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.
Cvitas I, Oberhaensli S, Leeb T, Marti E.Equine insect bite hypersensitivity (IBH) is the most common skin disease affecting horses. It is described as an IgE-mediated, Type I hypersensitivity reaction to salivary gland proteins of Culicoides insects. Together with Th2 cells, epithelial barrier cells play an important role in development of Type I hypersensitivities. In order to elucidate the role of equine keratinocytes in development of IBH, we stimulated keratinocytes derived from IBH-affected (IBH-KER) (n = 9) and healthy horses (H-KER) (n = 9) with Culicoides recombinant allergens and extract, allergic cytokine milieu (ACM) and ...
Cappelli K, Ciucis CG, Mecocci S, Nervo T, Crescio MI, Pepe M, Gialletti R, Pietrucci D, Migone LF, Turco S, Mechelli L, Passamonti F, Drago C....Equine Papillomavirus 2 (EcPV2) is responsible for squamous cell carcinomas (eSCCs) of external genitalia of both male and female horses. However, few studies report the EcPV2 prevalence among healthy horses. Currently, the lack of these data does not permit identifying at-risk populations and, thus, developing screening protocols aimed at the early detection of the infection, as for humans. The aim of our study was to estimate the genoprevalence of EcPV2 in clinically healthy horses in Italy and to evaluate their innate immune response. For this purpose, penile and vulvar swabs of 234 healthy...
Stefanovski D, Robinson MA, Van Eps A.Insulin dysregulation (ID) is the most important risk factor for the development of laminitis in horses and therapies to control it are needed. Objective: To assess the effects of a single dose of the synthetic GLP-1 analog exenatide on postprandial insulin dynamics. We hypothesized that exenatide would improve insulin sensitivity and lower postprandial blood insulin concentrations. Methods: Randomized, crossover, experimental study. Methods: Six horses (3 mares, 3 geldings; 2 with normal insulin regulation [NIR] and 4 with mild ID). Methods: Horses completed both study arms: subcutaneous admi...
Bonhomme D, Werts C.Leptospirosis is a zoonotic infectious disease affecting all vertebrates. It is caused by species of the genus Leptospira, among which are the highly pathogenic L. interrogans. Different mammals can be either resistant or susceptible to the disease which can present a large variety of symptoms. Humans are mostly asymptomatic after infection but can have in some cases symptoms varying from a flu-like syndrome to more severe forms such as Weil's disease, potentially leading to multiorgan failure and death. Similarly, cattle, pigs, and horses can suffer from acute forms of the disease, including ...
Boger BL, Manfredi JM, Yob C, Weber PSD, Jacobs CC.Diagnosis of equine septic arthritis is not straightforward, and increasing time between onset, diagnosis, and treatment can have serious consequences for quality of life. Defensins are used in diagnosis of human joint infection. The presence of beta defensins (BDs) in equine synovial fluid and their utility as a biomarker of sepsis has not been investigated; therefore, our objectives were to (1) compare in vitro gene expression of lipopolysaccharide (LPS)-stimulated equine neutrophils to unstimulated neutrophils and (2) compare BD protein expression from normal, aseptically inflamed, and sept...
Durán-Ferrer M, Villalba R, Fernández-Pacheco P, Tena-Tomás C, Jiménez-Clavero MÁ, Bouzada JA, Ruano MJ, Fernández-Pinero J, Arias M....This study described the clinical, virological, and serological responses of immunologically naïve and vaccinated horses to African horse sickness virus (AHSV) serotype 9. Naïve horses developed a clinical picture resembling the cardiac form of African horse sickness. This was characterized by inappetence, reduced activity, and hyperthermia leading to lethargy and immobility-recumbency by days 9-10 post-infection, an end-point criteria for euthanasia. After challenge, unvaccinated horses were viremic from days 3 or 4 post-infection till euthanasia, as detected by serogroup-specific (GS) real...
Jiménez-Cabello L, Utrilla-Trigo S, Barreiro-Piñeiro N, Pose-Boirazian T, Martínez-Costas J, Marín-López A, Ortego J.Bluetongue virus (BTV) and African horse sickness virus (AHSV) are widespread arboviruses that cause important economic losses in the livestock and equine industries, respectively. In addition to these, another arthropod-transmitted orbivirus known as epizootic hemorrhagic disease virus (EHDV) entails a major threat as there is a conducive landscape that nurtures its emergence in non-endemic countries. To date, only vaccinations with live attenuated or inactivated vaccines permit the control of these three viral diseases, although important drawbacks, e.g., low safety profile and effectiveness...
