Chemokines are a family of small cytokines or signaling proteins secreted by cells that play a key role in the immune system of horses. They are involved in the chemotaxis, or directed movement, of immune cells towards sites of inflammation, infection, or injury. Chemokines facilitate communication between cells and help coordinate the body's response to various pathological conditions. In horses, chemokines are studied for their involvement in inflammatory processes and their potential as biomarkers for disease detection and progression. This page provides a collection of peer-reviewed research studies and scholarly articles that explore the function, regulation, and clinical relevance of chemokines in equine health.
Steelman SM, Johnson D, Wagner B, Stokes A, Chowdhary BP.Chronic equine laminitis causes persistent pain and lameness in affected animals and often necessitates euthanasia when pain management strategies become ineffective. Published studies as well as anecdotal reports suggest that this chronic inflammatory disease is associated with systemic alterations in immune responsiveness, perhaps involving an autoimmune component. We investigated this broad hypothesis by measuring a variety of immune indicators in healthy control horses (CON) and horses with chronic laminitis (LMN). We found that white blood cells from LMN horses produced more IFNγ than di...
Buechli ME, Lamarre J, Koch TG.MicroRNAs are a class of short noncoding RNAs that are involved in various biological processes, including differentiation. MicroRNA-140 (miR-140) has been identified as a cartilage-specific microRNA with several targets involved in cartilage development and homeostasis. The aim of this study was to investigate the expression of miR-140 during chondrogenic differentiation of equine cord blood-derived mesenchymal stromal cells (eCB-MSCs). We demonstrate both that miR-140 is highly expressed in normal equine articular cartilage and that eCB-MSCs express significantly higher levels of this microR...
Mignot CC, Pirottin D, Farnir F, de Moffarts B, Molitor C, Lekeux P, Art T.The effects of strenuous exercise and ex vivo stimulation of TLR3 and TLR4 pathways on the expression of six inflammatory genes in equine pulmonary leukocytes were investigated. The genes tested were interferon-beta (IFN-β), interleukin-1-beta (IL-1β), interleukin-6 (IL-6), interferon gamma-induced protein 10 (IP-10), chemokine (c-c motif) ligand 5 (RANTES) and tumor necrosis factor-alpha (TNF-α). We hypothesized that strenuous exercise would modulate basal gene expression on one hand and modulate the response to bacterial lipopolysaccharide (LPS) and to polyinosinic:polycytidylic acid (Pol...
Ainsworth DM, Reyner CL.To examine the effects of in vitro exposure to solutions of autologous horse blood (AHB) and autologous horse serum (AHS) on expressions of selected cytokine genes in equine primary bronchial epithelial cell (BEC) cultures and to contrast these responses to those induced in BEC cultures by endotoxin and hay dust. Methods: BEC cultures established from bronchi of 6 healthy horses. Methods: 5-day-old BEC cultures were treated with PBS solution, AHB (2 concentrations), AHS, hay dust solution, and lipopolysaccharide solution for 24 hours. Gene expressions of interleukin (IL)-8, IL-1β, chemokine (...
Leise BS, Faleiros RR, Watts M, Johnson PJ, Black SJ, Belknap JK.A significant proinflammatory response is known to occur in the forelimb lamina after carbohydrate administration. As the hindlimbs are often less affected by laminitis compared with the forelimbs, we assessed hindlimb inflammatory response in the early stages of carbohydrate-induced laminitis to determine whether differences in the response existed. Objective: To determine whether a similar proinflammatory response occurs in the hindlimb laminae to that previously reported for the forelimb. Methods: Archived laminar samples from 12 horses administered 17.6 g of starch (85% corn starch, 15% wo...
Goodyear A, Troyer R, Bielefeldt-Ohmann H, Dow S.The Gram-negative bacterium Burkholderia mallei causes rapidly fatal illness in equines and humans when contracted by inhalation and also has the potential to be used as a bioweapon. However, little is known regarding the early innate immune responses and signaling mechanisms required to generate protection from pneumonic B. mallei infection. We showed previously that monocyte chemoattractant protein 1 (MCP-1) was a critical chemokine required for protection from pneumonic B. mallei infection. We have now extended those studies to identify key Toll-like receptor (TLR) signaling pathways, effec...
