The immune response in horses involves a complex network of cells, tissues, and molecules that work together to protect the animal from pathogens and other harmful agents. This process includes both innate and adaptive immune mechanisms. Innate immunity provides the first line of defense and involves components such as physical barriers, phagocytic cells, and the complement system. Adaptive immunity, on the other hand, is characterized by the activation of lymphocytes and the production of antibodies, which provide a targeted response to specific antigens. Key components of the equine immune system include T cells, B cells, and various cytokines that facilitate communication between immune cells. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and implications of immune responses in equine health.
Olbrich K, Venner M, Wagner B.Vaccination recommendations for foals against Clostridium tetani vary. Available studies assessing foal immune responses, maternal antibody interference, or individual variation often used small foal numbers. Objective: To quantify antibody responses after tetanus vaccination in foals and explore associations with passively transferred tetanus antibodies. Methods: Longitudinal cohort study. Methods: Sixty-two Warmblood foals from a single stud farm were followed from birth to 360 days of age. Foals received tetanus vaccinations at day 180 (d180) and d220 of life. Serum samples were collected...
Pinto EM, Hurtado LH, Cuervo MM, da Silva CB.Failure of passive transfer (FPT) is a major contributor to morbidity and mortality in neonatal foals worldwide. Adequate ingestion and intestinal absorption of colostral immunoglobulin G (IgG) during the first hours of life are essential to ensure protection against early-life infections, such as diarrhoea and pneumonia, frequently with fatal outcome. This review summarizes current knowledge on the physiology of passive immunization, risk factors for inadequate IgG absorption, diagnostic methods, therapeutic strategies, and evidence-based preventive measures. Recent research highlights the im...
Deniz Ö, Ekinci G, Çitil M, Onmaz AC, Derelli FM, Timur MC, Altınbay K, Mete A, Yeğen E, Hoven RVD, Fazio F, Aragona F.Equine herpesvirus type 1 (EHV-1) is a major cause of reproductive loss in mares. This cross-sectional field study evaluated serum concentrations of interleukin-2 (IL-2), interleukin-10 (IL-10), interferon-alpha (IFN-α), and interferon-gamma (IFN-γ), together with the IL-10/IL-2 and IFN-γ/IL-10 ratios, in 26 vaccinated pregnant Thoroughbred mares. The analytical cohort comprised healthy, EHV-1 PCR-negative mares (HM, n = 10), EHV-1 PCR-positive mares sampled within 4 h after fetal expulsion at approximately the sixth month of gestation (AM, n = 9), and EHV-1 PCR-positive pregnant mares with...
de Bruijn E, Pas ML, Castelain D, Dufourni A, Paulussen E, Pardon B.Single measurements of serum amyloid A (SAA) concentration at hospital admission has limited sensitivity for predicting sepsis and death. Objective: To determine whether differences in SAA during the first 2 days of hospitalization could predict sepsis and death in critically ill foals. Methods: One hundred twenty-seven critically ill neonatal foals, <14 days of age. Methods: Prospective cohort study. SAA was measured at hospital admission and on day 2 of hospitalization using a validated point-of-care test. Logistic regression was conducted to evaluate the predictive value of individual S...
Dörner C, Lagos N, Oyaneder L, González C, Ramírez-Toloza G, Menarim BC.Chronic synovial inflammation is a hallmark of osteoarthritis progression and is tightly regulated by synovial macrophages. Recently, voltage-gated sodium channels (NaV) have emerged as potent modulators of macrophage-driven inflammation, positioning them as novel therapeutic targets. Among selective NaV channel blockers, neosaxitoxin exerts remarkable anesthetic and immunomodulatory effects; however, its effects on joint inflammation upon intra-articular delivery remain unexplored. Using an equine model of bilateral carpal osteoarthritis, this study evaluated the immunomodulatory and tissue-p...
Wilson I, Kiger K, Reynolds S, Justice M, Kapadia C, Coleman SJ, Crook RA, Fedorka CE.Pulsed electromagnetic field (PEMF) therapy is commonly used in equine sports medicine for its proposed anti-inflammatory effects; however, limited controlled studies have evaluated its physiologic effects in horses. Objective: The objective of this study was to investigate the effects of PEMF therapy on flexion-induced lameness and circulating cytokines in horses with radiographic evidence of distal tarsal osteoarthritis. Methods: Six mares were enrolled in a repeated-measures crossover design in which each horse served as its own control. Horses were evaluated at baseline (sham PEMF) and at ...