Janssen P, Tosi I, Hego A, Maréchal P, Marichal T, Radermecker C.Asthma encompasses a spectrum of heterogenous immune-mediated respiratory disorders sharing a similar clinical pattern characterized by cough, wheeze and exercise intolerance. In horses, equine asthma can be subdivided into severe or moderate asthma according to clinical symptoms and the extent of airway neutrophilic inflammation. While severe asthmatic horses are characterized by an elevated neutrophilic inflammation of the lower airways, cough, dyspnea at rest and high mucus secretion, horses with moderate asthma show a milder neutrophilic inflammation, exhibit intolerance to exercise but no...
Gressler AE, Lübke S, Wagner B, Arnold C, Lohmann KL, Schnabel CL.Equine asthma (EA) is a highly relevant disease, estimated to affect up to 20% of all horses, and compares to human asthma. The pathogenesis of EA is most likely immune-mediated, yet incompletely understood. To study the immune response in the affected lower airways, mixed leukocytes were acquired through bronchoalveolar lavage (BAL) and the cell populations were analyzed on a single-cell basis by flow cytometry (FC). Samples of 38 horses grouped as respiratory healthy or affected by mild to moderate (mEA) or severe EA (sEA) according to their history, clinical signs, and BAL cytology were ana...
Jasiński T, Zdrojkowski Ł, Ferreira-Dias G, Kautz E, Juszczuk-Kubiak E, Domino M.Endometrosis is a frequently occurring disease decreasing mares' fertility. Thus, it is an important disease of the endometrium associated with epithelial and stromal cell alterations, endometrium gland degeneration and periglandular fibrosis. Multiple degenerative changes are found in uterine mucosa, the endometrium. However, their pathogenesis is not well known. It is thought that nuclear factor-κB (NF-κB), a cell metabolism regulator, and its activation pathways take part in it. The transcription of the profibrotic pathway genes of the NF-κB in fibrotic endometria differed between the fo...
Protection against infectious diseases can be obtained with vaccines generating immunogenic response through a combination of humoral and cellular immunity. In this study haematological and serum protein electrophoretic profiles of horses vaccinated against herpesvirus 1 (EHV-1) and 4 (EHV-4) were evaluated. Blood samples were collected from 16 horses before (T0), after 24h, 48h, 72h, 1st week, 2nd week and 3rd week (T1I, T2I, T3I, T7I, T14I and T21I) from the first EHV vaccine-dose administration as well as before (TPRE), and after 24h, 48h, 72h, 1st week, 2nd week, 3rd week and 4th week (T1I...
Hu D, Tang Y, Wang C, Qi Y, Ente M, Li X, Zhang D, Li K, Chu H.The microbiota and its metabolites play an important role in regulating the host metabolism and immunity. However, the underlying mechanism is still not well studied. Thus, we conducted the LC-MS/MS analysis and RNA-seq analysis on with and without horse botfly infestation to determine the metabolites produced by intestinal microbiota in feces and differentially expressed genes (DEGs) related to the immune response in blood and attempted to link them together. The results showed that parasite infection could change the composition of microbial metabolites. These identified metabolites could b...
Witkowski M, Duliban M, Rak A, Profaska-Szymik M, Gurgul A, Arent ZJ, Galuszka A, Kotula-Balak M.Endometrosis is a periglandular fibrosis associated with dysfunction of affected glandular epithelial cells that is the most common cause of reduced fertility in mares, although it is not fully understood. The etiology of the disease is still partially unknown. This study focuses on understanding the genetic mechanisms potentially underlying endometrosis in mares using the Next Generation Sequencing (NGS) technique. Endometrial samples, used in the study, were obtained in the anestrus phase both from healthy mares and those diagnosed with endometrosis. The NGS data were analyzed for gene invol...
Kimura S, McCoy AM, Boothe DM, Wooldridge AA, Graff E, Hammack SM, Cresci L, Hofmeister E, Lascola KM.To describe misoprostol pharmacokinetics and anti-inflammatory efficacy when administered orally or per rectum in endotoxin-challenged horses. Methods: 6 healthy geldings. Methods: A randomized 3-treatment crossover design was performed with a minimum washout period of 28 days between treatment arms. Prior to endotoxin challenge (lipopolysaccharide, 30 ng/kg IV over 30 minutes), horses received misoprostol (5 µg/kg once) per os (M-PO) or per rectum (M-PR) or water as control (CON). Clinical parameters were evaluated and blood samples obtained to measure plasma misoprostol free acid concentrat...
