Identification of Differential Responses of Goat PBMCs to PPRV Virulence Using a Multi-Omics Approach.

Peste des petits ruminants (PPR) is an acute transboundary infectious viral disease of small ruminants, mainly sheep and goats. Host susceptibility varies considerably depending on the PPR virus (PPRV) strain, the host species and breed. The effect of strains with different levels of virulence on the modulation of the immune system has not been thoroughly compared in an experimental setting so far.

High-Resolution Profiling of Innate Immune Responses by Porcine Dendritic Cell Subsets and .

The present study investigated the transcriptomic response of porcine dendritic cells (DC) to innate stimulation and . The aim was to identify DC subset-specialization, suitable Toll-like receptor (TLR) ligands targeting plasmacytoid DC (pDC), and the DC activation profile during highly and low virulent classical swine fever virus (CSFV, strain Eystrup and Pinar del Rio, respectively) infection, chosen as model for a virus causing a severe immunopathology. After identification of porcine conventional DC (cDC) 1, cDC2, pDC and a monocyte-derived subset in lymphoid tissues, we characterized DC activation using transcriptomics, and focused on chemokines, interferons, cytokines, as well as on co-stimulatory and inhibitory molecules.

Coinfections and their molecular consequences in the porcine respiratory tract.

Understudied, coinfections are more frequent in pig farms than single infections. In pigs, the term "Porcine Respiratory Disease Complex" (PRDC) is often used to describe coinfections involving viruses such as swine Influenza A Virus (swIAV), Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), and Porcine CircoVirus type 2 (PCV2) as well as bacteria like Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae and Bordetella bronchiseptica. The clinical outcome of the various coinfection or superinfection situations is usually assessed in the studies while in most of cases there is no clear elucidation of the fine mechanisms shaping the complex interactions occurring between microorganisms.

Differential innate immune responses induced by Mycoplasma hyopneumoniae and Mycoplasma hyorhinis in various types of antigen presenting cells.

Mycoplasma (M.) hyopneumoniae is the etiological agent of enzootic pneumonia in pigs and is closely related to M. hyorhinis, which can be isolated from the healthy mucosal surfaces of the upper respiratory tract.

Efficacy of three innovative bacterin vaccines against experimental infection with Mycoplasma hyopneumoniae.

New vaccine formulations that include novel strains of Mycoplasma hyopneumoniae and innovative adjuvants designed to induce cellular immunity could improve vaccine efficacy against this pathogen. The aim of this experimental study was to assess the efficacy of three experimental bacterin formulations based on M. hyopneumoniae field strain F7.

Systems Immunology Characterization of Novel Vaccine Formulations for Bacterins.

We characterized five different vaccine candidates and a commercial vaccine in terms of safety, immunogenicity and using a systems vaccinology approach, with the aim to select novel vaccine candidates against . Seven groups of six -free piglets were primo- and booster vaccinated with the different experimental bacterin formulations, the commercial vaccine Hyogen® as a positive control or PBS as a negative control. The experimental bacterin was formulated with cationic liposomes + c-di-AMP (Lipo_AMP), cationic liposomes + Toll-like receptor (TLR) 2/1, TLR7, and TLR9 ligands (TLR ligands; Lipo_TLR), micro-particles + TLR ligands (PLGA_TLR), squalene-in-water emulsion + TLR ligands (SWE_TLR), or DDA:TDB liposomes (Lipo_DDA:TDB).

Erratum: Author Correction: System immunology-based identification of blood transcriptional modules correlating to antibody responses in sheep.

[This corrects the article DOI: 10.1038/s41541-018-0078-0.].

System immunology-based identification of blood transcriptional modules correlating to antibody responses in sheep.

Inactivated vaccines lack immunogenicity and therefore require potent adjuvants. To understand the in vivo effects of adjuvants, we used a system immunology-based analysis of ovine blood transcriptional modules (BTMs) to dissect innate immune responses relating to either antibody or haptoglobin levels. Using inactivated foot-and-mouth disease virus as an antigen, we compared non-adjuvanted to liposomal-formulated vaccines complemented or not with TLR4 and TLR7 ligands.

