The immune system in horses is a complex network of cells, tissues, and organs that work together to protect the body from pathogens, such as bacteria, viruses, and parasites. This system includes both innate and adaptive immune responses, which function to identify and eliminate foreign invaders. The innate immune response provides an immediate, non-specific defense, while the adaptive immune response involves a more targeted and long-lasting protection through the production of antibodies. Key components of the equine immune system include white blood cells, such as lymphocytes and macrophages, as well as various signaling molecules like cytokines. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and regulation of the immune system in horses, with an emphasis on understanding its role in maintaining equine health and its response to diseases.
Khaliji E, Marycz K, Horna M, Morgan JM, Galuppo LD, Vapniarsky N, Cassano JM.To evaluate IA autologous platelet-derived mitochondrial preparation versus vehicle control in a bilateral lipopolysaccharide (LPS)-induced model of equine synovitis. Unassigned: 2 ng of LPS was injected into bilateral intercarpal joints of 6 horses over 3 months. Autologous mitochondria, isolated with a commercial kit, were injected into one joint, while the contralateral joint received a vehicle control, a within-subject controlled experimental design. Mitochondrial organelle appearance was visualized on transmission electron microscopy. Outcome measures included synovial fluid and whole-blo...
Hildebrandt D, Venner M, Hart KA, Berghaus L.Early and specific diagnosis of bronchopneumonia in foals is important to prevent severe disease. In human medicine, C-reactive protein (CRP) and interleukin-6 (IL-6) are important diagnostic and prognostic biomarkers in neonatal pneumonia in other species. Evaluation of these markers in foals with naturally occurring respiratory diseases is lacking. Objective: To determine if CRP and IL-6 were useful predictors of respiratory disease in foals from birth to weaning. Methods: Prospective cohort study. Methods: Periodic blood samples from 200 initially healthy foals were collected from birth to ...
Albornoz A, Morales B, Fernandez VB, Henriquez C, Quiroga J, Alarcón P, Moran G, Burgos RA.Equine asthma is a chronic respiratory disease characterised by neutrophilic inflammation, airway hyperresponsiveness, and impaired pulmonary function. Obesity, increasingly prevalent among domestic horses, has been identified as a potential risk factor for exacerbating inflammatory conditions. This study aimed to explore whether obesity modifies neutrophil metabolism and inflammatory responses in horses affected by asthma. Six asthmatic horses in clinical remission were categorised into two groups: obese and non-obese, based on body condition score. Serum levels of interleukin-1β (IL-1β) an...
Cserhalmi D, Wermer K.Our paper presents a case study of a Welsh pony mare with grazing-induced severe urticaria. The main clinical signs were eye swelling, depression and extensive urticaria. Physical examination revealed no other abnormalities. Botanical sampling revealed horseweed (Conyza canadensis) as the most abundant species and a potential allergen plant due to sesquiterpene lactones (SQL). Differential diagnosis strongly suggested that the clinical signs were the result of a hypersensitivity reaction to this plant. Former studies brought controversial data about the toxic or allergic potential of horsewee...
Perzyna M, Grzędzicka J, Milczek-Haduch D, Dąbrowska I, Trela M, Pawliński B, Witkowska-Piłaszewicz O.Donkeys are routinely vaccinated with protocols developed for horses, yet species-specific data on their immune responses are limited. Objective: We hypothesized that donkeys exhibit robust T-cell-mediated immunity and regulatory adaptation after vaccination, comparable to horses. Methods: Thirty-six healthy, seronegative donkeys (34 mares, 2 stallions), aged 0.5-23 years (median 8 years), from two farms with similar housing and management conditions. Methods: Prospective study. Animals were selected based on clinical health assessment and confirmed seronegativity for tetanus and equine in...
da Silveira BP, Kahn SK, Legere RM, Bray JM, Cole-Pfeiffer HM, Golding MC, Cohen ND, Bordin AI.Using a horse foal model, we show that enteral immunization of newborn foals with Rhodococcus equi overcomes neonatal vaccination challenges by reprogramming innate immune responses, inducing R. equi-specific adaptive humoral and cell-mediated immune responses and protecting foals against experimental pneumonia challenge. Foals were immunized twice via gavage of R. equi (immunized group) or saline (control group) at ages 1 and 3 days. At age 28 days, all foals were challenged intrabronchially with R. equi. Post-challenge, all 5 immunized foals remained healthy, whereas 67% (4/6) of control foa...
