HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Noone, C. M. Articles by Johnson, P. A. Search for Related Content PubMed PubMed Citation Articles by Noone, C. M. Articles by Johnson, P. A. Agricola Articles by Noone, C. M. Articles by Johnson, P. A.

Novel mechanism of immunosuppression by influenza virus haemagglutinin: selective suppression of interleukin 12 p35 transcription in murine bone marrow-derived dendritic cells

¹ Immunovirology Laboratory, Institute of Immunology and Biology Department, National University of Ireland, Maynooth, Co. Kildare, Ireland
² National Institute for Biological Standards and Controls, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK
³ Mucosal Immunology Laboratory, Institute of Immunology, National University of Ireland, Maynooth, Co. Kildare, Ireland
⁴ Immune Regulation Research Group, Biochemistry Department, Trinity College Dublin, Ireland

Correspondence
Patricia A. Johnson
p.johnson{at}may.ie

Infection with influenza virus strongly predisposes an individual to bacterial superinfection, which is often the significant cause of morbidity and mortality during influenza epidemics. Little is known about the immunomodulating properties of the virus that lead to this phenomenon, but the effect of the viral components on the development of immune dendritic cells (DCs) may prove vital. In this study, activation of and cytokine secretion by bacterial lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs) following treatment with the influenza virus major antigen haemagglutinin (HA) were examined. HA selectively inhibits the release of LPS-induced interleukin 12 (IL12) p70, which is independent of IL10 secretion. Suppression occurs at the transcriptional level, with selective inhibition of p35- and not p40-subunit mRNA expression. The downregulation of IL12 p70 by influenza HA is a novel and unexplored pathway that may be relevant in the predisposition to bacterial superinfection associated with influenza virus infections.