Stress-induced immunosuppression affecting avian influenza virus vaccine immune response through miR-20a-5p/NR4A3 pathway in chicken

Chicken adipose tissue is differentially involved in primary and secondary regional immune response to NDV through miR-20a-5p-NR4A3 pathway

The mammalian adipose tissue (AT) plays a key role in regulating immune function and anti-infective protection to maintain tissue regional homeostasis. However, it is still unclear whether there are differences in the participation of AT in primary and secondary immune response, and whether avian AT has the similar immune function characteristics to mammals. In this study, we used Newcastle disease virus (NDV) attenuated vaccine to induce primary and secondary immune response in chickens, and the changes of the key regulatory gene NR4A3 (nuclear receptor subfamily 4 group A member 3) of T cells activation and its targeted miR-20a-5p were detected by quantitative real-time PCR (qRT-PCR). The results showed that NR4A3 actively participated in immune response of AT, and showed significant differences in expression activities between the two immune processes. "MiR-20a-5p/NR4A3" pathway was a potential molecular mechanism involved in the regulation of immune function in AT. Moreover, AT responded differently to the primary and secondary immune response possibly through the different patterns of source, apoptosis and migration for lymphocytes (such as CD8β+ T cells). This study can provide directional guidance for further studying immune functions of avian AT.

Hermetia illucens Larvae Meal Enhances Immune Response by Improving Serum Immunoglobulin, Intestinal Barrier and Gut Microbiota of Sichuan White Geese After Avian Influenza Vaccination

Hermetia illucens Larvae Meal (HILM) has been observed to enhance growth performance and immune function, yet the effects and mechanisms in geese remain less understood. Experiment I included 64 Sichuan White Geese to investigate the optimal additive amount of HILM in diet, and experiment II included 32 Sichuan White Geese to access serum immunoglobulin, spleen immune-related genes, intestinal morphology and gut microbiota at the optimal additive amount of HILM. The results showed that the addition of 1% HILM significantly increased the ADG of Sichuan White Geese (p < 0.05), serum H5-R14 and H7-R4 strain titer at 33 d (p < 0.01) and H5-R13 strain titer (p < 0.05) at 40 d, which is the optimal dose of this trial. Experiment II revealed that the 1% HILM significantly increased serum IgG, IgG1, IgG2a, IgG3 and complement C3 (p < 0.05) and the mRNA expressions of IL-6 (p < 0.05) and CD4 (p < 0.01) in the spleen. The intestinal morphology was improved, and the secretion of SIgA and mRNA expression of Occludin in the jejunum were significantly increased (p < 0.05). Additionally, the abundance of Campilobacterota, Barnesiellaceae and Barnesiella was significantly decreased (p < 0.05), while the abundance of Lactobacillaceae was significantly increased (p < 0.05). This research provides new insights into the use of HILM in geese production.

MiR-20a-5p Targeting the TGFBR2 Gene Regulates Inflammatory Response of Chicken Macrophages Infected with Avian Pathogenic E. coli

Avian pathogenic E. coli (APEC) causes localized and systemic infections and are a threat to human health. microRNAs (miRNAs) play critical roles in inflammation and immune regulation following pathogen invasion. However, the related regulatory mechanism remains unclear. This study aimed to elucidate the involvement of chicken microRNA-20a-5p (gga-miR-20a-5p) in host defense against APEC in chickens and the underlying mechanisms. We evaluated the expression levels of gga-miR-20a-5p in chicken tissues and cells and observed a significant decrease in expression following APEC infection. Dual luciferase reporter assays showed that gga-miR-20a-5p directly targeted transforming growth factor-beta receptor 2 (TGFBR2), specifically by binding to the 3'-untranslated region (3'UTR) of TGFBR2. Overexpression of gga-miR-20a-5p markedly reduced both the mRNA and protein levels of TGFBR2, whereas inhibition of gga-miR-20a-5p significantly increased expression. Mechanistic investigations revealed that overexpression of gga-miR-20a-5p also attenuated the expression levels of the pro-inflammatory cytokines IL8, TNFα, IL6, and IL1β, whereas inhibition of gga-miR-20a-5p had the opposite effects. Collectively, our findings suggest that gga-miR-20a-5p regulates the immune response during APEC infection by targeting TGFBR2, thereby suppressing inflammatory cytokine production. This study provides valuable insights into the role of gga-miR-20a-5p in the host defense against APEC.

