Nef protein of HIV‐1 has B‐cell stimulatory activity

  title={Nef protein of HIV‐1 has B‐cell stimulatory activity},
  author={Narendra Chirmule and Naoki Oyaizu and Carl W. Saxinger and Savita Pahwa},
ObjectiveTo examine the B-cell stimulatory properties of the regulatory Nef protein of HIV-1. MethodsThe effect of the HIV-1 regulatory proteins Nef, Tat and Vif, were analyzed for their ability to induce differentiation of normal B lymphocytes into immunoglobulin secreting cells (ISC). ResultsA recombinant Nef protein, but neither Tat or Vif, was able to induce ISC in peripheral blood lymphocyte (PBL) cultures of HIV-1-seronegative donors. Another recombinant Nef protein, d-Nef, with a… 
HIV type 1 Nef protein is a viral factor for leukocyte recruitment into the central nervous system.
A mechanism by which HIV-1 Nef protein may be essential for AIDS neuropathogenesis is proposed, as a mediator of the recruitment of leukocytes that may serve as vehicles of the virus and perpetrators for disease through their production of neurotoxins.
Induction of interleukin-15 production by HIV-1 nef protein: a role in the proliferation of uninfected cells.
It is found that exogenous Nef protein induces activation of normal PBMC, increasing their proliferative response; modulates cytokine production; exerts its activating effects through IL-15 synthesis induction; and exerts these effects entering monocyte/macrophages.
Human immunodeficiency virus Tat induces functional unresponsiveness in T cells
It is demonstrated that the mechanism of the Tat-mediated inhibition of T-cell functions involves a phospholipase C gamma 1-independent pathway.
Human immunodeficiency virus type 1 TAT protein activates B lymphocytes.
It is indicated that exogenous Tat alone can activate B cells, suggesting that Tat may contribute to B cell hyperactivation during the early stage of HIV-1 infection and activation-induced B cell death mediated by Fas during the late stage of virus-encoded transactivator infection.
Loss of memory (CD27) B lymphocytes in HIV-1 infection
Ex vivo findings suggest that persistent T-cell activation may contribute to loss of memory B cells through upregulation of Fas/FasL on these cells and terminal differentiation into plasma cells.
Acquisition of Host-Derived CD40L by HIV-1 In Vivo and Its Functional Consequences in the B-Cell Compartment
It is proposed that a positive feedback loop involving CD40L-bearing HIV-1 particles issued from CD4+ T cells productively infected with HIV- 1 play a role in the virus-induced dysfunction of humoral immunity by chronically activating B cells through sustained CD40 signaling.
Interleukin 10 is induced by recombinant HIV-1 Nef protein involving the calcium/calmodulin-dependent phosphodiesterase signal transduction pathway.
  • E. Brigino, S. Haraguchi, +4 authors N. Day
  • Biology, Medicine
    Proceedings of the National Academy of Sciences of the United States of America
  • 1997
It is indicated that extracellular Nef may contribute to the immunopathogenesis of HIV infection by inducing IL-10, and this inhibition is reversed by the addition of calcium along with Nef.
HIV‐1 Nef protein inhibits the in vitro induction of a specific antibody response to Candida albicans by an early up‐regulation of IL‐15 production
The results suggest that Nef may inhibit the induction of a specific antibody response by an early up‐regulation of IL‐15 production.
Immunoregulatory effects of HIV‐1 Nef protein
Recent progress on the immunomodulatory effect of the accessory Nef protein and its role in the pathogenesis of HIV‐1 infection are reviewed.
Mitogenic effect of HIV‐infected human T cell lines on mouse B cells mediated by surface immunoglobulin
Following HIV‐1 infection, a number of disorders are induced in both normal T and B cells by virus products derived from infected CD4+ T cells. In the present study, we found that HIV‐infected, but