Li X, Hu S, Yu Z, He F, Zhao X, Liu R.Nanoplastics (NPs) are emerging pollutants worldwide. Particularly worrisome is that although studies have reported that NPs can amplify the biotoxicity of environmental pollutants, the specific mechanism remains unclear. Here, we found that NPs, even without significant toxicity (cell survival: 99.11%), amplified the hepatocyte toxicity of Cd. Mechanistically, higher Cd uptake (Δ = 23.80%) combined with crucial intracellular desorption behavior of Cd loaded in NPs (desorption rate: 82.70%) were identified as prerequisites for NPs amplifying Cd cytotoxicity. As for toxigenic pathways, the inf...
Ji Y, Xu D, Si W, Zhang Y, Khan MZ, Zhao X, Liu W.The present study investigated the host cell response to EHV-8 infection in rabbit kidney (RK-13) cells through transcriptomic and proteomic approaches. At 24 h post-infection, a total of 2118 differentially expressed genes (DEGs) were identified, with 1338 upregulated and 780 downregulated. At 48 h, 7388 DEGs were detected, with 4342 upregulated and 3046 downregulated genes. Proteomic analysis revealed 932 differentially expressed proteins (DEPs) at 24 h (364 upregulated and 568 downregulated) and 3866 DEPs at 48 h (2285 upregulated and 1581 downregulated). Of these, 237 upregulated and 336 d...
Giercuszkiewicz-Hecold B, Pajuelo D, Steczkiewicz Z, Cywinska A, Marycz K.Astaxanthin, a strong antioxidant carotenoid, has shown promising features in mitigating inflammation and oxidative stress and so that has been considered as a supplement for high-performance animals. In this study, we aimed to evaluate the effects of astaxanthin on oxidative stress, inflammation, and mitochondrial health in peripheral blood mononuclear cells (PBMC) isolated from Arabian racehorses. Horse-derived peripheral blood mononuclear cells exposed to hydrogen peroxide (H₂O₂) presented increased reactive oxygen species (ROS) accumulation and overexpression of pro-inflammatory cytoki...
da Silva-Álvarez E, Gómez-Arrones V, Correa-Fiz F, Martín-Cano FE, Gaitskell-Phillips G, Carrasco JJ, Rey J, Aparicio IM, Peña FJ, Alonso JM....This study aims to unveil potential differences in the vaginal and uterine microbiomes in mares and jennies, and to identify possible mechanisms involved in uterine immune homeostasis. The microbiota was characterized using 16S rRNA sequencing, and the uterine proteome was analyzed using UHPLC/MS/MS in 18 samples from healthy mares and 14 from jennies. While taxonomic analysis revealed high interspecies similarities, β-diversity analysis showed distinct clustering, with only two vaginal taxa and five uterine taxa differing between species. Despite compositional differences, PICRUSt analysis s...
Conley HE, Davis KU, Adler KB, Lavoie JP, Sheats MK.Asthma is a chronic inflammatory airway disease that affects millions of people worldwide. Horses develop asthma spontaneously and serve as a relevant model for multiple phenotypes and endotypes of human asthma. In horses with equine asthma (EA), environmental organic dust triggers increased inflammatory cytokines, excess airway mucus, reversible bronchoconstriction, and airway inflammation. In horses with severe EA (sEA), lower airway inflammation is invariably neutrophilic, making sEA a potential model for severe neutrophilic asthma in humans. Alveolar macrophages (AM) and airway neutrophils...
Simms N, Bertone JJ, Melgarejo T, O'Shea C, Linde A.Emerging research suggests the presence of a blood microbiome in clinically healthy individuals. Characterizing bacterial composition and abundance in blood from a group of healthy horses is of clinical interest. Objective: Horses in a closed herd environment will have blood microbiomes with similarities among individuals. Methods: Twenty trail-riding horses of different breeds and ages living in relative isolation on a dry lot pasture in Colorado at 7680 ft elevation. Methods: Cross-sectional study. Blood was collected from the jugular vein into serum, blood collection, and EDTA tubes. Samp...
de la Cuesta-Torrado M, Vitale V, Velloso Alvarez A, Neira-Egea P, Diss C, Cuervo-Arango J.Equine herpesvirus 1-induced myeloencephalopathy has a significant impact on the equine industry. Nevertheless, the clinical variables that may affect the severity of the disease are still under investigation. The objective of this research is studying the relationship between the level of lymphopenia and vaccination status with the severity of the disease in horses at an event, considering whether they had been correctly vaccinated or not prior to exposure to EHV-1. Ten horses were admitted to a veterinary teaching hospital following an equine herpesvirus myeloencephalopathy outbreak during a...
