Topic:Immunomodulatory
Immunomodulatory agents are substances that can modify or regulate one or more immune functions in horses. These agents can either enhance or suppress the immune response, depending on the desired outcome. In equine medicine, immunomodulatory therapies may be employed to manage various conditions, including autoimmune disorders, allergies, and infections. This topic encompasses research on the mechanisms of action, therapeutic applications, and effects of different immunomodulatory agents in horses. The page aggregates peer-reviewed studies and scholarly articles that investigate the efficacy, safety, and clinical implications of using immunomodulatory treatments in equine health management.
Identification and characterization of equine herpesvirus type 1 pUL56 and its role in virus-induced downregulation of major histocompatibility complex class I. Major histocompatibility complex class I (MHC-I) molecules play an important role in host immunity to infection by presenting antigenic peptides to cytotoxic T lymphocytes (CTLs), which recognize and destroy virus-infected cells. Members of the Herpesviridae have developed multiple mechanisms to avoid CTL recognition by virtue of downregulation of MHC-I on the cell surface. We report here on an immunomodulatory protein involved in this process, pUL56, which is encoded by ORF1 of equine herpesvirus type 1 (EHV-1), an alphaherpesvirus. We show that EHV-1 pUL56 is a phosphorylated early protein w...
Immunostimulation of bronchoalveolar lavage cells from recurrent airway obstruction-affected horses by different CpG-classes bound to gelatin nanoparticles. Recurrent airway obstruction (RAO) in horses has become a common problem in stabled horses in industrialized countries and deserves new therapeutic strategies. CpG-oligodeoxynucleotides (CpG-ODNs) were developed as effective immunostimulating agents to induce a Th2/Th1 shift. These agents showed a beneficial therapeutic effect in allergic diseases with predominant Th2 immunoresponse. CpG-ODN delivery by gelatin nanoparticles (GNPs) resulted in enhanced cellular uptake in murine and human in vitro studies and was a starting point for the present trial. The aim of this study was to identify an o...
Clinical and immunomodulating effects of ketamine in horses with experimental endotoxemia. Ketamine has immunomodulating effects both in vitro and in vivo during experimental endotoxemia in humans, rodents, and dogs. Objective: Subanesthetic doses of ketamine will attenuate the clinical and immunologic responses to experimental endotoxemia in horses. Methods: Nineteen healthy mares of various breeds. Methods: Experimental study. Horses were randomized into 2 groups: ketamine-treated horses (KET; n = 9) and saline-treated horses (SAL; n = 10). Both groups received 30 ng/kg of lipopolysaccharide (LPS, Escherichia coli, O55:B5) 1 hour after the start of a continuous rate infusion (CRI)...
Immunomodulation during and after castration under inhalation anaesthetic without genotoxic effects on equine lymphocytes. Genotoxic DNA damage due to inhalation anaesthesia has been demonstrated in human lymphocytes. In order to evaluate anaesthesia-associated changes in cell-mediated immunity on the basis of a potential DNA damage as a health risk in horses, single cell gel electrophoresis and lymphocyte proliferation assay were performed on equine lymphocytes which were obtained before, during and after regular castration under inhalation anaesthetic. No significant lymphocytic DNA damage due to isoflurane anaesthesia was observed, whereas lymphocyte proliferative reactivity and lymphocyte counts decreased sign...
Ascending placentitis in the mare: an update. Ascending placentitis is a common cause of premature birth, abortion and delivery of compromised, ill foals. Recent experimental models have investigated diagnostic procedures and treatment strategies in an attempt to improve live foal rate. Diagnostics such as transrectal and transabdominal ultrasonography are used to evaluate foetal well-being and placental separation, while measurement of plasma progestins or oestrogen identifies a stressed or hypoxic foetus. Treatment is directed at stopping spread of infection, maintaining uterine quiescence and blocking production of pro-inflammatory cyt...
Effect of altrenogest-treatment of mares in late gestation on adrenocortical function, blood count and plasma electrolytes in their foals. Mares with compromised pregnancies are often treated with altrenogest to prevent abortion. However, there is only limited information about effects on the foal when altrenogest treatment is continued during final maturation of the fetus. Objective: To determine effects of altrenogest treatment during late gestation in mares on maturity, haematology changes, adrenocortical function and serum electrolytes in their newborn foals. Methods: Six mares were treated with altrenogest (0.088 mg/kg bwt) once daily from Day 280 of pregnancy until foaling and 7 mares served as controls. Results: Foals born...
