1. Nef enhances c-Cbl phosphorylation in HIV-infected CD4+ T lymphocytes
- Author
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Yang, Polung and Henderson, Andrew J.
- Subjects
- *
LYMPHOCYTES , *T cells , *GROWTH factors , *CHEMICAL reactions - Abstract
Abstract: The multifunctional HIV-1 protein Nef possesses several motifs that interact with signaling molecules in infected T cells. In order to determine whether Nef influences T cell activation, cells were infected with Nef-positive and Nef-negative clones of HIV. CD28 expression and changes in tyrosine phosphorylation were monitored. We observed no Nef-dependent changes in CD28 expression or function. However, infection with Nef-positive virus led to changes in tyrosine phosphorylation. This Nef-induced phosphorylation was observed in unstimulated cells, and c-Cbl was identified as one of the proteins whose phosphorylation was upregulated by Nef. Furthermore, Lck is required for Nef-mediated c-Cbl tyrosine phosphorylation. These results suggest that Nef modifies T cell signaling in the absence of T cell receptor engagement and co-stimulation. [Copyright &y& Elsevier]
- Published
- 2005
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