Cho GJ, Jeon J, Eun JK, Almazbek I.The purpose of this study was to evaluate the clinical applicability of a multiplex serum specific Immunoglobulin E (sIgE) test kit 'ANITIA Equine IgE' for identifying the causes of allergic diseases in horses raised in Korea, and to determine the major sensitization antigen profiles in the domestic horse population. Serum or plasma samples were collected from a total of 140 horses, classified by management system (Group A, n=108) and purpose (Group B, n=32). IgE concentrations for 120 environmental and dietary allergens were measured using a multiplex line-blot assay based on an indirect immu...
Røgild ER, Mármol-Sánchez E, Toft K, Hansen S, Cirera S.Equine asthma (EA) is a highly prevalent, chronic, inflammatory disease of the lower airways ranging from mild-to-moderate to severe clinical presentations. Diagnosis currently relies on bronchoalveolar lavage fluid (BALF) cytology, an invasive method associated with interobserver variability, which highlights the need for more reproducible approaches. MicroRNAs (miRNAs) are small noncoding RNAs involved in gene regulation. They are stable and readily detectable in body fluids and have shown promising results as biomarkers in human asthma. The aim of this pilot study was to characterize miRNA ...
Biondi V, Gambadauro P, Bruno F, Palmieri V, Licata P, Sicuso DA, Passantino A, Pugliese M.Equine piroplasmosis, caused by the intraerythrocytic protozoan , is a globally distributed tick-borne disease characterized by persistent infection and variable clinical manifestations. Although oxidative stress has been implicated in the pathogenesis of several hemoprotozoan diseases, information regarding redox imbalance and its relationship with inflammatory responses in horses naturally infected with remains limited. This study aimed to evaluate oxidative stress, antioxidant status, inflammatory cytokines, and clinicopathological alterations in horses naturally infected with . Thirty-fiv...
Rajesh A, Harman RM, Van de Walle GR.Neutrophil chemotaxis and phagocytosis are critical for protection against bacteria, but can be compromised by methicillin-resistant Staphylococcus aureus (MRSA). MRSA can also circumvent macrophage surveillance by affecting polarization and reactive oxygen species (ROS) production. We previously demonstrated that the secretome of equine mesenchymal stromal cells (MSCs), comprised of all secreted bioactive factors and collected as conditioned medium (CM), reduces the growth of MRSA both in vitro and in vivo. This study aimed to determine if the equine MSC secretome has additional anti-MRSA pro...
Ząbek T, Szmatoła T, Witarski W, Ropka-Molik K.Cellular senescence is a biological state of a cell that triggers inflammation and gradually contributes to pathological conditions. Unlike programmed cell death, prolonged inhibition of cell division induces a metabolic state in senescent cells, in which they release pro-inflammatory factors that drive inflammation affecting the tissue microenvironment. Along with prolonged excessive mechanical stress, low-grade inflammation raised by senescent chondrocytes may contribute to articular cartilage defects, which are prevalent in ageing populations. Moreover, the use of chemotherapeutics used to ...
Albrecht M, Perez J, Wong D, Browne N, Burns T, Stevens ME, Dembek K.Hypothalamic-pituitary-adrenal gland axis (HPAA) dysfunction impairs survival and can be diagnosed with an arginine vasopressin (AVP) stimulation test. Objective: Adrenocorticotropic hormone (ACTH) and cortisol response to an AVP stimulation test will be attenuated in hospitalized foals compared to healthy foals and associated with severity of disease. Methods: Fifteen healthy and 45 hospitalized foals: 19 septic, 26 sick non-septic (SNS). Methods: A prospective, observational case-control design was utilized to assess HPAA function and compare corticotropin-releasing hormone, ACTH, and cortis...
Crook RA, Branch AE, Kapadia CL, Klinglesmith BA, Hatzel JN, Sones JL, Fedorka CE.Successful establishment of pregnancy requires maternal immune tolerance to paternal antigens introduced by insemination. Regulatory T cell (Treg)-associated responses are thought to play a central role in this process, whereas pro-inflammatory T helper 1 (Th1) responses may disrupt pregnancy success. In other species, seminal plasma (SP) has been shown to modulate maternal immune adaptation; however, this relationship remains poorly defined in mares, where SP is frequently reduced during routine breeding practices. The objectives of this study were to (1) characterize temporal changes in syst...