Dunkel B, Bolt DM, Smith RK, Cunningham FM.Platelet-rich plasma (PRP) is increasingly used for treatment of orthopaedic injuries. However, the effects of different stimuli on the release pattern of regenerative and proinflammatory factors from equine platelets are largely unknown and an optimal treatment protocol remains to be established. Objective: The aim of this study was to identify a stimulus that enhanced release of histopromotive factors (platelet-derived growth factor BB [PDGF] and transforming growth factor 1β[TGF]) without causing concurrent release of a proinflammatory mediator (CCL5). Methods: Washed platelets were prepar...
van Eps AW, Leise BS, Watts M, Pollitt CC, Belknap JK.The pathophysiological events inhibited by prophylactic digital hypothermia that result in reduction of the severity of acute laminitis are unknown. Objective: To determine if digital hypothermia inhibits lamellar inflammatory signalling during development of oligofructose (OF) induced laminitis. Methods: Fourteen Standardbred horses were given 10 g/kg bwt OF by nasogastric tube with one forelimb (CRYO) continuously cooled by immersion in ice and water and one forelimb (NON-RX) at ambient temperature. Lamellae were harvested prior to the onset of lameness (24 h post OF administration, DEV ...
Davies RS, Madigan JE, Hodzic E, Borjesson DL, Dumler JS.Anaplasma phagocytophilum is the zoonotic cause of granulocytic anaplasmosis. We hypothesized that immune response, specifically gamma interferon (IFN-γ), plays a role in disease severity. To test this, horses were infected and IFNG expression was pharmacologically downregulated using corticosteroids. Eight horses were infected with A. phagocytophilum; 4 received dexamethasone on days 4 to 8 of infection. Clinical signs, hematologic parameters, and transcription of cytokine/chemokine genes were compared among treated and untreated horses. Infection was quantitated by msp2 real-time PCR and mi...
Faleiros RR, Leise BS, Watts M, Johnson PJ, Black SJ, Belknap JK.Chemokines play a vital role in leukocyte activation and emigration that reportedly plays a central role in laminar injury in equine laminitis. The purpose of this study was to evaluate the pattern of laminar chemokine expression in horses in the classical carbohydrate overload (CHO)-model of laminitis. Laminar samples were obtained 24h following water administration in the control group (CON, n=8), and at the onset of fever (≥ 102°F, 12-22 h post CHO, DEV group, n=8) and at the onset of lameness (20-48 h post CHO, LAM group, n=8) in induced horses. Real time quantitative PCR was performed ...
Lin YZ, Cao XZ, Li L, Li L, Jiang CG, Wang XF, Ma J, Zhou JH.The attenuated equine infectious anemia virus (EIAV) vaccine was the first attenuated lentivirus vaccine to be used in a large-scale application and has been used to successfully control the spread of equine infectious anemia (EIA) in China. To better understand the potential role of cytokines in the pathogenesis of EIAV infection and resulting immune response, we used branched DNA technology to compare the mRNA expression levels of 12 cytokines and chemokines, including IL-1α, IL-1β, IL-4, IL-10, TNF-α, IFN-γ, IP-10, IL-8, MIP-1α, MIP-1β, MCP-1, and MCP-2, in equine monocyte-derived mac...
Hudgens E, Tompkins D, Boyd P, Lunney JK, Horohov D, Baldwin CL.This report describes the cloning and characterization of expressed gene sequences of bovine, equine, and swine CXCL9 from RNA obtained from peripheral blood mononuclear cells (PBMC) and other tissues. The bovine coding region was 378 nucleotides in length, while the equine and swine coding regions were 381 nucleotides. Mapping showed that all three sequences were coded for in four exons in the genome, as are the human and mouse genes. The bovine, equine, and swine coding regions shared 83%, 86%, and 84% homology with human CXCL9, respectively, and all three were 74% homologous with mouse CXCL...
Quintana AM, Landolt GA, Annis KM, Hussey GS.Our understanding of innate immunity within the equine respiratory tract is limited despite growing evidence for its key role in both the immediate defense and the shaping of downstream adaptive immune responses to respiratory disease. As the first interface to undergo pathogen invasion, the respiratory epithelium is a key player in these early events and our goal was to examine the innate immune characteristics of equine respiratory epithelia and compare them to an in vitro equine respiratory epithelial cell model cultured at the air-fluid interface (AFI). Respiratory epithelial tissues, isol...
Burns TA, Geor RJ, Mudge MC, McCutcheon LJ, Hinchcliff KW, Belknap JK.Insulin resistance has been associated with risk of laminitis in horses. Genes coding for proinflammatory cytokines and chemokines are expressed more in visceral adipose tissue than in subcutaneous adipose tissue of insulin-resistant (IR) humans and rodents. Objective: To investigate adipose depot-specific cytokine and chemokine gene expression in horses and its relationship to insulin sensitivity (SI). Methods: Eleven light breed mares. Methods: Animals were classified as IR (SI=0.58+/-0.31x10(-4) L/min/mU; n=5) or insulin sensitive (IS; SI=2.59+/-1.21x10(-4) L/min/mU; n=6) based on results o...
