White blood cells (WBCs) are integral components of the equine immune system, responsible for protecting horses against infections and foreign invaders. These cells circulate in the bloodstream and are produced in the bone marrow. The primary types of white blood cells in horses include neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with distinct functions in immune defense. Neutrophils are involved in the immediate response to infections, while lymphocytes play a role in adaptive immunity. Monocytes are involved in phagocytosis and the regulation of immune responses. Eosinophils and basophils are associated with allergic reactions and parasitic infections. Variations in white blood cell counts can indicate health conditions, making them valuable in veterinary diagnostics. This page compiles peer-reviewed research studies and scholarly articles that explore the function, regulation, and clinical relevance of white blood cells in equine health.
Jiang Z, Chen JW, Haughan J, Stefanovski D, Soma LR, Robinson MA.Extracorporeal shockwave therapy (ESWT) is a treatment applied to musculoskeletal injuries in equine athletes to alleviate pain and accelerate healing. ESWT also causes acute tissue damage. Therefore, its ability to act as an analgesic and cause tissue damage potentially increases the risk of a catastrophic event if used shortly before a strenuous competition such as horseracing. While ESWT is prohibited by many racing jurisdictions within 10 days prior to competition, a test to detect whether a horse has received ESWT is needed. ESWT changes the protein levels of inflammatory mediators in bl...
Raza F, Babasyan S, Larson EM, Freer HS, Schnabel CL, Wagner B.Interleukin-4 (IL-4) is a key cytokine secreted by type 2 T helper (Th2) cells that orchestrates immune responses during allergic reactions. Human and mouse studies additionally suggest that basophils have a unique role in the regulation of allergic diseases by providing initial IL-4 to drive T cell development towards the Th2 phenotype. Equine Culicoides hypersensitivity (CH) is a seasonal immunoglobulin E (IgE)-mediated allergic dermatitis in horses in response to salivary allergens from Culicoides (Cul) midges. Here, we analyzed IL-4 production in peripheral blood mononuclear cells (PBMC) o...
Witkowska-Piłaszewicz O, Pingwara R, Szczepaniak J, Winnicka A.Clenbuterol, the β2-adrenoceptor agonist, is gaining growing popularity because of its effects on weight loss (i.e., chemical liposuction). It is also popular in bodybuilding and professional sports, due to its effects that are similar to anabolic steroids. However, it is prohibited by anti-doping control. On the other hand, it is suggested that clenbuterol can inhibit the inflammatory process. The cells from 14 untrained and 14 well-trained race horses were collected after acute exercise and cultured with clenbuterol. The expressions of CD4, CD8, FoxP3, CD14, MHCII, and CD5 in PBMC, and reac...
van Galen G, Saegerman C, Hyldahl Laursen S, Jacobsen S, Andersson Munk M, Sjöström H, Holm Lindmark S, Verwilghen D.Non-steroidal anti-inflammatory drugs (NSAIDs) can cause right dorsal colitis, but longitudinal clinical studies are lacking. This study investigates whether NSAID treated horses develop right dorsal colonic pathology in a clinical setting. Non-gastrointestinal hospitalized horses treated with NSAIDs >4 days, and untreated hospital-owned teaching horses and non-gastrointestinal client-owned hospitalized horses were included. All horses were monitored over time with clinical examinations (focusing on presence of colic, depression, reduced appetite, unstructured feces), ultrasonographic intestin...
Li J, Zhao Y, Gao Y, Zhu Y, Holyoak GR, Zeng S.Bacterial infections are the main causes of endometritis in mares. It is well known that the most common bacterial pathogen is Streptococcus equi subspecies zooepidemicus (SEZ). This structured review was completed according to the PRISMA procedure to search endometritis treatment protocols published between 1990 and 2020 it was our intent to evaluate the actual effects of different treatment protocols for endometritis caused by SEZ. The trials included were collected from Pubmed, CAB and Agricola. Ten articles with 116 horses and 17 different interventions were identified. The results of this...
Frydendal C, Nielsen KB, Berg LC, van Galen G, Adler DMT, Andreassen SM, Jacobsen S.To investigate neutrophil gelatinase-associated lipocalin (NGAL) concentrations in serum and synovial fluid (SF) from horses with joint inflammation. Methods: Experimental studies and retrospective clinical study. Methods: Serum and SF samples were available from healthy horses (n = 19), clinical cases, and horses with experimental joint inflammation. Clinical cases included horses with (n = 10) or without (n = 10) septic arthritis. Experimental intra-articular inflammation was induced by lipopolysaccharide (LPS; n = 7, severe inflammation), lidocaine (n = 6, moderate inflammation), or mepivac...
