Preliminary Volumetric Calculation of the Mucosal Surface in the Nares of Lambs Using a Segmentation of Computed Tomographic Images.

Intranasal vaccinations are becoming more important in both human and animal medicine to generate a localized IgA immune response not seen with parenteral vaccinations. This localized IgA response is more effective at reducing pathogen load on the mucosal surface of a potential host. One prerequisite for a successful nasal vaccination is the need to understand the distribution pattern of the nebulized vaccine, which requires an understanding the volume of the nares as well as the mucosal surface area. The exact mucosal surface area of ruminant nares has not yet been investigated. The aim of this concept study is to provide a detailed breakdown of a new method of volumetric rendering that can be used to calculate the volume and mucosal surface area of ruminant nares from computed tomographic images. The program Seg 3D was used to perform semi-automatic segmentation of a CT scan of a 9-month-old lamb head. Threshold segmentation and manual segmentation were used in combination to select the lamb's nasal cavity. The segmentation process yielded a volumetric rendering that was used to calculate the surface area and volume of the lamb's nasal cavity, with the segmentation process was repeated for each individual side of the lamb's nares. The surface area of the mucosal surface of each nostril is approximately 448 cm2, and the volume is approximately 45 cm3. The methodology described in this study successfully calculated the volume and surface area of a lamb's nares using volumetric rendering.

Short communication: Pegbovigrastim treatment in vivo does not affect granulocyte ability to migrate to endometrial cells and kill bacteria in vitro in healthy cows.

In periparturient dairy cows, immune suppression, resulting in decreased neutrophil numbers and function, leads to increased susceptibility to postpartum conditions such as mastitis, retained placenta, and metritis. Administration of polyethylene glycol-conjugated bovine granulocyte colony stimulating factor (pegbovigrastim, Imrestor; Elanco Animal Health, Greenfield, IN) 7 d before and within 24 h of calving, effectively improves granulocyte production and function in vivo as well as in milk. A recently developed coculture assay was adapted for use with endometrial epithelial cells to assess the effects of pegbovigrastim application on directed granulocyte migration and bactericidal activity in vitro on a per-cell basis in endometrial cell cultures. Granulocytes from treated and untreated periparturient cows (6 and 5 per group, respectively) were evaluated for their ability to migrate to and kill bacteria after treatment, in context of the infected endometrium. We hypothesized that in addition to increasing the absolute concentration of circulating neutrophil granulocytes, pegbovigrastim treatment in vivo alters the ability of granulocytes to migrate to endometrial cells in vitro. The results clearly show a marked increase in the total concentration of granulocytes and monocytes between the 2 treatment groups as early as 2 d after the first injection, and this increased between the samples taken 2 d after calving. No migratory or killing differences were identified between granulocytes of both groups, suggesting that pegbovigrastim-induced granulocytes were as effective as non-induced cells. This may also be due to the absence of negative energy balance in the study animals and leads us to conclude that the positive effects seen in vivo are most likely based on the larger number of granulocytes present rather than a direct effect of pegbovigrastim treatment on the functionality of cells for the parameters tested in this study.

Retinoprotective Effects of TAT-Bound Vasoactive Intestinal Peptide and Pituitary Adenylate Cyclase Activating Polypeptide.

Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) belong to the same peptide family and exert a variety of biological functions. Both PACAP and VIP have protective effects in several tissues. While PACAP is known to be a stronger retinoprotective peptide, VIP has very potent anti-inflammatory effects. The need for a non-invasive therapeutic approach has emerged and PACAP has been shown to be retinoprotective when administered in the form of eye drops as well. The cell penetrating peptide TAT is composed of 11 amino acids and tagging of TAT at the C-terminus of neuropeptides PACAP/VIP can enhance the traversing ability of the peptides through the biological barriers. We hypothesized that TAT-bound PACAP and VIP could be more effective in exerting retinoprotective effects when given in eye drops, by increasing the traversing efficacy and enhancing the activation of the PAC1 receptor. Rats were subjected to bilateral carotid artery occlusion (BCCAO), and retinas were processed for histological analysis 14 days later. The efficiency of the TAT-bound peptides to reach the retina was assessed as well as their cAMP increasing ability. Our present study provides evidence, for the first time, that topically administered PACAP and VIP derivatives (PACAP-TAT and VIP-TAT) attenuate ischemic retinal degeneration via the PAC1 receptor presumably due to a multifactorial protective mechanism.

