Changes of CD4+CD25+ cells ratio in immune organs from chickens challenged with infectious bursal disease virus strains with varying virulences.

Xiaoxue Yu,Yanan Lu,Yongchao Zhang,Zandong Li,Haiwen Liu,Lei Rui,Qiang Shao

doi:10.3390/v7031357

Xiaoxue Yu, Yanan Lu + Show 5 more

Open Access

https://doi.org/10.3390/v7031357

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Journal: Viruses	Publication Date: Mar 20, 2015
Citations: 56	License type: CC BY 4.0

Affiliation: China Agricultural University

Abstract

In the current study, we investigate changes in CD4+CD25+ cells in chickens during infectious bursal disease virus (IBDV) infection. The percentage of CD4+CD25+ cells in lymph organs, e.g., the thymus, spleen, bursa of Fabricius and peripheral blood, during the first 1–5 days post infection (dpi) was assessed by flow cytometry. The data revealed a remarkable decrease in the percentage of CD4+CD25+ cells in the thymus from 1 to 5 dpi and in the spleen during early infection. An increase of the percentage of CD4+CD25+ cells among peripheral blood lymphocytes was observed during the first two days of IBDV infection. Additionally, CD4+CD25+ cells infiltrated the bursa along with CD4+ cells after IBDV infection. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to measure the mRNA levels of immune-related cytokines in IBDV-infected thymus and bursa of Fabricius tissues. The data revealed that IBDV caused a significant increase in interleukin (IL)-10 mRNA levels, with the Harbin-1 strain (vvIBDV) inducing higher IL-10 expression than the Ts strain. Taken together, our data suggest that chicken CD4+CD25+ cells may participate in IBDV pathogenicity by migrating from their sites of origin and storage, the thymus and spleen, to the virally targeted bursa of Fabricius during IBDV infection.

Highlights

Infectious bursal disease virus (IBDV) can lead to an acute, highly contagious immunosuppressive response in young chickens
Infectious bursal disease (IBD), which is caused by IBDV, can lead to significant economic losses in the poultry industry [1]
IBD, which is caused by IBDV, is an acute, highly contagious immunosuppressive disease of young chickens

Summary

Introduction

Infectious bursal disease virus (IBDV) can lead to an acute, highly contagious immunosuppressive response in young chickens. Mammalian CD4+CD25+ regulatory T cells have been reported to play a critical immunosuppressive role in many diseases; there is limited information regarding the function of CD4+CD25+ cells in chickens during IBDV infection. Infectious bursal disease (IBD), which is caused by IBDV, can lead to significant economic losses in the poultry industry [1]. IBDV belongs to the family Birnaviridae and consists of two segments, segments A (3.2 kb) and B (2.9 kb), which encode five proteins (VP1-VP5) [2,3]. IBDV can be differentiated into two serotypes (serotypes 1 and 2). IBDV infection causes a lymphoid depletion of B cells and the destruction of bursal tissues, which are crucial to its immunosuppressive effect [7]

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