Interferons are a group of signaling proteins produced by the cells of the immune system in horses in response to viral infections and other immune challenges. They are part of the innate immune response and help regulate the activity of the immune system by inhibiting viral replication and modulating the immune response. In horses, interferons are categorized into types I, II, and III, with type I interferons, such as interferon-alpha and interferon-beta, being the most extensively studied. These proteins are integral to the horse's defense mechanisms against viral pathogens and are also explored for their therapeutic potential. This page compiles peer-reviewed research studies and scholarly articles that investigate the production, function, and clinical applications of interferons in equine health.
Paillot R, Daly JM, Juillard V, Minke JM, Hannant D, Kydd JH.Equine cytotoxic T lymphocyte (CTL) responses to equine herpesvirus-1 (EHV-1) are well characterised but little is known about the cytokine response after infection or vaccination. EHV-1 is common in horses and infects lymphocytes in vivo. This virus was used as a model to measure the synthesis of interferon gamma (IFN-gamma) by equine peripheral blood mononuclear cells (PBMC) after in vivo infection and/or in vitro stimulation with EHV-1. Both flow cytometry and ELISPOT assays were used to quantify equine IFN-gamma using a mouse anti-bovine IFN-gamma monoclonal antibody (clone CC302; shown to...
Wagner B, Robeson J, McCracken M, Wattrang E, Antczak DF.Recombinant cytokines are valuable tools for functional studies and candidates for vaccine additives or therapeutic use in various diseases. They can also be used to generate specific antibodies to analyze the roles of different cytokines during immune responses. We generated a mammalian expression system for recombinant cytokines using the equine IgG1 heavy chain constant region as a tag for detection and purification of the expressed cytokine, demonstrated here using equine interferon-gamma (IFN-gamma), interleukin-2 (IL-2), interleukin-4 (IL4) and transforming growth factor-beta1 (TGF-beta1...
Kleiber C, McGorum BC, Horohov DW, Pirie RS, Zurbriggen A, Straub R.Equine recurrent airway obstruction (RAO) is thought to result from an aberrant immune response to inhaled antigens, modulated by T lymphocytes via the secretion of pro-inflammatory cytokines. However data relating to the phenotypes of the T lymphocytes present in peripheral blood and bronchoalveolar lavage fluid of RAO horses and their cytokine profiles are contradictory. The aim of this study was to further investigate the cytokine (IL-4, IL-5, IL-13 and INF-gamma) mRNA expression profile in peripheral blood lymphocytes and bronchoalveolar lavage lymphocytes from RAO and control horses, befo...
Gutmann S, Zawatzky R, Müller M.Interferon-gamma (IFN-gamma) is a key cytokine in cell-mediated immunity. To measure IFN-gamma production of equine lymphocytes (eqIFN-gamma), we developed a quantitative ELISA. Monoclonal antibodies (mAb) were produced against bacterially derived eqIFN-gamma. The mAbs recognised recombinant and lymphocyte-derived eqIFN-gamma in ELISA, Western blotting, as well as flow cytometric and microscopic analysis. In contrast to bacterially derived material, mammalian and insect cell-derived eqIFN-gamma was biologically active but could be neutralised by one of the monoclonal antibodies. Unexpectedly, ...
Breathnach CC, Soboll G, Suresh M, Lunn DP.A commercial bovine IFN-gamma-specific monoclonal antibody was used to measure antigen-specific IFN-gamma production by equine lymphocytes. Paired PBMC samples were collected from six ponies prior to and 10 days after challenge infection with equine herpesvirus-1 (EHV-1). Each sample was stimulated in vitro with EHV-1, virus-free medium, or PMA and ionomycin, and labelled with monoclonal antibodies specific for various equine lymphocyte subset markers. Following fixation, intracellular IFN-gamma was detected using a FITC-conjugated bovine IFN-gamma-specific monoclonal antibody. In vitro restim...
Davidson AJ, Hodgkinson JE, Proudman CJ, Matthews JB.To investigate cytokine responses in cyathostomin infection, we quantified mucosal interleukin-4 (IL-4), interleukin-10 (IL-10), tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma by reverse transcriptase-competitive polymerase chain reaction. The analysis was performed on large intestinal wall samples obtained from six anatomical sites spanning the caecum and colon of 17 naturally exposed horses. The numbers of developing larvae (DL) and early third stage larvae (EL3) were ascertained using transmural illumination and pepsin digestion techniques, respectively. Levels of each cytoki...