Schneider LG, Cox Self A, Hines MT, Lin-Zambito Ivey J.Each year in the United States, unwanted horses may become neglected, starved, or abandoned. Recovery therapies include refeeding and veterinary care, often requiring substantial time and financial investments. To better understand the likelihood for starved horses to successfully survive the first 100 days after initial evaluation, a retrospective case series was performed using hospital records of starved horses at the University of Tennessee College of Veterinary Medicine. A body condition score (BCS) of 3 or less and a malnourished diagnosis were utilized to select case records from an 11...
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...
Trimboli F, De Amicis I, Di Loria A, Ceniti C, Carluccio A.The Martina Franca donkey (MFd) is one of the largest Italian donkey breeds, considered as endangered breed. To support the conservation strategies, knowledge about the physiologic hematological parameters of MFds is needed. The aims of the study were to determine reference value for hematological and major serum parameters in a population of healthy MFds and to estimate the influence of age on these parameters. Eighty-one clinically healthy MFds (17 males and 64 females) in different ages were enrolled: group A (foals, n° 16, animals < 1 year old) group B (young animals, n° 36, from 1 to 3 ...
Witkowska-Piłaszewicz O, Pingwara R, Winnicka A.Physical activity has an influence on a variety of processes in an athlete's organism including the immune system. Unfortunately, there is a lack of studies regarding racehorse immune cells, especially when the horse model is compared to human exercise physiology. The aim of the study was to determine changes in immune cell proliferation, lymphocyte populations, and monocyte functionality in trained and untrained racehorses after exercise. In this study, field data were collected. The cells from 28 racehorses (14 untrained and 14 well-trained) were collected before and after exercise (800 m at...
Kammerer R, Ballesteros A, Bonsor D, Warren J, Williams JM, Moore T, Dveksler G.In early equine pregnancy, a highly invasive trophoblast cell subpopulation, the chorionic girdle cells, invade the endometrium and form endometrial cups (EC). These cells express classical MHC molecules, thereby stimulating a humoral and cellular immune response, resulting in a massive accumulation of maternal CD4+ and CD8+ T cells around the EC. Nevertheless, no immediate destruction of endometrial cups by maternal lymphoid cells occurs, presumably due to immune tolerance. Although the environment of EC is rich in TGFB and in FOXP3+, CD4+ T cells, the mechanisms leading to tolerance have not...
Pradella GD, Taschetto PM, Duarte CA, da Silva Azevedo M, Góss GC.Adverse drug reactions in horses are rare. The antimicrobials are in the list of the most common drugs associated with reaction in horses. The aim of this report is to describe the clinical presentation of an adverse drug reaction after the intramuscular administration of ceftiofur hydrochloride. A 5-year-old crioulo broodmare at one day postpartum presented signs of difficulty to walk, positive pulse in the four limbs, and heart rate of 80 beats per minute (bpm), with a history of fighting with another mare. The clinical suspicions were rhabdomyolysis and laminitis. Initially a dose of flunix...
Journal of proteomicsSeptember 23, 2020
Volume 230 103989 doi: 10.1016/j.jprot.2020.103989
Weigand M, Hauck SM, Deeg CA, Degroote RL.Equine recurrent uveitis (ERU) is a spontaneous, remitting-relapsing autoimmune disease driven by the adaptive immune system. Although T cells are described as the main effector cells in pathogenesis, granulocytes have also emerged as possible disease mediators. To explore the role of these innate immune cells, we investigated the whole cell proteome of granulocytes from equine recurrent uveitis cases and healthy controls. Among the 2362 proteins identified by mass spectrometry, we found 96 proteins with significantly changed abundance between groups (p < 0.05, fold change >1.2), representin...
Satué K, Hernández Á, Lorente C, Fazio E, Medica P.The purpose of this study was to test the hypothesis that age and sex significantly modulate the changes in hematological parameters of physiologically healthy Spanish Purebred horse, establishing the reference values. Blood samples were obtained on a total of 159 horses (n = 77 males and n = 82 females), classified in four age groups: group A (1-2 years; n = 39), group B (>2-3 years; n = 38), group C (>3-4 years; n = 41), and group D (>4-7 years; n = 41). By means ADVIA 2020i, red blood cell (RBC), hemoglobin concentration (HB), packed cell volume, mean corpuscular volume (MCV), mea...
Wilmink JM, Ladefoged S, Jongbloets A, Vernooij JCM.The effect of dressings saturated with either a standardized suspension of probiotic bacteria or saline on healing of traumatic distal limb wounds in horses was evaluated for 24 days, and the systemic inflammatory effect was assessed. The wounds were divided in two groups based on the phase of healing: wounds with an incomplete (ICGB) or a complete granulation bed (CGB). The wound area was expressed as percentage of the wound area at day 0 and defined as relative wound area. The mean relative wound area decreased faster in probiotic than saline treated wounds. The difference was most obvious i...