Vaccination of calves with yeast- and bacterial-expressed paramyosin from the bovine lungworm Dictyocaulus viviparus.

Previously, vaccination of cattle with Escherichia coli-expressed bovine lungworm paramyosin (EcPMY) adjuvanted with Quil A resulted in considerable reduction in worm burden and larvae shedding (Strube et al., 2015). To further evaluate the protective potential of PMY, cattle vaccination trials were performed using either E. coli- (EcPMY) or Pichia pastoris-expressed PMY (PpPMY) with different adjuvants (Matrix-Q(™) or Quil A). Combinations EcPMY+Matrix-Q(™) (trial 1), PpPMY+Matrix-Q(™) (trial 2) and PpPMY+Quil A (trial 3) were tested against challenge infections with 2000 Dictyocaulus viviparus larvae. Even though GM worm burden and larvae shedding was lower in almost all vaccinated groups, there were high variations between individuals hampering significant differences. However, in all vaccinated groups, lungworms were significantly shorter compared with those in controls. In vitro stimulation of peripheral blood mononuclear cells (PBMC) with recombinant (r)PMY revealed no significant proliferation following vaccinations or challenge infection. All vaccinated cattle showed a significant rise in specific antibodies, particularly IgG and its subclass IgG1, and detected the native lungworm PMY in immunoblots starting 2 weeks after the first vaccination. The use of a different rPMY-adjuvant combination or combined vaccination with additional recombinant antigens might be a promising future approach towards a new vaccine against lungworms in cattle.

A prospective, randomized, blinded, placebo-controlled pilot study on the effect of Enterococcus faecium on clinical activity and intestinal gene expression in canine food-responsive chronic enteropathy.

BACKGROUND: Canine chronic enteropathies (CE) are believed to be caused by an aberrant immune response towards the intestinal microbiome. Administration of probiotics can alleviate colitis in people. In vitro effects of the probiotic Enterococcus faecium NCIMB 10415 E1707 (EF) previously have been evaluated using canine cells (e.g., whole blood, intestinal biopsies), but data on in vivo efficacy are lacking. HYPOTHESIS/OBJECTIVES: Administration of EF to dogs with food-responsive CE will improve clinical outcome and decrease the intestinal inflammatory profile. ANIMALS: Dogs diagnosed with CE were prospectively recruited to receive a hydrolyzed elimination diet plus either a synbiotic product containing EF or placebo for 6 weeks. Both veterinary staff and owners were blinded to the treatment. METHODS: Clinical severity index (CCECAI), clinicopathological data and gene expression using intestinal biopsies (TLR2/4/5/9, IL-17A, IL-22, IL-23p19, RORC, IL-2, IL-12p35, TNFα, IL-4, IFNy, IL-10, TGFß, IL-1ß, IL-18, NLRP3, casp-1, TFF1, TFF3 and PPARy) before and after 6 weeks of treatment were analyzed using linear mixed modeling. RESULTS: Of the 45 cases recruited, 12 finished the clinical trial. Seven received the synbiotic and 5 the placebo product. There was no difference between groups or treatments regarding clinical efficacy, histology scores or expression of any of the investigated genes. CONCLUSIONS AND CLINICAL IMPORTANCE: Standard dietary treatment induced rapid clinical response in all cases. Because the study was underpowered, it was not possible to determine whether or not EF had an additional effect within the time period of 6 weeks.

Lack of correlation between mucosal immunoglobulin A-positive plasma cell numbers and TLR5 genotypes in German shepherd dogs with idiopathic chronic enteropathy.

