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Liu L, Cai P, Gu W, Duan X, Gao S, Ma X, Ma Y, Ma S, Li G, Wang X, Cai K, Wang Y, Cai T, Zhao H. Evaluation of vaccine candidates against Rhodococcus equi in BALB/c mice infection model: cellular and humoral immune responses. BMC Microbiol 2024; 24:249. [PMID: 38977999 PMCID: PMC11229254 DOI: 10.1186/s12866-024-03408-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 07/02/2024] [Indexed: 07/10/2024] Open
Abstract
Rhodococcus equi (R. equi) is a zoonotic opportunistic pathogen that mainly causes fatal lung and extrapulmonary abscesses in foals and immunocompromised individuals. To date, no commercial vaccine against R. equi exists. We previously screened all potential vaccine candidates from the complete genome of R. equi using a reverse vaccinology approach. Five of these candidates, namely ABC transporter substrate-binding protein (ABC transporter), penicillin-binding protein 2 (PBD2), NlpC/P60 family protein (NlpC/P60), esterase family protein (Esterase), and M23 family metallopeptidase (M23) were selected for the evaluation of immunogenicity and immunoprotective effects in BALB/c mice model challenged with R. equi. The results showed that all five vaccine candidate-immunized mice experienced a significant increase in spleen antigen-specific IFN-γ- and TNF-α-positive CD4 + and CD8 + T lymphocytes and generated robust Th1- and Th2-type immune responses and antibody responses. Two weeks after the R. equi challenge, immunization with the five vaccine candidates reduced the bacterial load in the lungs and improved the pathological damage to the lungs and livers compared with those in the control group. NlpC/P60, Esterase, and M23 were more effective than the ABC transporter and PBD2 in inducing protective immunity against R. equi challenge in mice. In addition, these vaccine candidates have the potential to induce T lymphocyte memory immune responses in mice. In summary, these antigens are effective candidates for the development of protective vaccines against R. equi. The R. equi antigen library has been expanded and provides new ideas for the development of multivalent vaccines.
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Affiliation(s)
- Lu Liu
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
- Xinjiang Key Laboratory of New Drug Study and Creation for Herbivorous Animal, Urumqi, China
| | - Peng Cai
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Weifang Gu
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Xingxun Duan
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Shiwen Gao
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Xuelian Ma
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
- Xinjiang Key Laboratory of New Drug Study and Creation for Herbivorous Animal, Urumqi, China
| | - Yuhui Ma
- Zhaosu Xiyu Horse Industry Co., Ltd., Yining, China
| | - Siyuan Ma
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Guoqing Li
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Xiangyu Wang
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Kuojun Cai
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Yanfeng Wang
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Tao Cai
- Xinjiang Agricultural Vocational Technical College, Changji, China
| | - Hongqiong Zhao
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China.
- Xinjiang Key Laboratory of New Drug Study and Creation for Herbivorous Animal, Urumqi, China.
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Giles C, Ndi O, Barton MD, Vanniasinkam T. An Adenoviral Vector Based Vaccine for Rhodococcus equi. PLoS One 2016; 11:e0152149. [PMID: 27008624 PMCID: PMC4805240 DOI: 10.1371/journal.pone.0152149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 03/09/2016] [Indexed: 11/26/2022] Open
Abstract
Rhodococcus equi is a respiratory pathogen which primarily infects foals and is endemic on farms around the world with 50% mortality and 80% morbidity in affected foals. Unless detected early and treated appropriately the disease can be fatal. Currently, there is no vaccine available to prevent this disease. For decades researchers have endeavoured to develop an effective vaccine to no avail. In this study a novel human adenoviral vector vaccine for R. equi was developed and tested in the mouse model. This vaccine generated a strong antibody and cytokine response and clearance of R. equi was demonstrated following challenge. These results show that this vaccine could potentially be developed further for use as a vaccine to prevent R. equi disease in foals.
