The Major Histocompatibility Complex (MHC) in horses is a group of genes that play a significant role in the immune system by encoding proteins responsible for antigen presentation. These proteins are essential for the recognition of foreign molecules by the immune system, facilitating the differentiation between self and non-self entities. In horses, the MHC is located on equine chromosome 20 and is divided into several regions, including class I and class II, which present antigens to different subsets of T cells. Variability in the MHC genes is associated with susceptibility or resistance to various diseases, influencing immune responses and vaccine efficacy. This page compiles peer-reviewed research studies and scholarly articles that explore the genetic diversity, expression patterns, and implications of MHC in equine health and disease.
Klonisch T, Mathias S, Cambridge G, Hombach-Klonisch S, Ryan PL, Allen WR.In situ hybridization employing a cRNA probe derived from a 428-bp fragment of equine relaxin was used to localize relaxin mRNA, and immunocytochemistry was used to localize relaxin itself, in tissues of the placenta-endometrium interface recovered between 33 and 153 days of gestation from mares carrying intraspecific horse, interspecific mule and extraspecific donkey conceptuses. Immunocytochemical staining was also used to localize trophoblast-specific and class I major histocompatibility complex (MHC) antigens on some specimens. Relaxin mRNA and relaxin were both present in the single-cell ...
Studer U, Marti E, Stornetta D, Lazary S, Gerber H.20 sarcoid-affected horses from a practice in the northern Jura were used in this experiment. The mean age of the 20 horses was 3.9 years at the time of the first observation of sarcoid tumors. On the average, 4.4 tumours were noted per horse. 10 of the horses were treated in a double-blind study with an unspecific immunostimulant (Baypamun P), 10 others received a placebo. One single tumour only was treated per horse. The injections were given under and around the sarcoid. In eight out of the 20 horses all tumours regressed totally or for more than 50% of their initial size. Five of these had...
Broström H, Troye-Bomberg M, Perlmann P.To analyze in vitro lymphocyte-mediated immune responses of horses with sarcoids against allogeneic sarcoid cells containing endogenous retrovirus but not expressing major histocompatibility complex antigens. Methods: Lymphocyte-mediated immune reactions were assessed by means of proliferative responses in mixed lymphocyte tumor cell culture (MLTC) assay and lymphocyte-mediated cytotoxicity against various equine target cells. Methods: 12 horses with sarcoid tumors and 15 control horses. Methods: Blood lymphocytes were cocultured in MLTC with allogeneic sarcoid cells (Mc-1, BayMc-1), equine te...
Maher JK, Tresnan DB, Deacon S, Hannah L, Antczak DF.Down-regulation of major histocompatibility complex (MHC) genes by trophoblast cells is considered to be a primary mechanism preventing maternal immune rejection of the fetal-placental unit in mammalian pregnancy by rendering these cells, which form the primary barrier between mother and fetus, relatively non-antigenic. In situ hybridization with probes encoding human and horse MHC class I genes was used to characterize the pattern of MHC class I mRNA expression in the various forms of horse trophoblast. Strong hybridization signals were observed in the invasive trophoblast cells of chorionic ...
Watson ED, Thomson SR.The density and distribution of MHC Class II positive cells and subpopulations of lymphocytes were studied in the endometrium of genitally normal mares and mares susceptible to endometritis. In genitally normal mares, more MHC Class II positive cells were present in the epithelium and stratum compactum during oestrus than dioestrus. Significantly more CD4+ and CD8+ lymphocytes were present in the stratum compactum than in the stratum spongiosum. CD4+ lymphocytes were present in greater numbers than CD8+ lymphocytes in the stratum compactum but approximately equal numbers were present in the st...
Vagnoni KE, Ginther OJ, Lunn DP.Chorionic girdle cells are a highly invasive subpopulation of trophoblastic cells of the horse conceptus that adhere to the uterine epithelium and begin to invade the endometrium on Days 34-36 (Day 0 = day of ovulation). Just prior to and during invasion (Days 32-36), chorionic girdle cells express high levels of major histocompatibility complex (MHC) I, but expression of this antigen decreases by Days 40-45 and is lost by Day 55. The mechanisms involved in the control of chorionic girdle cell invasion and altered MHCI expression over time are not known. The objective of this study, therefore,...
