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.
Barlough JE, Madigan JE, DeRock E, Dumler JS, Bakken JS.A Thoroughbred filly that developed clinical signs of equine granulocytic ehrlichiosis following inoculation with the human granulocytotropic ehrlichia was shown to be resistant to challenge with Ehrlichia equi, a closely related agent. This result further substantiates the close and potentially conspecific relationship between these two granulocytotropic ehrlichiae.
Swiderski CE, McClure JJ.The immune system is a complex interactive network. Defects in its function can be characterized broadly as being the result of actual deficiencies in the network or misdirection of normal immunologic functions. The assays that are available to detect deficiencies in the immunologic network barely scrape the surface of the possibilities. These assays primarily evaluate humoral immune function, but undetected defects in innate and cellular immunity are sure to exist. Although assays of humoral immunity have allowed the characterization of a number of immunodeficiency syndromes in horses, closer...
Cargile JL, MacKay RJ, Dankert JR, Skelley L.A monoclonal antibody (MAB) against equine tumor necrosis factor-alpha (Eq TNF) was used to investigate the role of TNF in cytokine, eicosanoid, and metabolic responses of Miniature Horses given endotoxin. Plasma concentrations of interleukin 6 (IL-6), lactate, thromboxane A2 metabolite, and prostacyclin metabolite (6-keto-PGF1 alpha) were measured in 10 Miniature Horses given 0.25 microgram of lipopolysaccharide (LPS; Escherichia coli O55:B5)/kg of body weight. Five horses were given Eq TNF MAB and 5 were given isotype-matched MAB as control. All horses were given 1.86 mg of antibody/kg by IV...
Kato H, Ohashi T, Nakamura N, Nishimura Y, Watari T, Goitsuka R, Tsujimoto H, Hasegawa A.Equine interleukin-1 alpha (IL-1 alpha) and IL-1 beta were molecularly cloned to establish a basis for research on inflammatory and immune responses in the horse. Equine peripheral blood mononuclear cells (PBMC) were stimulated with lipopolysaccharide (LPS), and cDNA clones of equine IL-1 alpha and IL-1 beta covering the whole coding sequences were isolated from them. These equine IL-1 alpha and IL-1 beta clones contained open reading frames encoding 271 and 269 amino acids, respectively. The deduced amino acid sequence of equine IL-1 alpha showed 71.6% and 60.2% similarity with that of human ...
Wallace FJ, Emery JD, Cripps AW, Husband AJ.The ability of mucosally administered antigen to provide protection against Streptococcus equi ('Strangles') infections in horses was examined. First, an enzyme linked immunosorbent assay (ELISA) was developed to detect the immune status of horses to S. equi. This assay was used to select Strangles-naive horses for the study and also to monitor their response to immunisation. Potential vaccine candidates were: (a) orally administered paraformaldehyde killed S. equi; (b) intraperitoneally (IP) administered paraformaldehyde killed S. equi in a non-inflammatory adjuvant; (c) orally administered l...
Whalley JM, Love DN, Tewari D, Field HJ.A series of recombinant baculoviruses containing genes for glycoproteins C, D, H and L of equine herpesvirus 1 (EHV-1) have been constructed, and the EHV-1 products characterised by gel electrophoresis and immunoblotting. The EHV-1 glycoproteins expressed in insect cells were similar but not identical in apparent sizes to those expressed in EHV-1 infected mammalian cells. Each of the EHV-1 products was recognised by convalescent equine sera, indicating that they were all targets for an equine immune response. Mice immunised with baculovirus-expressed EHV-1 gD and gC acquired an enhanced abilit...
Grünig G, Triplett L, Canady LK, Allen WR, Antczak DF.Invading trophoblasts form endometrial cups in the endometrium of the pregnant mare. In the present study we characterized the maternal leucocyte response to endometrial cups from their formation to their regression. The maternal leucocyte response was correlated with the stages of trophoblast development. (1) Aggregates of CD4+ and CD8+ cells were present between the migrating and differentiating endometrial cup trophoblasts and surrounding the forming endometrial cups. (2) Numbers of CD4+ cells within the mature endometrial cups were much reduced. At the periphery of the endometrial cups CD4...