Leal M, Silva E, Alpoim-Moreira J, Pinto-Bravo P, Rebordão MR, Quaresma M, Jalali B, Molcan T, Szóstek-Mioduchowska A, Skarzynski D, Ferreira-Dias G.Equine persistent post-breeding endometritis may lead to endometrosis, characterized by excessive fibrosis, which is a major cause of subfertility/infertility. Endometrial proteomic changes induced by endometritis, when associated with fibrosis, were investigated to identify the biological processes (BP) involved. Cyclic mares´ endometrial biopsies were histologically classified (Kenney and Doig's) as: category IIA (n = 5), category IIA with endometritis (IIA-E; n = 4), category IIB (n = 5), or category IIB with endometritis (IIB-E; n = 5). Proteome was assessed by LC-MS/MS. I...
Lam J, Eckert A, Rhiner T, Waldern N, Schwarz E, Birkmann K, Widmer D, Dietrich M, Kündig TM, Fettelschoss-Gabriel A.Insect bite hypersensitivity (IBH) is the most common allergic skin disease in horses, but existing clinical scoring systems lack extensive validation, limiting standardized disease monitoring and therapeutic evaluation. Objective: Develop and validate a standardized, sensitive, and reproducible clinical scoring system for IBH in horses. Methods: Forty-four privately-owned horses with clinically diagnosed IBH examined under field conditions in Switzerland. Methods: In this prospective field validation study, the equine IBH severity score (EqIS) integrates a lesion severity score and an area sc...
Cequier A, Romero A, Bernad E, Serrano B, Vitoria A, Fuente S, Fernández I, Zaragoza P, Vázquez FJ, Barrachina L, Rodellar C.Mesenchymal stem/stromal cells (MSCs) hold great potential for treating various conditions, but their effectiveness and safety in allogeneic therapies can be affected by the recipient's immune response, among other factors. Allogeneic MSC administration has been associated with immune recognition in different species, including horses. These animals are both veterinary patients and translational models, offering valuable insights into how allogeneic MSCs interact with the immune system in vivo. Factors such as inflammation, chondrogenic differentiation, and major histocompatibility complex (MH...
Chen K, Du C, Duan Y, Guo K, Liu D, Wang F, Wang X, Wen Y.Macrophage phenotypic adaptation critically regulates inflammatory balance during infection; however, progress in equine immunology has been limited by a lack of specific tools for standardized identification. To address this gap, we established a reliable, antibody-based detection method for characterizing equine macrophage M1-like and M2-like marker profiles. After initially validating canonical marker genes via qPCR, we developed specific monoclonal antibodies targeting the differentially expressed surface proteins CD80 (M1-like) and CD163 (M2-like). These novel antibodies enabled the creat...
Rodgers EE, Yates DT, Parrish BL, Luck LM.Housing horses in stalls restricts natural roaming behaviors, which in turn increases stress and stereotypic behaviors. Daily turnout for voluntary exercise is common for stress mitigation, but there is no consensus for optimal duration of turnout sessions. Objective: We sought to understand how minimal and moderate-duration daily turnout affects behavioral and physiological stress indicators. Methods: In a Latin-square design, adult Quarter horses (N=11) were allowed 0, 15, or 60 minutes/day of solitary turnout for 12-day periods. In-stall behaviors and 24-hour time budgets were assessed on d...
Pfeifle RL, Hart KA, Berghaus LJ, Coleman MC.Equine asthma is a chronic inflammatory airway disease with limited safe long-term treatments. Alpha-2-macroglobulin (A2M), a natural anti-inflammatory protease inhibitor, may provide a novel non-steroidal therapeutic option for horses with lower respiratory tract inflammation. Objective: To characterize the impact of nebulization with alpha-2-macroglobulin (A2M) on clinical signs, bronchoalveolar lavage cytology, and local and systemic cytokine response in horses with lower respiratory tract inflammation. Methods: Thirteen university-owned horses with lower airway inflammation were randomized...
Słyszewska M, Guerreiro M, Sadowska A, Jaworska J, Ferreira-Dias G, Szóstek-Mioduchowska A.Tissue fibrosis is described as the excessive accumulation of extracellular matrix (ECM) components. This process is associated with inflammation, and the interaction between fibroblasts and immune cells plays a key role, driving the progression of fibrosis. Results of recent study suggest that interleukin (IL)-12 may play a role in the processes associated with the development of fibrosis. This proinflammatory cytokine is synthesized and released by macrophages, dendritic cells, and B cells. Objective: The objective of this study was to determine: (i) the expression of IL-12 and its receptor ...