Horín P, Smola J, Matiasovic J, Vyskocil M, Lukeszová L, Tomanová K, Králík P, Glasnák V, Schröffelová D, Knoll A, Sedlinská M, Krenková L....Polymorphic markers identified in the horse genes encoding the interleukin 12 p40 subunit, interferon gamma, tumor necrosis factor receptor 1, and inducible nitric oxide synthase were identified and tested, along with additional markers, for associations with two important horse infections: Rhodococcus equi and Lawsonia intracellularis. Eight immune response-related and 14 microsatellite loci covering 12 out of 31 equine autosomes were used for the association analysis. Markers located on horse Chromosomes Eca10 and 15 were significantly associated with the presence of high numbers of R. equi ...
Sellon DC, Knowles DP, Greiner EC, Long MT, Hines MT, Hochstatter T, Hasel KM, Ueti M, Gillis K, Dame JB.Sarcocystis neurona is an apicomplexan parasite that is the primary etiologic agent of equine protozoal myeloencephalitis in horses. Protective immune responses in horses have not been determined, but interferon-gamma (IFN-gamma) is considered critical for protection from neurologic disease in mice. The role of adaptive and innate immune responses in control of parasites was explored by infecting BALB/c, IFN-gamma knockout (GKO), and severe combined immune deficient (SCID) mice with S. neurona (10(4) sporocysts/mouse). Immune competent BALB/c mice eliminated parasites within 30 days, with no s...
Moore I, Horney B, Day K, Lofstedt J, Cribb AE.The effect of oral treatment with natural or recombinant human interferon alpha (HIA) on inflammatory airway disease in young standardbreds was assessed in a double-blind, randomized clinical trial. A total of 34 horses with nasal discharge, excess mucus in the trachea, and a persistent cough of at least 2 weeks' duration that interfered with training completed the trial. Horses were rested for 1 week and received oral treatment with either a saline placebo, recombinant human interferon alpha (rHIA; 90 U/horse/day), or natural human interferon alpha (nHIA: 50 U/horse/day) for 5 days. There was...
Spencer JA, Ellison SE, Guarino AJ, Blagburn BL.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome seen in horses from the Americas and is mainly caused by Sarcocystis neurona. Cell-mediated immune responses to mitogens have been shown to be reduced in horses with EPM, although it is not known whether the parasite causes this immunosuppression or if the immunosuppression is required for disease manifestation. Recently, a 29-kDa surface antigen from S. neurona merozoites was identified as being highly immunodominant on Western blot. This antigen has been sequenced and cloned, and the expressed protein has been named SnSAG1. Is...
Janicke H, Taylor PM, Bryant CE.Equine endotoxaemia is an important cause of morbidity and mortality in horses caused by the interaction of bacterial lipopolysaccharide (LPS) with cells such as macrophages and vascular smooth muscle. In this study we isolated equine vascular smooth muscle from a variety of vessels and stimulated it with LPS and human interferon (hIFN)-gamma. Using reverse transcriptase polymerase chain reaction (rt-PCR) and Western blot analysis we show that cyclooxygenase-2 (COX-2) is readily expressed in equine vascular smooth muscle. Vascular smooth muscle cells produced prostaglandin E2 in response to LP...
Hicks BA, Etter SJ, Carnahan KG, Joyce MM, Assiri AA, Carling SJ, Kodali K, Johnson GA, Hansen TR, Mirando MA, Woods GL, Vanderwall DK, Ott TL.Pregnancy and interferon-tau (IFN tau) upregulate uterine Mx gene expression in ewes; however, the only known role for Mx is in the immune response to viral infection. We hypothesize that Mx functions as a conceptus-induced component of the anti-luteolytic mechanism and/or regulator of endometrial secretion or uterine remodeling during early pregnancy. This study was conducted to determine the effects of early pregnancy on uterine Mx expression in domestic farm species with varied mechanisms of pregnancy recognition. Endometrium from cows, gilts, and mares was collected during the first 20 d o...
Davis EG, Rush BR, Blecha F.Immunomodulation with Propionibacterium acnes is used for prophylaxis of respiratory disease or in horses suffering from chronic pulmonary inflammation; however, the mechanism for this response is poorly understood. Semiquantitative reverse transcriptase-polymerase chain reaction assays were used to evaluate gene expression of interleukin (IL)-2, IL-10, interferon (IFN)-gamma, and NK-lysin in healthy horses treated with P. acnes. Findings in the study indicated that horses treated with a P. acnes-based immunomodulator exhibited increased IFN-gamma and NK-lysin gene expression in peripheral blo...