Hurwitz A, Finci-Yeheskel Z, Dushnik M, Milwidsky A, Shimonovitz S, Yagel S, Adashi EY, Mayer M.This study examines the effects of interleukin-1 (IL-1) on plasminogen activator (PA) activity and prostaglandin (PG) E production in pregnant mare serum gonadotropin (PMSG)-primed granulosa cells and the potential involvement of PGE in the regulation of ovarian plasminogen activation. Methods: Granulosa cells were obtained from PMSG-primed rat (27-day-old) ovaries and cultured in serum-free conditions for 48 hours in the absence or presence of IL-1 beta (10 ng/mL) with and without transforming growth factor-beta 1 (10 ng/mL). Cellular PA activity was measured through the conversion of plasmin...
Kampl B, Dominis-Kramaric M, Bacar-Huskic L.The activities of leukocyte alkaline phosphatase (l-AP) and serum gamma-glutamil transferase (gamma-GT), and total leukocyte counts were determined in horses submitted to the production of hyper immune sera against tetanus (Clostridium tetani). The purpose of this work was to investigate the prospective changes of mentioned parameters in horses under the described circumstances. In addition, the suitability of these parameters in assessing the health condition of the same horses had to be evaluated. The average total leukocyte count increased in one month from the values considered as physiolo...
Guo Y, Wang M, Zheng GS, Li WK, Kawaoka Y, Webster RG.In May 1993, a severe epidemic of respiratory disease began in horses in Inner Mongolia and spread throughout horses in China. The disease affected mules and donkeys as well as horses but did not spread to other species, including humans. The severity of the disease raised the question of whether the outbreak might have been caused by the new avian-like influenza viruses detected in horses in China in 1989 or by current variants ofA/equine/Miami/1/63 (H3N8) (equine-2) or by a reassortant between these viruses. Antigenic and sequence analysis established that all gene segments of the influenza ...
Lunn DP, Holmes MA, Schram B, Duffus WP.Equine immunoglobulin G is currently classified as consisting of five sub-isotypes: IgGa, b, and c, IgG(T), and IgG(B). The study of the role of these immunoglobulins in antigen-specific responses, and the examination of their functional properties would be greatly facilitated by the availability of monoclonal antibodies (Mabs) that distinguish between them. The production and characterization of two Mabs that recognize an IgG sub-isotype with the characteristics of IgG(ab) is described. The immunoglobulin identified by these Mabs had a heavy chain weight of 53 kDa, was of rapid cathodal elect...
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...
Frayne J, Stokes CR.The use of tetanus toxoid as a recall antigen to investigate equine immune responses would be, in theory, a useful and cost-effective model in vitro. However, by using various regimens for culturing peripheral blood mononuclear cells from horses previously immunised with toxoid no proliferative response to the antigen was obtained in vitro, whereas lymph node mononuclear cells from the same animals proliferated significantly in response to it. The lack of response by the peripheral blood mononuclear cells was not due to the presence of a suppressive factor but to a lack of recognition of the a...
Powell DG, Watkins KL, Li PH, Shortridge KF.Equine-2 influenza virus A (H3N8) infection occurred among vaccinated thoroughbred horses in Hong Kong during November and December 1992. The outbreak was unique in that it occurred among a large population stabled under intensive conditions. It resulted in the postponement of seven race meetings over a period of 32 days. The outbreak originated after the importation of horses 25 to 32 days before any clinical signs were reported. Vaccination did not prevent 75 per cent of the population from becoming infected, and half the infected horses developed clinical signs. Vaccination did, however, co...
Timoney JF, Walker J, Zhou M, Ding J.Streptococcus equi subsp. zooepidemicus, a Lancefield group C streptococcus, is a frequently isolated opportunist pathogen from a variety of animal hosts, including the horse. Previous studies have indicated that equine strains carry antigens with characteristics of the antiphagocytic M proteins on the Lancefield groups A and G streptococci. We have cloned a protective M-like protein gene (SzPW60) of an equine strain of S. equi subsp. zooepidemicus W60 and determined its sequence. This gene encodes a protein with a molecular weight of 40,123 which protects mice against subsp. zooepidemicus but...
Ellis JA, Bogdan JR, Kanara EW, Morley PS, Haines DM.The ability of monovalent and bivalent equine herpesvirus (EHV) vaccines to stimulate cellular and antibody responses to EHV-1 and EHV-4 was compared in healthy horses. Comparison of data from lymphocyte blastogenesis tests in which live viruses were used as antigens and that were conducted prior to vaccination and after 2 vaccinations revealed that horses given modified-live EHV-1 had significant increases in proliferative responses to EHV-1 (P = 0.03) and EHV-4 (P = 0.04). Responses to EHV-1 and EHV-4 in horses given the inactivated-virus bivalent vaccine were less; however, significant diff...