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): CD14CD4CD172aCADM1) and conventional DCs (cDCs), being further divided into a cDC1 (CD14CD4CD172aCADM1) and a cDC2 (CD14CD4CD172aCADM1) 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.

Phenotypic and functional modulations of porcine macrophages by interferons and interleukin-4.

Considering that macrophage functions are strongly impacted by the local tissue environment and the type of immune response, the aim of this study was to carefully set the methodological baseline for phenotype and functions of polarized porcine monocyte-derived macrophages. To this end, macrophages were generated in autologous serum alone or with colony-stimulating factor (CSF)-1 or CSF-2, and subsequently polarized with interferon (IFN)γ, interleukin-4 or IFNβ. IFNγ promoted expression of MHC class I, MHC class II, CD11a, and CD40 as well as LPS-induced IL-6 and IL-12.

Characterization and Transcriptomic Analysis of Porcine Blood Conventional and Plasmacytoid Dendritic Cells Reveals Striking Species-Specific Differences.

Porcine dendritic cells (DCs) are relatively well characterized, but a clear-cut identification of all DC subsets combined with full transcriptional profiling was lacking, preventing an unbiased insight into the functional specializations of DC subsets. Using a large panel of Abs in multicolor flow cytometry, cell sorting, and RNA sequencing we identified and characterized the porcine equivalent of conventional DCs (cDC) 1 and cDC2 as well as plasmacytoid DCs (pDCs) in the peripheral blood of pigs. We demonstrate that cDC1 are CD135CD14CD172aCADM1wCD11R1 cells, cDC2 are CD135CD14CD172aCADM1CD115wCD11R1CD1 cells and pDCs are CD4CD135CD172aCD123CD303 cells.

Sensing of Porcine Reproductive and Respiratory Syndrome Virus-Infected Macrophages by Plasmacytoid Dendritic Cells.

Porcine reproductive and respiratory syndrome virus (PRRSV) represents a macrophage (MØ)-tropic virus which is unable to induce interferon (IFN) type I in its target cells. Nevertheless, infected pigs show a short but prominent systemic IFN alpha (IFN-α) response. A possible explanation for this discrepancy is the ability of plasmacytoid dendritic cells (pDC) to produce IFN-α in response to free PRRSV virions, independent of infection.

Transcriptional Analysis of PRRSV-Infected Porcine Dendritic Cell Response to Streptococcus suis Infection Reveals Up-Regulation of Inflammatory-Related Genes Expression.

The porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important swine pathogens and often serves as an entry door for other viral or bacterial pathogens, of which Streptococcus suis is one of the most common. Pre-infection with PRRSV leads to exacerbated disease caused by S. suis infection.

A Broad RNA Virus Survey Reveals Both miRNA Dependence and Functional Sequestration.

Small non-coding RNAs have emerged as key modulators of viral infection. However, with the exception of hepatitis C virus, which requires the liver-specific microRNA (miRNA)-122, the interactions of RNA viruses with host miRNAs remain poorly characterized. Here, we used crosslinking immunoprecipitation (CLIP) of the Argonaute (AGO) proteins to characterize strengths and specificities of miRNA interactions in the context of 15 different RNA virus infections, including several clinically relevant pathogens.

CCL20 Displays Antimicrobial Activity Against Cryptosporidium parvum, but Its Expression Is Reduced During Infection in the Intestine of Neonatal Mice.

CCL20 is a chemokine with antimicrobial activity. We investigated its expression and role during neonatal cryptosporidiosis, a worldwide protozoan enteric disease leading to severe diarrhea. Surprisingly, during infection by Cryptosporidium parvum, CCL20 production by the intestine of neonatal mice is reduced by a mechanism independent both of the enteric flora and of interferon γ, a key cytokine for the resolution of this infection.

Comparative dendritic cell biology of veterinary mammals.

Dendritic cells (DC) have a main function in innate immunity in that they sense infections and environmental antigens at the skin and mucosal surfaces and thereby critically influence decisions about immune activation or tolerance. As professional antigen-presenting cells, they are essential for induction of adaptive immune responses. Consequently, knowledge on this cell type is required to understand the immune systems of veterinary mammals, including cattle, sheep, pigs, dogs, cats, and horses.