It has been suggested previously that a deficiency in mucosal immunoglobulin (Ig) A production could be involved in the pathogenesis of chronic enteropathy in German shepherd dogs (GSDs). Recent research has shown that single nucleotide polymorphisms in the gene encoding Toll-like receptor (TLR)-5 are associated with an increased risk of development of chronic idiopathic enteropathy in this breed. IgA is essential for mucosal immunity and studies in mice have linked the interaction of TLR5 with its ligand flagellin to class switching of B cells into IgA-producing plasma cells. We hypothesized that dogs carrying the risk-associated (RA) genotypes for G22A and C100T genes of TLR5 would have a different number of IgA plasma cells in the duodenal and colonic mucosa compared with dogs carrying the risk-protective (RP) genotypes. Thirty-one GSDs were diagnosed with idiopathic chronic enteropathy by clinical exclusion diagnosis and histopathological confirmation. Immunohistochemistry was performed using goat anti-dog IgA primary antibody. Two sections of duodenum, and colon if available, were examined from each animal. Twelve images were captured from each section and IgA-positive cells were counted and expressed per 10,000 µm(2). TLR5 genotypes for the G22A and C100T genes were determined by polymerase chain reaction on blood samples. Numbers of IgA-positive cells in the duodenum and colon were slightly higher than those published previously for GSDs with or without chronic enteropathy (mean in the crypt area of the duodenum 52.6 ± 16.2; mean in the tip of the duodenal villus 51.12 ± 3.83; mean in the base of the duodenal villus 55.02 ± 3.3; mean in the crypt area of the colon 67.4 ± 4.3). There was no correlation between numbers of IgA-positive cells in duodenum or colon between dogs carrying the RA versus the RP alleles of TLR genes. Further studies are needed to assess the production of secretory IgA and its relationship to TLR5 genotypes.

Increased CYFIP1 dosage alters cellular and dendritic morphology and dysregulates mTOR.

Rare maternally inherited duplications at 15q11-13 are observed in ~1% of individuals with an autism spectrum disorder (ASD), making it among the most common causes of ASD. 15q11-13 comprises a complex region, and as this copy number variation encompasses many genes, it is important to explore individual genotype-phenotype relationships. Cytoplasmic FMR1-interacting protein 1 (CYFIP1) is of particular interest because of its interaction with Fragile X mental retardation protein (FMRP), its upregulation in transformed lymphoblastoid cell lines from patients with duplications at 15q11-13 and ASD and the presence of smaller overlapping deletions of CYFIP1 in patients with schizophrenia and intellectual disability. Here, we confirm that CYFIP1 is upregulated in transformed lymphoblastoid cell lines and demonstrate its upregulation in the post-mortem brain from 15q11-13 duplication patients for the first time. To investigate how increased CYFIP1 dosage might predispose to neurodevelopmental disease, we studied the consequence of its overexpression in multiple systems. We show that overexpression of CYFIP1 results in morphological abnormalities including cellular hypertrophy in SY5Y cells and differentiated mouse neuronal progenitors. We validate these results in vivo by generating a BAC transgenic mouse, which overexpresses Cyfip1 under the endogenous promotor, observing an increase in the proportion of mature dendritic spines and dendritic spine density. Gene expression profiling on embryonic day 15 suggested the dysregulation of mammalian target of rapamycin (mTOR) signaling, which was confirmed at the protein level. Importantly, similar evidence of mTOR-related dysregulation was seen in brains from 15q11-13 duplication patients with ASD. Finally, treatment of differentiated mouse neuronal progenitors with an mTOR inhibitor (rapamycin) rescued the morphological abnormalities resulting from CYFIP1 overexpression. Together, these data show that CYFIP1 overexpression results in specific cellular phenotypes and implicate modulation by mTOR signaling, further emphasizing its role as a potential convergent pathway in some forms of ASD.

Association between nucleotide oligomerisation domain two (Nod2) gene polymorphisms and canine inflammatory bowel disease.

The most important genetic associations that have been implicated to play a role in the etiology of Crohn's disease (CD) in humans are single nucleotide polymorphisms (SNPs) in nucleotide oligomerisation domain 2 (NOD2). The aim of this study was to investigate whether SNPs in the canine NOD2 gene are associated with inflammatory bowel disease (IBD) in German shepherd dogs (GSDs) and other canine breeds. A mutational analysis of the NOD2 gene was carried out in 10 randomly selected GSDs with IBD. The mutational analysis identified five non-synonymous SNPS, of which four in exon 3 of the NOD2 gene were evaluated in a case-control study using sequence based typing. Sequencing information from 55 GSDs with IBD were compared to a control group consisting of 61 GSDs. In addition, 85 dogs of other breeds with IBD and a breed-matched control group consisting of 162 dogs were also genotyped. All four SNPs were in complete linkage and, in the GSD population, were found to be in Hardy-Weinberg equilibrium. When the GSD case population was compared to the GSD control group, the heterozygote genotype for all four SNPs was more frequently found in the IBD population (p=0.03, OR=2.30, CI=1.07-4.94). However, these results were not mirrored in other canine breeds. Our study suggests that the four SNPs in exon 3 of NOD2 are significantly associated with IBD in GSDs when analyzed in an over-dominant model. However, these results were not mirrored in other canine breeds with IBD. This suggests that the etiology of this disease is complex and may involve the interaction of SNPs present in several genes or pathways to bring about the inflammatory changes seen in the intestine.