Wattrang E, Jessett DM, Yates P, Fuxler L, Hannant D.The production of interferon (IFN), interleukin-6 (IL-6), and tumor necrosis factor (TNF) was monitored in horses during the course of influenza A2 virus infections. The effects of two virus strains, Newmarket/2/93 and Sussex/89, were compared, of which the latter is considered the more pathogenic in terms of clinical signs. Ten naive ponies were infected with influenza A/equine/Sussex/89 and 10 with influenza A/equine/Newmarket/2/93, respectively. As expected ponies infected with Sussex/89 showed the most pronounced clinical signs but there was no notable difference in viral excretion compare...
Hines SA, Stone DM, Hines MT, Alperin DC, Knowles DP, Norton LK, Hamilton MJ, Davis WC, McGuire TC.Rhodococcus equi is a gram-positive bacterium that infects alveolar macrophages and causes rhodococcal pneumonia in horses and humans. The virulence plasmid of R. equi appears to be required for both pathogenicity in the horse and the induction of protective immunity. An understanding of the mechanisms by which virulent R. equi circumvents protective host responses and by which bacteria are ultimately cleared is important for development of an effective vaccine. Six adult horses were challenged with either virulent R. equi or an avirulent, plasmid-cured derivative. By using a flow cytometric m...
Lopez AM, Hines MT, Palmer GH, Alperin DC, Hines SA.Rhodococcus equi infects and causes pneumonia in foals between 2 and 4 months of age but does not induce disease in immunocompetent adults, which are immune and remain clinically normal upon challenge. Understanding the protective response against R. equi in adult horses is important in the development of vaccine strategies, since those mechanisms likely reflect the protective phenotype that an effective vaccine would generate in the foal. Twelve adult horses were challenged with virulent R. equi and shown to be protected against clinical disease. Stimulation of cells obtained from bronchoalve...
Fraser DG, Oaks JL, Brown WC, McGuire TC.Equine infectious anaemia virus (EIAV) is a horse lentivirus causing lifelong, persistent infection. During acute infection, CD8(+) cytotoxic T lymphocytes (CTL) are probably involved in terminating plasma viraemia. However, only a few EIAV CTL epitopes, restricted to fewer horse major histocompatibility complex (MHC) class I alleles, are known. As interferon-gamma (IFN-gamma)-secreting CD4(+), T helper 1 (Th1) lymphocytes promote CTL activity and help maintain memory CTL, identifying broadly recognized EIAV Th1 epitopes would contribute significantly to vaccine strategies seeking to promote s...
Steinbach F, Mauel S, Beier I.Interferons (IFNs) are important mediators of the immune system. Their antiviral activity is an integral part of the innate immune defence, but all IFNs have immune regulatory functions also. Besides rec.eq.IFN-beta detailed descriptions on other rec.IFNs were lacking and none of the proteins was available. To compare the equine IFNs and allow detailed studies on proteins and bioactivity, we performed the expression cloning of rec.eq.IFN-alpha, -beta and -gamma. To achieve maximal expression, a bacterial expression system was chosen. Additionally, rec.eq.IFN-beta and -gamma were expressed in m...
Furr M, Pontzer C.The following experiment was performed to test the hypothesis that transforming growth factor beta (TGF-beta) concentration varies in the cerebrospinal fluid and serum of horses with EPM and to determine if cerebrospinal fluid (CSF) alters the interferon-gamma (IFN-gamma) rersponse of equine peripheral blood mononuclear cells (PBMCs). The concentration of transforming growth factor-beta (TGF-beta2) was investigated in the serum and cerebrospinal fluid (CSF) of 18 horses (9 normal, 9 affected with equine protozoal myeloencephalitis [EPM]). The TGF-beta2 assay was validated in a group of 6 norma...
Rosypal AC, Lindsay DS, Duncan R, Ahmed SA, Zajac AM, Dubey JP.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome in horses from the Americas and is usually caused by infection with the apicomplexan parasite, Sarcocystis neurona. Little is known about the role of immunobiological mediators to this parasite. Nitric oxide (NO) is important in resistance to many intracellular parasites. We, therefore, investigated the role of inducible and endothelial NO in resistance to clinical disease caused by S. neurona in mice. Groups of interferon-gamma gene knockout (IFN-gamma-KO) mice, inducible nitric oxide synthase gene knockout (iNOS-KO) mice, endo...
The Journal of parasitologyFebruary 24, 2001
Volume 86, Issue 6 1276-1280 doi: 10.1645/0022-3395(2000)086[1276:COTLCO]2.0.CO;2
Dubey JP, Saville WJ, Lindsay DS, Stich RW, Stanek JF, Speert CA, Rosenthal BM, Njoku CJ, Kwok OC, Shen SK, Reed SM.Sarcocystis neurona is the most important cause of a neurologic disease in horses, equine protozoal myeloencephalitis (EPM). The complete life cycle of S. neurona, including the description of sarcocysts and intermediate hosts, has not been completed until now. Opossums (Didelphis spp.) are definitive hosts, and horses and other mammals are aberrant hosts. In the present study, laboratory-raised domestic cats (Felis domesticus) were fed sporocysts from the intestine of a naturally infected opossum (Didelphis virginiana). Microscopic sarcocysts, with a maximum size of 700 x 50 microm, developed...