Bauquier J, Tudor E, Bailey S.Doramapimod, a p38 MAPK inhibitor, is a potent anti-inflammatory drug that decreases inflammatory cytokine production in equine whole blood in vitro. It may have benefits for treating systemic inflammation in horses. Objective: To determine whether doramapimod is well tolerated when administered IV to horses, and whether it has anti-inflammatory effects in horses in a low-dose endotoxemia model. Methods: Six Standardbred horses. Methods: Tolerability study, followed by a blinded, randomized, placebo-controlled cross-over study. Horses were given doramapimod, and clinical and clinicopathologica...
Salinas C, Espinosa G, Morales N, Henríquez C, Morán G, Gajardo G, Uberti B.Obesity is a highly prevalent condition in horses. Dysfunctional neutrophil activity has been reported in metabolically healthy obese humans, but minimal data exist regarding horses. The present study evaluated the effect of obesity on apoptosis, phagocytosis and oxidative burst activity of peripheral blood neutrophils from lean and obese non-insulin dysregulated horses. Seven lean (BCS, body condition score 4-6/9) and five obese (BCS 8-9) horses were enrolled in the study. All animals underwent two metabolic tests (OGT, oral glucose test; IRT, insulin response test) before their selection to ...
Adler DMT, Serteyn D, Franck T, Jørgensen E, Christophersen MT, Denwood M, Verwilghen DR.To compare the extent of inflammation and catabolic collagen response in the middle carpal joints (MCJs) of healthy horses following intra-articular injection of 2% lidocaine, 2% mepivacaine, lactated Ringer solution (LRS), or 0.1% methyl parahydroxybenzoate. 17 adult horses. In the first of 2 experiments, the left middle carpal joint (MCJ) of each of 12 horses was injected with 10 mL of 2% lidocaine (n = 3), 2% mepivacaine (3), or LRS (control; 6). After a 4-week washout period, the right MCJ of the horses that received lidocaine or mepivacaine was injected with 10 mL of LRS, and the right MC...
Connelly C, Norton NA, Hurley DJ, Hart KA, Meichner K, Gogal RM.Peripheral blood is commonly sampled to assess the health status of human and veterinary patients. Venous blood collection is a minimally invasive procedure, and in the horse, the common collection site is the jugular vein. Post blood collection, sample processing for leukocyte enrichment can vary by research laboratory with the potential to yield different effects on the enriched cells and their function. The focus of the present study was to compare a common blood dilution-leukocyte enrichment technique using a Histopaque gradient medium (His) to a modified leukocyte buffy coat syringe-lymph...
Sotelo EDP, Vendruscolo CP, Fülber J, Seidel SRT, Jaramillo FM, Agreste FR, Silva LCLCD, Baccarin RYA.Several studies in human and equine medicine have produced controversial results regarding the role of dimethylsulfoxide (DMSO) as a therapeutic agent. This study aimed to evaluate the effect of joint lavage with different DMSO concentrations on biomarkers of synovial fluid inflammation and cartilage degradation in joints with lipopolysaccharide (LPS)-induced synovitis. Twenty-six tibiotarsal joints of 13 horses were randomly distributed into four groups (lactated Ringer's solution; 5% DMSO in lactated Ringer's; 10% DMSO in lactated Ringer's; and sham). All animals were evaluated for the prese...
Alonso JM, Schmidt EMS, Eckersall PD, Kjelgaard-Hansen M, Alves ALG, Rodrigues CA, Watanabe MJ, Crescencio AP, Hussni CA.The acute phase response is a response to injury and depends on the severity of the trauma. Heparin is routinely used for postsurgical treatment of horses to prevent abdominal adhesions; however, its effect on inflammation is unknown. This study aimed to assess systemic inflammatory response of horses subjected to small colon enterotomy and to evaluate heparin effects on postsurgical inflammation. Ten adult horses were subjected to small colon enterotomy and were assigned to a control or a treatment group. Both groups received prophylactic antibiotics and flunixin, and the treatment group rece...
Lange-Consiglio A, Romele P, Magatti M, Silini A, Idda A, Martino NA, Cremonesi F, Parolini O.Equine amniotic mesenchymal stromal cells (AMSCs) and their conditioned medium (CM) were evaluated for their ability to inhibit in vitro proliferation of peripheral blood mononuclear cells (PBMCs) with and without priming. Additionally, AMSC immunogenicity was assessed by expression of MHCI and MHCII and their ability to counteract the in vitro inflammatory process. Horse PBMC proliferation was induced with phytohemagglutinin. AMSC priming was performed with 10 ng/ml of TNF-α, 100 ng/ml of IFN-γ, and a combination of 5 ng/ml of TNF-α and 50 ng/ml of IFN-γ. The CM generated from na...