Stimulation of duodenal biopsies and whole blood from dogs with food-responsive chronic enteropathy and healthy dogs with Toll-like receptor ligands and probiotic Enterococcus faecium.

The composition of the microbiome plays a significant role in the pathogenesis of inflammatory bowel disease (IBD) in humans and chronic enteropathies (CE) in dogs. The administration of probiotic micro-organisms is one way of modulating the microbiome, but experiments elucidating mechanisms of action of probiotics in the intestine of healthy and CE dogs are lacking. The aim of our study was to investigate the effects of different Toll-like receptor (TLR) ligands and Enterococcus faecium (EF) on ex vivo cultured duodenal samples and whole blood (WB) from dogs with food-responsive chronic enteropathy (FRE) when compared to healthy dogs. Biopsy stimulation was performed in 17 FRE and 11 healthy dogs; WB stimulation was performed in 16 FRE and 16 healthy dogs. Expression of TLR2, 4, 5 and 9, IL-17A, IL-22, IFNy, TNFα, IL-4, IL-10, TGFß and PPARy was determined in biopsies by quantitative polymerase chain reaction (PCR). In addition, production of TNFα, IL-10, IFNy and IL-17A protein in WB and biopsy supernatants was assessed by ELISA. Treatment with individual TLR ligands or EF induced a variety of changes in the expression of different TLRs and cytokines, but not necessarily a consistent change with a single stimulating agent. Even though cytokine protein could not be detected in supernatants from ex vivo stimulated biopsies, we found TNFα protein responses in blood to be opposite of the transcriptional responses seen in the biopsies. Stimulation of canine duodenal biopsies with TLR ligands can potentially induce anti-inflammatory gene expression, especially in healthy tissue, whereas the effects of EF were limited.

Porcine circovirus type 2 infection before and during an outbreak of postweaning multisystemic wasting syndrome on a pig farm in the UK.

The presence of porcine circovirus type 2 (PCV-2) and other pathogens before and during an outbreak of postweaning multisystemic wasting syndrome (PWMS) in pigs is evaluated in this study. At the time of the outbreak on a large commercial pig farm in the UK, serum samples and data were collected in two independent on-going research projects, one in weaned pigs and the other in sows. Serum samples of growing pigs and sows were PCV-2-antibody and PCR positive before and during the PMWS outbreak. Upon sequencing, PCV-2 isolates collected before the outbreak were identified as PCV-2a, and isolates collected during the outbreak were identified as PCV-2b, suggesting a shift of PCV-2 genotypes present on the farm. Pigs in the weaner study were from sows originating from different breeders and an association of sow origin and PCV-2 serostatus in offspring was found. Further, pigs had higher odds to be PCV-2 antigen positive if the sow was PCV-2 antibody positive around farrowing, the sow was of higher parity, and were less likely to test antigen positive if the sow was sourced from a particular breeder. The findings of this study highlight the potential role of the immune status of the sow on the occurrence of PMWS.

Anti-apolipoprotein A-1 IgG in patients with myocardial infarction promotes inflammation through TLR2/CD14 complex.

OBJECTIVES: Toll-like receptor (TLR)-mediated vascular inflammation, inducible by - amongst other factors - auto-antibodies, is increasingly recognized as a potential mediator of cardiovascular disease. We investigated whether anti-apolipoprotein (Apo)A-1 IgG was associated with a pro-inflammatory cytokine profile in myocardial infarction (MI) patients and whether anti-ApoA-1 IgG elicited a pro-inflammatory response by activating TLRs. METHODS: As surrogate markers of atherosclerotic plaque vulnerability, interleukin (IL)-6, tumour necrosis factor (TNF)-α, matrix metalloproteinase (MMP)-9 and MMP-3 levels were assessed in 221 consecutive MI patients. Using human monocyte-derived macrophages (HMDMs) we investigated (i) the anti-ApoA-1 IgG interaction with TLRs using proximity ligation assay and (ii) anti-ApoA-1 IgG-dependent IL-6/TNF-α production. TLR involvement was further confirmed using HEK293-Blue TLR-2/-4 cells and by computational docking simulations. RESULTS: In MI patients, anti-ApoA-1 IgG positivity was associated with higher levels of IL-6, TNF-α and MMP-9, but lower MMP-3 levels. In in vitro experiments, anti-ApoA-1 antibodies bound to HDMDs in a TLR2-dependent manner, resulting in nuclear translocation of NFκB and a significant increase in TNF-α and IL-6 production. Subsequent functional studies highlighted the importance of CD14 as co-receptor in the anti-ApoA-1 IgG-TLR2-induced cytokine production. Additional bioinformatic studies identified structural homologies between TLR2 and ApoA-1, which may explain the observed cross-reactivity between antibodies against these two molecules. CONCLUSIONS: Anti-ApoA-1 IgG positivity in MI is associated with a high-risk cytokine profile. These auto-antibodies promote inflammation by stimulating the TLR2/CD14 receptor complex, probably because of molecular mimicry, which may contribute to atherosclerosis-related complications in patients.