Akçay S, Gurkok-Tan T, Ekici S.Intense physical activity in endurance horses triggers complex immune and inflammatory responses, yet the molecular mechanisms underlying these adaptations remain unclear. This study investigated immune-related transcriptomic changes following a 160 km endurance ride, focusing on sex-based differences. Using a bioinformatics approach, differentially expressed genes (DEGs), pathways, microRNAs (miRNAs), and transcription factors (TFs) were analyzed before (T0) and after (T1) the ride. A protein-protein interaction (PPI) analysis was conducted to identify key regulatory genes. Pathway enrichment...
Żak-Bochenek A, Drábková Z, Sergedaite V, Siwińska N, Bajzert J, Pasak D, Chełmońska-Soyta A.Colic-related obstructions can reduced intestinal mucosa function and cause dysbiosis in horses, but it is unclear how defense barrier and secretory immunoglobulin A (SIgA) secretion is disrupted. Objective: The aim of the study is to evaluate the effect of severity of colic signs and treatments on fecal SIgA and fecal lactate in horses. Methods: Sixty-two client owned hospitalised horses with colic and eight healthy horses. Methods: Prospective clinical trial. Fecal samples were taken daily for 7 days. SIgA was analyzed using ELISA, and D/L-lactate measured with a commercial kit. Results: A...
Chen X, Gulbahar K, Ding H, Nie C, Gao X.Horse milk is a highly valuable organic food that is a promising alternative to cow milk, exhibiting plenty of healthy and immune benefits to human. However, identification of proteins associated human wellness and underlying molecular mechanism in horse milk remain unclear. Unassigned: Label-free mass spectrometry-based protein quantification technology was employed to investigate protein composition of animal milk, including cow, goat, camel and horse milk. Prokaryotic expression and disk diffusion assay were applied to acquire and evaluate antimicrobial activity of candidate proteins. RAW2...
Asif S, Gulzar MW.Endometritis is a significant cause of infertility in mare. Some infectious agents disrupt the endometrium's innate immune system, resulting in a prolonged systemic inflammatory response that circulates via the blood or cellular degeneration, which ultimately leads to endometritis from bacterial endotoxins. Numerous biological processes use various small, non-coding RNA molecules called MicroRNAs. MicroRNAs (miRNAs) regulate gene expression after transcription by blocking transcription and translation. This manuscript examines patho-morphological discoveries in equine endometritis, the express...
Fedorka CE, Scoggin KE, Coleman SJ, Hatzel JN, Burleson MD, Troedsson MHT.Alterations during the early stages of embryo development have been associated with long-term effects on the fetus, neonate, and adult, but this has not been investigated in horses. In recent years, intracytoplasmic sperm injection (ICSI) has gained in commercial popularity in the equine population. Research suggests an association between ICSI-produced embryos and placental malformations, but there exists little understanding of the physiology involved. Therefore, we aim to produce a complete transcriptomic analysis of chorioallantois and provide potential pathways that may be impacted follow...
Płoneczka-Janeczko K, Armstrong E, Siemieniuch-Tartanus M, Magdziarz M.The aim of the study was to explore and characterise healthy foals' eye microbiomes in the first two months of life. Unassigned: Conjunctival swabs were collected three times, not later than 12 h after delivery and again at the end of the first and the second months of life from six clinically healthy foals of the Polish Konik breed. The average interval between the first and second samplings was 33.3 days and between the second and third was 35.6 days. Next-generation sequencing performed on a MiSeq sequencer in paired-end technology was used to analyse the composition of the conjunctival mic...
Helbig H, Berghaus LJ, Venner M, Berghaus R, Hart KA.Adequate vitamin availability is vital for cellular and immune function and for normal growth. Available data on age-related changes in serum concentrations of vitamins in foals are limited. In addition, associations between circulating vitamin concentrations and the development of bronchopneumonia in foals are not described. Objective: (1) To quantify circulating concentrations of vitamins C, D and E from birth to weaning in foals; (2) to determine associations between vitamin concentrations and the development of bronchopneumonia during this period. Methods: Prospective cohort study. Methods...
Durward-Akhurst SA, Valberg SJ.Several inflammatory myopathies have an infectious or immune-mediated basis in the horse. Myosin heavy chain myopathy is caused by a codominant missense variant in MYH1 and has 3 clinical presentations: immune-mediated myositis, calciphylaxis, and nonexertional rhabdomyolysis in Quarter Horse-related breeds. An infarctive form of purpura hemorrhagica affects numerous breeds, presenting with focal firm, painful muscle swelling, and subsequent infarction of multiple tissues. While Streptococcus equi equi is often the inciting cause, anaplasmosis, sarcocystis, piroplasmosis, viruses, and vaccines...
