Lymphocytes can heavily influence intestinal health, but resolving intestinal lymphocyte function is challenging, as the intestine contains a vastly heterogeneous mixture of cells. Pigs are an advantageous biomedical model, but deeper understanding of intestinal lymphocytes is warranted to improve model utility. Twenty-six cell types were identified in porcine ileum by single-cell RNA sequencing and further compared to cells in human and murine ileum. Though general consensus of cell subsets across species was revealed, some porcine-specific lymphocyte subsets were identified. Differential tissue dissection and in-situ analyses conferred spatial context, revealing similar locations of lymphocyte subsets in Peyer’s patches and epithelium in pig-to-human comparisons. Like humans, activated and effector lymphocytes were abundant in ileum but not periphery of pigs, suggesting tissue-specific and/or activation-associated gene expression. Gene signatures for peripheral and ileal innate lymphoid cells (ILCs) newly discovered in pigs were defined and highlighted similarities to human ILCs. Overall, we reveal novel lymphocyte subsets in pigs and highlight utility of pigs for intestinal research applications.

Authors: Jayne E. Wiarda, Julian M. Trachsel, Sathesh K. Sivasankaran, Christopher K. Tuggle, Crystal L. Loving

Abbreviations in dataset: ab (alpha beta); ASC (antibody-secreting cell); gd (gamma delta); ILC (innate lymphoid cell); IPP (ileum with Peyer's patches); NoPP (ileum without Peyer's patches); X2I (ileum whole cross section [containing regions both with and without Peyer's patches])

Also see provided links to data analysis code and manuscript preprint.