Bayless RL, Sheats MK, Jones SL.Neutrophils play a major role in many equine conditions, including equine asthma, laminitis, and intestinal ischemia and reperfusion injury, and therefore represent an attractive target for innovative therapeutic approaches. Novel strategies for reducing neutrophilic inflammation include modulation of neutrophil functions and lifespan. Withaferin A (WFA) is a phytochemical with well-established and anti-inflammatory properties, but its direct effects on neutrophils are largely unknown. We hypothesized that WFA would inhibit adhesion, migration, and respiratory burst by equine neutrophils and...
Taylor SD, Serpa PBS, Santos AP, Hart KA, Vaughn SA, Moore GE, Mukhopadhyay A, Page AE.A systemic and dysregulated immune response to infection contributes to morbidity and mortality associated with sepsis. Peripheral blood-derived mesenchymal stromal cells (PB-MSC) mitigate inflammation in animal models of sepsis. Allogeneic PB-MSC administered IV to horses is well-tolerated but therapeutic benefits are unknown. Objective: After IV lipopolysaccharide (LPS) infusion, horses treated with PB-MSC would have less severe clinical signs, clinicopathological abnormalities, inflammatory cytokine gene expression, and oxidative stress compared to controls administered a placebo. Methods: ...
Salinas C, Espinosa G, Morales N, Henríquez C, Morán G, Gajardo G, Burgos RA, Uberti B.Obesity and insulin dysregulation (ID) are increasingly prevalent conditions in equid populations worldwide. Immune impairment is well described in humans with metabolic dysfunction and is reported but still incompletely understood in horses. This study evaluated the effect of acute induced transient hyperglycemia on apoptosis, phagocytosis and oxidative burst activity of peripheral blood polymorphonuclear cells (PMN) of lean and obese adult horses with or without insulin dysregulation. Seventeen adult horses were allocated into three groups based on their body condition score (BCS) and metabo...
Lucassen A, Hankel J, Finkler-Schade C, Osbelt L, Strowig T, Visscher C, Schuberth HJ.Feed supplements such as fermentation products (SCFP) alter immune responses in horses. The purpose of this study was to analyze whether a prebiotic activity of the SCFP alters the gut microbiome in horses. Racehorses were fed either SCFP (Olimond BB, OLI, = 6) or placebo pellets (PLA, = 5) for 43 days. Fecal microbiota analysis was performed using 16S rRNA gene sequencing. The numbers and function of circulating immune cell subpopulations were analyzed by flow cytometry. SCFP supplementation resulted in non-consistent differences in fecal microbiota between the PLA and OLI during the feedi...
Lee DH, Lee EB, Seo JP, Ko EJ.Despite vaccination, equine influenza virus (EIV) and equine herpesvirus (EHV) infections still cause highly contagious respiratory diseases in horses. Recently, concurrent vaccination with EIV and EHV was suggested as a new approach; however, there have been no reports of concurrent vaccination with recombinant canarypox EIV and inactivated EHV vaccines. In this study, we aimed to compare the EIV-specific immune responses induced by concurrent administrations of a recombinant canarypox EIV vaccine and an inactivated bivalent EHV vaccine with those induced by a single recombinant canarypox EIV...
El-Hage C, Hartley C, Savage C, Watson J, Gilkerson J, Paillot R.During Australia's first and only outbreak of equine influenza (EI), which was restricted to two northeastern states, horses were strategically vaccinated with a recombinant canarypox-vectored vaccine (rCP-EIV; ProteqFlu™, Merial P/L). The vaccine encoded for haemagglutinin (HA) belonging to two equine influenza viruses (EIVs), including an American and Eurasian lineage subtype that predated the EIV responsible for the outbreak (A/equine/Sydney/07). Racehorses in Victoria (a southern state that remained free of EI) were vaccinated prophylactically. Although the vaccine encoded for (HA) belon...
One health outlookMay 9, 2022
Volume 4, Issue 1 9 doi: 10.1186/s42522-022-00065-y
Gömer A, Puff C, Reinecke B, Bracht S, Conze M, Baumgärtner W, Steinmann J, Feige K, Cavalleri JMV, Steinmann E, Todt D.The Equine Hepacivirus (EqHV) is an equine-specific and liver-tropic virus belonging to the diverse genus of Hepaciviruses. It was recently found in a large donkey (Equus asinus) cohort with a similar seroprevalence (30%), but lower rate of RNA-positive animals (0.3%) compared to horses. These rare infection events indicate either a lack of adaptation to the new host or a predominantly acute course of infection. Methods: In order to analyze the susceptibility and the course of EqHV infection in donkeys, we inoculated two adult female donkeys and one control horse intravenously with purified Eq...