Walsh CP, Duncan RB, Zajac AM, Blagburn BL, Lindsay DS.Neospora hughesi is a recently described cause of equine protozoal myeloencephalitis (EPM). A rodent model for pathogenicity would facilitate development of therapies to be used in horses. In the present study, we examined the susceptibility of BALB/c gamma-interferon gene knockout (gamma-INFKO), BALB/c, CD-1, and C57BL/6 strains of mice and gerbils to infection with tachyzoites of the Nh-A1 strain of N. hughesi isolated from a horse from AL, USA. Only the gamma-IFNKO mice developed severe clinical disease following infection with N. hughesi and died 19-25 days after infection and exhibited se...
Jahrling PB, Geisbert TW, Geisbert JB, Swearengen JR, Bray M, Jaax NK, Huggins JW, LeDuc JW, Peters CJ.A passive immunization strategy for treating Ebola virus infections was evaluated using BALB/ c mice, strain 13 guinea pigs, and cynomolgus monkeys. Guinea pigs were completely protected by injection of hyperimmune equine IgG when treatment was initiated early but not after viremia had developed. In contrast, mice were incompletely protected even when treatment was initiated on day 0, the day of virus inoculation. In monkeys treated with one dose of IgG on day 0, onset of illness and viremia was delayed, but all treated animals died. A second dose of IgG on day 5 had no additional beneficial e...
Hanafusa Y, Cho KO, Kanemaru T, Wada R, Sugimoto C, Onuma M.The present study was designed to investigate the role of cytokines in the pathogenesis of Babesia caballi in experimentally infected horses. The expression of cytokine mRNA was determined by using reverse transcription-polymerase chain reaction in two B. caballi-infected horses for 2 weeks after the infection. In one horse, there was up-regulation of interferon-gamma, tumor necrosis factor-alpha (TNF-alpha) and interleukin-2 mRNAs, while in the second horse, expression of only TNF-alpha mRNA was up-regulated. No change was observed in interleukin-4 mRNA in both of the horses. To know the rela...
Tornquist SJ, Oaks JL, Crawford TB.Thrombocytopenia is a common finding in infection with equine infectious anaemia virus (EIAV), a lentivirus with some homology to human immunodeficiency virus (HIV). The thrombocytopenia of EIA, like that in some HIV patients, appears to have a multifactorial pathogenesis. To investigate the decreased platelet production seen in experimental EIA, the levels of three potential negative regulators of platelet production--tumour necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta) and interferon-alpha (IFN-alpha)--were measured in serum and bone marrow of six severe combi...
Byrne KM, Davis WC, Holmes MA, Brassfield AL, McGuire TC.Two monoclonal antibodies (MAb), HB65A (IgG2a) and HB86A (IgGI), recognize a unique cell surface molecule on equine T-lymphocytes. The molecule, designated EqWC4, identified by these MAbs is present on a subpopulation of CD4+ equine lymphocytes (6.3-10.2% of Arabian lymphocytes CD4+ WC4+) and a smaller population of CD8+ lymphocytes (0.5% to 1.2% of Arabian lymphocytes CD8+ WC4+). EqWC4 is absent from B-lymphocytes, granulocytes, and macrophages. Both MAbs bound to a 46-kDa protein following immunoprecipitation reactions with lysates of surface labeled thymocytes. Immunoaffinity purification u...
Bonilla E, Valero-Fuenmayor N, Pons H, Chacín-Bonilla L.We investigated whether the administration of melatonin (MLT) reduces the death rate and evolution of the disease in mice infected with Venezuelan equine encephalomyelitis (VEE) virus. Our results show that, MLT protects mice infected with the virus. The mortality rate was reduced from 100% to 16% merely by increasing the dose from 0 to 1000 micrograms/MLT per kg body weight MLT significantly postponed the onset of the disease and death by several days. In surviving mice very high titres of VEE virus IgM antibodies were found seven weeks after virus inoculation. MLT significantly reduced VEE v...