Jagannathan V, Leeb T, Gerber V, Sage SE. Bulk RNA sequencing (RNA-seq) averages signals across heterogeneous cell populations. Computational deconvolution methods aim to infer cell type composition and cell type-specific gene expression from bulk data, but their performance in equine samples has not been evaluated. In this study, we assessed the ability of computational deconvolution to recover cellular composition and differential expression signals in bronchoalveolar lavage fluid (BALF) from horses with severe equine asthma (SEA) and controls (CTL). Cryopreserved BALF samples from six SEA and five CTL horses previously analyzed b...
Manguin E, Dickson RP, Jamon J, Dubuc V, Leclère M.The use of inhaled corticosteroids (ICs) could influence the respiratory microbiota. In animals with asthma it is, however, difficult to separate the immunomodulatory effects of ICs from their indirect effects via improvement of ventilation. Our objective was to determine if ICs alter the pulmonary microbiota independently from their effects on lung function, using a blinded, controlled trial in an experimental model of asthma exacerbation in horses. We treated horses with severe asthma with either bronchodilators alone, or in combination with ICs. Twelve horses in exacerbation received long-a...
DiSilvestro AN, Wesolowski LT, Williams BD, Warren LK, Athrey G, White-Springer SH.Energy-dense feeds commonly provided to equine athletes may be high in starch, which alter gastrointestinal microbiota and could promote systemic inflammation. Objective: To test the hypothesis that exercise-induced inflammation would be greater in horses receiving a starch- versus fiber-based concentrate. Methods: Quarter Horses (mean±SD 16±1mo; 337±30kg) received either a fiber-based control (CON; 7 fillies, 8 geldings) or an isocaloric, isonitrogenous starch concentrate (STARCH; 8 fillies, 7 geldings) for 24d. Fecal metagenomics were evaluated on d0 and 21. Blood inflammatory mediators w...
Mulcahy G, Byrne O, Walshe N.Cyathostomins (also known as small strongyles or small redworms) are ubiquitous parasites of equids. They are found in a wide range of climatic regions, and inhabit the large intestine of their hosts. While infections are often sub-clinical, clinical consequences ranging from chronic to acute, and most notably, acute larval cyathostominosis, can occur in specific circumstances. Control of cyathostomin infection is complicated by widespread drug resistance. This Chapter provides a broad review of cyathostomin biology and host-parasite relationships, and also highlights significant knowledge gap...
Baillou A, Botos M, Oberhaensli S, Cvitas I, Jonsdottir S, Ziegler A, Brito F, Summerfield A, Marti E, Talker SC.Detailed classification of equine dendritic cells (DC) is necessary to address various research questions, such as the role of DC subsets in immune-mediated diseases of horses. Unassigned: We applied single-cell RNA sequencing (scRNA-seq) on DC enriched from the blood of two horses. Unassigned: All main DC subsets were detected by key gene expression, including conventional DC type 1 (cDC1; ) and type 2 (cDC2; , ), as well as plasmacytoid DC (pDC; ). In addition, we detected a small cluster of hematopoietic progenitors, as well as transitional DC (tDC; , ) and putative DC type 3 (DC3; , ). Our...
Jehle MC, Reinthaler B, Patan-Zugaj B, Schwendenwein I, Licka TF.To evaluate an ex vivo model of synovitis induced by IA lipopolysaccharide (LPS) and IL-1β in isolated, perfused equine forelimbs. Unassigned: Forelimbs and blood were collected from 12 clinically unremarkable horses following slaughter at a licensed abattoir. In 8 limbs, 2 of 3 phalangeal joints were injected with LPS (0.5 to 5 ng, 4 limbs) or IL-1β (100 ng, 4 limbs) diluted in 1 mL of distilled water. All limbs were perfused with autologous perfusate for 8 hours. Synovial fluid cytology and synovium sample histology scores for synovitis (0 = no changes and 3 = marked changes) were assessed...
Długopolska D, Siwińska N, Noszczyk-Nowak A, Niedźwiedź A, Żak-Bochenek A.Equine Asthma (EA) is a common, lower airway disease. Yet current diagnostic standards rely on bronchoalveolar lavage fluid (BALF) cytology, which is moderately invasive and not always feasible in field conditions. This review aimed to synthesize current evidence on candidate biomarkers of EA, with a primary focus on blood-based matrices and BALF, while also including data on biomarkers measured in tracheal wash (TW), saliva and exhaled breath condensate (EBC), where available. Searches were performed in PubMed, Scopus and Google Scholar, and original studies in horses with mild-to-moderate or...
