CpG oligodeoxynucleotide protect neonatal piglets from challenge with the enterotoxigenic E. coli

LACpG10-HL Functions Effectively in Antibiotic-Free and Healthy Husbandry by Improving the Innate Immunity

Antibiotics are broadly restricted in modern husbandry farming, necessitating the need for efficient and low-cost immunomodulatory preparations in antibiotic-free and healthful farming. As is known to all, CpG oligonucleotides (CpG-ODNs, an effective innate immunostimulatory agent) recognized by TLR9 in mammals (while TLR21 in avians) could collaborate with some united agent to induce stronger immune responses, but the cost is prohibitively expensive for farmers. Here, considering the coordination between TLR2 and TLR9/TLR21, we firstly proposed the idea that the well-fermented Lactococcus lactis could be utilized as a CpG-plasmid carrier (LACpG10) to enhance the host’s innate immunity against pathogenic invasion. In the present study, after obtaining LACpG10-HL from homogenized and lyophilized recombinant strain LACpG10, we treated primary chicken lymphocytes, two cell lines (HD11 and IPEC-J2), and chickens with LACpG10-HL, CpG plasmids (pNZ8148-CpG10), and other stimulants, and respectively confirmed the effects by conducting qRT-PCR, bacterial infection assays, and a zoological experiment. Our data showed that LACpG10-HL could induce excellent innate immunity by regulating autophagy reactions, cytokine expression, and motivating PRRs. Interestingly, despite having no direct antiseptic effect, LACpG10-HL improved the antibacterial capacities of lymphocytes and enterocytes at the first line of defense. Most importantly, water-supplied LACpG10-HL treatment reduced the average adverse event rates, demonstrating that LACpG10-HL maintained its excellent immunostimulatory and protective properties under farming conditions. Our research not only contributes to revealing the satisfactory effects of LACpG10-HL but also sheds new light on a cost-effective solution with optimal immune effects in green, antibiotic-free, and healthful husbandry farming.

Neonatal porcine blood derived dendritic cell subsets show activation after TLR2 or TLR9 stimulation

The present study investigated the innate immune response in vitro to determine porcine neonate responses with Toll-like receptor (TLR)2 ligand (Pam3Cys) or TLR9 ligand (CpG) and compared these with adults. We identified the same phenotypically defined dendritic cell (DC) subsets and DC proportions in porcine neonate and adult blood by flow cytometry, which were plasmacytoid DCs (pDCs): CD14^-CD4⁺CD172a⁺CADM1^-) and conventional DCs (cDCs), being further divided into a cDC1 (CD14^-CD4^-CD172a^lowCADM1⁺) and a cDC2 (CD14^-CD4^-CD172a⁺CADM1⁺) subset. With neonatal cells, the TLR2 ligand induced a stronger TNF expression in monocytes and pDCs, and a stronger CD80/86 upregulation in cDC1, when compared to adult cells. Furthermore, in neonatal mononuclear cells TLR9 ligand was more potent at inducing IL12p40 mRNA expression. These results indicate clear responses of porcine neonatal antigen presenting cells after TLR2 and TLR9 stimulation, suggesting that corresponding ligands could be promising candidates for neonatal adjuvant application.

Immunological effects of different types of synthetic CpG oligodeoxynucleotides on porcine cells

The agonists of toll-like receptor 9, synthetic oligodeoxynucleotides (ODNs) containing CpG sequences, stimulate innate and adaptive immune responses in humans and a variety of animal species.

In ovo delivery of CpG DNA reduces avian infectious laryngotracheitis virus induced mortality and morbidity

Endosomal toll-like receptor-21 and -9 sense CpG DNA activating production of pro-inflammatory mediators with antimicrobial effects. Here, we investigated the induction of antiviral response of in ovo delivered CpG DNA against infectious laryngotracheitis virus (ILTV) infection. We found that in ovo delivered CpG DNA significantly reduces ILTV infection pre-hatch correlating with the expression of IL-1β and increase of macrophages in lungs. As assessed in vitro, CpG DNA stimulated avian macrophages could be a potential source of IL-1β and other pro-inflammatory mediators. Since we also found that in ovo CpG DNA delivery maintains increased macrophages in the lungs post-hatch, we infected the chickens on the day of hatch with ILTV. We found that in ovo delivered CpG DNA significantly reduces mortality and morbidity resulting from ILTV infection encountered post-hatch. Thus, CpG DNA can be a candidate innate immune stimulant worthy of further investigation for the control of ILTV infection in chickens.