C Speth1, B Joebstl, M Barcova, M P Dierich. 1. Institute for Hygiene, University of Innsbruck and Ludwig Boltzmann-Institute for AIDS Research, Austria.
Abstract
OBJECTIVE: To analyse the effect of HIV-1 transmembrane protein gp41 on cytokine production and chemokine receptor expression in blood and brain. DESIGN: Because previous results had demonstrated that recombinant gp41 contributes to HIV-induced dysfunction of blood immune cells we investigated its effect on interleukin (IL)-10 synthesis and expression of the HIV coreceptors CCR5 and CXCR4 in different human brain cells. METHODS: Astrocytic, microglial and neuronal cell lines were incubated with the extracellular domain of gp41 (aa565-647). Secretion of IL-10 into the medium was measured by ELISA. Chemokine receptor expression was analysed by fluorescence activated cell sorting and by RT-PCR. RESULTS: Incubation of the astrocytic cell line U87 with gp41 induced more than a 10 fold up-regulation of IL-10 secretion. This modulation was shown to be time- and dose-dependent. Use of inhibitors for different signal transduction pathways indicated a similar transduction cascade for the alteration of IL-10 production in astrocytes as in monocytes with participation of cAMP/adenylate cyclase and activation of p70S6 kinase. To a lesser extent IL-10 synthesis was also up-regulated by gp41 in the neuronal cell line SK-N-SH. In all cell types up-regulation of IL-10 paralleled by an enhanced expression of the chemokine receptor and HIV-1 coreceptor CCR5. This up-regulation was driven by IL-10 as shown by use of an IL-10 antibody. Expression of the chemokine receptor CXCR4 was only slightly altered. CONCLUSIONS: These findings suggest a role for gp41 in the modulation of brain-specific host defence, cell migration and cell infectivity by HIV.
OBJECTIVE: To analyse the effect of HIV-1 transmembrane protein gp41 on cytokine production and chemokine receptor expression in blood and brain. DESIGN: Because previous results had demonstrated that recombinant gp41 contributes to HIV-induced dysfunction of blood immune cells we investigated its effect on interleukin (IL)-10 synthesis and expression of the HIV coreceptors CCR5 and CXCR4 in different human brain cells. METHODS: Astrocytic, microglial and neuronal cell lines were incubated with the extracellular domain of gp41 (aa565-647). Secretion of IL-10 into the medium was measured by ELISA. Chemokine receptor expression was analysed by fluorescence activated cell sorting and by RT-PCR. RESULTS: Incubation of the astrocytic cell line U87 with gp41 induced more than a 10 fold up-regulation of IL-10 secretion. This modulation was shown to be time- and dose-dependent. Use of inhibitors for different signal transduction pathways indicated a similar transduction cascade for the alteration of IL-10 production in astrocytes as in monocytes with participation of cAMP/adenylate cyclase and activation of p70S6 kinase. To a lesser extent IL-10 synthesis was also up-regulated by gp41 in the neuronal cell line SK-N-SH. In all cell types up-regulation of IL-10 paralleled by an enhanced expression of the chemokine receptor and HIV-1 coreceptor CCR5. This up-regulation was driven by IL-10 as shown by use of an IL-10 antibody. Expression of the chemokine receptorCXCR4 was only slightly altered. CONCLUSIONS: These findings suggest a role for gp41 in the modulation of brain-specific host defence, cell migration and cell infectivity by HIV.
Authors: Kevin Rostasy; Gullue Gorgun; Yelena Kleyner; Anthony Garcia; Michael Kramer; Suzanne M Melanson; Jean Marie Mathys; Constantin Yiannoutsos; Paul R Skolnik; Bradford A Navia Journal: J Neurovirol Date: 2005-07 Impact factor: 2.643