Causey RC, Paccamonti DL, Todd WJ.A total of 22 clinical streptococcal isolates, predominantly Streptococcus zooepidemicus, associated with endometritis in horses were tested for their ability to withstand the natural bactericidal properties of freshly obtained blood. During a 3-hour incubation in blood from a single horse, 8 of these isolates survived and grew, the remainder were killed. To determine whether this ability to grow extended to blood of other horses, 5 of these growing isolates were tested for their ability to grow in the blood of 5 additional horses. The same 5 horses were used for each isolate. The isolates gre...
Osborne AC, Carter SD, May SA, Bennett D.An investigation was made into the possible contribution of autoimmune mechanisms to equine arthropathies. Serum and synovial fluid (SF) immune complexes and anti-collagen Type II antibodies were measured, by ELISA, in groups of horses with naturally occurring osteoarthritis (OA), osteochondritis dissecans (OCD), bone fracture, traumatised joints, synovitis, infected joints and non-diseased (control) joints. Significantly raised anti-collagen Type II antibodies were found in osteoarthritic (P < 0.02) and traumatised joint synovial fluids (P < 0.01) compared with the control, where ten of...
Grünig G, Antczak DF.The distribution of four cytokines was analyzed in the endometrium and trophoblast of the horse between Days 30 and 55 of gestation. Endometrial tissues, invasive trophoblast (chorionic girdle), and noninvasive trophoblast (chorion and allantochorion) were examined separately. Cytokine expression was determined by amplification of specific mRNA via the reverse transcriptase polymerase chain reaction (RT-PCR). Messenger RNA for interleukin 2 (IL-2), interleukin 4 (IL-4), and interferon gamma (IFN gamma) was detected in endometrial tissues, unstimulated peripheral blood lymphocytes, and control ...
Raidal SL, Love DN, Bailey GD.Confinement of horses with their heads elevated for periods up to 24 hours was used to evaluate the extent and the effects of bacterial contamination of the equine lower respiratory tract. Significant (P < 0.05) increases in bacterial numbers (up to 10(9) colony forming units/mL in transtracheal aspirate derived samples) occurred within 6 or 12 hours in most horses. Pasteurella/Actinobacillus spp and Streptococcus spp were most commonly isolated. Lowering of the head for 30 minutes every 6 hours to facilitate postural drainage did not prevent multiplication of organisms to levels equivalent...
Hunt AR, Roehrig JT.In order to define more precisely the protective epitope encoded within the first 25 amino acids (aa) of the E2 glycoprotein of the Trinidad donkey strain of Venezuelan equine encephalomyelitis (VEE) virus, we examined the immunogenicity of smaller peptides within the first 19 aa. pep1-9 and pep3-10 elicited virus-reactive antibody, but failed to protect mice from virus challenge. Additionally, pep3-10 was identified by a competitive binding assay using overlapping peptide octamers as the putative binding site of the antipeptide monoclonal antibody (mAb) 1A2B-10. Since the E2 amino-terminal se...
Widders PR, Warner S, Huntington PJ.Normal mares were immunised by the intramuscular and intrauterine administration of an antigen with adjuvant and they and unimmunised control mares were later challenged by the intrauterine instillation of pathogenic Streptococcus zooepidemicus; the response of all the mares was monitored clinically and bacteriologically for seven days. Significantly fewer S zooepidemicus were present in cervical swabs taken from the immunised mares than from the control mares (P < 0.01) and the degree of inflammation in the genital tract of the immunised mares was also significantly less (P < 0.001). Th...
Foster AP, Lees P, Cunningham FM.Hypersensitivity responses to biting flies such as Culicoides are believed to be the cause of sweet itch, a seasonal intensely pruritic skin condition of horses. Little is known about the mediators released by antigen in the skin of affected horses. In the present study the cutaneous vascular and cellular responses to intradermally injected platelet activating factor (PAF) have been characterised in sweet itch cases during the active phase of the disease and compared with those of Culicoides antigen extract. Histamine was used as a positive control in vascular permeability studies. Responses w...
