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Human Immunodeficiency Virus Viremia Induces Plasmacytoid Dendritic Cell Activation In Vivo and Diminished Alpha Interferon Production In Vitro▿

By John C. Tilton, Maura M. Manion, Marlise R. Luskin, Alison J. Johnson, Andy A. Patamawenu, Claire W. Hallahan, Nancy A. Cogliano-Shutta, JoAnn M. Mican, Richard T. Davey, Shyam Kottilil, Jeffrey D. Lifson, Julia A. Metcalf, Richard A. Lempicki and Mark Connors


Human immunodeficiency virus type 1 (HIV-1) infection has been associated with perturbations of plasmacytoid dendritic cells (PDC), including diminished frequencies in the peripheral blood and reduced production of type I interferons (IFNs) in response to in vitro stimulation. However, recent data suggest a paradoxical increase in production of type 1 interferons in vivo in HIV-infected patients compared to uninfected controls. Using a flow cytometric assay to detect IFN-α-producing cells within unseparated peripheral blood mononuclear cells, we observed that short-term interruptions of antiretroviral therapy are sufficient to result in significantly reduced IFN-α production by PDC in vitro in response to CpG A ligands or inactivated HIV particles. The primary cause of diminished IFN-α production was reduced responsiveness of PDC to de novo stimulation, not diminished per cell IFN-α production or migration of cells to lymphoid organs. Real-time PCR analysis of purified PDC from patients prior to and during treatment interruptions revealed that active HIV-1 replication is associated with upregulation of type I IFN-stimulated gene expression. Treatment of hepatitis C virus-infected patients with IFN-α2b and ribavirin for hepatitis C virus infection resulted in a profound suppression of de novo IFN-α production in response to CpG A or inactivated HIV particles, similar to the response observed in HIV-infected patients. Together, these results suggest that diminished production of type I interferons in vitro by PDC from HIV-1-infected patients may not represent diminished interferon production in vivo. Rather, diminished function in vitro is likely a consequence of prior activation via type I interferons or HIV virions in vivo

Topics: Cellular Response to Infection
Publisher: American Society for Microbiology (ASM)
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Provided by: PubMed Central
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