Stokol T.This article uses a case-based approach, complemented with diagnostic algorithms and images, to highlight hematologic changes of pathologic relevance in horses, namely, marked erythrocytosis, anemia or leukocytosis, inflammatory leukograms, lymphocytosis in adult horses, thrombocytopenia, and pancytopenia. These hematologic abnormalities occur with certain diseases and their identification can help clinicians narrow to down differential diagnostic lists. This article highlights the importance of blood smear examination, particularly, but not only, when numerical red flags are identified on aut...
Andrade DGA, Basso RM, Castiglioni MCR, Silva JP, Machado VMV, Laufer-Amorim R, Borges AS, Oliveira-Filho JP.Four causative mutations (D1, D2, D3*, and D4) of chondrodysplastic dwarfism have been described in the equine () gene. Homozygotes for one of these mutations and heterozygotes for any combination of these mutations exhibit the disproportionate dwarfism phenotype. However, no case description of homozygotes for D4 (D4/D4) has been reported in the literature, to our knowledge. We report 2 Miniature horses with the genotype D4/D4 in the gene. Clinically, the 2 dwarfs had a domed head that was large compared to the rest of the body, mandibular prognathism, and short and bowed limbs, mainly in t...
Fernandez NJ, Gilroy CV, Wagg CR, Kwong GPS, Roy MF.The detection of band neutrophils and toxic change via microscopic blood smear review is vitally important, as their presence indicates systemic inflammation. However, in-clinic evaluation of WBC morphology is often limited. Objective: We aimed to determine the agreement between expert raters in the detection of bands and toxic change. Methods: Three board-certified clinical pathologists each evaluated 109 blood smears from horses with acute disease, and 19 control smears from healthy horses. The pathologists determined if bands were present, and if so, the percentage of bands present. They a...
Neuenschwander HM, Moreira JJ, Vendruscolo CP, Fülber J, Seidel SRT, Michelacci YM, Baccarin RYA.The intra-articular use of hyaluronic acid (HA) for the treatment of synovitis and osteoarthritis is still controversial. As a consequence, corticosteroids remain the most frequently employed therapeutic agents, despite their potential systemic and local deleterious effects. This study examined the anti-inflammatory, antioxidant, and chondroprotective activities of low and high molecular weight hyaluronic acid (LMW-HA and HMW-HA) on lipopolysaccharide (LPS)-induced synovitis in horses compared to triamcinolone acetonide (TA). LPS was injected in the metacarpophalangeal joints, which were treat...
Espinosa G, Plaza A, Schenffeldt A, Alarcón P, Gajardo G, Uberti B, Morán G, Henríquez C.Polymorphonuclear neutrophils (PMN) are the largest leukocyte population in the blood of most mammals including horses, and play an important defensive role in many infectious diseases. However, the mechanisms that increase PMN as one of the main cellular subsets in the defense against pathogens could also be involved in the pathophysiology of dysregulated inflammatory conditions. Mesenchymal stem/stromal cells (MSCs) are a heterogeneous population with a modulatory potential on the inflammatory response and are known to interact with nearly all cells of the immune system, including PMN. In th...
Marín-López A, Barreiro-Piñeiro N, Utrilla-Trigo S, Barriales D, Benavente J, Nogales A, Martínez-Costas J, Ortego J, Calvo-Pinilla E.African horse sickness virus (AHSV) is an insect-borne pathogen that causes acute disease in horses and other equids. In an effort to improve the safety of currently available vaccines and to acquire new knowledge about the determinants of AHSV immunogenicity, new generation vaccines are being developed. In this work we have generated and tested a novel immunization approach comprised of nonstructural protein 1 (NS1) of AHSV serotype 4 (AHSV-4) incorporated into avian reovirus muNS protein microspheres (MS-NS1) and/or expressed using recombinant modified vaccinia virus Ankara vector (MVA-NS1)....
Wernery U, Rodriguez Caveney M, Wernery R, Raghavan R, Laroucau K, Syriac G, Thomas SM, John J, Joseph M, Jose S, Joseph S, Woo P.Six horses were challenged experimentally with a strain of Burkholderia pseudomallei isolated from a fatal case of the infection in a dromedary camel years earlier in the Emirate of Dubai. Three horses were inoculated subcutaneously and in 3 the bacterium was administered by the oral route. Four of the horses became serologically positive based on reactions to one or more of the OIE described tests for glanders. B. pseudomallei was re-isolated from the 4 serological positive horses. Only one of the subcutaneously infected horses, developed fever for 3 days. The white blood cell values and the ...
