection leads to deep immunologic dysfunctions, also as a consequence of alterations in the pattern of cytokine release. Recent studies on in vivo models demonstrated that the expression of HIV Nef alone mimics many pathogene...

background: toxoplasma gondii is an obligate intracellular parasite and its sexual and asexual cycles, respectively take place in the intestinal epithelial cell of definitive host and tissue of intermediate hosts. congenital toxoplasmosis is more impor tant when the mother acquired the infection during pregnancy period for the first time. serological tests are the only meth ods for diagnosis of...