Zandoná Meleiro MC, de Carvalho HJC, Ribeiro RR, da Silva MD, Salles Gomes CM, Miglino MA, de Santis Prada IL.Racehorses are constantly exposed to stress. Aiming to verify the state of blood components and cortisol alterations during their routine and after races, phagocytosis and oxidative neutrophil burst assays, serum cortisol determination, erythrocytes apoptosis evaluation, lymphoproliferation assays, and blood count tests were performed in thirty Thoroughbred racehorses, which were divided in two groups. The samples were taken right after races (moment 0 d), during rest periods (-11 d, +1 d, +3 d), and after training (-8, +2, +5). In both groups, the phagocytosis showed a decrease in percentage ...
Birdwhistell KE, Hurley DJ, Heins B, Peroni JF.Allogeneic solid organ transplantation is currently the only treatment option for end stage organ disease. The shortage of available donor organs has driven efforts to utilize xenogeneic organs for transplantation. In vitro methods for evaluating immune-compatibility are a quick and low cost means of screening novel tissue products prior to more involved, expensive, and invasive live animal studies. Recently, a new analog of the DNA base thymidine, 5-ethynyl-2'-deoxyuridine (EdU), was developed. It may be used in a fast, efficient and specific means of evaluating cell proliferation via flow cy...
Plummer CE, Polk T, Sharma J, Bae SS, Barr O, Jones A, Kitchen H, Wilhelmy M, Devin K, Clay Smith W, Kolaczkowski BD, Larkin J.Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease and represents the only spontaneous model of human recurrent uveitis (RU). Despite the efficacy of existing treatments, RU remains a leading cause of visual handicap in horses and humans. Cytokines, which utilize Janus kinase 2 (Jak2) for signaling, drive the inflammatory processes in ERU that promote blindness. Notably, suppressor of cytokine signaling 1 (SOCS1), which naturally limits the activation of Jak2 through binding interactions, is often deficient in autoimmune disease patients. Significantly, we previous...
Rosa GDS, Krieck AMT, Padula ET, Stievani FC, Rossi MC, Pfeifer JPH, Basso RM, Braz AMM, Golim MA, Alves ALG.Allogeneic mesenchymal stem cells (MSC) are widely used in clinical routine due to the shorter expansion time and reliability of its quality. However, some recipients can produce alloantibodies that recognize MSCs and activate the immune system, resulting in cell death. Although antibody production was already described after MSC injection, no previous studies described the immune response after intra-articular MSC injection in acute synovitis. This study aimed to evaluate the influence of inflammation on immune response after single and repeated intra-articular injections of synovial membrane...
Basano I, Romolo A, Iamone G, Memoli G, Riccio B, Lavoie JP, Miniscalco B, Bullone M.Equine asthma is currently diagnosed by the presence of increased neutrophil (>5%), mast cell (>2%), and/or eosinophil (>1%) differential cell count. Macrophages are normal resident cells within the alveoli. Their presence in BALF is considered normal, but the clinical implication of the presence of activated or fused macrophages (giant multinucleated cells, GMC) is currently overlooked. We aimed to assess the prevalence, cytological determinants, and clinical significance of increased GMC counts in BALF of 34 asthmatic horses compared to 10 controls. Counts were performed on 15 rando...
Schnabel CL, Fletemeyer B, Lübke S, Marti E, Wagner B, Alber G.Despite the relevance of adaptive immunity against equine pathogens antigen-specific T cell responses of horses are not well characterized and the lack of insight into T cell responses hampers the understanding of the pathogeneses of important diseases. In this study we used tetanus toxoid (TT) as a well-defined antigen to characterize antigen-reactive T cells. Six healthy adult horses received a routine booster against tetanus with an immune stimulating complex (ISCOM)-based vaccine and were followed for 28 days. TT-specific serum antibodies were quantified by ELISA and increased in all horse...
Asakawa MG, Jamieson CA, David F, Johnson JP, Mehmood W, Oikawa MA.A 5-year-old Arabian broodmare with acute colic was diagnosed with lymphocytic ganglioneuritis of the coeliac-mesenteric ganglia and lymphocytic‒plasmacytic enterocolitis resembling inflammatory bowel disease. No significant pathogens were identified by aerobic culture or histopathological examination. The ganglia were multifocally infiltrated with small lymphocytes that were immunopositive for CD3 and negative for CD20 and CD79a antigens, indicating CD3+ T-lymphocyte-mediated coeliac-mesenteric ganglioneuritis. The findings suggest immune-mediated inflammatory bowel disease resulting in dis...