Williams JM, Lin YJ, Loftus JP, Faleiros RR, Peroni JF, Hubbell JA, Ravis WR, Belknap JK.Laminitis is a serious complication of horses suffering from sepsis/endotoxaemia-related events. Laminitis in horses and organ injury in human sepsis are both reported to involve inflammatory injury to the laminae/organs including early activation of endothelium and leucocytes leading to emigration of neutrophils into the tissue interstitium. In the black walnut extract (BWE) model, systemic inflammatory events coincide with marked increase in laminar mRNA concentrations of inflammatory genes including proinflammatory cytokines (i.e. IL-1beta, IL-6), COX-2, chemokines (i.e. IL-8) and endotheli...
Covaleda L, Fuller FJ, Payne SL.Equine infectious anemia virus (EIAV) infection is distinctive in that it causes a rapid onset of clinical disease relative to other retroviruses. In order to understand the interaction dynamics between EIAV and the host immune response, we explored the effects of EIAV and its S2 protein in the regulation of the cytokine and chemokine response in macrophages. EIAV infection markedly altered the expression pattern of a variety of pro-inflammatory cytokines and chemokines monitored in the study. Comparative studies in the cytokine response between EIAV(17) and EIAV(17DeltaS2) infection revealed ...
Reyner CL, Wagner B, Young JC, Ainsworth DM.To examine gene expression of selected cytokines in pulmonary mononuclear cells isolated from healthy horses and horses susceptible to recurrent airway obstruction (RAO), and to determine whether interleukin (IL)-17 and IL-23 were associated with pulmonary inflammation. Methods: 6 RAO-susceptible and 5 healthy horses. Methods: Bronchoalveolar lavage cells were retrieved from horses that were stabled and fed dusty hay for 24 hours. Lavage cells devoid of neutrophils were incubated for 24 hours with solutions of PBS, hay dust, lipopolysaccharide, or B-glucan. Gene expression of IL-17, IL-23 (p19...
Faleiros RR, Leise BB, Westerman T, Yin C, Nuovo GJ, Belknap JK.C-X-C motif ligand 1 (CXCL1) is an important chemokine of epithelial origin in rodents and humans. Objective: To assess in vivo and in vitro the regulation of CXCL1 in equine laminitis. Methods: Twenty adult horses. Methods: Real-time quantitative polymerase chain reaction (PCR) was used to assess expression of CXCL1 in samples of laminae, liver, skin, and lung from the black walnut extract (BWE) model of laminitis, and in cultured equine epithelial cells (EpCs). Tissue was obtained from control animals (CON, n = 5), and at 1.5 hours (early time point [ETP] group, n = 5), at the onset of leuko...
Huang H, Lavoie-Lamoureux A, Lavoie JP.The endothelium plays a critical role in regulating leukocyte recruitment and migration during inflammation. Recent studies provide evidence that acetylcholine (ACh) and other cholinergic mediators block endothelial cells activation and leukocyte recruitment during inflammation. We thus postulated that the non-neuronal cholinergic system might modulate the recruitment of neutrophils during allergic pulmonary inflammation. In the present study, we examined the effects of cholinergic stimulation on the expression of neutrophil chemokines and adhesion molecules by endothelial cells stimulated by ...
Ainsworth DM, Matychak M, Reyner CL, Erb HN, Young JC.To examine effects of in vitro exposure to solutions of hay dust, lipopolysaccharide (LPS), or beta-glucan on chemokine and cell-surface receptor (CSR) gene expression in primary bronchial epithelial cell cultures (BECCs) established from healthy horses and horses with recurrent airway obstruction (RAO). Methods: BECCs established from bronchial biopsy specimens of 6 RAO-affected horses and 6 healthy horses. Methods: 5-day-old BECCs were treated with PBS solution, hay dust solutions, LPS, or beta-glucan for 6 or 24 hours. Gene expression of interleukin (IL)-8, chemokine (C-X-C motif) ligand 2 ...
Zou X, Zou L, Foldager C, Bendtsen M, Feng W, Bünger CE.To elucidate the molecular mechanisms of spinal fusion with different graft materials during an anterior lumbar interbody fusion, we examined the gene-expression profiles after implantation of equine bone protein extract, rhBMP-2 and autograft using microarray technology and data analysis, including hierarchical clustering, self-organizing maps (SOM), KEGG pathway and Biological process GO analyses in a porcine model. The results suggest that equine bone protein extract exhibited a more similar expression pattern with autograft than that of rhBMP-2. rhBMP-2 recruits progenitor cells, prolifera...