Differential modulation of lipopolysaccharide-induced expression of inflammatory genes in equine monocytes through activation of adenosine A2A receptors. Adenosine is an endogenous nucleoside that has potent receptor-mediated immunomodulatory effects on macrophage/monocyte function. In this study, we determined the effects of an adenosine A(2A) receptor agonist, ATL313, on the expression of mRNAs for four pro-inflammatory mediators, IL-1beta, IL-8, COX-2, and TNF-alpha, and the mRNA and protein for the anti-inflammatory cytokine, IL-10 in equine monocytes incubated with lipopolysaccharide (LPS). The results indicate that ATL313 significantly reduces LPS-induced expression of COX-2 and TNF-alpha, enhances the expression of IL-10 and IL-8, but do...
Clinical and subclinical endometritis in the mare: both threats to fertility. Endometritis, a major cause of mare infertility arising from failure to remove bacteria, spermatozoa and inflammatory exudate post-breeding, is often undiagnosed. Defects in genital anatomy, myometrial contractions, lymphatic drainage, mucociliary clearance, cervical function, plus vascular degeneration and inflamm-ageing underlie susceptibility to endometritis. Diagnosis is made through detecting uterine fluid, vaginitis, vaginal discharge, short inter-oestrous intervals, inflammatory uterine cytology and positive uterine culture. However, these signs may be absent in subclinical cases. Hyper...
Immune parameters in mares resistant and susceptible to persistent post-breeding endometritis: effects of immunomodulation. Our objective was to characterize immune parameters in susceptible (SM) and resistant (RM) mares, with and without artificial insemination (AI) and immunomodulation. Eight RM and eight SM were selected based on their reproductive history and functional tests. Both groups of mares were evaluated during three consecutive cycles: Cycle 1, untreated cycle (control); Cycle 2, AI with dead semen; Cycle 3, AI with dead semen and immunomodulation. Endometrial biopsies were taken during the three cycles as follows: Cycle 1--at estrus, when follicles > or =35mm and at diestrus (7+/-1 days after ovulatio...
Lactoferrin, a glycoprotein with immunomodulatory and mast cell stabilising properties, in skin of horses suffering from Culicoides hypersensitivity. Lactoferrin (LF), a glycogen of the transferrin family with anti-bacterial and immunomodulatory properties, is expressed in various secretions and tissues. Cutaneous LF serves as a mast cell stabilising compound, modulates T cell activity and is found during IgE-mediated late phase reactions at allergen challenged sites. Culicoides hypersensitivity (CHS) in horses is a common IgE-mediated allergic dermatitis, characterised by an early and late phase cutaneous reaction upon allergen challenge. The aim of the study presented here was to examine whether LF mRNA expression in skin biopsies from ho...
Endometrial IL-1beta, IL-6 and TNF-alpha, mRNA expression in mares resistant or susceptible to post-breeding endometritis. Effects of estrous cycle, artificial insemination and immunomodulation. Endometrial mRNA expression of the pro-inflammatory cytokines interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) was assessed in mares resistant (RM) or susceptible (SM) to persistent post-breeding endometritis (PPBE). Eight RM and eight SM, were selected based on reproductive records and functional tests out of a herd of 2,000 light cross-type mares. Three experiments were done to study transcription patterns in (i) basal conditions; (ii) after artificial insemination (AI); and (iii) after administration of an immunomodulator at time of artificial ...
Increases in cytokine and antimicrobial peptide gene expression in horses by immunomodulation with Propionibacterium acnes. 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...
Cytokine gene expression by peripheral blood leukocytes in horses experimentally infected with Anaplasma phagocytophila. Human granulocytic ehrlichiosis (HGE), a tick-borne zoonosis, is caused by an obligatory intragranulocytic bacterium, the HGE agent, a strain of Anaplasma phagocytophila. The equine model of HGE is considered valuable in understanding pathogenic and immune mechanisms of HGE. In the present study, cytokine mRNA expression by peripheral blood leukocytes (PBLs) in horses was examined during the course of infection by intravenous inoculation of A. phagocytophila or by allowing feeding by infected ticks. The p44 genes encoding the major outer membrane protein P44s of A. phagocytophila were detected...
