T cells are a type of lymphocyte that play a significant role in the adaptive immune system of horses. They are involved in identifying and responding to pathogens, such as viruses and bacteria, by recognizing specific antigens. T cells can be categorized into various subsets, including helper T cells (CD4+), cytotoxic T cells (CD8+), and regulatory T cells, each with specific functions in immune regulation and response. The study of T cells in horses encompasses their development, activation, and the mechanisms by which they mediate immune responses. This research area includes investigations into how T cells contribute to equine health, their response to vaccinations, and their involvement in immune-mediated diseases. This page compiles peer-reviewed research studies and scholarly articles that explore the biology, function, and clinical relevance of T cells in equine immunology.
Tarr MJ, Olsen RG, Krakowka GS, Cockerell GL, Gabel AA.Erythrocyte rosette (ER) formation of equine peripheral blood lymphocytes (PBL) was characterized. Guinea pig and, to a lesser extent, human erythrocytes formed ER; cat, cow, dog, hamster, mouse, rat, and sheep erythrocytes showed negligible rosetting properties. Conditions of the assay were varied to determine which procedure allowed the largest percentage of rosette formation. The PBL from 20 normal horses were then assayed, averaging 38 +/- 2% ER. To characterize the erythrocyte receptor as being on T or B cells, equine thymocytes from 6 foals were assayed; the thymocytes formed an average ...
Banerjee DP, Singh B, Gautam OP, Sarup S.An intradermal skin test, to demonstrate a delayed cutaneous hypersensitivity reaction in Babesia equi infection in donkeys, was developed. A skin reaction to B. equi antigen was elicited in vaccinnated, infected and carrier intact and splenectomised donkeys. The histopathological examination of the skin biopsy revealed infiltration of mononuclear cells and accumulation of oedematous fluid in the deeper layers of the dermis. A leucocyte migration inhibition test was developed and its specificity as an in vitro measure of cell-mediated immunity to B. equi antigen was established. The results of...
Poppie MJ, McGuire TC.Combined immunodeficiency (CID), a defect in both B- and T-lymphocytes, was found to occur in 2.3% of 257 foals of Arabian breeding. All affected foals died by 5 months of age. The belief that CID is transmitted as an autosomal recessive genetic defect was supported by results from matings of dams and sires that had previously produced affected foals. Based on a prevalence of 2.3%, the proportion of carriers of the CID trait among the adult population surveyed was estimated to be 25.7%. Recent descriptions of other immunologic defects in foals emphasized the need for careful differential diagn...
Poppie MJ, McGuire TC.Foals with combined immunodeficiency (CID), a fatal genetic defect in the production of both B and T lymphocytes, are born without immunoglobulins and are unable to synthesise them. CID foals receiving immunoglobulins via the dam's colostrum may live up to four months of age. Those CID foals with failure of passive transfer (FPT) die at a much earlier age. The occurrence of CID is of value in studying passive transfer of immunoglobulins, as no confusion exists as to when passive transfer ends and active synthesis of immunoglobulins begins. A high correlation has been found between early foal d...
Forssmann A.The islets of Langerhans of the equine pancreas were examined with the electron microscope after immersion or perfusion fixation. Five cell types could be distinguished after fixation by either technique: 1. A-cells, situated at the center of the islets, 2. B-cells, containing mostly "pale granules" and constituting the principal cell type of the periphery of the islets, 3. D-cells, also located mainly at the periphery of the islets, 4. G-cells, found at the edge of the islets and in the exocrine pancreas, and 5. S-cells, (small granule cells), which are relatively few in number and occur only...
Diethelm AG, Chambers LM, Balch CM, Phillips SJ.Anti-human thymocyte cell membrane antibody prepared by hyperimmunization of the horse produced an antiserum capable of prolonging skin allografts in the rhesus monkey for an average of 26 days. Lymphocyte depletion was present in paracortical areas of mesenteric lymph nodes of these animals after 28 days of treatment; the intravenous administration was tolerated without ill effects. Immunofluorescent studies identified both broad specificity antibodies reacting with numerous human cell types as well as thymus-dependent (T) cell antibodies reactive with human thymocytes and peripheral T-cells....