Moore BR, Krakowka S, Mcvey DS, Cummins JM, Robertson JT.Protein and eicosanoid concentrations and procoagulant activity were determined in bronchoalveolar lavage fluid (BALF) from 32 Standardbred racehorses with inflammatory airway disease (IAD) and 6 control horses. Total protein, albumin and immunoglobulin G (IgG) concentrations were high (P < 0.05) in the BALF from horses with IAD, a finding consistent with exudation of plasma protein into the airway. Immunoglobulin A (IgA) concentrations also were increased (P < 0.05) which may signify local immunoglobulin production. Difference was not detected in prostaglandin E2 and 6-ketoprostaglandin...
Chesters PM, Steele M, Purewal A, Edington N.A 2.6 kb cDNA species has been isolated from a cDNA library prepared from interferon-alpha stimulated equine peripheral blood leucocytes and the nucleotide sequence determined. The cDNA has a single open reading frame potentially encoding a 660 amino acid polypeptide showing a high degree of homology with known mammalian Mx proteins, including the possession of three consensus GTP-binding motifs. The protein has a calculated pI = 6.1 and in accordance with proposed nomenclature we have designated it equine MxA.
Moore BR.Interferons are efficacious therapeutic agents for treatment of several clinically important diseases in cattle and horses. In some instances, the therapeutic goal of IFN administration is prevention or clinical cure of acute viral infections. On the other hand, IFN may serve as adjunctive treatment to diminish clinical manifestations of disease and improve the quality of life. Oral administration of IFN alpha appears to be a safe and convenient route of administration, and the therapeutic benefit likely develops via unique mechanisms involving oropharyngeal-associated lymphoid tissue for diss...
Furr M, Pontzer C.The following experiment was performed to test the hypothesis that transforming growth factor beta (TGF-beta) concentration varies in the cerebrospinal fluid and serum of horses with EPM and to determine if cerebrospinal fluid (CSF) alters the interferon-gamma (IFN-gamma) rersponse of equine peripheral blood mononuclear cells (PBMCs). The concentration of transforming growth factor-beta (TGF-beta2) was investigated in the serum and cerebrospinal fluid (CSF) of 18 horses (9 normal, 9 affected with equine protozoal myeloencephalitis [EPM]). The TGF-beta2 assay was validated in a group of 6 norma...
Dominguez-Medina CC, Rash NL, Robillard S, Robinson C, Efstratiou A, Broughton K, Parkhill J, Holden MTG, Lopez-Alvarez MR, Paillot R, Waller AS.Bacterial superantigens (sAgs) are powerful activators of the immune response that trigger unspecific T cell responses accompanied by the release of proinflammatory cytokines. () and () produce sAgs that play an important role in their ability to cause disease. Strangles, caused by , is one of the most common infectious diseases of horses worldwide. Here, we report the identification of a new sAg of , SpeS, and show that mutation of the putative T cell receptor (TCR)-binding motif (YAY to IAY) abrogated TCR-binding, whilst maintaining interaction with major histocompatibility complex (MHC) c...
Dhama K, Kapoor S, Pawaiya RV, Chakraborty S, Tiwari R, Verma AK.A fascinating and important arbovirus is Ross River Virus (RRV) which is endemic and epizootic in nature in certain parts of the world. RRV is a member of the genus Alphavirus within the Semliki Forest complex of the family Togaviridae, which also includes the Getah virus. The virus is responsible for causing disease both in humans as well as horses. Mosquito species (Aedes camptorhynchus and Aedes vigilax; Culex annulirostris) are the most important vector for this virus. In places of low temperature as well as low rainfall or where there is lack of habitat of mosquito there is also limitatio...
Short CR, Horner MW, Blay PK, Moss MS, Edington N, Clarke CR.Several studies conducted during the past few years have shown that the pharmacokinetics of a variety of drugs may be altered following viral infection or vaccination. The elimination of drugs which are extensively metabolized, such as theophylline, may be prolonged, especially following exposure to RNA viruses such as Type A influenza or similar orthomyxoviruses. The purpose of this study was to determine whether vaccination of horses with equine influenza virus affected pharmacokinetic parameters describing the distribution and elimination of intravenously administered theophylline. Three th...
Heinz H, Marquardt J, Schuberth HJ, Adolf GR, Leibold W.Peripheral blood mononuclear cells (PBMC) and polymorphonuclear neutrophilic granulocytes (PMN) as well as embryonic equine dermal fibroblasts and the equine fibroblast line E. Derm which were used as controls, were treated with recombinant equine interferon-beta 1 (rEqIFN-beta 1) in vitro which induced the expression of different proteins in these cells. A 74 kDa protein was induced in PBMC and an 82 kDa protein was additionally found in the equine fibroblast E. Derm cell line following treatment with rEqFN-beta 1. Both proteins reacted with anti-mouse and anti-human Mx protein antisera in im...
