Profiling cell dynamic changes of goat peripheral blood mononuclear cells after Pasteurella multocida infection with single-cell transcriptomics and histopathology.

Abstract

Peripheral blood mononuclear cells (PBMCs) represent a critical component of the immune system, orchestrating both cellular and humoral responses while maintaining immunological homeostasis. This study investigates the PBMC immune response to Pasteurella multocida (P. multocida) infection in goats using single-cell RNA sequencing (scRNA-seq). PBMCs from goats before and after P. multocida infection were used for scRNA-seq), and pathological examinations were performed on different tissues of the infected hosts. Results demonstrated that recombinase polymerase amplification-lateral flow dipstick (RPA-LFD) detected P. multocida in peripheral blood and lungs, with histopathology confirming lesions. A total of 42 615 cells were annotated as nine cell subgroups, revealed dynamic alterations in immune cell populations, including significant increase in B cells and monocytes alongside decreased T cells and megakaryocytes post-infection. Further analysis identified 48 differentially expressed genes consistently modulated across comparison groups, with significant enrichment in immune-related Gene Ontology (GO) terms, as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways including IL-17 signaling pathway and cytokine-cytokine receptor interactions. Pseudotime trajectory uncovered four B cell and two T cell differentiation lineages. Inter-cell communication exhibited enhanced activity post-infection. Integration with RNA-seq data revealed key genes (IL1R2, RBM34, EDEM3, and MZB1) potentially critical in early infection. These findings substantially advance the understanding of PBMCs-mediated immune responses during the early stage of P. multocida infection in goats, identifying key genes and immune pathways. The study not only provides valuable insights into goat immunology but also establishes a foundation for developing improved diagnostic tools and targeted therapeutic interventions against this economically significant pathogen.