Systems Biology Approach to Understanding Immune Dysregulation During Newcastle Disease Virus Infection in Nigerian Poultry

This study applies a systems biology approach to comprehensively characterise the host immune response and dysregulation mechanisms during Newcastle disease virus infection in Nigerian indigenous and commercial poultry breeds, contributing an original mechanistic understanding of breed-specific disease outcomes. Newcastle disease continues to cause catastrophic losses in Nigerian poultry despite vaccination programmes, partly because the immunological basis of protection failure is not fully understood at the systems level. This study uses a multi-omics integration approach combining transcriptomics (RNA-seq), proteomics (LC-MS/MS), and metabolomics (NMR spectroscopy) applied to blood and bursal tissue from virulent NDV-challenged Nigerian indigenous chickens and Ross 308 broilers at 24, 48, 72, and 120 hours post-challenge. Network analysis using weighted gene co-expression network analysis and protein-protein interaction network construction identifies key immune regulatory hubs and pathways differentially activated in resistant versus susceptible birds. Pathway enrichment analysis uses Gene Ontology and KEGG databases. Findings reveal that Nigerian indigenous chickens mount a significantly earlier innate immune response characterised by strong type I interferon signalling activation within 24 hours, while commercial broilers show delayed and dysregulated inflammatory responses leading to cytokine storm-associated tissue damage. Ten hub genes and four metabolic pathway signatures are identified as potential biomarkers for NDV resistance. The study contributes an original systems biology model of NDV pathogenesis in Nigerian poultry and recommends the identified hub genes as targets for genomic selection for disease resistance.

Keywords: systems biology, Newcastle disease virus, immune response, transcriptomics, Nigeria.