Eckert RE, Sharief Y, Jones SL.Equine laminar tissues do not contain resident neutrophils and have less superoxide dismutase (SOD) activity than other equine tissues, which makes them inherently more vulnerable to damage induced by reactive oxygen species (ROS) produced by neutrophils that enter the tissues. In the advanced clinical stages of acute laminitis, pathologic events in affected feet include a breakdown in the basement membrane, neutrophil infiltration, and platelet-neutrophil aggregates in laminar dermal veins, highlighting the contribution of neutrophils to the pathophysiology of the disease. The aim of this stu...
Perelygin AA, Zharkikh AA, Astakhova NM, Lear TL, Brinton MA.Chemokine receptors (CCRs) play an essential role in the initiation of an innate immune host response. Several of these receptors have been shown to modulate the outcome of viral infections. The recent availability of complete genome sequences from a number of species provides a unique opportunity to analyze the evolution of the CCR genes. A phylogenetic analysis revealed that the CCR2 gene evolved in concert with the paralogous CCR5 gene, but not with another paralogous gene, CCR3, in the opossum, platypus, rabbit, guinea pig, cat, and rodent lineages. In addition, evidence of concerted evolu...
DeLuca L, Erb HN, Young JC, Perkins GA, Ainsworth DM.Chemokine expression in airway epithelium and bronchoalveolar lavage fluid (BALF) cells of horses with recurrent airway obstruction (RAO) is increased. Objective: For RAO-affected horses that are stabled and fed a pelleted ration, the addition of oral dexamethasone further improves pulmonary function and reduces inflammatory gene expression in pulmonary cells. Methods: Twelve RAO-affected horses. Methods: In a randomized cross-over experiment, the effect of feeding pellets in lieu of hay to stabled, RAO-affected horses was compared with the effect of feeding pellets and administering a 21-day ...
Weston MC, Collins ME, Cunningham FM.Inappropriately activated eosinophils can contribute to disease pathogenesis and intracellular signalling pathways that regulate functional responses may represent a therapeutic target. Little is known about intracellular signalling in equine eosinophils and this study examined the role of phospholipase C (PLC) and a range of protein kinases on responses to histamine and CCL11. Histamine (10(-4) M) or CCL11 (5.6 x 10(-9) M)-induced actin polymerization, migration and superoxide production by eosinophils from healthy horses were compared in the presence and absence of selective kinase inhibitor...
Ainsworth DM, Wagner B, Erb HN, Young JC, Retallick DE.To examine effects of in vitro exposure to solutions of hay dust, lipopolysaccharide (LPS), or beta-glucan on cytokine expression in pulmonary mononuclear cells isolated from healthy horses and horses with recurrent airway obstruction (RAO). Methods: 8 RAO-affected and 7 control horses (experiment 1) and 6 of the RAO-affected and 5 of the control horses (experiment 2). Methods: Bronchoalveolar lavage cells were isolated from horses that had been stabled and fed dusty hay for 14 days. Pulmonary mononuclear cells were incubated for 24 (experiment 1) or 6 (experiment 2) hours with PBS solution or...
Joubert P, Cordeau ME, Boyer A, Silversides DW, Lavoie JP.Heaves, also known as recurrent airway obstruction, is a common condition of horses characterised by pulmonary neutrophilia and reversible airway obstruction. This study evaluated the role of neutrophils in producing cytokines and chemokines that might be involved in the recruitment and activation of inflammatory cells in horses with heaves. Peripheral neutrophils were isolated from heaves-affected (n = 9) and control (n = 4) horses before and after 5 h of natural inhalation challenge. Expression of mRNA of two pro-inflammatory cytokines, tumour necrosis factor (TNF)-alpha and interleukin (IL)...
Van de Walle GR, May ML, Sukhumavasi W, von Einem J, Osterrieder N.Glycoprotein G (gG) of alphaherpesviruses has been described to function as a viral chemokine-binding protein (vCKBP). More recently, mutant viruses devoid of gG have been shown to result in increased virulence, but it remained unclear whether the potential of gG to serve as a vCKBP is responsible for this observation. In this study, we used equine herpesvirus type 1 (EHV-1) as a model to study the pathophysiological importance of vCKBP activity. First, in vitro chemotaxis assays studying migration of immune cells, an important function of chemokines, were established. In such assays, supernat...