Shinn LT, Wagner CB, Desai R, Marini BL.Horse antithymocyte globulin carries a black box warning for life-threatening anaphylactic reactions, and prescribing information recommends test doses to identify patients at highest risk of this adverse effect. The predictive value of such test doses is not well validated, and practicality of use is unclear. Methods: This was a planned secondary analysis of a multicenter, retrospective cohort study in adults with severe aplastic anemia being managed with horse antithymocyte globulin as part of their treatment regimen. Qualitative and quantitative descriptions of test doses and infusion react...
Alemi M, Ahmadi Sheikhsarmast S, Mohri M.The optimal amount of vitamin D required for the proper functioning of the immune system differs from the amount necessary for bone homeostasis. Furthermore, vitamin D metabolism varies among horses. Nevertheless, there is a dearth of information regarding reference values for vitamin D in horses, particularly in the Turkmen breed. The primary objectives of this study were to determine the concentrations of 25-hydroxyvitamin D (25(OH)Vit D) in Turkmen, Thoroughbred and mixed Turkmen × Thoroughbred horses and to explore the effects of various factors on it and its relationship with serum bio...
Jaworska J, Tobolski D, Salem SE, Kahler A, Wocławek-Potocka I, Mestre AM.Embryo implantation in the mare occurs just over one month after fertilization, coinciding with the production of chorionic gonadotropin. The factors that regulate this late implantation in the mare, and whether they are unique to horses or shared with more invasive embryo implantation in other species, remain poorly understood. This study aimed to determine and compare the transcriptome and subpopulations of endometrial cells before and after embryo implantation in the horse. Single-cell RNA sequencing was used to characterize the transcriptome of nearly 97,000 endometrial cells collected fro...
Chen JW, Stefanovski D, Haughan J, Jiang Z, Soma LR, Robinson MA.Interleukin 1 beta (IL-1β) and IL-1 receptor antagonist (IL-1RA) are both upregulated following traumatic injury. As IL-1RA blocks inflammatory signaling by IL-1β, overexpression of IL-1β relative to IL-1RA may drive inflammatory diseases. As such, determination of the relationship between IL-1β to IL-1RA expression levels in horses may provide insight into disease states or serve as a therapeutic readout of response to medical interventions. As techniques to detect plasma concentrations of IL-1β and IL-1RA in horses lack sensitivity, we developed and validated novel enzyme-linked immunos...
Magdesian KG.Knowledge of immunodeficiencies is crucial to neonatal medicine, in that they predispose to sepsis in the newborn and neonatal foal, as well as recurrent infections in older foals. The most common immunodeficiency in newborn and neonatal foals is failure of passive transfer, which is an example of an acquired immunodeficiency. Congenital or developmental immunodeficiencies may be transient or permanent, and can either affect the cell-mediated or humoral arms of immunity, and in some cases both. Affected foals often have chronic or recurrent respiratory or gastrointestinal infections, often wit...
Mainguy-Seers S, Holcombe SJ, Lavoie JP.Vitamin D deficiency is associated with asthma development and severity of symptoms in humans, but whether the same occurs in horses is unknown. We aimed to determine whether the serum vitamin D levels differ in horses with asthma compared to control animals and, secondarily, to explore clinical, respiratory, and environmental parameters associated with its concentration in equids in a retrospective cross-sectional study. The total serum vitamin D (25(OH)D) was measured by radioimmunoassay in 45 serum samples from the Equine Respiratory Tissue Biobank (15 control animals, 14 horses with mild o...
Pooja , Thapa N, Rani R, Shanmugasundaram K, Jhandai P, Rakshita , Bhattacharya TK, Singha H.Immunological aspects of B. mallei infection were rarely studied in natural cases of equines. The present study was conducted to determine IgG, IgM, IgA and IgG (T) titre against recombinant Hcp1, TssA and TssB proteins and PilA-Hcp1-TssN-BipD and BpaB-BpaC- BMAA0553 chimeras and cytokine responses in glanders affected equine serum. Methods: The study was conducted on serum samples collected from 151 glanders positive equines which include horses (n = 134), mules (n = 16), and donkeys (n = 01). The IgM, IgG, IgA and IgG (T) titre were determined against recombinant antigens by indirect E...
Migdał A, Migdał Ł, Oczkowicz M, Tombarkiewicz B, Okólski A.Colostrum contains substances such as hormones, enzymes, polyamides, nucleic acid derivatives, and amino acid derivatives and also includes immunomodulating substances, proline-rich polypeptides, immunoglobulins (Ig) as well as bacteriostatic compounds. The aim of the study was to evaluate the impact of colostral Ig on the level of expression of selected Toll-like receptor genes (TLR3, TLR4, and TLR7). The experiments were conducted on 25 Polish Pony foals. Blood samples were collected according to the following scheme: before first suckling, at the 1st, 3rd, 5th, 10th, 20th, and 30th, day of ...