McGuire TC, Banks KL, Evans DR, Poppie MJ.Agammaglobulinemia was diagnosed in a 1-year-old Thoroughbred horse on the basis of the following observations: (1) absence of serum immunoglobulins M, A, and G(T); (2) small amounts of serum immunoglobulin G (16 mg/100 ml); (3) absence of specific antibody in the serum of the horse following immunization and challenge exposure to 2 antigens; (4) absence of plasma cells, primary follicles, and germinal centers in a lymph node removed after antigenic stimulation; (5) absence of "natural" serum antibodies to rabbit-erythrocytes which were easily detectable in age-matched control horse serums; an...
Watson RE, Larson KA.Indirect immunofluorescence and lymphocyte cytotoxicity experiments demonstrated the presence of a tumor-specific antigen(s) on the surface of cells from an equine sarcoid cell line (Mc1). Autologous serum (taken from the horse from which the Mc1 cells were derived) and sera from three other sarcoid-bearing horses revealed a similar membrane immunofluorescence when reacted with Mc1 cells, indicating the existence of cross-reacting antibodies. Results of serum colony inhibition experiments indicate that these antibodies are not cytotoxic. Incubation of Mc1 cells with autologous lymphocytes resu...
McGuire TC, Poppie MJ, Banks KL.Thirty sick Arabian foals and 78 clinically normal Arabian foals were examined for combined (B- and T-lymphocyte) immunodeficiency. Diagnosis was based on lymphocyte counts and serum immunoglobulin (Ig) content or microscopic examination of lymphoid organs. Ten of the 30 sick foals and 2 of the 78 clinically normal foals had combined immunodeficiency. The 2 affected foals in the group of 78 subsequently developed fatal pneumonia.
Lymphocyte counts were made from 9 of the 12 immunodeficient foals; the range was 0 to 936/cmm., whereas the normal mean was 4,119/cmm., with a standard deviation ...
McGuire TC, Poppie MJ.A severe combined immunodeficiency disorder was demonstrated in two Arabian foals which were full siblings. The defect in the B-lymphocyte system was shown by hypogammaglobulinemia, lymphopenia, and absence of germinal centers. The almost total absence of thymic tissue in one foal and the lack of thymic dependent lymphocytes in the spleens of both foals demonstrate a T-lymphocyte defect. In a retrospective study of total available Arabian foal cases, 4 of 15 had evidence of immunodeficiency.
Science (New York, N.Y.)March 3, 1972
Volume 175, Issue 4025 996-997 doi: 10.1126/science.175.4025.996
Gershon RK, Kondo K.Mice rendered tolerant to sheep red cells and then given normal thymocytes, made no antibody when immunized with these cells. When immunized with horse red blood cells, however, they made significant amounts of noncross-reacting antibody to sheep red blood cells. This suggests that antibody-making precursor cells (B cells) which are nontolerant but nonactivatable by specific antigen, may exist in tolerant hosts.
Kader T, Lin JR, Hug C, Coy S, Chen YA, de Bruijn I, Shih N, Jung E, Pelletier RJ, Leon ML, Mingo G, Omran DK, Lee JS, Yapp C, Satravada BA, Kundra R....High-Grade Serous Ovarian Cancer (HGSOC) originates from fallopian tube (FT) precursors. However, the molecular changes that occur as precancerous lesions progress to HGSOC are not well understood. To address this, we integrated high-plex imaging and spatial transcriptomics to analyze human tissue samples at different stages of HGSOC development, including p53 signatures, serous tubal intraepithelial carcinomas (STIC), and invasive HGSOC. Our findings reveal immune modulating mechanisms within precursor epithelium, characterized by chromosomal instability, persistent interferon (IFN) signaling...
