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Cellular & Molecular Biology Letters

Open Access

S-nitrosoglutathione modulates CXCR4 and ICOS expression

  • Yoshihiko Yamamoto3, 1,
  • Rajendra Pahwa3, 2 and
  • Savita Pahwa3, 2
Cellular & Molecular Biology LettersAn International Journal200611:3

Received: 1 August 2005

Accepted: 17 November 2005

Published: 01 March 2006


The expression of CXCR4, a membrane protein which is involved in the entry of HIV-1, is down-modulated from the cell surface by Phorbol 12-myristate 13-acetate (PMA) and the Ca+ ionophore, Ionomycin. Inducible co-stimulator (ICOS), which contributes to lymphocyte proliferation, is up-regulated by PMA/Ionomycin. We examined the influence of S-nitrosoglutathione (SNG), an inhibitor of Vacuolar H+-ATPase (V-ATPase), on the expression of CXCR4 and ICOS in PMA/Ionomycin-treated peripheral mononuclear cells (PBMC), and of CXCR4 alone in lymphoid cell lines. In this report, we show that SNG interferes with both effects of PMA/Ionomycin, namely CXCR4 down-regulation and ICOS up-regulation. These studies imply opposing roles of V-ATPase in the regulation of CXCR4 and ICOS. The influence of SNG in modulating the susceptibility of T cells to HIV-1 and on their immune responses needs further investigation.

Key words

S-nitrosoglutathione (SNG)CXCR4ICOSHIV-1