Musoles-Cuenca B, de la Cuesta-Torrado M, Álvarez AV, Vitale V, Lorenzo-Bermejo T, Ballester B, Rubio-Guerri C, Álvarez L, Maiques E.Equine herpesvirus type 1 (EHV-1) outbreaks associated with international equestrian events have demonstrated the capacity of this virus for rapid transboundary dissemination. However, detailed longitudinal data integrating viral shedding across multiple biological matrices within the same animals during naturally occurring outbreaks remain limited. In this study, ten horses hospitalized during a naturally occurring EHV-1 outbreak linked to an international jumping competition were monitored for 10-12 days, from which 306 nasal, ocular, urine and faecal samples were obtained and analysed by qu...
Lewis NS, Daly JM, Russell CA, Horton DL, Skepner E, Bryant NA, Burke DF, Rash AS, Wood JL, Chambers TM, Fouchier RA, Mumford JA, Elton DM, Smith DJ.Equine influenza virus is a major respiratory pathogen in horses, and outbreaks of disease often lead to substantial disruption to and economic losses for equestrian industries. The hemagglutinin (HA) protein is of key importance in the control of equine influenza because HA is the primary target of the protective immune response and the main component of currently licensed influenza vaccines. However, the influenza virus HA protein changes over time, a process called antigenic drift, and vaccine strains must be updated to remain effective. Antigenic drift is assessed primarily by the hemagglu...
Guest DJ, Smith MR, Allen WR.Autologous mesenchymal progenitor cells (MPCs) purified from bone marrow aspirates are being used in the treatment of superficial digital flexor tendon (SDFT) injuries in the horse with promising results. In this study the fate of autologous and allogeneic MPCs following injection into the SDFT was monitored by stable transfection of MPCs with green fluorescent protein (GFP). Small lesions were created manually in one forelimb SDFT of 2 horses and injected with autologous MPCs, allogeneic MPCs or bone marrow supernatant alone. Post mortem examinations performed after 10 or 34 days revealed GFP...
Bowen RA, Nemeth NM.West Nile virus emerged recently in North America as a serious human and animal pathogen. This review summarizes the use of experimental infections with West Nile virus in diverse vertebrate species that have been used to answer fundamental questions about the host response, pathogenesis of West Nile virus infection and virus evolution. Results: West Nile virus has an extremely broad vertebrate host range. Infection of common species of birds has defined those with high vs. low potential to serve as amplifying hosts for the virus. In general, mammals (primates, horses, companion animals) are d...
Vargas A, Boivin R, Cano P, Murcia Y, Bazin I, Lavoie JP.Severe neutrophilic asthma is poorly responsive to glucocorticosteroids (GC). Neutrophil extracellular traps (NETs) within the lungs have been associated with the severity of airway obstruction and inflammation in asthma, and were found to be unaffected by GC in vitro. As IL-17 is overexpressed in neutrophilic asthma and contributes to steroid insensitivity in different cell types, we hypothesized that NETs formation in asthmatic airways would be resistant to GC through an IL-17 mediated pathway. Six neutrophilic severe asthmatic horses and six healthy controls were studied while being treated...
Marsh GA, Wang LF.Henipavirus, including Hendra and Nipah viruses, is a group of emerging bat-borne paramyxoviruses which were responsible for severe disease outbreaks in humans, horses and pigs. The mortality rate of human infection varies between 50 and 100%, making them one of the most deadly viruses known to infect humans. Its use of highly conserved cell surface molecules (ephrin) as entry receptors and its highly effective replication and fusion strategies are believed to be important characteristics responsible for its high pathogenicity. Henipavirus also encodes multiple accessory proteins which play a ...
Carrade Holt DD, Wood JA, Granick JL, Walker NJ, Clark KC, Borjesson DL.Mesenchymal stem cells (MSCs) are used in both human clinical trials and veterinary medicine for the treatment of inflammatory and immune-mediated diseases. MSCs modulate inflammation by decreasing the cells and products of the inflammatory response. Stimulated equine MSCs from bone marrow (BM), adipose tissue (AT), cord blood (CB), and umbilical cord tissue (CT) inhibit lymphocyte proliferation and decrease inflammatory cytokine production. We hypothesized that equine MSCs inhibit T cell proliferation through secreted mediators and that MSCs from different tissue sources decrease T cell proli...
