Conserved B cell signaling, activation, and differentiation in porcine jejunal and ileal Peyer’s patches despite distinct immune landscapes

Authors: WIARDA, JAYNE - Oak Ridge Institute For Science And Education (ORISE); Shircliff, Adrienne; Stasko, Judith; SIVASANKARAN, SATHESH - Iowa State University; Ackermann, Mark; Loving, Crystal

Submitted to: Mucosal Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Pigs are a major global food source. Consequently, understanding and promoting pig health is important for global food security. The gut is where the majority of the body’s immune cells reside and has large impacts on overall pig health and disease susceptibility, yet how immune cells function at different locations throughout the gut can vary and lead to different health outcomes. Therefore, it is critical to understand similarities and differences of immune cells across different locations of the gut in pigs. Immune cells at two different locations within the pig gut were studied to determine similarities and differences in regards to immune cell compositions, cell functions, interactions with other cells, and processes that activate cells. The percentage of different immune cell types varied across different intestinal locations, as did inferred cellular functions. Despite differences in immune compositions and functions, similar interactions between different cell types were found across both intestinal locations, as were similar processes that activated cells to provide immune responses. Overall, the work serves as a benchmark for understanding gut immunity in pigs, including similarities and differences across different intestinal locations. Data will be made publicly available to promote this work as a resource for further scientific exploration for advancement of animal health, food safety/security, and biomedical health.

Technical Abstract: Peyer’s patches (PPs) are B cell-rich sites of immune induction in the intestine, yet B cell signaling, activation, and differentiation associated with PPs are poorly defined. Single-cell and spatial transcriptomics were completed to study B cells from porcine jejunum and ileum containing PPs. Intestinal locations had distinct immune landscapes, including more follicular B cells in ileum and increased MHC-II-encoding gene expression in jejunal, non-resting B cells. Despite distinct landscapes, conserved B cell dynamics were detected across intestinal locations. B cell signaling to CD4+ macrophages that are putative phagocytic, cytotoxic, effector cells and deduced routes of B cell activation/differentiation, including resting B cells migrating into follicles to replicate/divide or differentiate into antibody-secreting cells residing in intestinal crypts, were conserved across locations. A six-biomarker panel recapitulated transcriptomics results of B cell phenotypes, frequencies, and spatial locations via ex vivo/in situ staining of gene/protein targets. Findings convey conserved B cell signaling, activation, and differentiation, despite location-specific immune environments in jejunum and ileum containing PPs. Results establish a benchmark of B cell dynamics for understanding intestinal immune induction important to promoting gut and overall health.