Broström H.Associations between clinical parameters of sarcoids and the equine leucocyte antigen system (ELA) were analysed for 120 Swedish horses. Median age of affected horses was 5.2 years, and the majority presented with solitary tumors between 2 and 5 cm in diameter and ventral abdomen was a predilection site. Clinical signs first appeared at a median age of 3.5 years, and sarcoids at different locations first appeared at different ages. Lesions at different sites differed in size, and multiple tumors, early onset, long duration, and older age all had an association with large size. Clinical manifes...
Allen G, Yeargan M, Costa LR, Cross R.An experimental system that permits sensitive and reproducible detection of equine herpesvirus 1 (EHV-1)-specific cytotoxic T-lymphocyte (CTL) activity in the horse was developed. Peripheral blood mononuclear cells (PBMC) collected from immune horses were restimulated in vitro by culture with live EHV-1. Cytotoxic activity against virus-infected, pokeweed mitogen-stimulated lymphoblast targets was assessed in a 4-h 51Cr release assay. The optimal conditions for in vitro stimulation of equine memory CTLs and for preparation of EHV-1-infected target cells expressing viral antigens were systemati...
Dolby CA, Hannant D, Mumford JA.Five yearling ponies were vaccinated with inactivated Equid herpesvirus type 1 (EHV-1) in Freund's complete adjuvant as a double emulsion and revaccinated 6 weeks later with EHV-1 in Freund's incomplete adjuvant. These ponies and three age-matched controls were challenged intra-nasally after a further 6 weeks with homologous live virus and monitored clinically, biologically and serologically. After challenge, clinical signs were mild in both groups. No cell-associated viraemias were detected in vaccinated ponies. Vaccination induced high levels of complement-fixing (CF) and virus-neutralizing ...
Holbrook TC, Moore JN.Endotoxemia and septicemia are encountered frequently in equine veterinary practice. The deleterious effects of endotoxin are related to the severity of the response of the host's inflammatory system. Consequently, it is imperative that appropriate steps be taken to identify animals at risk of developing endotoxemia or septicemia, and to initiate treatments that will reduce the inflammatory response. This article discusses the anti-inflammatory and immune support of horses and foals with endotoxemia and septicemia.
The Journal of nutritionDecember 1, 1994
Volume 124, Issue 12 Suppl 2723S-2729S doi: 10.1093/jn/124.suppl_12.2723S
Hintz HF.Some aspects of energy, protein and vitamin E nutrition of the performance horse are discussed. The amount, dietary source and time of ingestion of energy before exercise can influence performance. In 1989 the National Research Council (NRC) increased their estimates of energy required by racehorses. Recent studies indicate that the increase was reasonable. Many factors, however, can influence energy requirements. Therefore, the best measure would be body weight and composition of the horse. A proper balance of soluble carbohydrate, fiber, fat and protein is essential. Some guidelines are pres...
Saini S, Singha H, Siwach P, Tripathi BN.Interleukin (IL)-4 and IL-10 activate plethora of immune cells and induce the humoral immune response. However, recombinant version of horse IL-4 and IL-10 has not been investigated to understand their immunomodulating activities. This study aimed to produce recombinant horse mature IL-4 and IL-10 in . Immune-modulating activities of recombinant horse IL-4 and IL-10 were investigated in peripheral blood mononuclear cells (PBMCs). Methods: Equine PBMCs were stimulated with recombinant IL-4 and IL-10. A proliferation of PBMCs was measured by XTT assay and cytokines induction was measured by enzy...
O'Brien MA, Holmes MA, Duffus WP.Anti-tetanus toxoid (TT) antibody (Ig) levels in the supernatant of cultured, pre-immunised equine peripheral blood mononuclear cells (PBMC) were measured by an indirect enzyme-linked immunoabsorbent assay (ELISA). Optimal anti-TT Ig production occurred at concentrations of stimulating, purified TT of between 0.001 and 0.1 micrograms ml-1, which varied depending on the cell concentration. Optimal anti-TT Ig production was most consistently produced when the cell concentration was 5 x 10(6) ml-1. At this cell concentration maximal anti-TT Ig was induced using 0.1 micrograms ml-1 TT. At a cell c...