Scheel TK, Kapoor A, Nishiuchi E, Brock KV, Yu Y, Andrus L, Gu M, Renshaw RW, Dubovi EJ, McDonough SP, Van de Walle GR, Lipkin WI, Divers TJ....Nonprimate hepacivirus (NPHV) is the closest known relative of hepatitis C virus (HCV) and its study could enrich our understanding of HCV evolution, immunity, and pathogenesis. High seropositivity is found in horses worldwide with ∼ 3% viremic. NPHV natural history and molecular virology remain largely unexplored, however. Here, we show that NPHV, like HCV, can cause persistent infection for over a decade, with high titers and negative strand RNA in the liver. NPHV is a near-universal contaminant of commercial horse sera for cell culture. The complete NPHV 3'-UTR was determined and consists...
Katila T.This review attempts to summarize the current knowledge on uterine inflammatory response after mating in horses, pigs and cattle. Post-mating endometritis has been extensively studied in horses as it has been considered to cause infertility. The inflammation is known to occur also in cattle, but it has not been investigated to a similar extent. There are a number of publications about mechanisms of post-mating uterine inflammation in pigs, which seem to resemble those in horses. The major focus of this review is the horse, but relevant literature is presented also on swine and cattle. Spermato...
Grieder FB, Vogel SN.To investigate the role of type I interferon (IFN) and its regulatory transacting proteins, interferon regulatory factors (IRF-1 and IRF-2), in early protection against infection with virulent Venezuelan equine encephalitis virus (VEE), we utilized mice with targeted mutations in the IFN-alpha/beta receptor, IRF-1, or IRF-2 genes. IFN-alpha/beta-receptor knockout mice are highly susceptible to peripheral infection with virulent or attenuated VEE, resulting in their death within 24 and 48 h, respectively. Treatment of normal macrophages with anti-IFN-alpha/beta antibody prior to and during infe...
Ramsay JD, Evanoff R, Wilkinson TE, Divers TJ, Knowles DP, Mealey RH.Equine hepacivirus (EHCV; nonprimate hepacivirus) is a hepatotropic member of the Flaviviridae family that infects horses. Although EHCV is the closest known relative to hepatitis C virus (HCV), its complete replication kinetics in vivo have not been described, and direct evidence that it causes hepatitis has been lacking. In this study, we detected EHCV in 2 horses that developed post-transfusion hepatitis. Plasma and serum from these horses were used to experimentally transmit EHCV to 4 young adult Arabian horses, two 1-month-old foals (1 Arabian and 1 Arabian-pony cross), and 2 foals (1 Ara...
Carrade DD, Affolter VK, Outerbridge CA, Watson JL, Galuppo LD, Buerchler S, Kumar V, Walker NJ, Borjesson DL.BACKGROUND AIMS. The use of allogeneic mesenchymal stem cells (MSC) to treat acute equine lesions would greatly expand equine cellular therapy options; however, the safety and antigenicity of these cells have not been well-studied. We hypothesized that equine allogeneic umbilical cord tissue (UCT)-derived MSC would not elicit acute graft rejection or a delayed-type hypersensitivity response when injected intradermally. METHODS. Six Quarterhorse yearlings received 12 intradermal injections (autologous MSC, allogeneic MSC, positive control and negative control, in triplicate) followed by the sam...
Stewart AS, Pratt-Phillips S, Gonzalez LM.All species, including horses, suffer from alterations that increase intestinal permeability. These alterations, also known as "leaky gut," may lead to severe disease as the normal intestinal barrier becomes compromised and can no longer protect against harmful luminal contents including microbial toxins and pathogens. Leaky gut results from a variety of conditions including physical stressors, decreased blood flow to the intestine, inflammatory disease, and pathogenic infections, among others. Several testing methods exist to diagnose these alterations in both a clinical and research setting....
Nara PL, Garrity RR, Goudsmit J.The production of immunoglobulin capable of neutralizing the infectivity of a virus represents one of the most remarkable molecular accomplishments of the host's available immune defenses. It should be no surprise that a virus that has existed in the parenchyma of the immune system has evolved as an equally dynamic molecule (i.e., viral envelope) for survival. Neutralizing immunoglobulin (Ig) can best serve the host under conditions where the invading pathogen requires a well-defined cell-free state for establishing an infection or transmission. Evidence for a controlling and therefore protect...