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Affiliation(s)
- Carla Giles
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Olasumbo Ndi
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mary D. Barton
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Thiru Vanniasinkam
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, New South Wales, Australia
- * E-mail:
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Dossa RG, Alperin DC, Garzon D, Mealey RH, Brown WC, Jervis PJ, Besra GS, Cox LR, Hines SA. In contrast to other species, α-Galactosylceramide (α-GalCer) is not an immunostimulatory NKT cell agonist in horses. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2015; 49:49-58. [PMID: 25445911 DOI: 10.1016/j.dci.2014.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 11/06/2014] [Accepted: 11/06/2014] [Indexed: 06/04/2023]
Abstract
α-GalCer is a potent immunomodulatory molecule that is presented to NKT cells via the CD1 antigen-presenting system. We hypothesized that when used as an adjuvant α-GalCer would induce protective immune responses against Rhodococcus equi, an important pathogen of young horses. Here we demonstrate that the equine CD1d molecule shares most features found in CD1d from other species and has a suitable lipid-binding groove for presenting glycolipids to NKT cells. However, equine CTL stimulated with α-GalCer failed to kill cells infected with R. equi, and α-GalCer did not increase killing by CTL co-stimulated with R. equi antigen. Likewise, α-GalCer did not induce the lymphoproliferation of equine PBMC or increase the proliferation of R. equi-stimulated cells. Intradermal injection of α-GalCer in horses did not increase the recruitment of lymphocytes or cytokine production. Furthermore, α-GalCer-loaded CD1d tetramers, which have been shown to be broadly cross-reactive, did not bind equine lymphocytes. Altogether, our results demonstrate that in contrast to previously described species, horses are unable to respond to α-GalCer. This raises questions about the capabilities and function of NKT cells and other lipid-specific T lymphocytes in horses.
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Affiliation(s)
- Robson G Dossa
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, USA
| | - Debra C Alperin
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, USA
| | - Diana Garzon
- Unilever Centre for Molecular Science Informatics, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Robert H Mealey
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, USA
| | - Wendy C Brown
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, USA
| | - Peter J Jervis
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Gurdyal S Besra
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Liam R Cox
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Stephen A Hines
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, USA.
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Sturgill TL, Giguère S, Berghaus LJ, Hurley DJ, Hondalus MK. Comparison of antibody and cell-mediated immune responses of foals and adult horses after vaccination with live Mycobacterium bovis BCG. Vaccine 2014; 32:1362-7. [DOI: 10.1016/j.vaccine.2014.01.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 10/17/2013] [Accepted: 01/14/2014] [Indexed: 12/28/2022]
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The equine CD1 gene family is the largest and most diverse yet identified. Immunogenetics 2013; 66:33-42. [DOI: 10.1007/s00251-013-0741-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 10/17/2013] [Indexed: 10/26/2022]
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Vázquez-Boland JA, Giguère S, Hapeshi A, MacArthur I, Anastasi E, Valero-Rello A. Rhodococcus equi: the many facets of a pathogenic actinomycete. Vet Microbiol 2013; 167:9-33. [PMID: 23993705 DOI: 10.1016/j.vetmic.2013.06.016] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 06/27/2013] [Indexed: 12/20/2022]
Abstract
Rhodococcus equi is a soil-dwelling pathogenic actinomycete that causes pulmonary and extrapulmonary pyogranulomatous infections in a variety of animal species and people. Young foals are particularly susceptible and develop a life-threatening pneumonic disease that is endemic at many horse-breeding farms worldwide. R. equi is a facultative intracellular parasite of macrophages that replicates within a modified phagocytic vacuole. Its pathogenicity depends on a virulence plasmid that promotes intracellular survival by preventing phagosome-lysosome fusion. Species-specific tropism of R. equi for horses, pigs and cattle appears to be determined by host-adapted virulence plasmid types. Molecular epidemiological studies of these plasmids suggest that human R. equi infection is zoonotic. Analysis of the recently determined R. equi genome sequence has identified additional virulence determinants on the bacterial chromosome. This review summarizes our current understanding of the clinical aspects, biology, pathogenesis and immunity of this fascinating microbe with plasmid-governed infectivity.
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Affiliation(s)
- José A Vázquez-Boland
- Microbial Pathogenesis Unit, School of Biomedical Sciences and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH9 3JT, UK; Grupo de Patogenómica Bacteriana, Facultad de Veterinaria, Universidad de León, 24071 León, Spain.