Wernery U, Rodriguez Caveney M, Wernery R, Raghavan R, Laroucau K, Syriac G, Thomas SM, John J, Joseph M, Jose S, Joseph S, Woo P.Six horses were challenged experimentally with a strain of Burkholderia pseudomallei isolated from a fatal case of the infection in a dromedary camel years earlier in the Emirate of Dubai. Three horses were inoculated subcutaneously and in 3 the bacterium was administered by the oral route. Four of the horses became serologically positive based on reactions to one or more of the OIE described tests for glanders. B. pseudomallei was re-isolated from the 4 serological positive horses. Only one of the subcutaneously infected horses, developed fever for 3 days. The white blood cell values and the ...
Njoku CJ, Saville WJ, Reed SM, Oglesbee MJ, Rajala-Schultz PJ, Stich RW.Equine protozoal myeloencephalitis (EPM) is a disease of horses that is primarily associated with infection with the apicomplexan Sarcocystis neurona. Infection with this parasite alone is not sufficient to induce the disease, and the mechanism of neuropathogenesis associated with EPM has not been reported. Nitric oxide (NO) functions as a neurotransmitter, a vasodilator, and an immune effector and is produced in response to several parasitic protozoa. The purpose of this work was to determine if the concentration of NO metabolites (NO(x)(-)) in the cerebrospinal fluid (CSF) is correlated with...
Bannai H, Kambayashi Y, Tsujimura K, Nagashima T, Takebe N, Tominari M, Nemoto M, Ohta M.The antibody response in horses inoculated with 2 doses of a live equine herpesvirus type 1 vaccine with different vaccination intervals (1 to 3 months) was evaluated with regard to the persistence of virus-neutralizing (VN) antibodies. The durations for which the geometric mean VN titers were maintained significantly higher than those before the first vaccination (P<0.05) were up to 5 months in horses that received the vaccination with a 1-month interval (n=17) and 7 months for those that received it with a 2-month (n=17) or 3-month interval (n=14 or 17). The vaccination program with the 2...
Köhne M, Mönnig F, Papin J, Schöniger S, Tönissen A, Rohn K, Martinsson G, Schoon HA, Sieme H.The effects of standard uterine body and hysteroscopic insemination on endometrial health were investigated. For this purpose, 33 mares were assigned to five different protocols: control (no insemination; n = 7), sham AI (sham uterine body insemination; n = 6), sham HysAI (sham hysteroscopic insemination; n = 7), standard AI (standard uterine body insemination, 300 × 106 progressively motile sperms (PMS); n = 7) and HysAI (hysteroscopic insemination, 100 × 106 PMS; n = 6). Sampling included uterine swabbing for microbiological examination, cytology for determination of polymorphonucle...
Wong DM, Buechner-Maxwell VA, Manning TO, Ward DL.To evaluate the precision of intradermal testing (IDT) in horses. Methods: 12 healthy adult horses. Methods: IDT was performed on the neck of each horse by use of 2 positive control substances (histamine and phytohemagglutinin [PHA]) and a negative control substance. An equal volume (0.1 mL) for each injection was prepared to yield a total of 20 syringes ([4 concentrations of each positive control substance plus 1 negative control substance] times 2 positive control substances times 2 duplicative tests) for each side of the neck. Both sides of the neck were used for IDT; therefore, 40 syringes...
Milillo P, Traversa D, Elia G, Otranto D.Larvae of Rhinoestrus spp. (Diptera, Oestridae) infect nasal and sinus cavities of horses, causing a nasal myiasis characterized by severe respiratory distress. Presently, the diagnosis of horse nasal botfly relies on the observation of clinical signs, on the post mortem retrieval of larvae or on molecular assays performed using pharyngeal swabs. The present study was carried out to characterize larval somatic proteins and salivary glands of Rhinoestrus spp. in a preliminary assessment towards the immunodiagnosis of equine rhinoestrosis. Out of the 212 necropsied horses 13 were positive for th...
Bailey SR, Cunningham FM.To compare adherence of stimulated and unstimulated eosinophils from allergic and normal ponies to cultured equine vascular endothelial cells (equine digital vein endothelial cells; EDVEC) and examine the effect of eosinophil-derived factor(s) on cell adherence. Methods: Eosinophil adherence to unstimulated EDVEC or EDVEC pretreated with IL-1beta or supernatants from stimulated eosinophils was measured. Supernatants were also assayed for TNFalpha and IL-1beta-like bioactivity. Results: Adherence of unstimulated and rhIL-5 (10 ng/ml)-stimulated eosinophils from allergic ponies to rhIL-1beta-tre...