Botía M, Martín-Cuervo M, Martínez-Subiela S, Cerón JJ, Ayala I, Hansen S, Muñoz-Prieto A.Equine Gastric Ulcer Syndrome (EGUS) is a widespread disease with a very high prevalence and importance in horses. It includes two conditions: Equine squamous gastric disease (ESGD), linked to acid disturbances, and Equine Glandular Gastric Disease (EGGD), associated with inflammation and immune system issues. In saliva, increased levels of immunological markers have been observed in this disease, indicating immune system involvement. In addition, changes in biomarkers of oxidative stress have been described. In horses, IgG and IgA are proteins that appear in saliva and serum and are considere...
Wiler R, Leber R, Moore BB, VanDyk LF, Perryman LE, Meek K.V(D)J rearrangement is the molecular mechanism by which an almost infinite array of specific immune receptors are generated. Defects in this process result in profound immunodeficiency as is the case in the C.B-17 SCID mouse or in RAG-1 (recombination-activating gene 1) or RAG-2 deficient mice. It has recently become clear that the V(D)J recombinase most likely consists of both lymphoid-specific factors and ubiquitously expressed components of the DNA double-strand break repair pathway. The deficit in SCID mice is in a factor that is required for both of these pathways. In this report, we show...
Perryman LE, O'Rourke KI, McGuire TC.Six normal and four immunodeficient horses were injected with a cloned variant of equine infectious anemia virus (EIAV). The six normal horses had detectable EIAV in their plasma by 7 days postinjection. During their primary viremic episode, which was accompanied by fever and anemia, maximum titers of EIAV in plasma ranged from 10(3.8) to 10(4.8) 50% tissue culture infective doses per ml. All six normal horses cleared detectable virus from their plasma by 21 to 35 days after injection. Horses with combined immunodeficiency became viremic by 9 days postinjection and also developed anemia. In co...
Afable MG, Shaik M, Sugimoto Y, Elson P, Clemente M, Makishima H, Sekeres MA, Lichtin A, Advani A, Kalaycio M, Tiu RV, O'Keefe CL, Maciejewski JP.A combination of horse anti-thymocyte globulin and cyclosporine produces responses in 60-70% of patients with severe aplastic anemia. We performed a phase II study of rabbit anti-thymocyte globulin and cyclosporine as first-line therapy for severe aplastic anemia. Methods: Twenty patients with severe aplastic anemia treated with rabbit anti-thymocyte globulin were compared to 67 historical control cases with matched clinical characteristics treated with horse anti-thymocyte globulin. Results: Response rates at 3, 6 and 12 months were similar for patients treated with rabbit anti-thymocyte glob...
Allen GP.To identify risk factors associated with development of clinical neurologic signs in horses exposed to equine herpesvirus-1 (EHV-1). Methods: 36 adult horses. Methods: Blood samples collected before and after challenge inoculation with nonneuropathogenic or neuropathogenic EHV-1 were analyzed for leukocyte-associated viremia, serum neutralizing antibody, and EHV-1-specific cytotoxic T-lymphocyte precursors (CTLPs). Associations between variables and neurologic disease and correlations between age category or breed and development of neurologic disease were examined. Results: 9 horses developed...
Wood JL, Newton JR, Chanter N, Mumford JA.Respiratory disease is important in horses, particularly in young Thoroughbred racehorses, and inflammation that is detected in the trachea and bronchi (termed inflammatory airway disease [IAD]) is more significant in this population in terms of impact and frequency than other presentations of respiratory disease. IAD, which is characterized by neutrophilic inflammation, mild clinical signs, and accumulation of mucus in the trachea, may be multifactorial, possibly involving infections and environmental and immunological factors, and its etiology remains unclear. This 3-year longitudinal study ...
Lange-Consiglio A, Perrini C, Tasquier R, Deregibus MC, Camussi G, Pascucci L, Marini MG, Corradetti B, Bizzaro D, De Vita B, Romele P, Parolini O....Administration of horse amniotic mesenchymal cells (AMCs) and their conditioned medium (AMC-CM) improves the in vivo recovery of spontaneous equine tendon lesions and inhibits in vitro proliferation of peripheral blood mononuclear cells (PBMC). This process may involve microvesicles (MVs) as an integral component of cell-to-cell communication during tissue regeneration. In this study, the presence and type of MVs secreted by AMCs were investigated and the response of equine tendon cells to MVs was studied using a dose-response curve at different concentrations and times. Moreover, the ability ...