Hussey GS, Giessler KS.Equine herpesvirus-1 (EHV-1) myeloencephalopathy (EHM) is a devastating consequence of EHV-1 infection that has significant economic consequences. However, clinical EHM is relatively rare and occurs in only approximately 10% of infected horses. While there is a positive correlation between the duration and magnitude of viremia and incidence of EHM, it is likely that a combination of host and viral factors determine whether EHM occurs. The identification of these factors is of high interest for the equine community and has been the topic of much research for vaccine development and to predict w...
Roth SP, Burk J, Brehm W, Troillet A.Mesenchymal stromal cells (MSC) represent a promising treatment option for tendon disorders and joint diseases, primarily osteoarthritis. Since MSC are highly context-sensitive to their microenvironment, their therapeutic efficacy is influenced by their tissue-specific pathologically altered targets. These include not only cellular components, such as resident cells and invading immunocompetent cells, but also components of the tissue-characteristic extracellular matrix. Although numerous models have already shown potential MSC-related mechanisms of action in tendon and joint diseases, only a...
Crisman MV, Scarratt WK, Zimmerman KL.Activation of the host response to infection, the "acute-phase response," is a highly organized physiologic reaction that includes changes in concentrations of plasma acute-phase proteins (APPs). The APPs are increasingly being used as markers for prognosis and monitoring response to therapy along with general determinants of equine health. Use of APPs in veterinary medicine is becoming more widespread as more commercial diagnostic kits are being validated. This article reviews the salient features of APPs and examines their current application and potential utility in equine inflammatory diso...
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...
Reed DS, Glass PJ, Bakken RR, Barth JF, Lind CM, da Silva L, Hart MK, Rayner J, Alterson K, Custer M, Dudek J, Owens G, Kamrud KI, Parker MD, Smith J.Alphavirus replicons were evaluated as potential vaccine candidates for Venezuelan equine encephalitis virus (VEEV), western equine encephalitis virus (WEEV), or eastern equine encephalitis virus (EEEV) when given individually or in combination (V/W/E) to mice or cynomolgus macaques. Individual replicon vaccines or the combination V/W/E replicon vaccine elicited strong neutralizing antibodies in mice to their respective alphavirus. Protection from either subcutaneous or aerosol challenge with VEEV, WEEV, or EEEV was demonstrated out to 12 months after vaccination in mice. Individual replicon v...
Schmallenbach KH, Rahman I, Sasse HH, Dixon PM, Halliwell RE, McGorum BC, Crameri R, Miller HR.Inhalant exposure to Aspergillus fumigatus (Asp. f.) antigens induces marked inflammatory and immunological alterations in the lungs of horses affected with chronic obstructive pulmonary disease (COPD). In this study we investigated the role of specific allergen(s) present in Asp. f. on systemic and pulmonary IgE and IgG responses in control and COPD-affected horses, using an enzyme-linked immunosorbent assay (ELISA) and immunoblotting techniques. Compared with controls, horses affected with COPD had significantly higher levels of BALF IgE and IgG to somatic Asp. f. antigens as well as to the ...
Harrington DJ, Sutcliffe IC, Chanter N.Streptococcus equi is the aetiological agent of strangles, one of the most prevalent diseases of the horse. The animal suffering and economic burden associated with this disease necessitate effective treatment. Current antibiotic therapy is often ineffective and thus recent attention has focused on vaccine development. A systematic understanding of S. equi virulence, leading to the identification of targets to which protective immunity can be directed, is a prerequisite of the development of such a vaccine. Here, the virulence factors of S. equi are reviewed.
Cywes-Bentley C, Rocha JN, Bordin AI, Vinacur M, Rehman S, Zaidi TS, Meyer M, Anthony S, Lambert M, Vlock DR, Giguère S, Cohen ND, Pier GB.Immune correlates of protection against intracellular bacterial pathogens are largely thought to be cell-mediated, although a reasonable amount of data supports a role for antibody-mediated protection. To define a role for antibody-mediated immunity against an intracellular pathogen, Rhodococcus equi, that causes granulomatous pneumonia in horse foals, we devised and tested an experimental system relying solely on antibody-mediated protection against this host-specific etiologic agent. Immunity was induced by vaccinating pregnant mares 6 and 3 weeks prior to predicted parturition with a conjug...
