IgG-derived Fc down-regulates virus-induced plasmacytoid dendritic cell (pDC) IFNα production

• Published in: Cytokine (Philadelphia, Pa.) Vol. 26; no. 5; pp. 209 - 216
• Main Authors: Green, Daniel S, Lum, Tom, Green, Jon A
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 07.06.2004
• Subjects: Herpes simplex virus; HIV; HSV; Human immunodeficiency virus; IFNα; IgG; pDC; Vesicular stomatitis virus; VSV; IFNα; HIV; IgG; VSV; HSV; Fc; pDC
• ISSN: 1043-4666; 1096-0023
• DOI: 10.1016/j.cyto.2004.02.012

Interferon alpha (IFNα) produced primarily by plasmacytoid dendritic cells (pDC) is a potent component of the anti-viral innate immune response, and modulates adaptive immunity. Primary control of IFNα production occurs at a cellular level and is highly dependent upon regulatory factors and their products. Recent studies have identified up-regulation of IFNα production mediated by the adaptive immune response in the form of immune specific IgG. These studies establish a role for the external control of IFNα production. The current work demonstrates that the Fc portion of IgG is a potent inhibitor of IFNα produced by pDCs in response to HIV, HSV, and VSV. Fc down-regulation occurs after IFNα production can be detected by bioassay, and suggests the existence of late regulatory events in the control of IFNα production. Down-regulation of IFNα is not caused by Fc-induced necrosis, apoptosis or neutralization of IFNα activity. Demonstration of Fc-mediated down-regulation of IFNα provides additional evidence of the role of IgG in the regulation of IFNα production.