Innate immune response of human alveolar macrophages during influenza A infection

PLoS One. 2012;7(3):e29879. doi: 10.1371/journal.pone.0029879. Epub 2012 Mar 2.

Abstract

Alveolar macrophages (AM) are one of the key cell types for initiating inflammatory and immune responses to influenza virus in the lung. However, the genome-wide changes in response to influenza infection in AM have not been defined. We performed gene profiling of human AM in response to H1N1 influenza A virus PR/8 using Affymetrix HG-U133 Plus 2.0 chips and verified the changes at both mRNA and protein levels by real-time RT-PCR and ELISA. We confirmed the response with a contemporary H3N2 influenza virus A/New York/238/2005 (NY/238). To understand the local cellular response, we also evaluated the impact of paracrine factors on virus-induced chemokine and cytokine secretion. In addition, we investigated the changes in the expression of macrophage receptors and uptake of pathogens after PR/8 infection. Although macrophages fail to release a large amount of infectious virus, we observed a robust induction of type I and type III interferons and several cytokines and chemokines following influenza infection. CXCL9, 10, and 11 were the most highly induced chemokines by influenza infection. UV-inactivation abolished virus-induced cytokine and chemokine response, with the exception of CXCL10. The contemporary influenza virus NY/238 infection of AM induced a similar response as PR/8. Inhibition of TNF and/or IL-1β activity significantly decreased the secretion of the proinflammatory chemokines CCL5 and CXCL8 by over 50%. PR/8 infection also significantly decreased mRNA levels of macrophage receptors including C-type lectin domain family 7 member A (CLEC7A), macrophage scavenger receptor 1 (MSR1), and CD36, and reduced uptake of zymosan. In conclusion, influenza infection induced an extensive proinflammatory response in human AM. Targeting local components of innate immune response might provide a strategy for controlling influenza A infection-induced proinflammatory response in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Chemokines / metabolism
  • Cytokines / metabolism
  • Enzyme-Linked Immunosorbent Assay / methods
  • Gene Expression Regulation*
  • Humans
  • Immunity, Innate
  • Influenza A Virus, H1N1 Subtype / genetics*
  • Influenza, Human / immunology*
  • Kinetics
  • Lectins, C-Type / biosynthesis
  • Macrophages / immunology
  • Macrophages / virology*
  • Oligonucleotide Array Sequence Analysis
  • Phagocytosis
  • Pulmonary Alveoli / immunology
  • Pulmonary Alveoli / virology*
  • Real-Time Polymerase Chain Reaction / methods

Substances

  • Chemokines
  • Cytokines
  • Lectins, C-Type
  • dectin 1