Moore BR, Krakowka S, Mcvey DS, Cummins JM, Robertson JT.Protein and eicosanoid concentrations and procoagulant activity were determined in bronchoalveolar lavage fluid (BALF) from 32 Standardbred racehorses with inflammatory airway disease (IAD) and 6 control horses. Total protein, albumin and immunoglobulin G (IgG) concentrations were high (P < 0.05) in the BALF from horses with IAD, a finding consistent with exudation of plasma protein into the airway. Immunoglobulin A (IgA) concentrations also were increased (P < 0.05) which may signify local immunoglobulin production. Difference was not detected in prostaglandin E2 and 6-ketoprostaglandin...
Hanafusa Y, Cho KO, Kanemaru T, Wada R, Sugimoto C, Onuma M.The present study was designed to investigate the role of cytokines in the pathogenesis of Babesia caballi in experimentally infected horses. The expression of cytokine mRNA was determined by using reverse transcription-polymerase chain reaction in two B. caballi-infected horses for 2 weeks after the infection. In one horse, there was up-regulation of interferon-gamma, tumor necrosis factor-alpha (TNF-alpha) and interleukin-2 mRNAs, while in the second horse, expression of only TNF-alpha mRNA was up-regulated. No change was observed in interleukin-4 mRNA in both of the horses. To know the rela...
Yin X, Guo M, Gu Q, Wu X, Wei P, Wang X.Tetherin is an interferon-inducible host cell factor that blocks the viral particle release of the enveloped viruses. Most knowledge regarding the interaction between tetherin and viruses has been obtained using the primate lentiviral system. However, much less is known about the functional roles of tetherin on other lentiviruses. Equine infectious anemia virus (EIAV) is an important macrophage-tropic lentivirus that has been widely used as a practical model for investigating the evolution of the host-virus relationship. The host range of EIAV is reported to include all members of the Equidae ...
Wotman KL, Chow L, Martabano B, Pezzanite LM, Dow S.Ocular surface squamous neoplasia (OSSN) is the major cause of corneal cancer in man and horses worldwide, and the prevalence of OSSN is increasing due to greater UVB exposure globally. Currently, there are no approved treatments for OSSN in either species, and most patients are managed with surgical excision or off-label treatment with locally injected interferon alpha, or topically applied cytotoxic drugs such as mitomycin C. A more broadly effective and readily applied immunotherapy could exert a significant impact on management of OSSN worldwide. We therefore evaluated the effectiveness of...
Sturgill TL, Strong D, Rashid C, Betancourt A, Horohov DW.Production of the Th1 cytokine interferon gamma (IFNγ) is associated with resistance to intracellular pathogens, including Rhodococcus equi. While neonatal foals are initially deficient in IFNγ production, expression of this cytokine increases throughout their first year of life. This is presumably the result of stimulation by environmental antigens including pathogen associated molecular patterns (PAMPS) signaling through toll-like receptors (TLR). This increased expression of IFNγ is likewise associated with an age-related resistance to R. equi infection. While immunostimulants containing...
Meulenbroeks C, van der Lugt JJ, van der Meide NM, Willemse T, Rutten VP, Zaiss DM.The immunological mechanisms explaining development of an allergy in some individuals and not in others remain incompletely understood. Insect bite hypersensitivity (IBH) is a common, seasonal, IgE-mediated, pruritic skin disorder that affects considerable proportions of horses of different breeds, which is caused by bites of the insect Culicoides obsoletus (C. obsoletus). We investigated the allergen-specific immune status of individual horses that had either been diagnosed to be healthy or to suffer of IBH. Following intradermal allergen injection, skin biopsies were taken of IBH-affected an...
Lin Y, Deng X, Shen N, Zhao L, Meng Q, Max J, Wang J, Shao Y, Zhou J.The attenuated vaccine of equine infectious anemia virus (EIAV) is the first lentiviral vaccine that provides solid protection against the infection of EIAV virulent strains. Study of the immune response induced by EIAV vaccine is an important approach to understand the immunity to other lentiviruses. IFN-gamma expressed by specifically stimulated lymphocytes is an important indicator for the evaluation of T cell-mediated immunity. A flow cytometry based assay was established in this study to accurately and effectively detect IFN-gamma expression in different subtypes of T lymphocytes in EIAV-...
Holmes CM, Babasyan S, Eady N, Schnabel CL, Wagner B.Equine herpesvirus type 1 (EHV-1) is one of the most prevalent respiratory pathogens in horses with a high impact on animal health worldwide. Entry of the virus into epithelial cells of the upper respiratory tract and rapid local viral replication is followed by infection of local lymphoid tissues leading to cell-associated viremia and disease progression. Pre-existing mucosal immunity has previously been shown to reduce viral shedding and prevent viremia, consequently limiting severe disease manifestations. Here, nasopharyngeal transcriptomic profiling was used to identify differentially expr...
