Antigen-specific T-cell responses to a recombinant fowlpox virus are dependent on MyD88 and interleukin-18 and independent of Toll-like receptor 7 (TLR7)- and TLR9-mediated innate immune recognition.

Abstract

Fowlpox virus (FWPV) is a double-stranded DNA virus long used as a live-attenuated vaccine against poultry diseases, but more recent interest has focused on its use as a mammalian vaccine vector. Here, in a mouse model system using FWPV encoding the nominal target antigen chicken ovalbumin (OVA) (FWPV(OVA)), we describe for the first time some of the fundamental processes by which FWPV engages both the innate and adaptive immune systems. We show that Toll-like receptor 7 (TLR7) and TLR9 are important for type I interferon secretion by dendritic cells, while TLR9 is solely required for proinflammatory cytokine secretion. Despite this functional role for TLR7 and TLR9 in vitro, only the adapter protein myeloid differentiation primary response gene 88 (MyD88) was shown to be essential for the formation of adaptive immunity to FWPV(OVA) in vivo. The dependence on MyD88 was confined only to the T-cell compartment and was not related to its contribution to TLR signaling, dendritic cell maturation, or the capture and presentation of FWPV-derived OVA antigen. We demonstrate that this is not by means of mediating T-cell-dependent interleukin-1 (IL-1) signaling, but rather, we suggest that MyD88 functions to support T-cell-specific IL-18 receptor signaling, which in turn is essential for the formation of adaptive immunity to FWPV-encoded OVA.

• Authors: Erin L Lousberg, Kerrilyn R Diener, Cara K Fraser, Simon Phipps, Paul S Foster, Weisan Chen, Satoshi Uematsu, Shizuo Akira, Sarah A Robertson, Michael P Brown, John D Hayball
• Journal: Journal of virology (J Virol) Vol. 85 Issue 7 Pg. 3385-96 (Apr 2011) ISSN: 1098-5514 [Electronic] United States
• PMID: 21248035 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Interleukin-18
• Membrane Glycoproteins
• Myd88 protein, mouse
• Myeloid Differentiation Factor 88
• Recombinant Proteins
• Tlr7 protein, mouse
• Tlr9 protein, mouse
• Toll-Like Receptor 7
• Toll-Like Receptor 9
• Viral Vaccines
• Ovalbumin

Topics

• Animals
• Chickens
• Fowlpox virus (genetics, immunology)
• Interleukin-18 (metabolism)
• Membrane Glycoproteins (immunology)
• Mice
• Mice, Inbred BALB C
• Mice, Inbred C57BL
• Myeloid Differentiation Factor 88 (metabolism)
• Ovalbumin (genetics, immunology)
• Recombinant Proteins (genetics, immunology)
• T-Lymphocytes (immunology)
• Toll-Like Receptor 7 (immunology)
• Toll-Like Receptor 9 (immunology)
• Viral Vaccines (genetics, immunology)