Daden R, Zarhouni FZ, Chakir J, Piro M, Achaâban MR, Ouassat M, El Allali K.To evaluate the effect of plasmapheresis on clinical, hematological, and biochemical parameters after exercise, a plasmapheresis session was realized on six jumping horses (plasmapheresis group) that underwent three consecutive days of physical graded exercise. The control group (n = 6) went through the same exercise but not subjected to the plasmapheresis session. Seventeen milliliters of plasma/kg of body weight was harvested from each horse. The procedure was well tolerated by the horses. The plasmapheresis leads to a significant increase of the hemoglobin, hematocrit, red blood cell, whit...
Andersen SA, Petersen HH, Ersbøll AK, Falk-Rønne J, Jacobsen S.European and American guidelines for vaccination against tetanus and influenza in horses recommend annual and annual/semi-annual vaccinations, respectively, against the two pathogens. Too-frequent vaccination may, however, have adverse effects, among other things because an inflammatory response is elicited with subsequent alterations in homeostasis. The objective of the study was to compare the acute phase response (APR) in 10 horses following administration of two different types of vaccines, namely, an inactivated Immune Stimulating COMplex (ISCOM) vaccine and a live recombinant vector vacc...
Casella S, Fazio F, Giannetto C, Giudice E, Piccione G.The modifications of Haptoglobin (Hp), Serum Amyloid A (SAA), Fibrinogen (Fbg) and White Blood Cells (WBCs) were evaluated in 15 Saddle Italian horses. Ten horses were transported covering a distance of about 320 km within 4 h with an average speed of 80 km/h (experimental group) and five horses were not subject to transportation (control group). Blood was collected via jugular venipuncture before the transportation (T0), immediately after the transportation (T1), 12 (T12), 24 (T24) and 48 (T48)hours after the transportation in experimental group and at the same time point in control group. Fo...
O'Neill T, Kydd JH, Allen GP, Wattrang E, Mumford JA, Hannant D.The frequency of antigen-specific, genetically restricted cytotoxic T lymphocyte precursors (CTLp) was measured in peripheral blood mononuclear cells (PBMC) of ponies before and after infection with equid herpesvirus 1 (EHV1). Split-well limiting dilution analysis (LDA) was developed to measure CTLp frequency using EHV1-infected 51Cr-labelled lymphoblasts as targets. Extensive characterisation showed that recombinant human interleukin-2, autologous antigen presenting cells and equine serum containing virus neutralising antibody were necessary for maturation of CTLp into effector CTL in vitro. ...
Chesters PM, Allsop R, Purewal A, Edington N.Results from Southern hybridization and PCR amplification experiments using a randomly synthesized reverse transcription-PCR product showed that peripheral blood leukocytes from horses showing no clinical signs of disease expressed a putative latency-associated transcript antisense to and overlapping the 3' end of the equid herpesvirus 1 (EHV-1) immediate-early gene (gene 64). A PCR product derived from this transcript has > or =96% identity with the published EHV-1 sequence. In situ hybridization studies of equine bronchial lymph nodes corroborated these findings and are consistent with re...
Kydd JH, Wattrang E, Hannant D.In general, vaccines containing inactivated equine herpesvirus-1 (EHV-1) fail to prevent abortion in pregnant mares following infection with a virulent strain of EHV-1. We have tested the hypothesis that resistance to EHV-1-induced abortion in pregnant mares is associated with high frequencies of EHV-1 specific, major histocompatibility complex (MHC) class I-restricted, cytotoxic T lymphocytes (CTL) in the circulation. To test this theory, three groups of pregnant mares were assembled with varying backgrounds of infection or vaccination in an attempt to mimic the immune status of the general p...
Dutta SK, Penney BE, Myrup AC, Robl MG, Rice RM.Fifty-five horses were inoculated IV and/or SC with materials containing Ehrlichia risticii, ie, infected whole blood, buffy coat cells, or cell culture, to study clinical and hematologic features of equine monocytic ehrlichiosis (Potomac horse fever). Major clinical and hematologic features of induced E risticii infection were biphasic increase in rectal temperature with peak increases of 38.9 C and 39.3 C on postinoculation days (PID) 5 and 12, respectively; depression; anorexia; decreased WBC count (maximal decrease of 47% on PID 12); and diarrhea from PID 14 to PID 18. Increased WBC count ...
Carrick JB, Begg AP.Assessment of peripheral blood leukocytes is the most common clinical pathology test in equine practice. It is always a part of complete body function assessment and frequently is used alone, or in conjunction with, fibrinogen to monitor response to treatment.