Cacciolatti C, Meyer-Ficca ML, Southwood LL, Meyer RG, Bertolotti L, Zarucco L.To evaluate effects of poly(ADP-ribose) polymerase-1 (PARP1) inhibitors on the production of tumor necrosis factor-α (TNF-α) by interferon-γ (IFN-γ)- and lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) of horses as an in vitro model of inflammation in horses. Methods: 1,440 samples of PBMCs from 6 healthy research horses. Methods: From heparinized whole blood samples, PBMC cultures were obtained. An initial dose-response trial on 48 PBMC samples from 2 horses (24 samples each) was used to determine concentrations of IFN-γ and LPS for use as low- and high-lev...
Hagen J, Hartnett C, Houchins JP, Giguère S, Kalyuzhny AE.Human and mouse immune system cells are the most frequently used specimens in ELISPOT assays. In an effect to expand the application of ELISPOT assay to other species, we developed matched antibody pairs for ready-to-use kits designed for studying the frequency of equine IFNγ- and IL-4-secreting peripheral blood mononuclear cells (PBMCs). Equine PBMCs were stimulated with either concanavalin A (Con A) or calcium ionomycin mixed with phorbol 12-myristate 13-acetate (CaI + PMA). We found that Con A, in general, had a more profound stimulating effect than CaI + PMA on IL-4 secretion, whereas bot...
Curran JA, Argyle DJ, Cox P, Onions DE, Nicolson L.Interferon gamma, a cytokine produced by T-lymphocytes and natural killer cells, plays a central role in the modulation of the immune response, and its antiviral and antitumourigenic properties have made it a potential candidate for use in immunoprophylactic and therapeutic regimes. We have cloned the equine IFN gamma cDNA to facilitate production of this cytokine for clinical evaluation in the horse. The predicted equine IFN gamma amino acid sequence is 67% identical to that of the human equivalent and 78% to the bovine equivalent.
Minato E, Kobayashi A, Aoshima K, Fukushi H, Kimura T.Equine herpesvirus-1 (EHV-1), which causes encephalomyelitis in horses, shows endotheliotropism in the central nervous system of horses, and generally does not infect neurons. However, little is known about the mechanism underlying the resistance of neuron to EHV-1, due to the lack of convenient cell culture systems. In this study, we examined EHV-1 infection in immortalized Rn33B rat neuronal cells, which differentiate into neurons when cultured under nonpermissive conditions. Because murine cell lines are resistant to EHV-1 infections due to the lack of functional entry receptors for EHV-1, ...
Ley KD, Burger D, McGuire T, Henson JB.The role of interferon in the pathogenesis of per-
sistent or chronic viral diseases has not been elu-
cidated. However, interferon or inducers of inter-
feron may have a marked effect on the course of
certain chronic viral diseases [1-3]. Equine infec-
tious anemia (EIA) is a viral disease of horses
that may take an inapparent, acute, subacute, or
chronic course in the affected host [4]. Chronically
infected horses suffer from recurrent attacks of
fever that are accompanied by severe anemia.
After the infection has been established, infected
horses may carry the virus for the rest ...
Maeda Y, Ohtsuka H, Tomioka M, Tanabe T, Nambo Y, Uematsu H, Oikawa MA.Escherichia coli(E. coli) isolated from the uterus of a Thoroughbred mare with bacterial endometritis was used to evaluate the effect of progesterone (P(4)) on the immune response of mares. Peripheral blood mononuclear cells (PBMCs) were collected from 10 nonpregnant clinically healthy adult mares (range, 4-12 years) during diestrus, four Thoroughbreds and six Hokkaido native horses. Cell proliferation and expression of cytokine mRNA, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α and interleukin (IL)-10, of PBMCs stimulated with E. coli and P(4) were examined in vitro. P(4) was...
Luce R, Shepherd M, Paillot R, Blacklawst B, Wood JL, Kydd JH.An assay has been developed that measures EHV-1 specific interferon gamma synthesis (IFNgamma), a cytokine produced following the activation of memory T lymphocytes and therefore a measure of cell mediated immunity. The method requires validation in the field. Objective: To measure the frequency of EHV-1 specific, IFNgamma synthesising peripheral blood mononuclear cells (PBMC) in a population of Thoroughbred horses, and examine its relationship with age, gender, premises and history of vaccination or field infection with EHV-1. Methods: Lymphocytes from 200 Thoroughbred horses were stimulated ...