Breathnach CC, Sturgill-Wright T, Stiltner JL, Adams AA, Lunn DP, Horohov DW.The increased vulnerability of foals to specific pathogens such as Rhodococcus equi is believed to reflect an innate immunodeficiency, the nature of which remains poorly understood. Previous studies have demonstrated that neonates of many species fail to mount potent Th1 responses. The current research investigates the ability of circulating and pulmonary lymphocytes of developing foals to produce interferon gamma (IFNgamma). Peripheral blood mononuclear cells (PBMC) were prepared from up to 10 horse foals at regular intervals throughout the first 6 months of life. Bronchoalveolar lavage (BAL)...
Kirschvink N, de Moffarts B, Lekeux P.Since "free radical research" started in 1954, understanding the role of oxidants and antioxidants in physiological and pathological conditions has increased continuously. Oxidants are essentially generated by metabolic enzymes, inflammatory cells and mitochondrial electron leakage; they are indispensable for the cellular redox regulation and may, under certain conditions, have a pro-inflammatory stimulatory role. Endogenous and exogenous antioxidants counterbalance the oxidative processes and so maintain the oxidant/antioxidant equilibrium. Excessive oxidant generation or antioxidant insuffic...
Kydd JH, Townsend HG, Hannant D.Equine herpesvirus-1 (EHV-1) is an alphaherpesvirus which infects horses, causing respiratory and neurological disease and abortion in pregnant mares. Latency is established in trigeminal ganglia and lymphocytes. Immunity to EHV-1 lasts between 3 and 6 months. Current vaccines, many of which contain inactivated virus, have reduced the incidence of abortion storms in pregnant mares but individual animals, which may be of high commercial value, remain susceptible to infection. The development of effective vaccines which stimulate both humoral and cellular immune responses remains a priority. Uti...
Colbath AC, Dow SW, Phillips JN, McIlwraith CW, Goodrich LR.The use of allogeneic bone marrow-derived mesenchymal stem cells (BMDMSCs) may provide an effective alternative to autologous BMDMSCs for treatment of equine musculoskeletal injuries. However, concerns have been raised regarding the potential safety and effectiveness of allogeneic BMDMSCs. We conducted studies to assess the immunological properties of equine allogeneic BMDMSCs compared with those of autologous BMDMSCs. For assessment of inherent immunogenicity, the relative ability of allogeneic and autologous BMDMSCs to stimulate spontaneous proliferation of equine lymphocytes was compared. T...
Sheats MK.The most recent definition of sepsis in human medicine can be summarized as organ dysfunction caused by a dysregulated host response to infection. In equine medicine, although no consensus definition is available, sepsis is commonly described as a dysregulated host systemic inflammatory response to infection. Defense against host infection is the primary role of innate immune cells known as neutrophils. Neutrophils also contribute to host injury during sepsis, making them important potential targets for sepsis prevention, diagnosis, and treatment. This review will present both historical and u...
Harrold SM, Cook SJ, Cook RF, Rushlow KE, Issel CJ, Montelaro RC.Equine infectious anemia virus (EIAV) infection of horses is characterized by recurring cycles of disease and viremia that typically progress to an inapparent infection in which clinical symptoms are absent as host immune responses maintain control of virus replication indefinitely. The dynamics of EIAV viremia and its association with disease cycles have been well characterized, but there has been to date no comprehensive quantitative analyses of the specific tissue sites of EIAV infection and replication in experimentally infected equids during acute disease episodes and during asymptomatic ...
Kydd JH, Smith KC, Hannant D, Livesay GJ, Mumford JA.Twelve adult ponies and 2 conventional foals were exposed intranasally to EHV-1, strain Ab4 (TCID50 10(-6.6) and samples of respiratory tract associated lymphoid tissues were recovered between 12 h and 13 days after infection. Infectious virus was detected in tissue homogenates using susceptible cell monolayers and expression of viral antigens was monitored using indirect immunoperoxidase histochemistry on paraffin sections. The results showed both infectious EHV-1 and viral antigens in respiratory tract associated lymph nodes 12 h after exposure. Infected leucocytes were identified morphologi...
Atta EH, Dias DS, Marra VL, de Azevedo AM.The best antithymocyte globulin preparation for first-line immune suppression in patients with severe aplastic anemia is still not clear. The aim of this study was to compare hematological response and overall survival in patients submitted to horse or rabbit antithymocyte globulin as first-line treatment for severe aplastic anemia. We retrospectively compared 71 consecutive patients with severe aplastic anemia, classified according to the antithymocyte globulin preparation. Analyses included variables related to patients and to immune suppression. Forty two patients (59.1%) received horse and...