Fraser DG, Bailey E.Single-strand conformational polymorphism (SSCP) gel electrophoresis and DNA sequencing were used to characterize the second exon of the horse DRB homologue as well as to identify eight new DRB alleles. The SSCP gels presented a complex pattern, with phenotypes exhibiting between 4 and 13 bands. The DRB SSCP patterns were studied for two families (6 to 13 bands per pattern). For both families, the patterns showed simple Mendelian inheritance. The polymerase chain reaction products from two individuals possessing homozygous major histocompatibility complex (MHC) alleles by descent were cloned a...
Bilzer T, Planz O, Lipkin WI, Stitz L.Tissues from 9 horses and 1 donkey suffering from natural Borna disease were investigated immunomorphologically. Lymphocytic inflammatory reactions and increased expressions of MHC class I and class II antigen were found in the brain as well as in the trigeminal and olfactory system. Perivascular inflammatory infiltrates were dominated by CD4+ T cells, whereas the majority of CD8+ T cells were disseminated intraparenchymally. No evidence of inflammation was found in the retina. Borna disease virus proteins and nucleic acids were present in the hippocampus, thalamus and medulla oblongata in all...
Ellis SA, Martin AJ, Holmes EC, Morrison WI.Nineteen horse MHC class I specificities have been serologically identified previously at a single locus (ELA-A), and two other specificities appear to be coded at other loci. Biochemical studies indicate that there are at least two expressed loci. In order to establish the number of transcribed horse MHC class I genes, we made a cDNA library from a heterozygous animal (ELA-A3/A7), and screened for positive clones using a bovine class I probe. More than 200 class I clones were isolated in this way, and so far seven unique full length sequences have been identified. All of the sequences are pre...
Koets AP.The function of eCG in equine pregnancy is far from clear but it has become evident that eCG has little or no FSH activity in the horse and is therefore probably not responsible for the secondary ovulations. eCG does have luteotrophic activity and it could play a role in the resurgence of the primary corpus luteum (1,7,44). Some evidence exists that the receptor population on the equine gonads is heterogenous in a way that makes it possible to distinguish eCG from eLH, resulting in different post-receptor effects (7). There is also evidence that eCG itself is heterogenous, both in glycosylatio...
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...
Asahina M, Murakami K, Ajito T, Goryo M, Okada K.The tissues of an 8-year-old thoroughbred castrated male horse with equine lymphoma were examined immunohistochemically. Neoplastic masses were observed in the mediastinum, mesenteric lymph nodes, gastric mucosa and serosa, liver capsule, and spleen capsule with associated lymph nodes. Histopathologically, the neoplastic cells were seen to consist predominantly of a mixture of well differentiated small and large types. Immunohistochemically, the small lymphoid cells were MHC class IIlow+ and PanT- and the large lymphoid cells were MHC class IIhigh+ and PanT-. These findings revealed that the n...
Kydd J, Antczak DF, Allen WR, Barbis D, Butcher G, Davis W, Duffus WP, Edington N, Grünig G, Holmes MA.The First International Workshop on Equine Leucocyte Antigens was organized and convened for the purposes of identifying immunologically relevant cell surface molecules of equine leucocytes and establishing a system of nomenclature for those molecules. Participating members of the workshop represented the majority of laboratories world-wide engaged in the tasks of production and characterization of equine leucocyte and lymphocyte markers using monoclonal antibodies. The workshop confirmed the identification of several equine CD molecules described previously by individual laboratories, and in ...
Zhang CH, Grünig G, Davis W, Antczak DF.The regulatory effects of phorbol myristate acetate (PMA) on the expression of the CD4 molecule on horse T cells were investigated. On both peripheral blood lymphocytes and thymocytes, PMA resulted in a rapid and transient down-regulation of equine CD4 expression, but had no such effect on the surface expression of equine CD5, CD8 or major histocompatibility complex (MHC) class I and class II molecules. Over 75% of the surface CD4 molecules per cell were lost after a 4 h exposure to PMA at 37 degrees C. The regulation of equine CD4 expression induced by PMA was temperature dependent and revers...
Barbis DP, Bainbridge D, Crump AL, Zhang CH, Antczak DF.A panel of monoclonal antibodies was used to characterize the expression of equine Major Histocompatibility Complex (MHC) class II antigens on lymphocytes of horses of different MHC types. MHC class II antigen expression was compared between adult horses and foals, and the level of expression of MHC class II antigens on horse T cell subpopulations was also determined. Peripheral blood lymphocytes (PBL) from young and adult healthy horses of different MHC haplotypes were labeled with the antibodies and assayed by single- and two-color immunofluorescence flow cytometry. A variation in the expres...