Migdał A, Migdał Ł, Oczkowicz M, Tombarkiewicz B, Okólski A.Colostrum contains substances such as hormones, enzymes, polyamides, nucleic acid derivatives, and amino acid derivatives and also includes immunomodulating substances, proline-rich polypeptides, immunoglobulins (Ig) as well as bacteriostatic compounds. The aim of the study was to evaluate the impact of colostral Ig on the level of expression of selected Toll-like receptor genes (TLR3, TLR4, and TLR7). The experiments were conducted on 25 Polish Pony foals. Blood samples were collected according to the following scheme: before first suckling, at the 1st, 3rd, 5th, 10th, 20th, and 30th, day of ...
Söth R, Hoffmann ALC, Deeg CA.Equine recurrent uveitis (ERU) is a spontaneously occurring autoimmune disease and one of the leading causes of blindness in horses worldwide. Its similarities to autoimmune-mediated uveitis in humans make it a unique spontaneous animal model for this disease. Although many aspects of ERU pathogenesis have been elucidated, it remains not fully understood and requires further research. CD4+ T cells have been a particular focus of research. In a previous study, we showed metabolic alterations in CD4+ T cells from ERU cases, including an increased basal oxygen consumption rate (OCR) and elevated ...
Ammons DT, Chow L, Goodrich L, Bass L, Larson B, Williams ZJ, Stoneback JW, Dow S, Pezzanite LM.Osteoarthritis (OA) is a major source of pain and disability worldwide. Understanding of disease progression is evolving, but OA is increasingly thought to be a multifactorial disease in which the innate immune system plays a role in regulating and perpetuating low-grade inflammation. The aim of this study was to enhance our understanding of OA immunopathogenesis through characterization of the transcriptomic responses in OA joints, with the goal to facilitate the development of targeted therapies. Unassigned: Single-cell RNA sequencing (scRNA-seq) was completed on cells isolated from the syno...
Holmes CM, Wagner B.Equine herpesvirus type 1 (EHV-1) enters through the upper respiratory tract (URT). Mucosal immunity at the URT is crucial in limiting viral infection and morbidity. Here, intranasal immune cells were collected from horses (n = 15) during an experimental EHV-1 infection. CD4+ and CD8+ T cells were the major intranasal cell populations before infection and increased significantly by day six and fourteen post-infection, respectively. Nasal mucosal T cells were further characterized in healthy horses. Compared to peripheral blood mononuclear cells (PBMC), mucosal CD8+ T-cell percentages were elev...
Stafford LS, Plummer CE, Smith WC, Gibson DJ, Sharma J, Vicuna V, Diakite S, Larkin J.Recurrent uveitis (RU), an autoimmune disease, is a leading cause of ocular detriment in humans and horses. Equine and human RU share many similarities including spontaneous disease and aberrant cytokine signaling. Reduced levels of SOCS1, a critical regulator of cytokine signaling, is associated with several autoimmune diseases. Topical administration of SOCS1-KIR, a peptide mimic of SOCS1, was previously correlated to reduced ocular pathologies within ERU patients. Unassigned: To further assess the translational potential of a SOCS1 mimetic to treat RU, we assessed peptide-mediated modulatio...
Fegraeus K, Riihimäki M, Nordlund J, Akula S, Wernersson S, Raine A.Single-cell RNA sequencing (scRNA-seq) is a valuable tool for investigating cellular heterogeneity in diseases such as equine asthma (EA). This study evaluates the HIVE™ scRNA-seq method, a pico-well-based technology, for processing bronchoalveolar lavage (BAL) cells from horses with EA. The HIVE method offers practical advantages, including compatibility with both field and clinical settings, as well as a gentle workflow suited for handling sensitive cells. Our results show that the major cell types in equine BAL were successfully identified; however, the proportions of T cells and macropha...
Qiu Y, Jiang J, Yi X, Wang S, Sun X.This study investigated the immunoglobulins (IG) gene locus structure and expression diversity in local Chinese horse and donkey breeds, including Ningqiang, Guanzhong horses, and varieties such as Guanzhong, Jiami, and Northern Shaanxi donkey using genome alignment and high-throughput sequencing. The aim was to expand understanding of IG expression patterns in horses, donkeys, and their different breeds. The results revealed that the donkey IGH locus contains 117 VH genes (23 functional), 44 DH genes, and 8 JH genes, arranged in a VH-DH-JH sequence on chromosome 7, spanning approximately 1189...