Cokelaere SM, Plomp SGM, de Boef E, de Leeuw M, Bool S, van de Lest CHA, van Weeren PR, Korthagen NM.Synovial inflammation is an important characteristic of arthritic disorders like osteoarthritis and rheumatoid arthritis. Orally administered non-steroidal anti-inflammatory drugs (NSAIDs) such as celecoxib are among the most widely prescribed drugs to manage these debilitating diseases. Intra-articular delivery in biodegradable in situ forming hydrogels overcomes adverse systemic effects and prolongs drug retention in the joint. In this study two formulations of celecoxib (40 mg/g and 120 mg/g) in a propyl-capped PCLA-PEG-PCLA triblock copolymer were sequentially evaluated in a multiple L...
Witkowska-Piłaszewicz O, Pingwara R, Winnicka A.Physical activity has an influence on a variety of processes in an athlete's organism including the immune system. Unfortunately, there is a lack of studies regarding racehorse immune cells, especially when the horse model is compared to human exercise physiology. The aim of the study was to determine changes in immune cell proliferation, lymphocyte populations, and monocyte functionality in trained and untrained racehorses after exercise. In this study, field data were collected. The cells from 28 racehorses (14 untrained and 14 well-trained) were collected before and after exercise (800 m at...
Hines MT, Paasch KM, Alperin DC, Palmer GH, Westhoff NC, Hines SA.Rhodococcal pneumonia is an important disease of young horses that is not seen in immunocompetent adults. Since all foals are normally exposed to Rhodococcus equi in their environment, we hypothesized that most develop protective immune responses. Furthermore, these antigen-specific responses were hypothesized to operate throughout adult life to prevent rhodococcal pneumonia. A better understanding of the mechanisms of immune clearance in adult horses would help define the requirements for an effective vaccine in foals. Adult horses were challenged with virulent R. equi by intrabronchial inocu...
Sutter WW, Kaneps AJ, Bertone AL.To evaluate the buffy coat and apheresis methods for preparation of platelet concentrates from equine blood by comparing platelet and growth factor concentrations. Methods: 15 mature mixed-breed geldings. Methods: Whole blood samples were collected and processed by use of a buffy coat or apheresis method to obtain platelet poor and platelet concentrated fractions. The PCV, WBC count, and platelet count were compared among whole blood samples, platelet poor fractions, concentrates obtained by use of the apheresis method (ie, apheresis platelet concentrates), and concentrates obtained by use of ...
Kleiber C, McGorum BC, Horohov DW, Pirie RS, Zurbriggen A, Straub R.Equine recurrent airway obstruction (RAO) is thought to result from an aberrant immune response to inhaled antigens, modulated by T lymphocytes via the secretion of pro-inflammatory cytokines. However data relating to the phenotypes of the T lymphocytes present in peripheral blood and bronchoalveolar lavage fluid of RAO horses and their cytokine profiles are contradictory. The aim of this study was to further investigate the cytokine (IL-4, IL-5, IL-13 and INF-gamma) mRNA expression profile in peripheral blood lymphocytes and bronchoalveolar lavage lymphocytes from RAO and control horses, befo...
Capomaccio S, Cappelli K, Barrey E, Felicetti M, Silvestrelli M, Verini-Supplizi A.It is known that moderate physical activity may have beneficial effects on health, whereas strenuous effort induces a state resembling inflammation. The molecular mechanisms underlying the cellular response to exercise remain unclear, although it is clear that the immune system plays a key role. It has been hypothesized that the physio-pathological condition that develops in athletes subjected to heavy training is caused by derangement of cellular immune regulation. The purpose of the present study was to obtain information on endurance horse gene transcription under strenuous conditions and t...
Hammond SA, Cook SJ, Falo LD, Issel CJ, Montelaro RC.Immunization regimens that induce a broadly reactive cytolytic T lymphocyte (CTL) response specific for lentiviral antigens have emerged as the leading candidates in efficacy trials conducted in both animal modelshumans. To date, lentivirus vaccination strategies have overlooked one such immunization strategy, namely the use of particulate antigens. To evaluate the efficacy of targeting antigen into the phagocytic pathway to elicit a cell-mediated immune response to lentiviral antigens, we initiated the first study of a particulate-based vaccination protocol using a large animal model system. ...
Paillot R, Daly JM, Juillard V, Minke JM, Hannant D, Kydd JH.Equine cytotoxic T lymphocyte (CTL) responses to equine herpesvirus-1 (EHV-1) are well characterised but little is known about the cytokine response after infection or vaccination. EHV-1 is common in horses and infects lymphocytes in vivo. This virus was used as a model to measure the synthesis of interferon gamma (IFN-gamma) by equine peripheral blood mononuclear cells (PBMC) after in vivo infection and/or in vitro stimulation with EHV-1. Both flow cytometry and ELISPOT assays were used to quantify equine IFN-gamma using a mouse anti-bovine IFN-gamma monoclonal antibody (clone CC302; shown to...
