Commensal microbiota modulates phenotypic characteristics and gene expression in piglet Peyer’s patches

Abstract

The gastrointestinal tract contains a complex microbial community. Peyer’s patches (PPs) play an important role in inducing mucosal immune responses in the gastrointestinal tract. However, little is known about the effect of commensal microbiota on the host’s PPs. Here, we analyzed the phenotypic-to-transcriptome changes in the intestine PPs of specific pathogen-free (SPF) and germ-free (GF) piglets (fed in an environment with and without commensal microbiota, respectively) to elucidate the role of commensal microbiota in host intestine mucosal immunity. Analyses of anatomical and histological characteristics showed that commensal microbiota deficiency led to PP hypoplasia, especially regarding B and T cells. A total of 12,444 mRNAs were expressed in 12 libraries; 2,156 and 425 differentially expressed (DE) mRNAs were detected in the jejunal PP (JPP) and ileal PP (IPP), respectively (SPF vs. GF). The shared DE mRNAs of the JPP and IPP were mainly involved in basic physiological and metabolic processes, while the specific DE mRNAs were enriched in regulating immune cells in the JPP and microbial responses and cellular immunity in the IPP. Commensal microbiota significantly modulated the expression of genes related to B-cell functions, including activation, proliferation, differentiation, apoptosis, receptor signaling, germinal center formation, and IgA isotype class switching, particularly in the JPP. TLR4 pathway-related genes were induced in response to microbial colonization and in LPS/SCFA-treated B cells. We also detected 69 and 21 DE lncRNAs in the JPP and IPP, respectively, and four one-to-one lncRNA-mRNA pairs were identified. These findings might represent key regulatory axes for host intestine mucosal immunity development during microbial colonization. Overall, the findings of this study revealed that commensal microbiota modulated phenotypic characteristics and gene expression in the piglet intestine PPs and underscored the importance of early microbial colonization for host mucosal immunity development.

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

“…Distinctions between porcine jejunal and ileal PPs included greater B cell abundance with larger, more prominent follicles in ileal PPs and greater T cell abundance with larger IFZs/PFZs in jejunal PPs, similar to previous findings 56- 61 . Previous studies have also compared transcriptomic profiles of porcine jejunal and ileal PPs using traditional, or "bulk", RNA sequencing methods to capture general interpretations of the immune landscapes at different intestinal locations containing PPs 62,63 , but results presented herein further expand knowledge. Novel findings include highly-resolved cellular and spatial insights, leading to discovery of different B lineage cell type compositions and gene expression across intestinal locations, including greater follicle-associated B cell abundance in ileum and higher MHC-IIrelated gene expression of non-resting B cells in jejunum.…”

Effects of the commensal microbiota on spleen and mesenteric lymph node immune function: investigation in a germ-free piglet model

“…All animals were fed at the experimental base of Chongqing Academy of Animal Sciences. The preparation of Bama strain GF piglets and GF environment testing were based on Zhang et al (2023) . The GF piglets were reared in sterile isolators under GF conditions and were handfed Co60 γ-irradiated sterile 4.8%-fat cow milk powder diluted with sterile water (Anyou Group, Jiangsu, China).…”

“…B- and T-cell distributions were examined by immunohistochemistry (IHC) staining using CD3 + and CD20 + pig-specific makers, respectively. IHC staining was performed following the method described by Zhang et al (2023) . Semi-quantitative evaluation of IHC staining using an Image-Pro Plus (version 6.0) followed the method introduced in a previous report ( Wang et al, 2009 ).…”

“…The cells were divided into five treatment groups: control (treated with Phosphate Buffered Saline) (Servicebio, China), SCFAs (acetic acid, propionic acid, and butyric acid), lipopolysaccharide (LPS) (Beyotime, China), and concanavalin A (ConA) (Beyotime, China). SCFAs concentrations were based on Zhang et al (2023) , LPS and ConA concentrations were based on Cho et al (2023) .…”

Diversity and host interaction of the gut microbiota in specific pathogen-free pigs

“…Six female piglets were randomly selected as subjects for this study (Figure 1). These piglets were reared following the SPF pig model construction and rearing standards (Zhang et al, 2023) on the standardized aseptic pig breeding platform at the Institute of Biotechnology, Chongqing Academy of Animal Science. In summary, SPF piglets were fed with sterilized milk powder (0-21 days) and pelleted feed (21-42 days) diluted 1:4 with sterile water and sterilized using Co60 γ radiation.…”