Lazary S, Marti E, Szalai G, Gaillard C, Gerber H.The equine leucocyte antigen (ELA) types and the clinical diagnosis for equine sarcoid and summer dermatitis were evaluated in 2026 horses representing five breeds. Data were analysed in unrelated animals and in family material. In the case of equine sarcoid, a strong association was observed between the ELA class II DW13 antigen and its effect on Swiss (cP < 0.001), French (cP < 0.0001) and Irish (cP < 0.01) Warmblood horses. The class I antigen A3 occurred more frequently in sarcoid-affected French horses (cP < 0.001). These results confirm our earlier findings (Gerber et al. 1988). Among Fr...
Frayne J, Stokes CR.The quantity and distribution of MHC Class II positive cells and T cells in the equine endometrium was investigated throughout the oestrous cycle. Significantly more MHC Class II positive cells were detected in the stratum compactum and stratum spongiosum of endometria from naturally cycling mares during the follicular than during the luteal phase of the oestrous cycle. Significantly more T cells were also detected in the stratum compactum, but not stratum spongiosum, of these mares during the follicular phase. Furthermore, there was a marked increase in the number of MHC Class II positive cel...
McGuire TC, Tumas DB, Byrne KM, Hines MT, Leib SR, Brassfield AL, O'Rourke KI, Perryman LE.Cytotoxic T lymphocytes (CTL) can control some viral infections and may be important in the control of lentiviruses, including human immunodeficiency virus type 1. Since there is limited evidence for an in vivo role of CTL in control of lentiviruses, dissection of immune mechanisms in animal lentiviral infections may provide needed information. Horses infected with equine infectious anemia virus (EIAV) a lentivirus, have acute plasma viremia which is terminated in immunocompetent horses. Viremic episodes may recur, but most horses ultimately control infection and become asymptomatic carriers. ...
Hedrick PW, Miller PS.In recent years, more detailed genetic information has become available for individuals of endangered species in captive breeding programs. There have been suggestions that this information be used to identify rare alleles, particularly those at the MHC, that can be subsequently selected for captive breeding programs. First, we summarize the current information on the MHC relevant to conservation genetics, so that such a possible breeding program is seen in a proper perspective. For example, very few specific alleles at the MHC have been identified as selectively advantageous, even though ther...
Szalai G, Bailey E, Gerber H, Lazary S.The genetic diversity at the ELA DQ beta locus was investigated using polymerase chain reaction and DNA sequencing. Based upon serological methods 16 class II homozygous animals were selected and their genomic DNA was used. A DQ beta gene from an equine cDNA library was also sequenced. Our methodology and the similarity between the genomic and the cDNA sequences suggest that the studied locus is expressed on equine lymphocytes. In the predicted amino acid sequence the most extensive variation is located at residues 56-60. The pattern of these five amino acids is strongly correlated to the sero...
Mohammed HO, Cummings JF, Divers TJ, Valentine B, de Lahunta A, Summers B, Farrow BR, Trembicki-Graves K, Mauskopf A.Equine motor neuron disease (EMND), a newly described neurodegenerative disease, bears a striking resemblance to progressive muscular atrophy (PMA) in humans. We present a comparison of the equine and human diseases and the results of a case-control study conducted to identify intrinsic factors associated with EMND. Cases included all horses with a confirmed diagnosis of EMND diagnosed in the United States since 1985 (32 cases). Controls included horses diagnosed with either cervical stenotic myelopathy, equine degenerative myeloencephalopathy, or protozoan myelitis at the Veterinary Teaching ...
Watson ED, Dixon CE.The distribution of T lymphocytes and of cells bearing MHC Class II antigens in the endometrium of the mare was studied using an avidin-biotin-peroxidase staining method. The cells within the endometrium which expressed MHC Class II were macrophages, lymphocytes, monocytes, dendritic cells, epithelial cells and endothelial cells. MHC Class II expression increased significantly (P < 0.05) in the luminal epithelium and tended (P = 0.0573) to increase in the subepithelial layers during oestrus. Numbers of T lymphocytes did not differ between oestrus and dioestrus. MHC Class II expression and T...
