Non-Primate Monocytes - CD14, CD16 - Ziegler-Heitbrock

Single-cell transcriptomic and chromatin accessibility atlas of peripheral blood mononuclear cells reveals immune cell heterogeneity and breed-specific characteristics in Duroc and Meishan pigs.

Abstract

BACKGROUND: Pig is an important model for biomedical studies, yet the immune cell heterogeneity, the subtle relationship between immune cells and the inter-breed immune variation in pigs remains poorly characterized. Here, we generate single-cell transcriptomes for the Peripheral Blood Mononuclear Cells (PBMCs) of two pig breeds with distinct immune traits including Duroc and Meishan pigs – with the latter have better immune capacity. RESULTS: Dozens of cell types are annotated, with γδ T lymphocytes making up one-fifth of all PBMCs. A list of putative novel markers is identified in each cell type, such as GATA3, SYTL3 and C9H1orf186 which are enriched in γδ T lymphocytes. The cellular composition and immune gene expression abundance are compared across breeds, showing that Meishan pigs have higher proportion of monocytes and their monocytes have enhanced expression of immune-related genes. Re-clustering analysis further identified the sub-populations of T, B and monocytes, with their inter-breed differences further characterized. We also generate single-cell chromatin maps for PBMCs of Duroc pigs and identify a list of transcription factors associated with each immune lineage. Comparison with human data demonstrates that while most cell populations and the corresponding markers match between pig and human, CD4+CD8+ DPTCs and γδ T cells are absent in human and one monocyte subset are absent in pigs. CONCLUSIONS: Overall, the present study examined the transcription levels and constructed the single-cell maps of blood immune cells between Duroc and Meishan pigs, which revealed the heterogeneity of immune cells in pigs and their differential characteristics among Duroc and Meishan pigs. This observation would be valuable for better understanding of the immune heterogeneity and immune traits in pigs