Chaiyabutr N, Wattanaphansak S, Tantilerdcharoen R, Akesowan S, Ouisuwan S, Naraporn D.African horse sickness (AHS) is a non-contagious, high mortality, and insect-borne disease caused by a double-stranded RNA virus from the genus Orbivirus. The study aimed to develop inactivated vaccines serotype 1 inactivated AHS vaccine (IAV) and to compare the effect of IAV on antibody responses in young naïve horses and adult horses pre-immunized with live-attenuated AHS virus (AHSV) serotypes 1, 3, and 4 live-attenuated vaccine (LAV). Unassigned: A total of 27 horses were vaccinated in two trials. Twelve AHS naïve young horses and 15 adult horses were divided into three groups of 4 and 5...
Raidal SL, Bailey GD, Love DN.Flow cytometric techniques were developed for the evaluation of oxidative burst activity in equine peripheral blood neutrophils and lymphocytes, as well as bronchoalveolar lavage derived pulmonary alveolar macrophages and lymphocytes. The oxidation of dichlorofluorescin was measured by the increased fluorescence of cells stimulated with phorbol myristate acetate or a variety of other stimulants. Flow cytometry was a suitable method for the evaluation of the intracellular oxidation in all cell populations evaluated. Analysis was rapid and cell separation before analysis was not required. Hetero...
Bergmann T, Lindvall M, Moore E, Moore E, Sidney J, Miller D, Tallmadge RL, Myers PT, Malaker SA, Shabanowitz J, Osterrieder N, Peters B, Hunt DF....Quantitative peptide-binding motifs of MHC class I alleles provide a valuable tool to efficiently identify putative T cell epitopes. Detailed information on equine MHC class I alleles is still very limited, and to date, only a single equine MHC class I allele, Eqca-1*00101 (ELA-A3 haplotype), has been characterized. The present study extends the number of characterized ELA class I specificities in two additional haplotypes found commonly in the Thoroughbred breed. Accordingly, we here report quantitative binding motifs for the ELA-A2 allele Eqca-16*00101 and the ELA-A9 allele Eqca-1*00201. Uti...
Wong DM, Young L, Dembek KA.Sepsis is common in foals and several treatments are used to facilitate recovery. Evidence in people suggests an association between low blood concentrations of thiamine, ascorbic acid, and cortisol and sepsis, with further evidence suggesting that administration of hydrocortisone, thiamine, and ascorbic acid may improve outcome. No information is available with regard to these treatments in foals. Objective: To compare blood concentrations of thiamine, ascorbic acid, and cortisol in healthy and ill foals. Methods: Fifteen healthy and 27 ill (septic and sick-nonseptic [SNS]) foals were evaluat...
Atwal OS, McDonell W.The pulmonary intravascular macrophages (PIMs) of equines contain a unique electron-dense surface coat that is predominantly composed of lipoproteins. A single exposure of inhalatory halothane causes mobilization of the surface coat into the endocytotic system of the PIMs, followed by expansion of the Golgi apparatus and its enrichment with acid phosphatase. Simultaneously, the cells of the lymphocytic series show hyperplasia in the form of mitotic changes inside the microvascular compartment of the lung. Halothane is known to cause acute and chronic hepatotoxicity because of its biotransforma...
Nikolakopoulos E, Kindahl H, Watson ED.Mares resistant (n=7) and susceptible (n=9) to persistent mating-induced endometritis were artificially inseminated (AI) during oestrus with chilled extended semen. Blood samples were collected from 30 min before AI, for 2 h after AI and again between 16 and 18 h after AI. Samples were assayed for oxytocin and the PGF2alpha metabolite 13,14-dihydro-15-keto PGF2alpha (PGFM). AI caused a significant increase in oxytocin concentrations in both the resistant and susceptible mares and there was no significant difference in oxytocin release between the two groups of mares. Mean PGFM concentrations w...
Rozario C, Martínez-Sobrido L, McSorley HJ, Chauché C.Influenza A viruses (IAVs) are important respiratory pathogens of horses and humans. Infected individuals develop typical respiratory disorders associated with the death of airway epithelial cells (AECs) in infected areas. Virulence and risk of secondary bacterial infections vary among IAV strains. The IAV non-structural proteins, NS1, PB1-F2, and PA-X are important virulence factors controlling AEC death and host immune responses to viral and bacterial infection. Polymorphism in these proteins impacts their function. Evidence from human and mouse studies indicates that upon IAV infection, the...