Schnabel CL, Steinig P, Koy M, Schuberth HJ, Juhls C, Oswald D, Wittig B, Willenbrock S, Murua Escobar H, Pfarrer C, Wagner B, Jaehnig P, Moritz A....Deoxyribonucleic acid (DNA) vaccines are used for experimental immunotherapy of equine melanoma. The injection of complexed linear DNA encoding interleukin (IL)-12/IL-18 induced partial tumour remission in a clinical study including 27 grey horses. To date, the detailed mechanism of the anti-tumour effect of this treatment is unknown. Results: In the present study, the clinical and cellular responses of 24 healthy horses were monitored over 72 h after simultaneous intradermal and intramuscular application of equine IL-12/IL-18 DNA (complexed with a transfection reagent) or comparative substanc...
Sun L, Adams AA, Betancourt A, Stewart JC, Liu C, Horohov DW.Interferon-gamma (IFNγ) plays an important role against viral and intracellular bacterial infections and its production is deficient in foals. Cellular proliferation provides an opportunity for de novo gene expression, though little is known about its role in regulating IFNγ expression in foals. While stimulation of foal peripheral blood mononuclear cells (PBMCs) with concanavalin A (ConA) increased the frequency of IFNγ(+) cells, the overall percentage of IFNγ(+) cells remained below that of adults. By contrast, the proliferative response of foal PBMC was significantly greater than that o...
Byrne KM, Davis WC, Holmes MA, Brassfield AL, McGuire TC.Two monoclonal antibodies (MAb), HB65A (IgG2a) and HB86A (IgGI), recognize a unique cell surface molecule on equine T-lymphocytes. The molecule, designated EqWC4, identified by these MAbs is present on a subpopulation of CD4+ equine lymphocytes (6.3-10.2% of Arabian lymphocytes CD4+ WC4+) and a smaller population of CD8+ lymphocytes (0.5% to 1.2% of Arabian lymphocytes CD8+ WC4+). EqWC4 is absent from B-lymphocytes, granulocytes, and macrophages. Both MAbs bound to a 46-kDa protein following immunoprecipitation reactions with lysates of surface labeled thymocytes. Immunoaffinity purification u...
Yilma T, Perryman LE, McGuire TC.The results of a study on the induction of IFN-alpha, IFN-beta, and IFN-gamma in normal and SCID foals showed a deficiency of IFN-gamma but not IFN-beta in SCID foals. The ability of SCID mononuclear cells to produce IFN-alpha in response to poly I:C but not to NDV may indicate a partial deficiency of IFN-alpha in SCID foals. The deficiency of IFN-gamma and presence of IFN-beta in SCID foals supports the classification of IFN-gamma and IFN-beta as immune and nonimmune interferons, respectively. Furthermore, the deficiency of IFN-gamma in SCID foals may in part explain the high susceptibility t...
Sentsui H, Wu D, Murakami K, Kondo T, Matsumura T.Recombinant equine interferon-gamma (reIFN-gamma) was prepared using a baculovirus expression system and its antiviral activity was investigated using several equine viruses. The reIFN-gamma suppressed the replication of all equine viruses used in the present experiment in horse cell cultures, but did not affect the growth of host cells at concentrations of less than 1000 u/ml. A strong antiviral effect was observed, especially against RNA viruses. Equine picornavirus, equine rhinovirus and equine arteritis virus could not be propagated at all in 100 u/ml reIFN-gamma when 100 TCID(50) of infec...
Adolf GR, Traxler E, Maurer-Fogy I.Equine interferon-beta 1 (EqIFN-beta 1) was purified from extracts of recombinant Escherichia coli by sequential chromatography on hydroxylapatite, anion-, and cation-exchangers. The resulting protein was greater than 98% pure as determined by sodium dodecylsulfate gel electrophoresis, gel permeation HPLC, and reverse-phase HPLC. Amino-terminal amino acid sequencing revealed that essentially all molecules contained an additional amino-terminal methionine. The specific antiviral activity of EqIFN-beta 1 determined on equine dermal fibroblasts challenged with vesicular stomatitis virus (VSV) was...
Rosypal AC, Lindsay DS, Duncan R, Ahmed SA, Zajac AM, Dubey JP.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome in horses from the Americas and is usually caused by infection with the apicomplexan parasite, Sarcocystis neurona. Little is known about the role of immunobiological mediators to this parasite. Nitric oxide (NO) is important in resistance to many intracellular parasites. We, therefore, investigated the role of inducible and endothelial NO in resistance to clinical disease caused by S. neurona in mice. Groups of interferon-gamma gene knockout (IFN-gamma-KO) mice, inducible nitric oxide synthase gene knockout (iNOS-KO) mice, endo...
