TY - JOUR T1 - Local Not Systemic Modulation of Dendritic Cell S1P Receptors in Lung Blunts Virus-Specific Immune Responses to Influenza JF - Molecular Pharmacology JO - Mol Pharmacol SP - 896 LP - 903 DO - 10.1124/mol.108.048769 VL - 74 IS - 3 AU - David Marsolais AU - Bumsuk Hahm AU - Kurt H. Edelmann AU - Kevin B. Walsh AU - Miguel Guerrero AU - Yasuko Hatta AU - Yoshihiro Kawaoka AU - Edward Roberts AU - Michael B. A. Oldstone AU - Hugh Rosen Y1 - 2008/09/01 UR - http://molpharm.aspetjournals.org/content/74/3/896.abstract N2 - The mechanism by which locally delivered sphingosine analogs regulate host response to localized viral infection has never been addressed. In this report, we show that intratracheal delivery of the chiral sphingosine analog (R)-2-amino-4-(4-heptyloxyphenyl)-2-methylbutanol (AAL-R) or its phosphate ester inhibits the T-cell response to influenza virus infection. In contrast, neither intraperitoneal delivery of AAL-R nor intratracheal instillation of the non-phosphorylatable stereoisomer AAL-S suppressed virus-specific T-cell response, indicating that in vivo phosphorylation of AAL-R and sphingosine 1-phosphate (S1P) receptor modulation in lungs is essential for immunomodulation. Intratracheal delivery of water-soluble S1P1 receptor agonist at doses sufficient to induce systemic lymphopenia did not inhibit virus-specific T-cell response, indicating that S1P1 is not involved in the immunosuppressive activities of AAL-R and that immunosuppression acts independently of naive lymphocyte recirculation. Accumulation of dendritic cells (DCs) in draining lymph nodes was inhibited by intratracheal but not intraperitoneal delivery of AAL-R. Direct modulation of DCs is demonstrated by the impaired ability of virus-infected bone marrow-derived DCs treated in vitro with AAL-R to trigger in vivo T-cell response after adoptive transfer to the airways. Thus, our results suggest that locally delivered sphingosine analogs induce immunosuppression by modulating S1P receptors other than S1P1 or S1P2 on dendritic cells in the lungs after influenza virus infection. ER -