Proteomic Characterisation of Acute-Phase Response Proteins in Blood Serum of Cattle Experimentally Infected with Contagious Bovine Pleuropneumonia in Kaduna State, North West Nigeria

Contagious bovine pleuropneumonia caused by Mycoplasma mycoides subspecies mycoides is an economically devastating respiratory disease in sub-Saharan African cattle populations, and a comprehensive proteomic characterisation of the acute-phase serum response during infection has not been accomplished in Nigerian cattle. This doctoral study applied two-dimensional differential gel electrophoresis combined with liquid chromatography-tandem mass spectrometry to characterise the differential serum proteome of Zebu cattle at defined intervals following experimental infection with M. mycoides in a biosecurity level-three facility in Kaduna State, North West Nigeria. Twenty Zebu cattle were experimentally infected by intratracheal inoculation, with ten serving as sham-inoculated controls. Serum samples collected at days zero, three, seven, fourteen, and twenty-one post-infection were subjected to immunodepletion of albumin and IgG prior to proteomic analysis. Seventy-eight differentially expressed proteins were identified, of which thirty-two were novel, not previously reported in bovine experimental infection studies. Upregulated proteins included several complement factors, serum amyloid A isoforms, and a previously uncharacterised glycoprotein identified as structurally homologous to human inter-alpha-trypsin inhibitor. Downregulated proteins included apolipoproteins and retinol-binding protein. Pathway enrichment analysis confirmed complement activation, lipid transport disruption, and coagulation cascade modulation as dominant pathogenic themes. These proteomic contributions advance the mechanistic understanding of contagious bovine pleuropneumonia pathogenesis in Nigerian cattle and provide candidate biomarkers for improved disease diagnostics. Keywords: contagious bovine pleuropneumonia, serum proteomics, acute-phase proteins, mass spectrometry, Kaduna.