Shimada M, Yanai Y, Okazaki T, Yamashita Y, Sriraman V, Wilson MC, Richards JS.During ovulation, granulosa cells and cumulus cells synthesize and secrete a wide variety of factors including members of the IL cytokine family via the process of exocytosis. Exocytosis is controlled by the soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor complex consisting of proteins residing in the vesicle membrane and the plasma membrane. One of the soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor proteins, synaptosomal-associated protein (SNAP)25, is expressed abundantly in neuronal cells and is also induced transiently in the rat...
Huang H, Lavoie-Lamoureux A, Moran K, Lavoie JP.Little is known concerning the possible contribution of T helper 2 (Th2)-type cytokines to the recruitment of neutrophils into the lung tissue. In the present study, endothelial cells from equine pulmonary arteries were cultured in the presence of recombinant equine (re) IL-4 and reIL-5, and the cytokine mRNA expression of molecules implicated in the chemotaxis and migration of neutrophils was studied using real-time RT-PCR. The functional response of reIL-4-induced endothelial cell stimulation on neutrophil migration was also studied using a chemotaxis chamber. ReIL-4 either increased the exp...
Watts MR, Hegedus OC, Eades SC, Belknap JK, Burns TA.Hyperinsulinemia is associated with equine laminitis, and digital lamellar inflammation in equine metabolic syndrome-associated laminitis (EMSAL) is modest when compared with sepsis-associated laminitis. Objective: To characterize digital lamellar inflammation in horses in a euglycemic-hyperinsulinemic clamp (EHC) model of laminitis. Methods: Sixteen healthy adult Standardbred horses. Methods: Prospective experimental study. Horses underwent EHC or saline infusion (CON) for 48 hours or until the onset of Obel grade 1 laminitis. Horses were euthanized, and digital lamellar tissue was collecte...
Labens R, Daniel C, Hall S, Xia XR, Schwarz T.Early diagnosis of cartilage disease at a time when changes are limited to depletion of extracellular matrix components represents an important diagnostic target to reduce patient morbidity. This report is to present proof of concept for nanoparticle dependent cartilage barrier imaging in a large animal model including the use of clinical magnetic resonance imaging (MRI). Conditioned (following matrix depletion) and unconditioned porcine metacarpophalangeal cartilage was evaluated on the basis of fluorophore conjugated 30 nm and 80 nm spherical gold nanoparticle permeation and multiphoton lase...
Benarafa C, Cunningham FM, Hamblin AS, Horohov DW, Collins ME.We report the cloning of four equine CC chemokines, eotaxin, monocyte chemoattractant protein (MCP)-1, MCP-2 and MCP-4, which show high levels of identity with their respective homologous sequences in other species. Using a multiplex RT-PCR, we have studied the constitutive mRNA expression of these four CC chemokines in skin, lung, liver, spleen, jejunum, colon and kidney of normal adult horses and compared this data with the eosinophil counts in the same samples. We demonstrate that eotaxin mRNA is only expressed in jejunum and colon, where there are large numbers of eosinophils suggesting th...
Wagner B.Host immune analyses require specific reagents to identify cellular and soluble components of the immune system. These immune reagents are often species-specific. For horses, various immunological tools have been developed and tested by different initiatives during the past decades. This article summarizes the development of well characterized monoclonal antibodies (mAbs) for equine immune cells, immunoglobulin isotypes, cytokines, and chemokines.
Schnabel CL, Babasyan S, Freer H, Wagner B.C-X-C motif ligand 10 (CXCL10) is a pro-inflammatory chemokine and has been extensively evaluated in people and mice. In horses, CXCL10 and its involvement in host immunity has rarely been analyzed due to the lack of specific antibodies. We generated a mAb specific for the equine chemokine CXCL10 using hybridoma technology. Antibody specificity was confirmed by intracellular staining and flow cytometric analysis of Chinese Hamster Ovary (CHO) cells expressing equine rCXCL10, while CHO cells expressing equine rCXCL9 were not detected. Native CXCL10 expression in PBMC from horses of different ag...
Dunkel B, Bolt DM, Smith RK, Cunningham FM.Platelet-rich plasma (PRP) is increasingly used for treatment of orthopaedic injuries. However, the effects of different stimuli on the release pattern of regenerative and proinflammatory factors from equine platelets are largely unknown and an optimal treatment protocol remains to be established. Objective: The aim of this study was to identify a stimulus that enhanced release of histopromotive factors (platelet-derived growth factor BB [PDGF] and transforming growth factor 1β[TGF]) without causing concurrent release of a proinflammatory mediator (CCL5). Methods: Washed platelets were prepar...
