T-independent B-cell effect of agents associated with swine grower-finisher diarrhea

• Published in: Veterinary research communications Vol. 48; no. 2; pp. 991 - 1001
• Main Authors: Barbosa, Jéssica A., Yang, Christine T., Finatto, Arthur N., Cantarelli, Vinícius S., de Oliveira Costa, Matheus
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2024; Springer Nature B.V
• Subjects: Animals; Antigens; Biomedical and Life Sciences; Brachyspira; CD19 antigen; Cell activation; Cell viability; Colitis; Diarrhea; Diarrhea - pathology; Diarrhea - veterinary; Dysentery; Escherichia coli; Gram-Negative Bacterial Infections - pathology; Gram-Negative Bacterial Infections - veterinary; Hogs; Inoculum; Kinases; Life Sciences; Lipopolysaccharides; Lipopolysaccharides - toxicity; Lymphocytes B; Lymphoma; Lyn protein; Reverse transcription; Salmonellosis; Swine; Swine Diseases; Swine dysentery; Syk protein; Transcription activation; Tumor necrosis factor-TNF; Tumor necrosis factor-α; Veterinary Medicine/Veterinary Science; Zoology; Swine dysentery; Gene pathways; Salmonellosis; Colitis; Humoral immunomodulation
• ISSN: 0165-7380; 1573-7446
• DOI: 10.1007/s11259-023-10257-0

Swine dysentery, spirochetal colitis, and salmonellosis are production-limiting enteric diseases of global importance to the swine industry. Despite decades of efforts, mitigation of these diseases still relies on antibiotic therapy. A common knowledge gap among the 3 agents is the early B-cell response to infection in pigs. Thus, this study aimed to characterize the porcine B-cell response to Brachyspira hyodysenteriae, Brachyspira hampsonii (virulent and avirulent strains), Brachyspira pilosicoli , and Salmonella Typhimurium, the agents of the syndromes mentioned above. Immortalized porcine B-cell line derived from a crossbred pig with lymphoma were co-incubated for 8 h with each pathogen, as well as E. coli lipopolysaccharide (LPS) and a sham-inoculum (n = 3/treatment). B-cell viability following treatments was evaluated using trypan blue, and the expression levels of B-cell activation-related genes was profiled using reverse transcription quantitative PCR. Only S. Typhimurium and LPS led to increased B-cell mortality. B. pilosicoli downregulated B-lymphocyte antigen (CD19), spleen associated tyrosine Kinase (syk), tyrosine-protein kinase (lyn), and Tumour Necrosis Factor alpha (TNF-α), and elicited no change in immunoglobulin-associated beta (CD79b) and swine leukocyte antigen class II (SLA-DRA) expression levels, when compared to the sham-inoculated group. In contrast, all other treatments significantly upregulated CD79b and stimulated responses in other B-cell downstream genes. These findings suggest that B. pilosicoli does not elicit an immediate T-independent B-cell response, nor does it trigger antigen-presenting mechanisms. All other agents activated at least one trigger within the T-independent pathways, as well as peptide antigen presenting mechanisms. Future research is warranted to verify these findings in vivo.