Edington N, Bridges CG, Patel JR.Eight mares were infected with equid herpesvirus-1 subtype 1 isolated from a case of equine paresis. In two mares killed at 4 d.p.i. immunofluorescence showed endothelial cell infection together with thrombosis in the rete arteriosus of the nasal mucosa and also in the spinal cord of one of these mares. Circulating platelet counts in the other six mares fell as early as 2 d.p.i. and remained depressed for seven days. Circulating immune complexes started to appear at 2 d.p.i., reached maximum levels at 10 d.p.i., but were undetectable at 28 d.p.i. Three of the six remaining mares developed vary...
Berglund AK, Schnabel LV.Allogeneic mesenchymal stem cells (MSCs) are a promising cell source for treating musculoskeletal injuries in horses. Controversy exists, however, over whether major histocompatibility complex (MHC)-mismatched MSCs are recognised by the recipient immune system and targeted for death by a cytotoxic antibody response. Objective: To determine if cytotoxic anti-MHC antibodies generated in vivo following MHC-mismatched MSC injections are capable of initiating complement-dependent cytotoxicity of MSCs. Methods: Experimental controlled study. Methods: Antisera previously collected at Days 0, 7, 14 an...
Pigott JH, Ishihara A, Wellman ML, Russell DS, Bertone AL.Mesenchymal stem cells have demonstrated immunomodulatory capabilities as well as modest efficacy in animal models of joint injury, warranting further study as a potential treatment of joint disease. The goal of the study was to investigate the blood and synovial immune and histologic response to intra-articular injection of autologous, allogeneic, and xenogeneic bone marrow-derived mesenchymal stem cells (MSC) in horses. The study group consisted of 6 five-year-old Thoroughbred mares that had been injected previously with 15 million, genetically modified autologous, allogeneic, or xenogeneic ...
Jacobsen S, Kjelgaard-Hansen M, Hagbard Petersen H, Jensen AL.The aim of the present study was to evaluate whether equine serum amyloid A (SAA) concentrations could be measured reliably with a turbidometric immunoassay (TIA) developed for use with human serum. Intra- and inter-assay imprecision were evaluated by multiple measurements on equine serum pools. Assay inaccuracy was determined by linearity under dilution. The assay was subsequently used for measuring SAA concentrations in clinically healthy horses, horses with inflammatory diseases, horses with non-inflammatory diseases, and in horses before and after castration. In pools with low, intermediat...
Leclere M, Lavoie-Lamoureux A, Joubert P, Relave F, Setlakwe EL, Beauchamp G, Couture C, Martin JG, Lavoie JP.Recent studies suggest that airway smooth muscle remodeling is an early event in the course of asthma. Little is known of the effects of long-term antigen avoidance and inhaled corticosteroids on chronically established airway remodeling. We sought to measure the effects of inhaled corticosteroids and antigen avoidance on airway remodeling in the peripheral airways of horses with heaves, a naturally occurring asthma-like disease. Heaves-affected adult horses with ongoing airway inflammation and bronchoconstriction were treated with fluticasone propionate (with and without concurrent antigen av...
Ma G, Azab W, Osterrieder N.The equine herpesviruses type 1 (EHV-1) and 4 (EHV-4) are ubiquitous pathogens that affect horse populations on all continents. Despite widespread vaccination, EHV-1 and EHV-4 infections remain a permanent risk. While the two viruses share a high degree of genetic and antigenic similarity, they differ significantly in host range and pathogenicity. Compared to EHV-4, which mainly infects horses and causes respiratory disease, EHV-1 has a broader host range and can result in respiratory disease, abortions, neonatal death, and equine herpesvirusmyeloencephalopathy (EHM). Recent studies have eluci...
Meijer WG, Prescott JF.Rhodococcus equi is an important cause of subacute or chronic abscessating bronchopneumonia of foals up to 3-5 months of age. It shares the lipid-rich cell wall envelope characteristic of the mycolata, including Mycobacterium tuberculosis, as well as the ability of pathogenic members of this group to survive within macrophages. The possession of a large virulence plasmid in isolates recovered from pneumonic foals is crucial for virulence. The plasmid contains an 27 kb pathogenicity island (PI) that encodes seven related virulence-associated proteins (Vaps), including the immunodominant surface...
Giguère S, Prescott JF.Since the 1986 Rhodococcus equi workshop, there have been major breakthroughs in understanding the epidemiology of, the virulence of, and the immune response to, this intriguing pathogen. However, with the exception of the use of hyperimmune plasma for the prevention of the disease (Martens et al., 1989; Madigan et al., 1991) the clinical aspects of R. equi infections have essentially remained unchanged. This article reviews the various clinical manifestations and summarizes recent advances in diagnosis, treatment and prevention of R. equi infections in foals.
