Riemerella anatipestifer infection in ducks induces IL-17A production, but not IL-23p19

Rochelle A Flores,Wongi Min,Fahmida Afrin,Cherry P Fernandez-Colorado,Woo H Kim,Paula Leona T Cammayo,Suk Kim

doi:10.1038/s41598-019-49516-z

Abstract

R. anatipestifer (RA) is one of the most harmful bacterial pathogens affecting the duck industry, and infection is associated with the production of proinflammatory cytokines, including IL-17A. Another proinflammatory cytokine, IL-23, is critical for the development of Th17 cells, which produce IL-17. However, IL-23 roles have not been studied in this infection. Here, we describe the identification and mRNA expression analysis of duck IL-23p19 (duIL-23p19) in splenic lymphocytes and macrophages stimulated with killed RA and in spleens of RA-infected ducks. Expression of duIL-23p19 transcript identified in this study was relatively high in livers of healthy ducks and was upregulated in mitogen-activated splenic lymphocytes as well as in splenic lymphocytes and macrophages stimulated with killed RA. In spleens of RA-infected ducks, expression levels of duIL-23p19 transcript were unchanged at all time points except on days 4 and 7 post-infection; however, duIL-17A and IL-17F expression levels were upregulated in both spleens of RA-infected ducks and splenic lymphocytes and macrophages stimulated with killed RA. In sera collected at 24 h after this infection, duIL-23p19 expression levels were unchanged, whereas IL-17A significantly upregulated. These results suggest that IL-23p19 does not play a critical role in the IL-17A response in early stages of RA-infected ducks.

Highlights

Riemerella anatipestifer is a Gram-negative, non-motile, extracellular bacterium that belongs to the Flavobacteriaceae family, and infection of ducks with this pathogen causes acute and chronic septicaemia characterized by fibrinous polyserositis, and meningitis[1,2]
Comparative expression analyses of immune-related genes in ducks and chickens indicated that duck interleukin (IL)-17A was significantly increased in R. anatipestifer-infected ducks as well as in splenic lymphocytes activated with killed R. anatipestifer[9,10]
We describe the comparative expression profiles of duIL-23p19 and related cytokines in duck splenic lymphocytes and macrophages stimulated with killed R. anatipestifer and in the spleens of R. anatipestifer-infected ducks

Summary

Introduction

Riemerella anatipestifer is a Gram-negative, non-motile, extracellular bacterium that belongs to the Flavobacteriaceae family, and infection of ducks with this pathogen causes acute and chronic septicaemia characterized by fibrinous polyserositis, and meningitis[1,2]. Host genes involved in the immune response were identified in duck livers following R. anatipestifer infection[8]. The protective effects of IL-17 in host defence were demonstrated for Escherichia coli[17], Klebsiella pneumoniae[18], Porphyromonas gingivalis[19], Toxoplasma gondii[20], and Candida albicans[21] Dysregulation of this cytokine is known to contribute to development of tissue inflammation and autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis, psoriasis, and inflammatory bowel disease[22,23,24]. We describe the comparative expression profiles of duIL-23p19 and related cytokines in duck splenic lymphocytes and macrophages stimulated with killed R. anatipestifer and in the spleens of R. anatipestifer-infected ducks

Methods

Results

Conclusion