Santos AC, Nogueira CEW, Dos Santos Suñe Moraes B, Müller V, Mousquer MA, Leite FPL.Equine theileriosis, caused by the Theileria equi protozoan, is a disease of worldwide importance. T. equi expresses surface proteins, of which the EMA-2 protein is a promising antigen for vaccine use. The aim of this study was to evaluate the immune response of adult horses, pregnant mares, and foals to an experimental EMA-2 protein of recombinant T. equi vaccine. A total of 46 horses were used in this study for vaccine trials and challenges. Twelve geldings, 14 pregnant mares, and 14 foals were divided into vaccinated and control groups. Total serum specific anti-rEMA-2 IgG, IgG subclasses, ...
Lepage OM, Laverty S, Marcoux M, Dumas G.The effect of triamcinolone acetonide (0.09 mg/kg of body weight, IM) on serum osteocalcin concentration was studied. Two groups of horses were investigated and included clinically normal horses (group 1, n = 5) and horses with chronic obstructive pulmonary disease (group 2, n = 5). Before treatment, results of a t-test did not reveal any significant difference in serum osteocalcin concentration between the 2 groups. After treatment, a significant (P < 0.05) decrease in serum osteocalcin concentration was observed for both groups. Osteocalcin concentration in individual horses reached a min...
Palmer JE, Whitlock RH, Benson CE.Equine ehrlichial colitis was experimentally induced in 18 ponies, using Ehrlichia risticii-infected blood. Four ponies (group 1) were treated with oxytetracycline (6.6 mg/kg of body weight, IV, q 12 h), beginning 14 hours before inoculation and continuing for 5 days after inoculation. Four additional ponies (group 2) were treated similarly for 10 days after inoculation. The remaining 10 ponies were used as nontreated, infected controls. Clinical disease was delayed in 3 group-1 ponies and in 4 group-2 ponies. Protective immunity developed in the remaining pony that did not develop clinical di...
Hammond A, Bailey SR, Marr CM, Cunningham FM.Platelets contribute to the pathogenesis of human allergic airway disease. The aim of this study was to compare platelet activating factor (PAF)-induced platelet aggregation and thromboxane (Tx) production, plasma Tx and 5-hydroxytryptamine (5-HT) in ponies with recurrent airway obstruction (RAO), an hypersensitivity to inhaled antigens, and normal ponies, before and after antigen exposure. Plasma 5-HT was significantly higher in ponies with RAO but was not further increased by antigen challenge. There was no difference between PAF-induced platelet aggregation or Tx production, or in plasma Tx...
Catunda APN, Alves GES, Paes Leme FO, Carvalho AM, Leise BS, Johnson PJ, Faleiros RR.Inflammation and apoptosis in the hoof lamellar interface both contribute to the early stages of sepsis-associated laminitis, but it is not clear whether apoptosis is occurring before the onset of inflammation or is being provoked by inflammation. Apoptosis and inflammation were therefore measured in lamellar tissues obtained at different time points throughout the early stages of experimentally induced laminitis. Apoptotic cells and leukocyte were enumerated in archived paraffin embedded lamellar tissue samples from previous experiments in which acute laminitis was induced using Black Walnut ...
Rodrigues MA, Figueiredo L, Padrela L, Cadete A, Tiago J, Matos HA, Gomes de Azevedo E, Florindo HF, Gonçalves LM, Almeida AJ.Strangles is an extremely contagious and sometimes deadly disease of the Equidae. The development of an effective vaccine should constitute an important asset to eradicate this worldwide infectious disease. In this work, we address the development of a mucosal vaccine by using a Supercritical Enhanced Atomization (SEA) spray-drying technique. Aqueous solutions containing the Streptococcus equi extracts and chitosan were converted into nanospheres with no use of organic solvents. The immune response in a mouse model showed that the nanospheres induced a well-balanced Th1 and Th2 response charac...
Foster AP, Cunningham FM.Equine eosinophils and neutrophils are believed to play an important part in the protection of horses against parasitic and bacterial invasion. Eosinophils may also play a key role in the pathogenesis of equine inflammatory conditions such as the allergic skin disease, insect hypersensitivity. The factors which stimulate the respiratory burst of equine eosinophils and neutrophils are poorly understood. The first aim of the present study was to determine the effects of the phorbol ester, phorbol myristate acetate (PMA), which is believed to activate intracellular protein kinase C, and opsonised...