The objective of the present study was to investigate the influence of daily rhythms on the immune and inflammatory systems in horses, considering white blood cell count (WBCs), leukocyte subpopulations (neutrophils, basophils, eosinophils, lymphocytes, and monocytes), CD4+, and CD8+ lymphocyte populations, interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Ten Italian Saddle horses (7-12 years old, body weight 480 ± 30 kg) underwent blood sampling every 4 h over a 24-h period. The COSINOR method was used to identify rhythms and their parameters. A one-way ...
Giercuszkiewicz-Hecold B, Pajuelo D, Steczkiewicz Z, Cywinska A, Marycz K.Astaxanthin, a strong antioxidant carotenoid, has shown promising features in mitigating inflammation and oxidative stress and so that has been considered as a supplement for high-performance animals. In this study, we aimed to evaluate the effects of astaxanthin on oxidative stress, inflammation, and mitochondrial health in peripheral blood mononuclear cells (PBMC) isolated from Arabian racehorses. Horse-derived peripheral blood mononuclear cells exposed to hydrogen peroxide (H₂O₂) presented increased reactive oxygen species (ROS) accumulation and overexpression of pro-inflammatory cytoki...
Perzyna M, Grzędzicka J, Milczek-Haduch D, Dąbrowska I, Trela M, Pawliński B, Witkowska-Piłaszewicz O.Donkeys are routinely vaccinated with protocols developed for horses, yet species-specific data on their immune responses are limited. Objective: We hypothesized that donkeys exhibit robust T-cell-mediated immunity and regulatory adaptation after vaccination, comparable to horses. Methods: Thirty-six healthy, seronegative donkeys (34 mares, 2 stallions), aged 0.5-23 years (median 8 years), from two farms with similar housing and management conditions. Methods: Prospective study. Animals were selected based on clinical health assessment and confirmed seronegativity for tetanus and equine in...
da Silveira BP, Kahn SK, Legere RM, Bray JM, Cole-Pfeiffer HM, Golding MC, Cohen ND, Bordin AI.Using a horse foal model, we show that enteral immunization of newborn foals with Rhodococcus equi overcomes neonatal vaccination challenges by reprogramming innate immune responses, inducing R. equi-specific adaptive humoral and cell-mediated immune responses and protecting foals against experimental pneumonia challenge. Foals were immunized twice via gavage of R. equi (immunized group) or saline (control group) at ages 1 and 3 days. At age 28 days, all foals were challenged intrabronchially with R. equi. Post-challenge, all 5 immunized foals remained healthy, whereas 67% (4/6) of control foa...
B B, G M, L G, G A, B B, T F, A G, D B, A K, G T, G S, A B, M F, L R.Equine penile tumors are common in horses and are often related to infection with equine papillomavirus type 2 (EcPV2). This study investigated the immune cell infiltrate (ICI) of these tumors in horses, focusing on the role of EcPV2. Using multiplex immunohistochemistry (mIHC) for CD3, CD20, and IBA-1 and immunohistochemistry (IHC) for FoxP3, 27 horses with papillomas (5/27), in situ carcinomas (CISs) (3/27), and squamous cell carcinomas (SCCs) (19/27) were evaluated. Eighteen cases tested positive for EcPV2 by either or both in situ hybridization (ISH) and polymerase chain reaction (PCR) (18...
Maloney SM, Shaw TM, Nennig KM, Larsen MS, Shah A, Kumar A, Marcotrigiano J, Grove J, Snijder EJ, Kirchdoerfer RN, Bailey AL.Arteriviruses are a family of single-stranded, positive-sense RNA (+ssRNA) viruses that infect diverse animal hosts. Many arteriviruses are macrophage-tropic, consistent with their utilization of the macrophage-specific molecule CD163 as a receptor. However, the horse arterivirus (equine arteritis virus, EAV), which infects additional cell types beyond macrophages, does not utilize CD163 in its entry mechanism. Here, we use a genome-wide CRISPR knockout screen to identify alternative receptors that could explain this discrepancy in arterivirus receptor utilization and tropism, identifying the ...