Takahashi T, Yawata M, Raudsepp T, Lear TL, Chowdhary BP, Antczak DF, Kasahara M.In rodents, the Ly49 family encodes natural killer (NK) receptors interacting with classical MHC class I molecules, whereas the corresponding receptors in primates are members of the killer cell immunoglobulin-like receptor (KIR) family. Recent evidence indicates that the cattle, domestic cat, dog, and pig have a single LY49 and multiple KIR genes, suggesting that predominant NK receptors in most non-rodent mammals might be KIR. Here, we show that the horse has at least six LY49 genes, five with an immunoreceptor tyrosine-based inhibition motif (ITIM) and one with arginine in the transmembrane...
Smith T.The foregoing and earlier data taken together demonstrate that an active immunity lasting several years can be produced in guinea-pigs, by the injection of toxin-antitoxin mixtures which have no recognizable harmful effect either immediate or remote. They also show, what might have been anticipated, that under the same conditions mixtures which produce local lesions and which, therefore, contain an excess of toxin produce a much higher degree of immunity than the neutral mixtures, and that an excess of antitoxin reduces the possibility of producing an active immunity, and may extinguish it alt...
Chang MH, Kim KH, Kim HS, Jun HJ, Kim DH, Jang JH, Kim K, Jung CW.Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) plus cyclosporine (CSA) is standard therapy in patients with severe aplastic anemia (SAA) who do not have an available HLA-matched sibling donor. Methods: The current study aimed to determine the predictive factors for response to IST in patients with SAA and to identify prognostic factors following IST. A total of 62 patients diagnosed with SAA who received IST with either rabbit ATG (n = 33) or horse ATG (n = 29) plus CSA between October 1994 and December 2007 were included. Results: With a median follow-up duration of 60.5 mo...
McGuire TC, Tumas DB, Byrne KM, Hines MT, Leib SR, Brassfield AL, O'Rourke KI, Perryman LE.Cytotoxic T lymphocytes (CTL) can control some viral infections and may be important in the control of lentiviruses, including human immunodeficiency virus type 1. Since there is limited evidence for an in vivo role of CTL in control of lentiviruses, dissection of immune mechanisms in animal lentiviral infections may provide needed information. Horses infected with equine infectious anemia virus (EIAV) a lentivirus, have acute plasma viremia which is terminated in immunocompetent horses. Viremic episodes may recur, but most horses ultimately control infection and become asymptomatic carriers. ...
Bullone M, Lavoie JP.Aging is associated with a dysregulation of the immune system, leading to a general pro-inflammatory state of the organism, a process that has been named inflamm-aging. Oxidative stress has an important role in aging and in the regulation of immune responses, probably playing a role in the development of age-related diseases. The respiratory system function physiologically declines with the advancement of age. In elderly asthmatic patients, this may contribute to disease expression. In this review, we will focus on age-related changes affecting the immune system and in respiratory structure an...
Carpenter S, Evans LH, Sevoian M, Chesebro B.Equine infectious anemia virus was isolated from peripheral blood leukocytes collected during two early febrile cycles of an experimentally infected horse. RNase T1-resistant oligonucleotide fingerprint analyses indicated that the nucleotide sequences of the isolates differed by approximately 0.25% and that the differences appeared randomly distributed throughout the genome. Serum collected in the interval between virus isolations was able to distinguish the isolates by membrane immunofluorescence on live cells. However, no neutralizing antibody was detected in the interval between virus isola...
Schoster A, Weese JS, Guardabassi L.The gastrointestinal microbiota is extremely important for human and animal health. Investigations into the composition of the microbiota and its therapeutic modification have received increasing interest in human and veterinary medicine. Probiotics are a way of modifying the microbiota and have been tested to prevent and treat diseases. Probiotics are proposed to exert their beneficial effects through various pathways. Production of antimicrobial compounds targeting intestinal pathogens, general immune stimulation, and colonization resistance are among these mechanisms. Despite widespread ava...
Perkins GA, Wagner B.The development of equine immunity from the fetus to adulthood is complex. The foal's immune response and the immune mechanisms that they are equipped with, along with changes over the first months of life until the immune system becomes adult-like, are only partially understood. While several innate immune responses seem to be fully functional from birth, the onset of adaptive immune response is delayed. For some adaptive immune parameters, such as immunoglobin (Ig)G1, IgG3, IgG5 and IgA antibodies, the immune response starts before or at birth and matures within 3 months of life. Other antib...