Goehring LS, Wagner B, Bigbie R, Hussey SB, Rao S, Morley PS, Lunn DP.Equine herpesvirus-1 is a cause of outbreaks of abortion and neurological disease. The pathogenesis of both these diseases depends on establishment of viremia. An experiment was performed to determine the protective efficacy of two commercially available vaccines used with an optimized 3-dose vaccination regime: a modified-live viral (MLV) and a high antigen load killed vaccine licensed for abortion control. The study design was a blinded, randomized challenge trial. Three groups of 8 yearling ponies received one of three treatments: MLV vaccine (Rhinomune, Boehringer Ingelheim Vetmedica, Inc....
Woodward EM, Christoffersen M, Campos J, Betancourt A, Horohov D, Scoggin KE, Squires EL, Troedsson MH.Transient endometritis after breeding is necessary for clearance of bacteria and spermatozoa; however, in a subpopulation of mares, the inflammation fails to resolve in a timely fashion. The objective of this study was to describe the uterine inflammatory response in mares susceptible or resistant to persistent breeding-induced endometritis (PBIE) during the first 24 h after induction of uterine inflammation.Twelve mares were classified as susceptible (nZ6) or resistant (nZ6) to PBIE. Mares were inseminated over five estrous cycles and endometrial biopsies were collected at one time point per ...
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...
Yager JA.The pathogenesis of Rhodococcus equi pneumonia in foals is reviewed. The main routes of infection are respiratory and alimentary. The latter is probably the chief route of exposure in all foals and probably leads to development of specific immunity. Susceptible foals, those whose maternal immunity wanes before generation of their own immune response, readily develop disease if exposed aerogenously to sufficient numbers of R. equi. Management and environmental circumstances have a major role to play in determining the magnitude of this challenge and, therefore, in the prevalence of the disease....
Mumford JA, Wilson H, Hannant D, Jessett DM.Equine influenza vaccines containing inactivated whole virus and Carbomer adjuvant stimulated higher levels and longer lasting antibody to haemagglutinin in ponies than vaccines of equivalent antigenic content containing aluminium phosphate adjuvants. Five months after the third dose of vaccine containing Carbomer adjuvant, ponies were protected against clinical disease induced by an aerosol of virulent influenza virus (A/equine/Newmarket/79, H3N8). In contrast ponies which received vaccine containing aluminium phosphate adjuvant were susceptible to infection and disease. There was an inverse ...
de Mestre A, Noronha L, Wagner B, Antczak DF.Split immunological tolerance refers to states in which an individual is capable of mounting certain types of immune responses to a particular antigenic challenge, but is tolerant of the same antigen in other compartments of the immune system. This concept is applicable to the immunological relationship between mother and fetus, and particularly relevant in equine pregnancy. In pregnant mares, antibody responses to paternal foreign Major Histocompatibility Complex class I antigens are robust, while anti-paternal cytotoxic T cell responses are diminished compared to those mounted by non-pregnan...
Wang X, Rikihisa Y, Lai TH, Kumagai Y, Zhi N, Reed SM.Anaplasma phagocytophilum immunodominant polymorphic major surface protein P44s have been hypothesized to go through antigenic variation, but the within-host dynamics of p44 expression has not been demonstrated. In the present study we investigated the composition and changes of p44 transcripts in the blood during the acute phase of well-defined laboratory A. phagocytophilum infections in naive equine hosts. Three traveling waves of sequential population changeovers of the p44 transcript species were observed within a single peak of rickettsemia of less than 1 month. During the logarithmic inc...
Christoffersen M, Baagoe CD, Jacobsen S, Bojesen AM, Petersen MR, Lehn-Jensen H.Infectious infertility in the mare is clinically well described, little is however known about the systemic acute phase reaction (APR) and local immunological responses accompanying equine endometritis. The aim of this study was to monitor selected markers of the APR in the systemic circulation and to correlate them to the local innate immune response in the uterus during infectious endometritis. Six adult standard bred mares received an intrauterine infusion of 10(9)CFU Escherichia coli. Blood samples were obtained before (0 h) and 3, 6, 12, 24, 36, 48, 72, 96 and 120 h post inoculation (pi),...