Lunn DP, Holmes MA, Duffus WP.This paper describes the characteristics of a monoclonal antibody (CVS10) that reacts with an equine leukocyte antigen. On the basis of tissue distribution and biochemical characteristics, this antigen is equine MHC II. The equine MHC II antigen was found on a large subset of T-lymphocytes in addition to all B-lymphocytes, as has been reported previously. In addition MHC II was found to be present on a large proportion of both the mutually exclusive equine T-lymphocyte subpopulations which express either the equine homologues of CD4, or CD8. In a study of changes in equine MHC II expression wi...
Díaz S, Giovambattista G, Peral-García P.Sequence information was obtained on the variation of the ELA-DRB upstream regulatory region (URR) after polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) cloning and sequencing of approximately 220 bp upstream of the first exon of horse DRB genes. The sequence of the proximal URR of equine DRB is composed of highly conserved sequence motifs, showing the presence of the W, X, Y, CAAT and TATA conserved boxes of major histocompatibility complex (MHC) class II promoters. Five different polymorphic horse DRB promoter sequences were detected in five horse breeds. The res...
Donaldson WL, Crump AL, Zhang CH, Kornbluth J, Kamoun M, Davis W, Antczak DF.Six monoclonal antibodies and ten alloantisera were used to precipitate cell surface molecules of approximately 44 kDa (class I MHC antigens) from radiolabelled equine peripheral blood lymphocytes. All ten antisera were raised against antigens of a single donor horse (horse 0834, ELA-A2,-A2). Four methods of producing antisera were compared: one or two pregnancies, skin allografting, and skin grafting followed by pregnancy. Immunization by pregnancy appeared to produce antibodies against class I products only, while skin grafting raised antibodies to class II antigens as well. Nine of the anti...
Liu L, Yu W, Cai K, Ma S, Wang Y, Ma Y, Zhao H. () is a zoonotic opportunistic pathogen that can cause life-threatening infections. The rapid evolution of multidrug-resistant and the fact that there is no currently licensed effective vaccine against warrant the need for vaccine development. Reverse vaccinology (RV), which involves screening a pathogen's entire genome and proteome using various web-based prediction tools, is considered one of the most effective approaches for identifying vaccine candidates. Here, we performed a pangenome analysis to determine the core proteins of . We then used the RV approach to examine the subcellular l...
Brown JJ, Ollier WE, Thomson W, Matthews JB, Carter SD, Binns M, Pinchbeck G, Clegg PD.Tumour necrosis factor alpha (TNF-alpha) is a pro-inflammatory cytokine that plays a crucial role in the regulation of inflammatory and immune responses. In all vertebrate species the genes encoding TNF-alpha are located within the major histocompatability complex. In the horse TNF-alpha has been ascribed a role in a variety of important disease processes. Previously two single nucleotide polymorphisms (SNPs) have been reported within the 5' un-translated region of the equine TNF-alpha gene. We have examined the equine TNF-alpha promoter region further for additional SNPs by analysing DNA from...
Kalsow CM, Dubielzig RR, Dwyer AE.Pinealitis accompanying uveitis is well established in laboratory models of experimental autoimmune uveoretinitis. In naturally occurring uveitis, pinealitis has been demonstrated in the pineal gland from a mare with active uveitis and is suspected in some human uveitides. We have evaluated pineal glands from horses with various stages of uveitis for signs of immunopathology accompanying spontaneous uveitis. Methods: Pineal glands from 10 horses with uveitis and from 13 horses without uveitis were evaluated for histochemical (H&E, collagen) and immunohistochemical (MHC class II antigen exp...
Cequier A, Vázquez FJ, Vitoria A, Bernad E, Fuente S, Serrano MB, Zaragoza MP, Romero A, Rodellar C, Barrachina L.The effectiveness and safety of allogeneic mesenchymal stem/stromal cells (MSCs) can be affected by patient's immune recognition. Thus, MSC immunogenicity and their immunomodulatory properties are crucial aspects for therapy. Immune responses after allogeneic MSC administration have been reported in different species, including equine. Interactions of allogenic MSCs with the recipient's immune system can be influenced by factors like matching or mismatching for the major histocompatibility complex (MHC) between donor-recipient, and by the levels of MHC expression in MSCs. The latter can vary u...