Hedia M, Ibrahim S, Mahmoud K, Ahmed Y, Ismail S, El-Belely M.Apparently healthy mares with conception failure or embryonic loss may have subclinical endometritis (SE). Our objective was to document evidence of systemic immune responses against SE in mares. In apparently healthy (control) mares as well as those with chronic endometritis (ChE) or subacute suppurative endometritis (SSE), both considered classes of SE, serum concentrations of cytokines (IL-1β, IL-6, IL-10 and TNF), chemokines (IL-8), acute phase protein (SAA), and plasma concentrations of prostaglandins (PGF and PGE) were measured using validated enzyme linked immunoassays (EIA). Mixed-bre...
Gilger BC, Yang P, Salmon JH, Jaffe GJ, Allen JB.To determine whether a chemokine (RANTES)-like protein expressed by ciliary epithelium plays a role in uveitis. Methods: 3 clinically normal horses intradermal, 5 eyes from 5 horses with recurrent uveitis, and 10 normal eyes from 5 age- and sex-matched horses. Methods: Cross-reactivity and sensitivity of recombinant human (rh)-regulated upon activation, normal T-cell expressed and secreted (RANTES) protein were evaluated in horses by use of intradermal hypersensitivity reactions and a chemotaxis assay. Aqueous humor and ciliary body of eyes from clinically normal horses and horses with uveitis...
Zarski LM, Vaala WE, Barnett DC, Bain FT, Soboll Hussey G.Equine herpesvirus 1 (EHV-1) ubiquitously infects horses worldwide and causes respiratory disease, abortion, and equine herpesvirus myeloencephalopathy. Protection against EHV-1 disease is elusive due to establishment of latency and immune-modulatory features of the virus. These include the modulation of interferons, cytokines, chemokines, antigen presentation, and cellular immunity. Because the modulation of immunity likely occurs at the site of first infection-the respiratory epithelium, we hypothesized that the mucosal influenza vaccine Flu Avert I.N. (Flu Avert), which is known to stimulat...
Zinkl JG, Brown PD.Horse polymorphonuclear leukocytes (PMN) isolated from horse blood by sedimentation and isotonic lysis and having about 25% accompanying lymphocytes were as effective at chemotaxis as nearly pure PMN isolated by density gradient techniques. N-Formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP), used as a representative of the formylmethionyl peptides (produced by prokaryocytic organisms), was effective as a chemoattractant only at the high concentration of 10(-4) M. When serum was preincubated with FMLP at concentrations as low as 10(-8) M, the serum attracted horse PMN. This activity was not g...
Reyner CL, Wagner B, Young JC, Ainsworth DM.To examine gene expression of selected cytokines in pulmonary mononuclear cells isolated from healthy horses and horses susceptible to recurrent airway obstruction (RAO), and to determine whether interleukin (IL)-17 and IL-23 were associated with pulmonary inflammation. Methods: 6 RAO-susceptible and 5 healthy horses. Methods: Bronchoalveolar lavage cells were retrieved from horses that were stabled and fed dusty hay for 24 hours. Lavage cells devoid of neutrophils were incubated for 24 hours with solutions of PBS, hay dust, lipopolysaccharide, or B-glucan. Gene expression of IL-17, IL-23 (p19...
Airway inflammation and airway hyperresponsiveness (AHR) are pivotal characteristics of equine asthma. Lipopolysaccharide (LPS) may have a central role in modulating airway inflammation and dysfunction. Therefore, the aim of this study was to match the inflammatory and contractile profile in LPS-challenged equine isolated bronchi to identify molecular targets potentially suitable to counteract AHR in asthmatic horses. Equine isolated bronchi were incubated overnight with LPS (0.1-100 ng/ml). The contractile response to electrical field stimulation (EFS) and the levels of cytokines, chemokines...
Dunowska M, Meers J, Johnson RD, Wilks CR.Representational difference analysis (RDA) was used to compare gene expression in equine mononuclear cells either infected with equine herpesvirus-2 (EHV-2) or adsorbed with inactivated EHV-2. Seven clones identified in non-infected cells after three rounds of selective subtraction and enrichment for differentially expressed genes contained sequences homologous to equine monocyte chemoattractant protein 1 (MCP-1). This suggested that EHV-2 may down-regulate MCP-1 transcription in infected cells. These findings correlate well with similar findings described for human cytomegalovirus and support...