Bureau F, Delhalle S, Bonizzi G, Fiévez L, Dogné S, Kirschvink N, Vanderplasschen A, Merville MP, Bours V, Lekeux P.In most cells trans-activating NF-kappaB induces many inflammatory proteins as well as its own inhibitor, IkappaB-alpha, thus assuring a transient response upon stimulation. However, NF-kappaB-dependent inflammatory gene expression is persistent in asthmatic bronchi, even after allergen eviction. In the present report we used bronchial brushing samples (BBSs) from heaves-affected horses (a spontaneous model of asthma) to elucidate the mechanisms by which NF-kappaB activity is maintained in asthmatic airways. NF-kappaB activity was high in granulocytic and nongranulocytic BBS cells. However, NF...
Martens RJ, Martens JG, Fiske RA, Hietala SK.The immunoprophylactic capacity of specific immune plasma was evaluated in pony foals infected experimentally with Rhodococcus equi. Immune plasma, produced by repeated parenteral administration of viable R. equi to adult horses, was harvested and frozen. Group I (six control foals) and Group II (six principal foals) received lactated Ringers solution and immune plasma respectively at three and five days of age. R. equi were aerosolised into a caudal lung lobe of all foals at seven days of age. Clinical signs, haematological alterations, immune responses, thoracic radiographs and technetium99m...
Summerfield A, Auray G, Ricklin M.Dendritic cells (DC) have a main function in innate immunity in that they sense infections and environmental antigens at the skin and mucosal surfaces and thereby critically influence decisions about immune activation or tolerance. As professional antigen-presenting cells, they are essential for induction of adaptive immune responses. Consequently, knowledge on this cell type is required to understand the immune systems of veterinary mammals, including cattle, sheep, pigs, dogs, cats, and horses. Recent ontogenic studies define bona fide DC as an independent lineage of hematopoietic cells orig...
Fortier G, van Erck E, Pronost S, Lekeux P, Thiry E.Equine gammaherpesviruses (γEHV) have been widely studied over the past 45 years and many isolates have been characterised. Despite this, the diagnosis of γEHV infection remains difficult to establish as its clinical manifestations lack specificity, ranging from mild respiratory signs in a small number of animals to outbreaks in large groups of young horses. This review focuses on the epidemiology, pathogenesis, clinical manifestations and diagnosis of equine herpesvirus (EHV)-2 and -5 infections, as well as on the genetic variation of these viruses. Study of these variations has resulted in...
Fenton JI, Chlebek-Brown KA, Peters TL, Caron JP, Orth MW.Objective To determine whether glucosamine inhibits experimentally induced degradation of equine articular cartilage explants. Methods Articular cartilage was obtained from the antebrachio-carpal and middle joints of horses (2-8 years old) killed for reasons unrelated to lameness. Cartilage discs were harvested from the weight-bearing region of the articular surface and cultured. Media were exchanged daily and the recovered media stored at 4 degrees C. Explants were maintained in basal media 2 days prior to the start of four treatment days. On days 1-4 lipopolysaccharide (LPS, 10 microg/ml) or...
Mealey RH, Zhang B, Leib SR, Littke MH, McGuire TC.Equine infectious anemia virus (EIAV) is a lentivirus that causes persistent infections in horses. We hypothesized that high-avidity CTL specific for nonvariable epitopes might be associated with low viral load and minimal disease in EIAV-infected horses. To test this hypothesis, memory CTL (CTLm) responses were analyzed in two infected horses with high plasma viral loads and recurrent disease (progressors), and in two infected horses with low-to-undetectable viral loads and mild disease (nonprogressors). High-avidity CTLm in one progressor recognized an envelope gp90 epitope, and the data doc...
Kanaly ST, Hines SA, Palmer GH.Rhodococcus equi, a facultative intracellular bacterium, causes chronic, often fatal granulomatous pneumonia in young horses and in humans with AIDS. The inability of host alveolar macrophages to kill intracellular R. equi results in the development of granulomas and progressive loss of pulmonary parenchyma. Clearance of the organism from the lung requires functional CD4+ T cells. The purpose of this study was to identify the cytokine effector mechanisms that mediate clearance of R. equi from the lung. Mice were treated with monoclonal antibodies (MAbs) to either gamma interferon (IFN-gamma) o...
Neuder LE, Keener JM, Eckert RE, Trujillo JC, Jones SL.Endotoxemia occurs when bacterial lipopolysaccharide (LPS) in the blood induces a dysregulated inflammatory response, resulting in circulatory shock and multi-organ failure. Laminitis is a common complication in endotoxemic horses and is frequently the reason for humane euthanasia of these cases. Blood leukocytes are a principal target of LPS in endotoxemia leading to activation of multiple signal transduction pathways involved in the induction of a number of pro-inflammatory genes. In other animal models, the p38 mitogen activated protein kinase (MAPK) pathway has been associated with induced...