Breathnach CC, Soboll G, Suresh M, Lunn DP.A commercial bovine IFN-gamma-specific monoclonal antibody was used to measure antigen-specific IFN-gamma production by equine lymphocytes. Paired PBMC samples were collected from six ponies prior to and 10 days after challenge infection with equine herpesvirus-1 (EHV-1). Each sample was stimulated in vitro with EHV-1, virus-free medium, or PMA and ionomycin, and labelled with monoclonal antibodies specific for various equine lymphocyte subset markers. Following fixation, intracellular IFN-gamma was detected using a FITC-conjugated bovine IFN-gamma-specific monoclonal antibody. In vitro restim...
Mealey RH, Sharif A, Ellis SA, Littke MH, Leib SR, McGuire TC.Cytotoxic T lymphocytes (CTL) are critical for control of lentiviruses, including equine infectious anemia virus (EIAV). Measurement of equine CTL responses has relied on chromium-release assays, which do not allow accurate quantitation. Recently, the equine MHC class I molecule 7-6, associated with the ELA-A1 haplotype, was shown to present both the Gag-GW12 and Env-RW12 EIAV CTL epitopes. In this study, 7-6/Gag-GW12 and 7-6/Env-RW12 MHC class I/peptide tetrameric complexes were constructed and used to analyze Gag-GW12- and Env-RW12-specific CTL responses in two EIAV-infected horses (A2164 an...
Ibrahim S, Saunders K, Kydd JH, Lunn DP, Steinbach F.Three hundred and seventy-nine monoclonal antibodies (mAbs) against various human CD molecules supplied to the HLDA8 animal homologues section (including four isotype controls) were analysed for cross-reactivity with equine leukocytes. First, flow cytometric identification of positively reacting mAbs was performed in one laboratory. Thereafter, a second round of flow cytometric evaluation was performed, involving three laboratories participating in the study. The first test-round indicated 17 mAbs as potentially positive. After the second round of flow cytometric analysis, 14 mAbs remained (di...
Robbin MG, Wagner B, Noronha LE, Antczak DF, de Mestre AM.Several distinct T lymphocyte subpopulations with immunoregulatory activity have been described in a number of mammalian species. This study performed a phenotypic analysis of cells expressing regulatory T cell (Treg) markers in the peripheral blood of a cohort of 18 horses aged 6 months to 23 years, using antibodies to both intracellular and cell surface markers, including Forkhead box P3 (FOXP3), CD4, CD8, CD25, interferon gamma (IFNγ) and interleukin 10 (IL-10). In peripheral blood, a mean of 2.2 ± 0.2% CD4+ and 0.5 ± 0.1% CD8+ lymphocytes expressed FOXP3. The mean percentage of CD4+FOXP...
Castagnetti C, Mariella J, Pirrone A, Cinotti S, Mari G, Peli A.To evaluate and compare the gene expression of interleukin(IL)-1β, IL-8, and interferon-γ during the first 72 hours after birth in healthy foals and during the first 72 hours after hospitalization in sick neonatal foals and investigate correlations of clinicopathologic variables with cytokine expressions in healthy and sick neonatal foals. Methods: 33 foals < 7 days old (10 healthy foals, 7 foals with sepsis, 6 foals with peripartum asphyxia syndrome, and 12 foals with other diseases [2 with failure of passive transfer of immunity only were not further evaluated]). Methods: A blood sample...
Tumas DB, Hines MT, Perryman LE, Davis WC, McGuire TC.The immune control of chronic equine infectious anaemia (EIA) lentiviral infection was investigated by specifically depleting CD5+ T lymphocytes in vivo with monoclonal antibody (MAb) or by immunosuppression with corticosteroids. MAb was given at 25 to 50 mg/day intravenously for 11 days. Murine IgG1 anti-equine CD2 MAb (n = 2 horses) or IgG1 (n = 2) and IgG2a control MAb (n = 2 normal; 2 EIA-infected) did not deplete CD2+ T lymphocytes in horses. Horses given murine IgG2a anti-CD5 MAb HB19A (n = 4 normal; 5 EIA-infected) had depletion of peripheral blood CD5+ T lymphocytes during treatment. T...
Wagner B, Burton A, Ainsworth D.Cytokines produced by T helper (Th) cells are important in orchestrating the immune response during health and disease. Recent reports indicated that cytokine mRNA expression in foals is often quantitatively lower than that of adult horses suggesting that foal T cells are not fully mature. Here, peripheral blood mononuclear cells from foals and adult horses were stimulated with phorbol 12-myristate 13-acetate and analyzed for intracellular interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and IL-10 production, representing the Th1, Th2 and regulatory TR1 cell phenotypes respectively, by flow ...