miR-214-PTEN pathway is a potential mechanism for stress-induced immunosuppression affecting chicken immune response to avian influenza virus vaccine

Stress-induced immunosuppression (SIIS) is one of common problems in the intensive poultry industry, affecting the effect of vaccine immunization and leading to high incidences of diseases. In this study, the expression characteristics and regulatory mechanisms of miR-214 in the processes of SIIS and its influence on the immune response to avian influenza virus (AIV) vaccine in chicken were explored. The qRT-PCR results showed that serum circulating miR-214 was significantly differentially expressed (especially on 2, 5, and 28 days post immunization (dpi)) in the processes, so had the potential as a molecular marker. MiR-214 expressions from multiple tissues were closely associated with the changes in circulating miR-214 expression levels. MiR-214-PTEN regulatory network was a potential key regulatory mechanism for the heart, bursa of Fabricius, and glandular stomach to participate in the process of SIIS affecting AIV immune response. This study can provide references for further understanding of stress affecting immune response.

CircMYO1B/miR-155 pathway is a common mechanism of stress-induced immunosuppression affecting immune response to three vaccines in chicken

Stress-induced immunosuppression (SIIS) can weaken the immune response effect of poultry vaccination, and bring huge hidden dangers and economic losses to the poultry industry. However, the detailed molecular mechanisms are still not fully understood. Unveiling the common mechanism of SIIS affecting the immune response to different vaccines is critical for detecting and minimizing the losses caused by SIIS. This study used glucocorticoid dexamethasone (Dex) to simulate SIIS, and three classic avian vaccines (including avian influenza virus (AIV), Newcastle disease virus (NDV), and infectious bursal disease virus (IBDV)) were used to induce immune responses in chicken. Quantitative real-time PCR (qRT-PCR) revealed the expression characteristics and functions of circMYO1B and miR-155 in the processes of SIIS affecting the immune response to the aforementioned avian vaccines, as well as their targeted regulatory relationship. Subsequent bioinformatics analysis predicted FOS, one of the potential target genes of miR-155. The results showed that circMYO1B/miR-155 pathway served as a key common mechanism by which SIIS affected the immune response to the three vaccines. Both heart and proventriculus appeared to be the crucial tissues for this process, with five days post immunization (dpi) emerging as the primary time of interest. Moreover, mitogen-activated protein kinase (MAPK) signaling system played a key role in modulating the immune response subsequent to SIIS administration. Our findings provide new insights into the immune function of competitive endogenous RNA (ceRNA), which have important function in the detection and treatment of SIIS affecting vaccine immunity.

Integrated analysis of miRNA-mRNA expression of newly emerging swine H3N2 influenza virus cross-species infection with tree shrews

BACKGROUND

Cross-species transmission of zoonotic IAVs to humans is potentially widespread and lethal, posing a great threat to human health, and their cross-species transmission mechanism has attracted much attention. miRNAs have been shown to be involved in the regulation of IAVs infection and immunity, however, few studies have focused on the molecular mechanisms underlying miRNAs and mRNAs expression after IAVs cross-species infection.

METHODS

We used tree shrews, a close relative of primates, as a model and used RNA-Seq and bioinformatics tools to analyze the expression profiles of DEMs and DEGs in the nasal turbinate tissue at different time points after the newly emerged swine influenza A virus SW2783 cross-species infection with tree shrews, and miRNA-mRNA interaction maps were constructed and verified by RT-qPCR, miRNA transfection and luciferase reporter assay.