Canine breeds at high risk of developing inflammatory bowel disease in the south-eastern UK.

Genetics are an important factor in the development of human inflammatory bowel disease (IBD); however, there is very little information available regarding the role of genetics in canine IBD. The purpose of this study was to gather information about which canine breeds in the south-eastern UK are at a high risk for developing IBD. Determination of such breeds may help further genetic research in this complex disease. The computer medical records at the Queen Mother Hospital for Animals, Royal Veterinary College dating from August 1, 2003 to December 31, 2009 were retrospectively searched for cases diagnosed with IBD. Five hundred and forty-six dogs with IBD were identified, representing 86 different breeds. The comparison group consisted of all dogs from these same 86 breeds without IBD admitted to the hospital during the same period that amounted to 27,463 dogs. The breeds at significantly higher risk of developing IBD compared with mixed-breed dogs consisted of weimaraner (odds ratio [OR]=3.6797, 95 per cent confidence interval [CI]=2.0167 to 6.7141, P<0.0001), rottweiler (OR=2.9697, 95 per cent CI=1.7569 to 5.0196, P<0.0001), German shepherd dog (GSD) (OR=2.4101, 95 per cent CI=1.5826 to 3.36705, P<0.0001), border collie (OR=1.9936, 95 per cent CI=1.1655 to 3.4101, P=0.0118) and boxer (OR=1.6961, 95 per cent CI=1.0441 to 2.755, P=0.0328). This study demonstrates for the first time canine breeds in the south-eastern UK that are highly susceptible to developing IBD. Identification of such breeds may allow for a more focused investigation of genetic mutations associated with canine IBD.

Calcium influx, a new potential therapeutic target in the control of neutrophil-dependent inflammatory diseases in bovines.

Neutrophils are the first line of defense against pathogens in bovines; however, they are also one of the most aggressive cells during the inflammatory process, causing injury in surrounding tissues. At present, anti-inflammatory drugs are limited in acute diseases, such as pneumonia, mastitis and endometritis, because neutrophils are mostly insensitive. One of the earliest events during neutrophil activation is the increase in intracellular calcium concentration. The calcium movement is attributed to the release from intracellular stores and influx through the calcium channels in the plasma membrane, a process called store operated calcium entry (SOCE). Recently, several calcium influx blockers have been shown to have strong effects on bovine neutrophils, and this suggests that the manipulation of this pathway can be useful in the control of neutrophil functions during acute inflammatory processes. In this paper, we will review the role of calcium influx as a potential anti-inflammatory target and summarize the most recent evidences for this in bovine neutrophils.

Breed-independent toll-like receptor 5 polymorphisms show association with canine inflammatory bowel disease.

Inflammatory bowel disease (IBD) is thought to be the most common cause of vomiting and diarrhoea in dogs. Although IBD can occur in any canine breed, certain breeds are more susceptible. We have previously shown that polymorphisms in the TLR4 and TLR5 (toll-like receptor) genes are significantly associated with IBD in German Shepherd dogs (GSDs). In order to allow for the development of novel diagnostics and therapeutics suitable for all dogs suffering from IBD, it would be useful to determine if the described polymorphisms are also significantly associated with IBD in other breeds. Therefore, the aim of this study was to investigate whether polymorphisms in the canine TLR4 and TLR5 genes are associated with IBD in other non-GSD canine breeds. The significance of the previously identified non-synonymous single nucleotide polymorphisms (SNPs) in the TLR4 (T23C, G1039A, A1571T and G1807A) and TLR5 genes (G22A, C100T and T1844C) were evaluated in a case-control study using a SNaPSHOT multiplex reaction. Sequencing information from 85 unrelated dogs with IBD consisting of 38 different breeds was compared with a breed-matched control group consisting of 162 unrelated dogs. Indeed, as in the GSD IBD population, the two TLR5 SNPs (C100T and T1844C) were found to be significantly protective for IBD in other breeds (P = 0.023 and P = 0.0195 respectively). Our study suggests that the two TLR5 SNPs, C100T and T1844C could play a role in canine IBD as these were found to be protective factors for this disease in 38 different canine breeds. Thus, targeting TLR5 in the canine system may represent a suitable way to develop new treatment for IBD in dogs.