Rebordão MR, Carneiro C, Alexandre-Pires G, Brito P, Pereira C, Nunes T, Galvão A, Leitão A, Vilela C, Ferreira-Dias G.Besides the classical functions, neutrophils (PMNs) are able to release DNA in response to infectious stimuli, forming neutrophil extracellular traps (NETs) and killing pathogens. The pathogenesis of endometritis in the mare is not completely understood. The aim was to evaluate the in vitro capacity of equine PMNs to secrete NETs by chemical activation, or stimulated with Streptococcus equi subspecies zooepidemicus (Szoo), Escherichia coli (Ecoli) or Staphylococcus capitis (Scap) strains obtained from mares with endometritis. Ex vivo endometrial mucus from mares with bacterial endometritis wer...
Li F, Craigo JK, Howe L, Steckbeck JD, Cook S, Issel C, Montelaro RC.Previous evaluations of inactivated whole-virus and envelope subunit vaccines to equine infectious anemia virus (EIAV) have revealed a broad spectrum of efficacy ranging from highly type-specific protection to severe enhancement of viral replication and disease in experimentally immunized equids. Among experimental animal lentivirus vaccines, immunizations with live attenuated viral strains have proven most effective, but the vaccine efficacy has been shown to be highly dependent on the nature and severity of the vaccine virus attenuation. We describe here for the first time the characterizati...
Rwambo PM, Issel CJ, Adams WV, Hussain KA, Miller M, Montelaro RC.Three ponies were inoculated with plasma containing 10(4.8) TCID50 of equine infectious anemia virus (EIAV) and observed for 165 to 440 days. Each pony developed a febrile response within 3 weeks of infection during which a plasma viremia greater than or equal to 10(3.5) TCID50/ml was observed. Analyses of four isolates from sequential febrile episodes in a single pony were conducted by two-dimensional tryptic peptide maps and with monoclonal antibodies in immunoblots. Structural and antigenic alterations were observed in the envelope glycoproteins gp90 and gp45, with greatest variation in gp9...
Beards GM, Brown DW, Green J, Flewett TH.Pleomorphic virus-like particles have been observed by electron microscopy in the faeces of children and adults with diarrhoea. Some of these particles were approximately 100 nm in diameter and had a "fringe" of closely applied peplomers approximately 10 nm long; they closely resembled Berne virus of horses and Breda virus of calves, the two representatives of a newly proposed family called the Toroviridae. In one sample a toroidal nucleoprotein-like structure was observed within the particles. For two samples a buoyant density of 1.14 g/ml was determined by centrifugation through a sucrose de...
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...
Newton JR, Townsend HG, Wood JL, Sinclair R, Hannant D, Mumford JA.Field outbreaks of influenza that occurred in vaccinated Thoroughbred racehorses in Newmarket in 1995 and 1996 were investigated by nucleoprotein ELISA and serology. Investigations showed that serum levels of vaccine-induced single radial haemolysis (SRH) antibody correlated closely with protective immunity against equine influenza and were consistent with observations made in previous experimental studies using nebulised aerosol challenge. In the second part of this study, antibody levels stimulated by vaccination were investigated to examine probable protection in high risk groups, such as y...
Lee JS, Pushko P, Parker MD, Dertzbaugh MT, Smith LA, Smith JF.A candidate vaccine against botulinum neurotoxin serotype A (BoNT/A) was developed by using a Venezuelan equine encephalitis (VEE) virus replicon vector. This vaccine vector is composed of a self-replicating RNA containing all of the VEE nonstructural genes and cis-acting elements and also a heterologous immunogen gene placed downstream of the subgenomic 26S promoter in place of the viral structural genes. In this study, the nontoxic 50-kDa carboxy-terminal fragment (H(C)) of the BoNT/A heavy chain was cloned into the replicon vector (H(C)-replicon). Cotransfection of BHK cells in vitro with t...
Padalino B, Raidal SL, Carter N, Celi P, Muscatello G, Jeffcott L, de Silva K.Horses are transported frequently and often over long distances. Transportation may represent a physiological stressor with consequential health and welfare implications. This study reports the effects of a long distance journey on immunological, clinical, haematological, inflammatory and oxidative parameters in an Experimental Group (EG) of ten horses, comparing them with six horses of similar age and breed used as a non-transported Control Group (CG). Clinical examination and blood sampling were performed twice on all horses: immediately after unloading for the EG, and at rest on the same da...