RESULTS

14 DEMs were screened based on functional analysis and interaction map, miR-760-3p, miR-449b-2, miR-30e-3p, and miR-429 were involved in the signal transduction process of replication and proliferation after infection, miR-324-3p, miR-1301-1, miR-103-1, miR-134-5p, miR-29a, miR-31, miR-16b, miR-34a, and miR-125b participate in negative feedback regulation of genes related to the immune function of the body to activate the antiviral immune response, and miR-106b-3p may be related to the cross-species infection potential of SW2783, and the expression level of these miRNAs varies in different days after infection.

CONCLUSIONS

The miRNA regulatory networks were constructed and 14 DEMs were identified, some of them can affect the replication and proliferation of viruses by regulating signal transduction, while others can play an antiviral role by regulating the immune response. It indicates that abnormal expression of miRNAs plays a crucial role in the regulation of cross-species IAVs infection, which lays a solid foundation for further exploration of the molecular regulatory mechanism of miRNAs in IAVs cross-species infection and anti-influenza virus targets.

Circular RNA circAKIRIN2 participates in the process of stress-induced immunosuppression affecting immune response to infectious bursal disease virus vaccine in chicken

At present, stress-induced immunosuppression is still a hidden threat that leads to immunization failure and outbreaks of poultry diseases, and causes huge economic losses to the modern poultry industry. However, the molecular mechanisms of stress-induced immunosuppression affecting viral vaccine immunity are still poorly understood. Here, we identified circAKIRIN2 as a conserved circular transcript in chicken, and explored its expression patterns in different immune states by quantitative real-time PCR (qRT-PCR), then conducted bioinformatics analysis. The results showed that circAKIRIN2 actively participated in the process of stress-induced immunosuppression affecting the immune response to infectious bursal disease virus (IBDV) vaccine. The key time points for circAKIRIN2 involving in the process were 2 day post immunization (dpi), 5 dpi, and 28 dpi, especially at the acquired immune stage. The important tissues that responded to the process included the heart, liver, and lung, all of which changed significantly. In addition, circAKIRIN2 as a competing endogenous RNA (ceRNA) sponging zinc finger and BTB domain containing 20 (ZBTB20) was a potential molecular mechanism for regulating immune functions in the process. In conclusion, circAKIRIN2 is a key regulatory factor for stress-induced immunosuppression affecting the IBDV vaccine immune response, and this study can provide a new perspective for exploring the molecular regulatory mechanisms of stress-induced immunosuppression affecting immune response.

Stress-Induced Immunosuppression Affects Immune Response to Newcastle Disease Virus Vaccine via Circulating miRNAs

Simple Summary

Circulating miRNAs play important roles in immune response and stress-induced immunosuppression, but the function and mechanism of stress-induced immunosuppression affecting the NDV vaccine immune response remain unknown. In our study, key timepoints, functions, mechanisms, and potential biomarkers of circulating miRNAs involved in immune response and immunosuppression were discovered, providing a theoretical basis for studying the roles of circulating miRNAs in immune regulation.

Abstract

Studies have shown that circulating microRNAs (miRNAs) are important players in the immune response and stress-induced immunosuppression. However, the function and mechanism of stress-induced immunosuppression affecting the immune response to the Newcastle disease virus (NDV) vaccine remain largely unknown. This study analyzed the changes of 15 NDV-related circulating miRNAs at different immune stages by qRT-PCR, aiming to explore the key timepoints, potential biomarkers, and mechanisms for the functional regulation of candidate circulating miRNAs under immunosuppressed conditions. The results showed that stress-induced immunosuppression induced differential expressions of the candidate circulating miRNAs, especially at 2 days post immunization (dpi), 14 dpi, and 28 dpi. In addition, stress-induced immunosuppression significantly affected the immune response to NDV vaccine, which was manifested by significant changes in candidate circulating miRNAs at 2 dpi, 5 dpi, and 21 dpi. The featured expressions of candidate circulating miRNAs indicated their potential application as biomarkers in immunity and immunosuppression. Bioinformatics analysis revealed that the candidate circulating miRNAs possibly regulated immune function through key targeted genes, such as Mg²⁺/Mn²⁺-dependent 1A (PPM1A) and Nemo-like kinase (NLK), in the MAPK signaling pathway. This study provides a theoretical reference for studying the function and mechanism of circulating miRNAs in immune regulation.