Antibody response specific to the capsular polysaccharide is impaired in Streptococcus suis serotype 2-infected animals.

Streptococcus suis serotype 2 is an extracellular encapsulated bacterium that causes severe septicemia and meningitis in swine and humans. Albeit crucial in the fight against encapsulated bacteria, the nature of the capsular polysaccharide (CPS)-specific antibody (Ab) response during S. suis type 2 infection is unknown.

Porcine neonatal blood dendritic cells, but not monocytes, are more responsive to TLRs stimulation than their adult counterparts.

The neonatal immune system is often considered as immature or impaired compared to the adult immune system. This higher susceptibility to infections is partly due to the skewing of the neonatal immune response towards a Th2 response. Activation and maturation of dendritic cells (DCs) play an important role in shaping the immune response, therefore, DCs are a target of choice for the development of efficient and protective vaccine formulations able to redirect the neonatal immune response to a protective Th1 response.

Stability of expression of reference genes in porcine peripheral blood mononuclear and dendritic cells.

Real-time quantitative PCR (RT-qPCR) is a critical tool used to evaluate changes in gene expression. The precision of this tool is reliant upon the selection of reference genes whose expression remains unaltered in culture conditions and following stimulation. Stably expressed reference genes are used to normalize data so observed changes in expression are not due to artifacts but rather reflect physiological changes.

Combination adjuvants: the next generation of adjuvants?

Adjuvants are critical components of many vaccines. The majority of existing vaccines contain a single adjuvant. Owing to their inherent limitations, no single adjuvant is capable of inducing all the protective immune responses required in the many different vaccines.

Differential activation and maturation of two porcine DC populations following TLR ligand stimulation.

Dendritic cells (DCs) are at the interface of innate and adaptive immune responses. Once activated via triggering of their pattern recognition receptors (PRRs), they acquire a mature state and migrate to the lymph nodes where they activate T cells and direct the immune response. Compounds that trigger PRRs are potential vaccine adjuvants, hence in this study we stimulated two porcine DC populations, namely monocyte-derived DCs (MoDCs) and blood DCs (BDCs), with a broad range of toll-like receptors (TLRs) ligands and assessed the activation/maturation state of these porcine DCs.

A comparison between isolated blood dendritic cells and monocyte-derived dendritic cells in pigs.

Various dendritic cell (DC) populations exist that differ in phenotype and ability to present antigen to T cells. For example, plasmacytoid DCs (pDCs) are less potent T cell activators compared with conventional DCs (cDCs). Here, we compared porcine blood DCs (BDCs), containing pDCs and cDCs, and monocyte-derived DCs (MoDC), consisting of cDCs, in their phenotype, ability to uptake antigen, activation and maturation and their ability to present antigen to autologous T cells.

Early immune response following Salmonella enterica subspecies enterica serovar Typhimurium infection in porcine jejunal gut loops.

Salmonella enterica subspecies enterica serovar Typhimurium, commonly called S. Typhimurium, can cause intestinal infections in humans and various animal species such as swine. To analyze the host response to Salmonella infection in the pig we used an in vivo gut loop model, which allows the analysis of multiple immune responses within the same animal.

CCR5 is involved in controlling the early stage of Cryptosporidium parvum infection in neonates but is dispensable for parasite elimination.

Chemokines play a critical role in immune cell trafficking and the transition from an innate to an acquired immune response. We analyzed host response in neonatal mice deficient in chemokine receptor CCR5 following infection with the intracellular protozoan parasite Cryptosporidium parvum. CCR5 neonatal mice had a higher parasite burden at the early stage of infection but eliminated the parasite as efficiently as their wild-type counterparts.

Involvement of intestinal epithelial cells in dendritic cell recruitment during C. parvum infection.

Dendritic cells (DCs) play a key role in activating and orientating immune responses. Little is currently known about DC recruitment during Cryptosporidium parvum infection. In the intestine, epithelial cells act as sensors, providing the first signals in response to infection by enteric pathogens.