Morales N, Henriquez C, Sarmiento J, Uberti B, Moran G.Neutrophils are terminally differentiated innate effector cells at the first line of host defense. Neutrophil migration within tissues is complex and involves several steps, during which these cells must be able to interpret a variety of chemical and physical signals. Exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including equine asthma. Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous studies showed that TX treatment in horses with induced acute pulmonary inflamma...
Giessler KS, Goehring LS, Jacob SI, Davis A, Esser MM, Lee Y, Zarski LM, Weber PSD, Hussey GS.Herpesviruses establish a well-adapted balance with their host's immune system. Despite this co-evolutionary balance, infections can lead to severe disease including neurological disorders in their natural host. In horses, equine herpesvirus 1 (EHV-1) causes respiratory disease, abortions, neonatal foal death and myeloencephalopathy (EHM) in ~10 % of acute infections worldwide. Many aspects of EHM pathogenesis and protection from EHM are still poorly understood. However, it has been shown that the incidence of EHM increases to >70 % in female horses >20 years of age. In this study we use...
Faber E, Tshilwane SI, Kleef MV, Pretorius A.African horse sickness (AHS) is caused by African horse sickness virus (AHSV), a double stranded RNA (dsRNA) virus of the genus Orbivirus, family Reoviridae. For the development of new generation AHS vaccines or antiviral treatments, it is crucial to understand the host immune response against the virus and the immune evasion strategies the virus employs. To achieve this, the current study used transcriptome analysis of RNA sequences to characterize and compare the innate immune responses activated during the attenuated AHSV serotype 4 (attAHSV4) (in vivo) and the virulent AHSV4 (virAHSV4) (in...
Camp CJ, Leid RW.A method for the isolation of equine neutrophils was developed using metrizamide cushions. A purity of greater than 95% was routinely obtained with greater than 90% viability. These cells were radiolabeled and tested for their chemotactic response in Boyden chambers to zymosan-activated equine serum, the partially purified equine complement component C5a, and formyl-L-methionyl-L-leucyl-L-phenylalanine. The time and ionic requirements for chemotaxis of radiolabeled equine neutrophils were investigated and maximal movement was observed at 2 hours' incubation and 1.0 mM Ca and 0.5 mM Mg. Dinitro...
Barton AK, Richter IG, Ahrens T, Merle R, Alalwani A, Lilge S, Purschke K, Barnewitz D, Gehlen H.The purpose of the study was to compare the results of sepsis scoring (clinical examination and clinical pathology) to the concentrations of matrix-metalloproteinases (MMPs) -2, -8, and -9; tissue-inhibitor of metalloproteinases (TIMPs) -1 and -2; and inflammatory chemokines interleukin (IL) 1β and tumor-necrosis-factor-alpha (TNF-α) in plasma and peritoneal fluid of equine colic patients. A modified sepsis scoring including general condition, heart and respiratory rate, rectal temperature, mucous membranes, white blood cell count (WBC), and ionized calcium was applied in 47 horses presented...
Blancquaert AM, Colgan SP, Bruyninckx WJ.Although equine neutrophils did not respond towards formylated methionyl peptides, Streptococcus faecalis culture supernatant caused an in vitro stimulation of equine neutrophil motility when measured by an under-agarose assay. The migration of neutrophils towards the culture supernatant increased sigmoidally with the logarithmic concentration of the culture supernatant in the chemoattractant wells. The streptococcal culture supernatant was chemokinetic because it stimulated the random motility of the phagocytes. Because granulocytes migrated further towards the supernatant than could be expla...
Keller LE, Tait Wojno ED, Begum L, Fortier LA.Infiltration of cluster of differentiation (CD) 3 (CD3) T cells into the synovium and synovial fluid occurs in most patients with posttraumatic osteoarthritis. During disease progression, proinflammatory T helper 17 cells and anti-inflammatory regulatory T cells infiltrate the joint in response to inflammation. This study aimed to characterize the dynamics of regulatory T and T helper 17 cell populations in synovial fluid from equine clinical patients with posttraumatic osteoarthritis to determine whether phenotype and function are associated with potential immunotherapeutic targets. An imbala...
Bernoco M, Liu IK, Wuest-Ehlert CJ, Miller ME, Bowers J.Chemotactic and phagocytic responsiveness of peripheral blood polymorphonuclear leucocytes (PMNLs) from 11 foals were analysed immediately after birth (pre-colostral) and at different times after colostrum ingestion. The number of foal PMNLs per microscopic field that had migrated through the filter in chemotaxis and the number of yeast particles ingested per foal PMNL in phagocytosis were significantly lower when tested with foal plasma before colostrum ingestion (chemotaxis, 2.0 +/- 0.55 (s.e.m.); phagocytosis, 0.98 +/- 0.352) than in tests 4 or more days after colostrum ingestion (chemotaxi...