Morgan SJ, Storts RW, Stromberg PC, Sowa BA, Lay JC.Factors involved in the proliferation of equine vascular smooth muscle cells were studied in vitro. The most prominent proliferative responses in cultured vascular smooth muscle cells were induced by Strongylus vulgaris larval antigen extract (LAE) and platelet-derived factors. Less significant proliferative responses were obtained with conditioned media from S. vulgaris LAE stimulated and from unstimulated equine mononuclear leukocytes. Additionally, vascular smooth muscle cells exposed to S. vulgaris LAE developed numerous perinuclear vacuoles and were more spindle-shaped than control or smo...
Bannai H, Tominari M, Kambayashi Y, Nemoto M, Tsujimura K, Ohta M.Antibody response in horses after accelerated-schedule Getah virus vaccination was evaluated for its potential adoption during outbreaks. One-year-old Thoroughbred horses received two doses of priming vaccinations following an accelerated schedule (accelerated group: 14-day interval, n = 30) or the conventional schedule (control group: 28-day interval, n = 30). At Day 14, both groups showed similar seropositive rates (66.7% in control group and 73.3% in accelerated group) and geometric mean (GM) virus-neutralizing titers (5.2 [95% confidence interval (CI), 3.0-8.8] in control group and 5.3...
Faber E, Tshilwane SI, Van Kleef M, Pretorius A.Transcriptome analysis was used to characterise the in vitro primary and secondary immune responses induced in horse peripheral blood mononuclear cells (PBMC) stimulated for 24 h with the individual recombinant proteins of a virulent AHSV serotype 4 (AHSV4) field isolate (rAHSV4 proteins) that were previously expressed in Escherichia coli (E. coli). The results showed that the E. coli contamination products greatly affected the innate and humoral immune response transcripts. Hence, the impact of E. coli contamination products present in the individual rAHSV4 proteins on the translational immu...
Harrington JR, Wilkerson CP, Brake CN, Cohen ND.The innate immune system plays a critical role in protecting neonates against infections early in life and Toll-like receptors (TLRs) are key components of innate immune recognition of pathogens. This study examined the effects of age and stimulation with a TLR 7/8 agonist (R848) on TLR8 mRNA expression by foal neutrophils during the first month of life. We also examined the effects of R848 stimulation on mRNA expression of interleukin (IL)-6 and IL-8 at 1 and 14 days of life. We observed that TLR8 mRNA was constitutively expressed (P<0.05) at all ages examined, and its expression did not c...
Bailey M, Martin SC, Lloyd S.Immunologic and hematologic responses were examined in 4 ponies with experimentally induced Strongylus vulgaris infection and in 5 helminth-free ponies. Two ponies were inoculated with 200 larvae and 2 were inoculated with 700 larvae of S vulgaris and then were reinoculated with the same numbers of larvae 34 weeks later. Initial response of the ponies inoculated with S vulgaris was S vulgaris antigen-induced lymphocyte response that developed 1.5 to 3 weeks after inoculation and did not persist. Development of antigen-reactive lymphocytes was followed sequentially by a biphasic complement-fixi...
Minguet G, de la Rebière G, Franck T, Joris J, Serteyn D, Sandersen C.To investigate the effects of the volatile anaesthetic sevoflurane on the release of total and active myeloperoxidase (MPO) by non-stimulated and stimulated polymorphonuclear neutrophils (PMNs) in whole blood from healthy horses. Methods: In vitro experimental study. Methods: Adult healthy horses. Methods: Samples of whole venous blood were collected and incubated in air or in air plus 2.3% or 4.6% sevoflurane for 1 hour. PMNs were stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP), with a combination of cytochalasin B (CB) and fMLP or with phorbol myristate acetate (PMA). Total an...
Rusek J, Klumplerova M, Molinkova D, Sedlinska M, Dusek L, Muzik J, Putnova L, Vrtkova I, Celer V, Horin P.Individual variation in immune responses to herpesviruses was observed in various species. Here, associations between polymorphic molecular markers and life-long anti-EHV-1/4 antibody immune responses were analyzed in a model EHV-infected population of the Old Kladruber horses. Two-dimensional analysis including overall mean titers and titer dynamics expressed by differences between spring and autumn titers allowed identification of low-responders. 50 randomly selected microsatellites and nine single nucleotide polymorphisms in nine immunity-related candidate genes were genotyped. Due to diffe...