Pargass IS, Wills TB, Davis WC, Wardrop KJ, Alperin DC, Hines SA.There is a distinct age-associated susceptibility of horses to Rhodococcus equi infection. Initial infection is thought to occur in the neonatal and perinatal period, and only foals less than 6 months of age are typically affected. R. equi is closely related and structurally similar to Mycobacterium tuberculosis, and causes similar pathologic lesions. Protective immune responses to M. tuberculosis involve classical major histocompatibility complex (MHC)-restricted T cells that recognize peptide antigen, as well as MHC-independent T cells that recognize mycobacterial lipid antigen presented by ...
Miyata H, Sugiura T, Kai M, Hiraga A, Tokuriki M.To determine histochemical and biochemical properties of muscle during adaptation to training on a flat or sloped track. Methods: 22 Thoroughbreds. Methods: Samples were obtained from the middle gluteus muscle before and after training programs were conducted, using a needle-biopsy technique. Training programs consisted of horses running 1,600 m on a flat or sloped track for 16 weeks. Amplitude of middle gluteus muscle activity per burst was calculated. Muscle fiber composition and area were examined on serial cross sections processed by standard histochemical staining procedures (ATPase stain...
Mottironi VD, Perryman LE, Pollara B, Mickey MR, Swift R, McGrath P.Combined immunodeficiency disease (CID) is a genetic disorder of T and B lymphocyte production which results in a nonfunctional immune system. It is inherited as an autosomal recessive trait and has been reported in humans and in horses of the Arabian breed. Arabian horses known to have the CID gene and horses of unknown carrier status were tested using a microlymphocytotoxicity technique. Computer chi 2 analysis distinguished six serologically defined specificities. The study of unrelated horses and a limited number of families showed that the specificities behave as codominant alleles segreg...
Díaz S, Echeverría MG, It V, Posik DM, Rogberg-Muñoz A, Pena NL, Peral-García P, Vega-Pla JL, Giovambattista G.The polymorphism of equine lymphocyte antigen (ELA) class II DRA gene had been detected by polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) and reference strand-mediated conformation analysis. These methodologies allowed to identify 11 ELA-DRA exon 2 sequences, three of which are widely distributed among domestic horse breeds. Herein, we describe the development of a pyrosequencing-based method applicable to ELA-DRA typing, by screening samples from eight different horse breeds previously typed by PCR-SSCP. This sequence-based method would be useful in high-throug...
Bell SC, Savidge C, Taylor P, Knottenbelt DC, Carter SD.A putative immunodeficiency, causing mortality in UK Fell pony foals (Fell pony syndrome), was studied in affected foals and compared with healthy, age-matched foals. Differential cell counts of peripheral blood indicated that the syndrome foals were lymphopenic (P<0.05). Flow cytometric analysis of circulating leucocytes showed a reduced MHC II expression (P<0.01) on lymphocytes but not on polymorphonuclear cells in affected foals. There were no changes in the percentages of CD4+ or CD8+ T cells. There was an increased (P<0.05) expression of CD11a/18 by the lymphocytes of the syndrom...
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...
Yao S, Qi J, Liu J, Chen R, Pan X, Li X, Gao F, Xia C.In order to clarify the structure and the peptide-presentation characteristics of the equine major histocompatibility complex (MHC) class I molecule, a complex of equine MHC class I molecule (ELA-A1 haplotype, 7-6 allele) with mouse β(2)-microglobulin and the cytotoxic T lymphocyte (CTL) epitope Env-RW12 (RVEDVTNTAEYW) derived from equine infectious anaemia virus (EIAV) envelope protein (residues 195-206) was refolded and crystallized. The crystal, which belonged to space group P2(1), diffracted to 2.3 Å resolution and had unit-cell parameters a = 82.5, b = 71.4, c = 99.8 Å, β = 102.9°. T...
Kydd J, Miller J, Antczak DF, Allen WR.The maternal immunological response to the developing equine fetus was investigated in 69 pregnancies of various genotypes. In normal intraspecies horse pregnancy (N = 16), 94% of mares produced strong cytotoxic antibody responses to paternal histocompatibility antigens which were first detectable between 44 and 70 days after ovulation. In all other types of pregnancy examined (intraspecies donkey, N = 19; interspecies mule, N = 6; interspecies hinny, N = 2; extraspecies horse-in-donkey, N = 3; and extraspecies donkey-in-horse, N = 21), antibody production was observed less frequently, and som...
