Human immunodeficiency virus type 1 (HIV-1) Nef interferes with the endocytic machinery to modulate the cell surface expression of CD4. However, the basal trafficking of CD4 is governed by different rules in the target cells of HIV-1: whereas CD4 is rapidly internalized from the cell surface in myeloid cells, CD4 is stabilized at the plasma membrane through its interaction with the p56(lck) kin...

Human immunodeficiency virus infection is characterized by dysregulation of antigen-presenting cell function and defects in cell-mediated immunity. Recent evidence suggests that impaired ability of CD4+ T cells to upregulate the costimulatory molecule CD154 is at the core of this dysregulation. To test the hypothesis that increased expression of CD154 on infected CD4+ T cells could modulate imm...

Monocytes and macrophages utilize the class A and B scavenger receptors to recognize and perform phagocytosis of invading microbes before a pathogen-specific immune response is generated. HIV-1 Nef protein affects the innate immune system impairing oxidative burst response and phagocytic capacity of macrophages. Our data show that exogenous recombinant myristoylated Nef protein induces a marked...

BACKGROUND The potential role of the human immunodeficiency virus-1 (HIV-1) accessory protein Nef in the pathogenesis of neuroAIDS is still poorly understood. Nef is a molecular adapter that influences several cellular signal transduction events and membrane trafficking. In human macrophages, Nef expression induces the production of extracellular factors (e.g. pro-inflammatory chemokines and cy...

Human Immunodeficiency Virus-1 (HIV-1), exploits a number of host cellular factors for successful survival and propagation. The viral protein, Nef plays an important role in HIV-1 pathogenesis by interacting with various cellular proteins. In the present work, we have identified Cyclin K (CycK) as a novel Nefinteracting protein and for the first time we show that CycK inhibits HIV-1 gene expres...

Introduction: The Nef accessory protein is an attractive antigenic candidate in the development of HIV-1 DNA- or protein-based vaccines. The most crucial disadvantage of DNA and protein-based vaccines is their low immunogenicity, which can be improved by cell-penetrating peptides (CPPs) as effective carrier molecules. Methods: In this study, the HIV-1 Nef protein was generated in the Escherichi...

BACKGROUND In recent years, different HIV antigens have been successfully expressed in plants by either stable transformation or transient expression systems. Among HIV proteins, Nef is considered a promising target for the formulation of a multi-component vaccine due to its implication in the first steps of viral infection. Attempts to express Nef as a single protein product (not fused to a st...

To characterize the effect of human immunodeficiency virus-1 (HIV-1) nef expression in human monocytes/macrophage (HMO) and U937 on the levels of FcgammaRs, HLA antigens, and monokines, elutriated HMOs and U937 cells were transfected with an adenovirus-mediated Nef expression system. Nef-expressing cells downmodulated FcgammaRI, FcgammaRII, and upregulated HLA class I molecules. Nef-expressing ...

background: numerous evidences indicate that in some hiv-1 positive patients, the humoral and cellular immune responses are induced against hiv-1 proteins and this is inversely related to the progress of infection. objective: the aim of this study was the evaluation of the adenovectors containing hiv genes in induction of immune responses in mice. methods: the hiv-1 genes including gag p24, rev...

Nef alters the cell surface expression of several immunoreceptors, which may contribute to viral escape. We show that Nef modifies major histocompatibility complex class II (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, whereas immature (invariant [Ii] cha...