CD11c+ cells are significantly decreased in the duodenum, ileum and colon of dogs with inflammatory bowel disease.

CD11c serves as a marker for human and murine dendritic cells (DCs) and cells expressing this marker have been shown to have similar morphological and functional characteristics in the canine immune system. The aim of this study was to quantify CD11c(+) cells in the duodenum, ileum and colon of healthy dogs and dogs with inflammatory bowel disease (IBD). Endoscopic biopsies from the duodenum (n=12 cases), ileum (n=8 cases) and colon (n=12 cases) were obtained from dogs diagnosed with IBD. Intestinal tissue from 10 healthy beagle dogs was used as control. Immunofluorescence microscopy was carried out using an anti-canine CD11c monoclonal antibody. Labelled cells were recorded as cells per 120,000 µm(2). The canine chronic enteropathy clinical activity index (CCECAI) was calculated for all dogs with IBD. In addition, sections from all dogs with IBD were evaluated according to the guidelines of the World Small Animal Veterinary Association Gastrointestinal Standardization Group. The number of CD11c(+) cells in the duodenum, ileum and colon of dogs with IBD was significantly reduced compared with controls (P<0.01, P<0.01 and P<0.05, respectively). There was a significant negative correlation between the number of CD11c(+) cells in the colon of dogs with IBD and the CCECAI (P=0.044, r(2)=-0.558). Chronic inflammation in canine IBD appears to involve an imbalance in the intestinal DC population. Future studies will determine whether reduced expression of CD11c could be a useful marker for the diagnosis and monitoring of canine IBD.

Induction of reactive oxygen species in bovine neutrophils is CD11b, but not dectin-1-dependent.

Neutrophils play a key role in initiating an innate immune response, being the first type of immune cell arriving at the site of injury or infection. These cells are able to mount a direct anti-bactericidal response by the production of reactive oxygen or reactive nitrogen species (ROS/RNS). An important component of the host innate immune response is recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs). Toll-like receptors (TLRs) are an important family of PRRs and, are a key component in activation of innate immune mechanisms. In the present study we described the presence of mRNA transcripts for TLR1, TLR2, TLR4, TLR6, TLR7 and TLR10 in bovine neutrophils. In contrast, the presence of mRNA transcripts for TLR3 varied between animals, whereas no transcripts were detected for TLR5, TLR8, TLR9 or the C-type lectin receptor dectin-1 in neutrophils isolated from bovine blood. Additionally, zymosan, a dectin-1/TLR2 ligand, induced ROS, but not RNS production in a CD11b-, but not dectin-1-dependent manner. This effect was dependent on Store Operated Calcium Entry (SOCE), and partially inhibited using monoclonal antibodies to CD11b. Taken together, our data describe the presence of specific PRRs transcripts in the mRNA isolated from bovine neutrophil and show a CD11b-/Ca(2+) dependent ROS production by these cells.

Evaluation of mucosal bacteria and histopathology, clinical disease activity and expression of Toll-like receptors in German shepherd dogs with chronic enteropathies.