El Garch H, Minke JM, Rehder J, Richard S, Edlund Toulemonde C, Dinic S, Andreoni C, Audonnet JC, Nordgren R, Juillard V.Successful vaccination against West Nile virus (WNV) requires induction of both neutralizing antibodies and cell-mediated immune responses. In this study, we have assessed the ability of a recombinant ALVAC-WNV vaccine (RECOMBITEK WNV) to elicit neutralizing antibodies and virus-specific cell-mediated immune responses in horses. In addition, we examined whether prior exposure to ALVAC-WNV vaccine would inhibit B and cell-mediated immune responses against the transgene product upon subsequent booster immunizations with the same vaccine. The results demonstrated that the recombinant ALVAC-WNV va...
H A Morris L, M McCue P, Aurich C.Endometritis in the mare begins as a normal physiological inflammatory response to breeding that involves both a mechanical and immunological response pathway activated to rid the uterus of semen and bacteria. With successful resolution of this inflammation, the mare's uterus will provide a hospitable environment for the development of the semi-allogenic conceptus. If the mare fails to resolve this inflammatory response within 48 h of breeding, she will become susceptible to persistent breeding-induced endometritis (PBIE) which will have detrimental effects on her fertility. This condition can...
Hondalus MK.Inhalation of the soil-borne organism, Rhodococcus equi, can lead to a chronic and severe pyogranulomatous pneumonia in young horses and immunocompromised people. In addition, ulcerative colitis is a common sequela to infection in foals, and dissemination from the lung to other body sites is not uncommon in either the horse or man. Although the facultative intracellular bacterium is susceptible to neutrophil-mediated killing, it is able to resist innate macrophage defenses and establish residence within the intracellular environment of that phagocyte. Definitive virulence factors of R. equi ha...
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...
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...
Muscatello G, Leadon DP, Klayt M, Ocampo-Sosa A, Lewis DA, Fogarty U, Buckley T, Gilkerson JR, Meijer WG, Vazquez-Boland JA.Infection with Rhodococcus (Corynebacterium) equi is a well-recognised condition in foals that represents a consistent and serious risk worldwide. The condition manifests itself primarily as one of pulmonary abscessation and bronchitis, hence the terminology of 'rattles' derived from its most obvious clinical sign, frequently terminal when first identified. This review addresses the clinical manifestation, bacteriology and pathogenesis of the condition together with recent developments providing knowledge of the organism in terms of virulence, epidemiology, transmission and immune responses. E...
Lavoie JP, Maghni K, Desnoyers M, Taha R, Martin JG, Hamid QA.Heaves in horses shares many similarities with human asthma, including lower airway inflammation, reversible airway obstruction, and bronchial hyperresponsiveness. Extrinsic asthma is an allergic response to environmental allergens and a similar immunologic mechanism may be implicated in heaves. It is now recognized that a Th2 subset of CD4+ lymphocytes is associated with allergic diseases such as atopic asthma. The purpose of this study was to determine whether airway inflammation in heaves is associated with a pattern of expression of cytokine suggestive of a Th2 type response. The expressio...
Lewis MJ, Wagner B, Woof JM.Recombinant versions of the seven equine IgG subclasses were expressed in CHO cells. All assembled into intact immunoglobulins stabilised by disulphide bridges, although, reminiscent of human IgG4, a small proportion of equine IgG4 and IgG7 were held together by non-covalent bonds alone. All seven IgGs were N-glycosylated. In addition IgG3 appeared to be O-glycosylated and could bind the lectin jacalin. Staphylococcal protein A displayed weak binding for the equine IgGs in the order: IgG1>IgG3>IgG4>IgG7>IgG2=IgG5>IgG6. Streptococcal protein G bound strongly to IgG1, IgG4 and IgG...
Goodman LB, Wagner B, Flaminio MJ, Sussman KH, Metzger SM, Holland R, Osterrieder N.Equine herpesvirus type 1 (EHV-1) is a ubiquitous alphaherpesvirus of horses which causes rhinopneumonitis, abortion and myeloencephalopathy. To test the efficacy of commercial vaccines in protection against neurological EHV-1 challenge, groups of five horses were immunized with modified-live virus or an inactivated vaccine, or received placebo. Horses were challenged by aerosol with a recent virus isolate obtained from a case of paralytic EHV-1. The duration of fever decreased significantly in the modified-live virus vaccine group. Three animals in each of the inactivate and control groups sh...
