Novel insights into the host immune response of chicken Harderian gland tissue during Newcastle disease virus infection and heat treatment

Abstract

BackgroundNewcastle disease virus, in its most pathogenic form, threatens the livelihood of rural poultry farmers where there is a limited infrastructure and service for vaccinations to prevent outbreaks of the virus. Previously reported studies on the host response to Newcastle disease in chickens have not examined the disease under abiotic stressors, such as heat, which commonly experienced by chickens in regions such as Africa. The objective of this study was to elucidate the underlying biological mechanisms that contribute to disease resistance in chickens to the Newcastle disease virus while under the effects of heat stress.ResultsDifferential gene expression analysis identified genes differentially expressed between treated and non-treated birds across three time points (2, 6, and 10 days post-infection) in Fayoumi and Leghorn birds. Across the three time points, Fayoumi had very few genes differentially expressed between treated and non-treated groups at 2 and 6 days post-infection. However, 202 genes were differentially expressed at 10 days post-infection. Alternatively, Leghorn had very few genes differentially expressed at 2 and 10 days post-infection but had 167 differentially expressed genes at 6 days post-infection. Very few differentially expressed genes were shared between the two genetic lines, and pathway analysis found unique signaling pathways specific to each genetic line. Fayoumi had significantly lower viral load, higher viral clearance, higher anti-NDV antibody levels, and fewer viral transcripts detected compared to Leghorns. Fayoumis activated immune related pathways including SAPK/JNK and p38 MAPK signaling pathways at earlier time points, while Leghorn would activate these same pathways at a later time. Further analysis revealed activation of the GP6 signaling pathway that may be responsible for the susceptible Leghorn response.ConclusionsThe findings in this study confirmed our hypothesis that the Fayoumi line was more resistant to Newcastle disease virus infection compared to the Leghorn line. Within line and interaction analysis demonstrated substantial differences in response patterns between the two genetic lines that was not observed from the within line contrasts. This study has provided novel insights into the transcriptome response of the Harderian gland tissue during Newcastle disease virus infection while under heat stress utilizing a unique resistant and susceptible model.Electronic supplementary materialThe online version of this article (10.1186/s12917-018-1583-0) contains supplementary material, which is available to authorized users.

Integrated Transcriptome and Histone Modification Analysis Reveals NDV Infection Under Heat Stress Affects Bursa Development and Proliferation in Susceptible Chicken Line

“…Leghorns have significantly lower levels of NDV-specific antibody titers compared to Fayoumis (Saelao et al, 2018b), which supports the notion that that Leghorns had more markedly decreased B-cell counts through inhibition of proliferation than Fayoumis. However, one caveat that must be considered is that B cells responsible for producing NDV-specific antibodies were most likely from peripheral tissues rather than from the bursa.…”

“…We took advantage of two genetically distinct and inbred chicken lines, Fayoumi and Leghorn, with Fayoumi being the more relatively resistant line compared to Leghorn as observed through their lower NDV titers and higher NDV-specific antibody levels. Additionally, Fayoumi is hypothesized to be more heat stress-resistant because the line originated from Egypt therefore historically had adapted through natural selection to an environment with higher climate (Wang et al, 2014;Deist et al, 2017;Saelao et al, 2018b). Physiological responses to heat stress have been shown to be significantly different between the two lines, with electrolyte levels appearing to be more well-maintained during heat stress in Fayoumis compared to Leghorns (Wang et al, 2018).…”

Induction of Chicken Host Defense Peptides within Disease-Resistant and -Susceptible Lines

“…The inbred Fayoumi line included in this study has been shown to be relatively more resistant against various pathogens and environmental stresses than the inbred Leghorn line or a broiler line, including the Fayoumi line activating immune-related signaling pathways against viral infection and LPS treatment with/without heat stress [ 32 , 59 , 60 , 61 ]. In this study, we investigated the expression of 20 chicken HDPs before and after induction by LPS and poly(I:C) in embryonic fibroblasts and bone marrow-derived cells from the inbred Fayoumi M15.2 and Leghorn Ghs6 chicken lines.…”

“…The Fayoumi line M15.2 was segregated from the Egyptian Fayoumi breed, has been highly inbred, and has large genetic distance from broiler and Leghorn lines [ 29 , 31 ]. From past comparisons between inbred Fayoumi and Leghorn chickens, the Fayoumi line has shown more resistance against various pathogens and stressful environments, suggesting superior immune responses [ 29 , 30 , 32 , 33 ]. In previous studies, Fayoumis have been demonstrated to have different expression of several HDPs [ 34 ] and association of genetic variants with disease response [ 35 ].…”

Transcriptome Analysis Reveals Inhibitory Effects of Lentogenic Newcastle Disease Virus on Cell Survival and Immune Function in Spleen of Commercial Layer Chicks

“…showed consistent expression changes in response to NDV in spleen of Hy-Line Brown birds and in spleen [8,13,14], Harderian gland [9,12], trachea [4], lung [10] Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 4 August 2020 doi:10.20944/preprints202008.0103.v1…”