The pathogenesis of chronic enteropathies in dogs likely involves an interaction between the intestinal immune system and luminal intestinal bacteria. German shepherd dogs (GSD) are particularly predisposed to chronic enteropathies. The present study sought to evaluate expression patterns of certain pattern recognition receptors of the innate immunity (Toll-like receptors, TLR), clinical disease activity and histopathological severity in GSD with chronic enteropathies. Mucosal biopsies were collected from the duodenum, colon and ileum of 13 affected GSD and 10 healthy greyhounds as controls. Dogs were objectively assessed using published scoring systems for clinical and histological severity of disease. Diversity of the duodenal microbiota was assessed by construction of 16S rRNA gene libraries. Expression of TLR2, TLR4, TLR5 and TLR9 in biopsies of the duodenum, ileum and colon was assessed by quantitative real-time PCR. TLR4 expression was increased in all intestinal segments in GSD, however, TLR5 expression was very low compared to the healthy dogs. The microbiota in the duodenum of GSDs was significantly different to that of the greyhounds, with an over-representation of 16S rRNA gene sequences belonging to the classes of Bacilli, and Erysipelotrichi, and to the orders of Lactobacillales, Actinomycetales and Erysipelotrichales. These findings could point to a distinct pathogenesis of chronic enteropathies in GSD, with differentially high and low expression of TLR4 and TLR5, respectively, and increased proportions of specific members of the Lactobacillales potentially playing a role.

LRRfinder: a web application for the identification of leucine-rich repeats and an integrative Toll-like receptor database.

Homology modelling is considered the most accurate technique for computational prediction of protein structure. However, this technique comes with fundamental caveats of dependency on template quality, identification of structural features and accuracy of alignment. Leucine-rich repeats (LRRs) characterise a diverse family of proteins. Recently resolved structures reveal a highly conserved region in LRRs that assemble into the curved parallel beta-sheet lining the inner circumference of their solenoid structure. Thus, prediction of these structurally important regions is essential in the comparative modelling of LRR proteins and their interactions. Here, we describe the generation of tLRRdb, a database of selected Toll-like receptor (TLR) sequences with annotated co-ordinates. Derived from this is LRRfinder, a web application for the identification of LRRs within user-defined sequences to facilitate identification of structurally important regions, particularly relevant for protein-protein interaction studies and classification of novel sequences. LRRfinder is available at: www.lrrfinder.com.

Flagellin expression enhances Salmonella accumulation in TLR5-positive macrophages.

Recently, it has been reported that Salmonella secrete flagellin in response to host produced lysophospholipids. However, this monomer of the bacterial flagella activates Toll-like receptor 5 (TLR5) in the innate immune system. The objective of this study was to examine the role of flagellin expression during infection of species-specific macrophages (MPhi) which either expressed or lacked TLR5. Initially, TLR5-activity was confirmed in bovine MPhi using Salmonella typhimurium derived-flagellin. Within these cells, recombinant FliC induced a potent CXCL8 response when compared to the heterogeneous (FliC/FljB) form of purified flagellin. Furthermore, neither form of flagellin induced nitrite secretion which was subsequently detected after exposing bovine MPhi to LPS in the presence of IFN-gamma. Flagellin enhanced the accumulation of Salmonella enteritidis in TLR5-positive bovine and human MPhi which was independent of adhesion in bovine MPhi. In contrast, murine MPhis which lacked TLR5 were equally susceptible to hosting S. enteritidis, with or without flagellin. However, lack of flagellin in S. typhimurium marginally inhibited bacterial accumulation in bovine MPhi, where FljB and FliC compensated for the lack of each other. This study suggests that flagellin may be inducing TLR5-dependent internalisation mechanisms in Mcapital EF, Cyrillic which vary qualitatively between different species and Salmonella serotypes.

Expression of Toll-like receptor 2 in duodenal biopsies from dogs with inflammatory bowel disease is associated with severity of disease.

There is growing evidence that aberrant innate immune responses towards the bacterial flora of the gut play a role in the pathogenesis of canine inflammatory bowel disease (IBD). Toll-like receptors (TLR) play an important role as primary sensors of invading pathogens and have gained significant attention in human IBD as differential expression and polymorphisms of certain TLR have been shown to occur in ulcerative colitis (UC) and Crohn's disease (CD). The aim of the current study was to evaluate the expression of two TLR important for recognition of commensals in the gut. TLR2 and TLR4 mRNA expression in duodenal biopsies from dogs with IBD was measured and correlated with clinical and histological disease severity. Endoscopic duodenal biopsies from 20 clinical cases and 7 healthy control dogs were used to extract mRNA. TLR2 and TLR4 mRNA expression was assessed using quantitative real-time PCR. TLR2 mRNA expression was significantly increased in the IBD dogs compared to controls, whereas TLR4 mRNA expression was similar in IBD and control cases. In addition, TLR2 mRNA expression was mildly correlated with clinical severity of disease, however, there was no correlation between TLR2 expression and histological severity of disease.