Abstract
It has been proposed that signal transduction defects may, at least partially, account for the functional impairment of CD4+ lymphocytes during HIV-1 infection. Recently, we have demonstrated that unresponsive CD4+ lymphocytes from these patients had reduced protein tyrosine phosphorylation after CD3 engagement, and that this defect was associated with constitutively altered levels of p56lck and p59fyn kinases. Since CD45 is essential for T cell receptor (TCR) and CD2-mediated activation of protein tyrosine kinases, we study here CD45-associated tyrosine phosphatase activity in resting and activated CD4 T cells from HIV-infected patients. We found a significant decrease in the basal and post-activation phosphatase activity of CD45 which correlated well with impairment of proliferative responses. In addition, decreased levels of cellular thiols observed in resting CD4+ lymphocytes from these patients suggested a disturbed redox status. Although expression levels of CD45 were decreased in most patients, a significant recovery of phosphatase activity and proliferative responses was observed in most patients by preincubating cells with N-acetyl-L-cysteine and beta2-mercaptoethanol. In some patients, anti-oxidant treatment failed to...Continue Reading
Citations
Mar 10, 2000·AIDS Research and Human Retroviruses·A GiovannettiF Aiuti
Dec 5, 1998·AIDS Research and Human Retroviruses·W MalorniR Paganelli
May 2, 2012·The Journal of Clinical Investigation·Kai Soo TanYunn-Hwen Gan
Oct 28, 1998·Environmental Health Perspectives·C M Krejsa, G L Schieven
Jan 27, 2009·Biological Chemistry·Nazzareno BallatoriChristine L Hammond
Aug 12, 1998·Journal of Molecular Neuroscience : MN·Y H ChongH K Park
Sep 1, 1999·Free Radical Biology & Medicine·N W Schoene, K S Kamara
Sep 22, 2000·Clinical Immunology : the Official Journal of the Clinical Immunology Society·L A PintoV Blazevic
Mar 27, 2018·Microbiology and Immunology·Poonam SuryawanshiAshwini Shete
Sep 16, 2003·Journal of Leukocyte Biology·Anna Maria MasciLuigi Racioppi
Apr 17, 2002·The Journal of Biological Chemistry·Gilles A RobichaudMichel J Tremblay
Apr 5, 2003·The Journal of Biological Chemistry·Francisco J SalgadoMontserrat Nogueira
Aug 18, 2001·The Journal of Immunology : Official Journal of the American Association of Immunologists·B BarbeauM J Tremblay
Jun 12, 2003·Journal of Immunological Methods·David A Rider, Stephen P Young