Caprine serum fraction immunomodulator as supplemental treatment of lower respiratory disease in the horse. Suppurative lower airway disease is a common debilitating disease in performance horses and, while rarely fatal, is often recalcitrant to conventional therapy. A variety of treatments have been used to combat this condition and we conducted two types of studies to determine if caprine serum fraction--immunomodulator (CSFI), a nonspecific immunomodulator, improved recovery from lower respiratory disease. Two dose response studies were performed to ascertain the efficacy of CSFI. Horses were maintained daily on conventional antibiotic therapy. Respiratory tract exudate, nasal discharge, dyspnoea...
The diagnosis and treatment of periorbital sarcoid in the horse: 445 cases from 1974 to 1999. OBJECTIVE: Diagnosis and management of periorbital sarcoids in horses is a significant clinical challenge for the practicing veterinary surgeon and pathologist. The purpose of this study was to investigate the response of various types of sarcoids to different therapeutic methods. Animals studied Medical records of 445 clinical patients. Procedures This paper retrospectively examines the clinical and histological features of periorbital sarcoids and the treatment of 445 cases. Treatment by surgical excision, cryosurgery, Bacillus-Calmette-Gaérin (BCG) immunomodulation, topical cytotoxic appli...
Immunomodulation in horses. Nonspecific immunomodulators are substances that induce non-antigen-specific enhancement of the body's native or acquired defense mechanisms. Immunomodulant preparations are most often used for treatment of chronic, viral, or bacterial infection with evidence of secondary immunosuppression. The proposed mechanism of action of these products is macrophage activation and subsequent release of cytokines that enhance humoral and cell-mediated immunity. In equine medicine, nonspecific immunostimulant products are used for prevention and treatment of infectious respiratory disease and treatment of s...
The use of Baypamun N in crowding associated infectious respiratory disease: efficacy of Baypamun N (freeze dried product) in 4-10 month old horses. The efficacy of an immunomodulator, Baypamun N, was tested in 4-10-month-old horses which were exposed to stress by weaning, transport and commingling with yearlings from different breeders (crowding). Verum (n = 26) and placebo animals (n = 27) received three intramuscular injections of the investigational preparations (days 0, 2, 9) starting at the day of commingling in one stable. The incidence of acute respiratory disease was high during the first 4 weeks after commingling. Approximately 50% of all horses showed seroconversion due to field infection by EHV1 and EHV4 during the observation ...
Pathogenesis of Borna disease. Borna disease represents a unique model of a virus-induced immunological disease of the brain. Naturally occurring in horses and sheep, the mechanisms of pathogenesis have been studied in experimental animals, namely in the rat. Many investigations have revealed that the infection of the natural hosts principally follows the same pathogenic pathways as observed in rats, leading to a severe encephalomyelitis. This affliction of the central nervous system results in severe neurological disorders that again, are fully comparable in laboratory animals to those in the natural and the different expe...
[Respiratory infectious diseases in horses]. Among all infectious diseases affecting horses, respiratory disease pose the greatest threat to horses kept in stables, horses used for breeding and race horses. Here a distinction should be made between the so-called monocausal infectious diseases (so-called Henle-Koch postulates) and multicausal infectious diseases which are the result of the synergistic interaction of different processes, that alone do not lead to disease. There is no clearcut distinction between the two groups. The most important monocausal respiratory infections of horses are caused by equine influenza virus (subtypes 1 a...
Equine immunology 3: immunopharmacology–anti-inflammatory and antihypersensitivity drugs. This article reviews anti-inflammatory and antihypersensitivity drugs under these 4 headings: Functional or physiological antagonists; Selective pharmacological inhibitors; Broad spectrum anti-inflammatory drugs; Miscellaneous inhibitors. The compounds considered include sympathomimetic amines, anticholinergic drugs, antihistamine drugs, tryptamine antagonists and dopamine antagonists, glucocorticosteroids and non-steroidal anti-inflammatory drugs, disodium cromoglycate and diethylcarbamazine citrate. The relationship of the pharmacological actions of these compounds is considered in the conte...