Muhktar MM, Timoney JF.Streptococcus equi infection in horses is characterised by intense infiltration of lymph nodes by polymorphonuclear leucocytes (PMNs) suggesting a potent chemotactic response to the organism or its products. Equine PMNs were separated using Ficoll-Hypaque medium and used in an assay of chemotaxis under agarose to study the components of S equi involved in this response. Results showed that complement-derived chemotactic factors generated by activation of the alternative complement pathway were important in chemotactic responses to S equi. Both whole bacteria and peptidoglycan preparations were...
Potter KA, Leid RW, Kolattukudy PE, Espelie KE.Lipoxygenase products of arachidonic acid are important mediators of inflammation, affecting several aspects of cell function. Monohydroxyeicosatetraenoic acid (mono-HETE) and 5,12-dihydroxyeicosatetraenoic acid (LTB4) enhance migration of both neutrophils and eosinophils in several species. The relative ability of positional isomers of HETE and of LTB4 to affect migration of equine eosinophils was studied. The 5, 8, 9, 11, 12, and 15 isomers of HETE were prepared by autooxidation of arachidonic acid, separated by sequential normal phase and reverse phase high performance liquid chromatography...
Lection J, Wagner B, Byron M, Miller A, Rollins A, Chenier T, Cheong SH, Diel de Amorim M.Endometrial biopsy is required to diagnose mares with chronic endometritis and endometrial degenerative fibrosis. An increase in understanding of equine reproductive immunology could be utilised to create less-invasive, time-efficient diagnostic tools especially when evaluating mares for chronic endometritis. Objective: To evaluate inflammatory cytokine and chemokine concentrations in uterine fluid samples collected by low-volume lavage (LVL) as a potential screening diagnostic biomarker for endometritis. Methods: Prospective cross-sectional clinical study. Methods: Forty-six mares underwent a...
Joubert P, Cordeau ME, Boyer A, Silversides DW, Lavoie JP.Heaves, also known as recurrent airway obstruction, is a common condition of horses characterised by pulmonary neutrophilia and reversible airway obstruction. This study evaluated the role of neutrophils in producing cytokines and chemokines that might be involved in the recruitment and activation of inflammatory cells in horses with heaves. Peripheral neutrophils were isolated from heaves-affected (n = 9) and control (n = 4) horses before and after 5 h of natural inhalation challenge. Expression of mRNA of two pro-inflammatory cytokines, tumour necrosis factor (TNF)-alpha and interleukin (IL)...
Ainsworth DM, Reyner CL.To examine the effects of in vitro exposure to solutions of autologous horse blood (AHB) and autologous horse serum (AHS) on expressions of selected cytokine genes in equine primary bronchial epithelial cell (BEC) cultures and to contrast these responses to those induced in BEC cultures by endotoxin and hay dust. Methods: BEC cultures established from bronchi of 6 healthy horses. Methods: 5-day-old BEC cultures were treated with PBS solution, AHB (2 concentrations), AHS, hay dust solution, and lipopolysaccharide solution for 24 hours. Gene expressions of interleukin (IL)-8, IL-1β, chemokine (...
Swiderski CE.Hypersensitivity is an exaggerated immunologic response to a foreign agent that results in inflammation and organ dysfunction. Hypersensitivity disorders are broadly divided into antibody-mediated and T-cell-mediated reactions. The inflammatory pathways that result in disease are initiated in an antigen-specific manner through Fab portions of antibodies or the T-cell receptor, causing the up-regulation of effector mechanisms designed to clear the offending agent. Effector mechanisms include the generation of inflammatory chemicals such as cytokines and chemokines and the attraction of leukocyt...
Benarafa C, Collins ME, Hamblin AS, Sabroe I, Cunningham FM.The chemokine eotaxin (CCL11) is a key player in the trafficking of eosinophils to normal tissues and in the tissue eosinophilia associated with human allergic disease. We have recently cloned equine eotaxin and here we report the production of rEq eotaxin, with and without a C-terminal fusion peptide, in a novel expression system utilising stably transfected insect cells. rEq eotaxin induced equine eosinophil migration and superoxide production in vitro. A shape change in human eosinophils that could be blocked by 7B11, a monoclonal antibody against human CCR3, was also observed. Biological a...
