Oral administration of a select mixture of Bacillus probiotics generates Tr1 cells in weaned F4ab/acR- pigs challenged with an F4+ ETEC/VTEC/EPEC strain

• Published in: Veterinary research (Paris) Vol. 46; no. 1; p. 95
• Main Authors: Zhou, Dong, Zhu, Yao-Hong, Zhang, Wei, Wang, Meng-Ling, Fan, Wen-Yi, Song, Dan, Yang, Gui-Yan, Jensen, Bent Borg, Wang, Jiu-Feng
• Format: Journal Article
• Language: English
• Published: England BioMed Central 17.09.2015
• Subjects: Administration, Oral; Animals; Bacillus - chemistry; Enteropathogenic Escherichia coli - physiology; Enterotoxigenic Escherichia coli - physiology; Escherichia coli - physiology; Escherichia coli Infections - immunology; Escherichia coli Infections - microbiology; Escherichia coli Infections - therapy; Escherichia coli Infections - veterinary; Female; Intestine, Small - immunology; Life Sciences; Male; Medical research; Probiotics; Probiotics - administration & dosage; Shiga-Toxigenic Escherichia coli - physiology; Swine; Swine Diseases - immunology; Swine Diseases - microbiology; Swine Diseases - therapy; T-Lymphocytes, Regulatory - immunology; T-Lymphocytes, Regulatory - metabolism; Veterinary medicine; Weaning
• ISSN: 1297-9716; 0928-4249; 1297-9716
• DOI: 10.1186/s13567-015-0223-y

Although breeding of F4 receptor - negative (F4R(-)) pigs may prevent post-weaning diarrhea, the underlying immunity is poorly understood. Here, various doses of a Bacillus licheniformis and Bacillus subtilis mixture (BLS-mix) were orally administered to F4ab/acR(-) pigs for 1 week before F4 (K88) - positive ETEC/VTEC/EPEC challenge. Administration of BLS-mix increased the percentage of Foxp3(-)IL-10(+) T cells but not of Foxp3(+)IL-10(+) regulatory T (Treg) cells among peripheral blood CD4(+) T cells. A low dose of BLS-mix feeding resulted in increased the expression of IL-6, TNF-α, IL-10, and the transcription factors Foxp3 and T-bet mRNAs in the jejunum. Administration of either a low or high dose BLS-mix also led to an increase in the percentage of CD4(+)Foxp3(+) Treg cells among intraepithelial lymphocytes and CD4(+)IL-10(+) T cells in the small intestinal Peyer's patches and the lamina propria of F4ab/acR(-) pigs following F4(+) ETEC/VTEC/EPEC challenge. The increased number of IL-10-producing CD4(+) T cells was attributed to an increase in the proportion of Foxp3(-)IL-10(+) Treg cells rather than Foxp3(+)IL-10(+) Treg cells. Our data indicate that oral administration of BLS-mix to newly weaned F4ab/acR(-) pigs ameliorates enteritis in an F4(+) ETEC/VTEC/EPEC model; however, induction of IL-10-producing Foxp3(-) Treg cells by BLS-mix administration cannot account for the protection of newly weaned F4ab/acR(-) pigs from F4(+) ETEC/VTEC/EPEC infection, and that excessive generation of CD4(+)IL-10(+) T cells following consumption of BLS-mix during episodes of intestinal inflammation that is caused by enteric pathogens might prohibit clearance of the pathogen. Select probiotic mixtures may allow for tailoring strategies to prevent infectious diseases.