Dawson TRMY, Horohov DW, Meijer WG, Muscatello G.Rhodococcus equi is recognised to cause chronic purulent bronchopneumonia in foals of less than 6 months of age. Virulent strains of the bacteria possess a large 80-90 kb plasmid encoding several virulence-associated proteins, including virulence-associated protein A (VapA), which is associated with disease. R. equi pneumonia can represent significant costs and wastage to the equine breeding industry, especially on stud farms where the disease is endemic. This article reviews knowledge of the equine immune response, both in the immune adult and susceptible neonate, with respect to this pathoge...
Moore BR, Krakowka S, Robertson JT, Cummins JM.Cytologic examination of bronchoalveolar lavage fluid (BALF), including phenotypic analysis of lymphocytes, was performed on 32 Standardbreds with poor race performance and endoscopic examination findings characteristic of inflammatory airway disease (IAD). Nucleated cell counts in BALF from IAD-affected horses were higher than those in control horses; the cytologic profile of BALF in affected horses included mixed inflammation, characterized by mild neutrophilia, lymphocytosis, and monocytosis. Eosinophil and mast cell counts were not higher in the IAD-affected group, compared with those in t...
Sheats MK, Pescosolido KC, Hefner EM, Sung EJ, Adler KB, Jones SL.Neutrophil infiltration is a prominent feature in a number of pathologic conditions affecting horses including recurrent airway obstruction, ischemia-reperfusion injury, and laminitis. Cell signaling components involved in neutrophil migration represent targets for novel anti-inflammatory therapies. In order to migrate into tissue, neutrophils must respond to chemoattractant signals in their external environment through activation of adhesion receptors (i.e. integrins) and reorganization of the actin cytoskeleton. Myristoylated Alanine-Rich C-Kinase Substrate (MARCKS), a highly conserved actin...
Faubladier C, Chaucheyras-Durand F, da Veiga L, Julliand V.This study evaluated the effect of transportation on fecal bacterial communities and activities in horses with or without supplementation of live yeast and attempted to link those effects with changes in blood stress markers. Four mature horses were assigned to a crossover design and fed a basal diet (60:40 forage to concentrate; 1.45% BW on a DM basis), with or without supplementation, of 2 × 10(10) cfu/d of Saccharomyces cerevisiae CNCM I-1077. After a 14-d adaptation to dietary treatments, the 5-d experiment started 1 d before transportation (d -1). At d 0, horses were simultaneously trans...
Flaminio MJ, Antczak DF.At days 36-38 of gestation, the equine invasive trophoblast cells migrate into the endometrium of the pregnant mare to form the endometrial cups. During their migration, they become surrounded by maternal CD4+ and CD8+ T lymphocytes, and stimulate a cytotoxic antibody response to the paternal major histocompatibility complex class I antigens that they express. Nevertheless, endometrial cup cells remain viable at the site of uterine invasion up to days 80-100 of gestation, suggesting the participation of immunomodulatory mechanisms to the maternal cellular immune response. To determine the effe...
Tonkin DR, Whitmore A, Johnston RE, Barro M.Replicon particles derived from Venezuelan equine encephalitis virus (VEE) are infectious non-propagating particles which act as a safe and potent systemic, mucosal, and cellular adjuvant when delivered with antigen. VEE and VEE replicon particles (VRP) can target multiple cell types including dendritic cells (DCs). The role of these cell types in VRP adjuvant activity has not been previously evaluated, and for these studies we focused on the contribution of DCs to the response to VRP. By analysis of VRP targeting in the draining lymph node, we found that VRP induced rapid recruitment of TNF-s...
Trapp S, von Einem J, Hofmann H, Köstler J, Wild J, Wagner R, Beer M, Osterrieder N.Key problems using viral vectors for vaccination and gene therapy are antivector immunity, low transduction efficiencies, acute toxicity, and limited capacity to package foreign genetic information. It could be demonstrated that animal and human cells were efficiently transduced with equine herpesvirus 1 (EHV-1) reconstituted from viral DNA maintained and manipulated in Escherichia coli. Between 13 and 23% of primary human CD3+, CD4+, CD8+, CD11b+, and CD19+ cells and more than 70% of CD4+ MT4 cells or various human tumor cell lines (MeWo, Huh7, HeLa, 293T, or H1299) could be transduced with o...
Giguère S, Hernandez J, Gaskin J, Miller C, Bowman JL.To evaluate WBC concentration, plasma fibrinogen concentration, and an agar gel immunodiffusion (AGID) test for early identification of Rhodococcus equi-infected foals. Methods: Prospective study. Methods: 162 foals from a farm with enzootic R equi infection. Methods: Blood samples were obtained from each foal at 4-week intervals for measurement of WBC and plasma fibrinogen concentrations and at 2-week intervals for detection of anti-R equi antibody by an AGID assay. Diagnostic performance of WBC and fibrinogen concentrations was assessed by use of receiver operating characteristic curve analy...