Chaucheyras-Durand F, Sacy A, Karges K, Apper E.Horses are large non-ruminant herbivores and rely on microbial fermentation for energy, with more than half of their maintenance energy requirement coming from microbial fermentation occurring in their enlarged caecum and colon. To achieve that, the gastro-intestinal tract (GIT) of horses harbors a broad range of various microorganisms, differing in each GIT segment, which are essential for efficient utilization of feed, especially to use nutrients that are not or little degraded by endogenous enzymes. In addition, like in other animal species, the GIT microbiota is in permanent interplay with...
Deeg CA, Hauck SM, Amann B, Pompetzki D, Altmann F, Raith A, Schmalzl T, Stangassinger M, Ueffing M.Equine recurrent uveitis (ERU) is an autoimmune disease that occurs with a high prevalence (10%) in horses. ERU represents the only reliable spontaneous model for human autoimmune uveitis. We already identified and characterized novel autoantigens (malate dehydrogenase, recoverin, CRALBP) by analyzing the autoantibody-binding pattern of horses affected by spontaneous recurrent uveitis (ERU) to the retinal proteome. CRALBP also seems to be relevant to human autoimmune uveitis. Proteomic screening of vitreous and retinal samples from ERU diseased cases in comparison to healthy controls has led t...
Welch HM, Bridges CG, Lyon AM, Griffiths L, Edington N.The polymerase chain reaction (PCR) and co-cultivation were used to identify the lymphoreticular system as the site of latency of equid herpesvirus I (EHV-1). Primers for PCR were designed from aligned nucleotide sequences of the glycoprotein gB genes to amplify the same region of both the EHV-1 and EHV-4 genomes. Subsequent restriction digests using specific enzymes distinguished the amplified fragments of the EHV-1 genome from those of the EHV-4 genome. Ten weeks following an experimental infection of five ponies with EHV-1, latent virus was detected by PCR and recovered by co-cultivation, p...
Christensen M, Jacobsen S, Ichiyanagi T, Kjelgaard-Hansen M.Major acute phase proteins (APPs) have proven diagnostically useful in dogs, cats and horses with routine use facilitated by commercially available automated heterologous assays. An automated assay applicable across all three species would highly facilitate further dissemination of routine use, and the aim of this study was to validate an automated latex agglutination turbidimetric immunoassay based on monoclonal anti-human serum amyloid A (SAA) antibodies for measurement of canine, feline and equine SAA. Serum samples from 60 dogs, 40 cats and 40 horses were included. Intra- and inter-assay i...
Morein B, Blomqvist G, Hu K.The maintenance of pregnancy requires suppression of the maternal immune system which would naturally recognize the developing fetus as an allograft and seek to destroy it by mounting a Th1 regulated cytotoxic immune response. During pregnancy a range of soluble factors are produced by the placenta which switch maternal immune regulation towards a protective Th2 phenotype. These factors also influence the developing fetal immune system and all newborns initially have an immunological milieu skewed towards Th2 immunity. Vaccination during the neonatal period must therefore overcome the dual cha...
Jörg A, Henderson WR, Murphy RC, Klebanoff SJ.Horse eosinophils purified to greater than 98% generated slow reacting substance (SRS) when incubated with the calcium ionophore A23187. On a per cell basis, eosinophils generated four to five times the SRS produced by similarly treated horse neutrophils. Eosinophil SRS production was inhibited by 5,8,11,14-eicosatetraynoic acid and augmented by indomethacin and arachidonic acid, suggesting that it was a product(s) of the lipoxygenase pathway of arachidonic acid metabolism. Compounds with SRS activity were purified by high-pressure liquid chromatography (HPLC) and identified by ultraviolet spe...
Barlough JE, Madigan JE, DeRock E, Dumler JS, Bakken JS.A Thoroughbred filly that developed clinical signs of equine granulocytic ehrlichiosis following inoculation with the human granulocytotropic ehrlichia was shown to be resistant to challenge with Ehrlichia equi, a closely related agent. This result further substantiates the close and potentially conspecific relationship between these two granulocytotropic ehrlichiae.
Walshe N, Duggan V, Cabrera-Rubio R, Crispie F, Cotter P, Feehan O, Mulcahy G.The interactions between parasitic helminths and gut microbiota are considered to be an important, although as yet incompletely understood, factor in the regulation of immunity, inflammation and a range of diseases. Infection with intestinal helminths is ubiquitous in grazing horses, with cyathostomins (about 50 species of which are recorded) predominating. Consequences of infection include both chronic effects, and an acute inflammatory syndrome, acute larval cyathostominosis, which sometimes follows removal of adult helminths by administration of anthelmintic drugs. The presence of cyathosto...