Baker JM, Bamford AI, Carlson ML, Mcculloch CE, Antczak DF.A cytotoxic T-lymphocyte assay was used to determine whether equine chorionic girdle cells are susceptible to lysis by CD8+ cytotoxic T cells primed in vitro against allogeneic lymphocytes. Classical cytotoxic T-lymphocyte activity against fresh or cultured trophoblast targets was demonstrated using peripheral blood lymphocytes from nonpregnant mares. Lysis of allogeneic (horse) and xenogeneic (donkey) lymphocyte targets was used as a control for trophoblast lysis. The major histocompatibility complex (MHC) class I specificity of the cytotoxic T-lymphocyte reactions was determined using panels...
Ridgely SL, McGuire TC.The immunogenicity of equine infectious anemia virus (EIAV) Gag and Env equine leukocyte alloantigen (ELA)-A5.1, -A9, and -A1 restricted cytotoxic T lymphocyte (CTL) epitopes synthesized on multiple antigenic peptide (MAP) system coupled to tripalmitoyl-S-glycerylcysteine (P3C) was evaluated in vitro. P3C-MAP-peptide-stimulated peripheral blood mononuclear cells (PBMCs) from horses, chronically infected with EIAV, had memory CTL (CTLm) similar to that of PBMCs stimulated with either the minimal CTL epitopes, longer peptides containing the CTL epitopes, or EIAV. The stimulated CTL lysed EIAV-in...
Kalsow CM, Dwyer AE, Smith AW, Nifong TP.Although experimental models of autoimmune uveitis predict pinealitis coincident with uveitis, there is no direct evidence of pineal pathology accompanying a human uveitis. Horses with naturally occurring uveitis are a potential source of eye and pineal tissues that are not available from human patients with active uveitis. We have observed pinealitis in a mare with equine recurrent uveitis. By immunohistochemistry we demonstrated immunoglobulin and MHC Class II antigen on infiltrating and resident cells of eye and pineal gland. These results support the relevance of the animal models and sugg...
Vostry L, Vostra-Vydrova H, Citek J, Gorjanc G, Curik I.Inbreeding depression is the reduction of performance caused by mating of close relatives. In livestock populations, inbreeding depression has been traditionally estimated by regression of phenotypes on pedigree inbreeding coefficients. This estimation can be improved by utilising genomic inbreeding coefficients. Here we estimate inbreeding depression for insect bite hypersensitivity (IBH) prevalence, the most common allergic horse disease worldwide, in Old Kladruber horse. In a deep pedigree with 3214 horses (187 genotyped), we used a generalised linear mixed model with IBH phenotype from 558...
Sano Y, Matsuda K, Okamoto M, Takehana K, Hirayama K, Taniyama H.In horse, the characterizations of hyalocytes under the steady state are still unclear. Therefore, we investigated characterizations of hyalocytes in normal equine eyes by their immunohistochemical phenotype, histomorphology and distribution. Thirty-one eyes from 18 horses, divided into 4 groups (G) by age, were used: early (G1) and late gestation (G2) fetuses, 1- to 3-year-old (G3) and 8- to 24-year-old (G4) horses. Equine hyalocytes were histologically classified into 4 types, and they immunohistochemically expressed MHC II and CD163. Hyalocytes were detected on and/or around ciliary process...
Antczak DF, Allen WR.There is little evidence for maternal immunological recognition of pregnancy in most species with the striking exception of the members of the genus Equus. Almost all mares make strong cytotoxic antibody responses to paternally inherited fetal antigens by Day 60 of gestation. Most of these responses are directed against antigens of the Major Histocompatibility Complex (MHC), which constitutes the primary immunogenetic barrier to successful organ transplantation. The source of fetal MHC antigens in the pregnant mare appears to be the specialized trophoblast cells of the chorionic girdle region ...
Liu C, Lei H, Ran X, Wang J.The Guizhou pony (GZP) is an indigenous species of equid found in the mountains of the Guizhou province in southwest China. We selected four regions of the equine leukocyte antigen (ELA), including , , and and used them to assess the diversity of the major histocompatibility complex (MHC) class II gene using direct sequencing technology. had the lowest / ratio (0.560) compared with the other three loci, indicating that was conserved and could be conserved after undergoing selective processes. Nine , five , nine and seven codons were under significant positive selection at the antigen b...
Kydd JH, Case R, Minke J, Audonnet JC, Wagner B, Antczak DF.Cytotoxic T-lymphocytes (CTLs) are associated with protective immunity against disease caused by equid herpesvirus type 1 (EHV-1). However, the EHV-1 target proteins for CTLs are poorly defined. This limits the development of vaccine candidates designed to stimulate strong CTL immunity. Here, classical CTL assays using lymphocytes from horses of three defined MHC class I types that experienced natural infection with EHV-1 and a modified vaccinia virus construct containing an EHV-1 gene encoding the immediate-early (IE) protein are reported. Horses homozygous for the equine leukocyte antigen (E...
Hedrick PW, Miller PS.In recent years, more detailed genetic information has become available for individuals of endangered species in captive breeding programs. There have been suggestions that this information be used to identify rare alleles, particularly those at the MHC, that can be subsequently selected for captive breeding programs. First, we summarize the current information on the MHC relevant to conservation genetics, so that such a possible breeding program is seen in a proper perspective. For example, very few specific alleles at the MHC have been identified as selectively advantageous, even though ther...
Kydd JH, Butcher GW, Antczak DF, Allen WR.The expression of class I Major Histocompatibility Complex (MHC) molecules by early trophoblast of intraspecific horse and donkey, interspecific mule and extraspecific donkey-in-horse conceptuses was determined using a rat monoclonal antibody (MAC 291) in a peroxidase anti-peroxidase immunohistochemical technique. Most non-invasive allantochorion of horse, donkey and mule conceptuses did not express class I MHC molecules at any stage of gestation except in small isolated patches of pseudostratified trophoblast lying adjacent to the openings of endometrial glands. In contrast, MHC class I molec...
Boudreaux MK, Humphries DM.Platelet alloantigens in horses may play an important role in the development of neonatal alloimmune thrombocytopenia (NAIT). Objective: The objective of this study was to evaluate genes encoding major platelet glycoproteins within the Equidae family in an effort to identify potential alloantigens. Methods: DNA was isolated from blood samples obtained from Equidae family members, including a Holsteiner-Oldenburg cross, a Quarter horse, a donkey, and a Plains zebra (Equus burchelli). Gene sequences encoding equine platelet membrane glycoproteins IIb, IIIa (integrin subunits αIIb and β3), Ia (...
Ramsay JD, Leib SR, Orfe L, Call DR, Tallmadge RL, Fraser DG, Mealey RH.Development of an accurate and efficient molecular-based equine MHC class I typing method would facilitate the study of T lymphocyte immune responses in horses. Here, a DNA microarray was designed to detect expressed classical MHC class I genes comprising serologically defined equine leukocyte antigen (ELA)-A haplotypes represented in a closed Arabian horse breeding herd. Initially, cloning and sequencing of RT-PCR products were used to identify sequences associated with the ELA-A1, A4, and W11 haplotypes, and one undefined haplotype, in six horses. Subsequently, sequence-specific, conserved (...
Brinkmeyer-Langford CL, Murphy WJ, Childers CP, Skow LC.The assembled genomic sequence of the horse major histocompatibility complex (MHC) (equine lymphocyte antigen, ELA) is very similar to the homologous human HLA, with the notable exception of a large segmental duplication at the boundary of ELA class I and class III that is absent in HLA. The segmental duplication consists of a ∼ 710 kb region of at least 11 repeated blocks: 10 blocks each contain an MHC class I-like sequence and the helicase domain portion of a BAT1-like sequence, and the remaining unit contains the full-length BAT1 gene. Similar genomic features were found in other Perissod...
Heilen LB, Roßgardt J, Dern-Wieloch J, Vogelsberg J, Staszyk C.The lifelong eruption places a great demand on the dental pulp and periodontal ligament (PDL) of horse teeth. Cells within the pulp and PDL seem to play a key role during this remodeling. Unassigned: In this study, we isolated and cultivated MSCs (medicinal signaling cells) from dental pulp, PDL and retrobulbar fat of four horses. Subsequently, we analyzed them by flow cytometry and immunohistochemistry to determine and compare their characteristics. In addition, we localized these cells within the tissue structure via immunohistochemistry of histological sections. For these analyses, several ...