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Lohmann KL, Lopez AM, Manning ST, Marques FJ, Brownlie R, Allen AL, Sangster AE, Mutwiri G, Gerdts V, Potter A, Townsend HG. Failure of a VapA/CpG oligodeoxynucleotide vaccine to protect foals against experimental Rhocococcus equi pneumonia despite induction of VapA-specific antibody and interferon-γ response. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 2013; 77:161-169. [PMID: 24101791 PMCID: PMC3700440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 06/28/2012] [Indexed: 06/02/2023]
Abstract
We evaluated the immunogenic and protective potential of a recombinant VapA/CpG oligodeoxynucleotide (ODN) 2395 vaccine in neonatal foals undergoing experimental Rhodococcus equi challenge. Foals (n = 8) were vaccinated by intramuscular injection on days 1 and 15 of the study; control foals (n = 7) received a phosphate-buffered saline (PBS) solution. All foals were challenged by intrabronchial administration of 5 × 10⁶ R. equi 103⁺ on day 29. Bronchoalveolar lavages were done on days 15, 29, and 36 and total cell count, differential cell count, rVapA-stimulated cell proliferation and interferon (IFN)-γ mRNA expression determined. Clinical examination, complete blood (cell) counts, serology for VapA-specific antibodies, and culture of nasal and fecal swabs were done on days 1, 15, 29, 36, 43, and 50. Foals were humanely euthanized on day 50 and severity of pneumonia scored on a 4-point scale. Vaccination resulted in a significant increase in VapA-specific immunoglobulin (Ig) production, with total IgG and IgG(T) being increased by day 15. Expression of VapA-specific IFN-γ mRNA by BAL cells was increased in the vaccinated foals following challenge. Postmortem lung severity scores did not differ between groups. Two foals shed virulent R. equi in feces; however, real-time polymerase chain reaction (PCR) revealed the isolates to be different from the challenge strain.
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Affiliation(s)
- Katharina L. Lohmann
- Address all correspondence to Dr. Katharina L. Lohmann; telephone: (306) 966-7157; fax: (306) 966-7159; e-mail:
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Bordin AI, Suchodolski JS, Markel ME, Weaver KB, Steiner JM, Dowd SE, Pillai S, Cohen ND. Effects of administration of live or inactivated virulent Rhodococccus equi and age on the fecal microbiome of neonatal foals. PLoS One 2013; 8:e66640. [PMID: 23785508 PMCID: PMC3681940 DOI: 10.1371/journal.pone.0066640] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 05/08/2013] [Indexed: 01/30/2023] Open
Abstract
Background Rhodococcus equi is an important pathogen of foals. Enteral administration of live, virulent R. equi during early life has been documented to protect against subsequent intrabronchial challenge with R. equi, indicating that enteral mucosal immunization may be protective. Evidence exists that mucosal immune responses develop against both live and inactivated micro-organisms. The extent to which live or inactivated R. equi might alter the intestinal microbiome of foals is unknown. This is an important question because the intestinal microbiome of neonates of other species is known to change over time and to influence host development. To our knowledge, changes in the intestinal microbiome of foals during early life have not been reported. Thus, the purpose of this study was to determine whether age (during the first month of life) or administration of either live virulent R. equi (at a dose reported to protect foals against subsequent intrabronchial challenge, viz., 1×1010 colony forming units [CFU]) or inactivated virulent R. equi (at higher doses, viz., 2×1010 and 1×1011 [CFU]) altered the fecal microbiome of foals. Methodology/Principal Findings Fecal swab samples from 42 healthy foals after vaccination with low-dose inactivated R. equi (n = 9), high-dose inactivated R. equi (n = 10), live R. equi (n = 6), control with cholera toxin B (CTB, n = 9), and control without CTB (n = 8) were evaluated by 454-pyrosequencing of the 16S rRNA gene and by qPCR. No impact of treatment was observed among vaccinated foals; however, marked and significant differences in microbial communities and diversity were observed between foals at 30 days of age relative to 2 days of age. Conclusions The results suggest age-related changes in the fecal microbial population of healthy foals do occur, however, mucosal vaccination does not result in major changes of the fecal microbiome in foals.
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Affiliation(s)
- Angela I. Bordin
- Equine Infectious Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Jan S. Suchodolski
- Gastrointestinal Laboratory, Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Melissa E. Markel
- Gastrointestinal Laboratory, Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Kaytee B. Weaver
- Equine Infectious Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Jörg M. Steiner
- Gastrointestinal Laboratory, Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Scot E. Dowd
- Molecular Research DNA Laboratory, Shallowater, Texas, United States of America
| | - Suresh Pillai
- National Center for Electron Beam Research and Department of Poultry Science, Texas A&M University, College Station, Texas, United States of America
| | - Noah D. Cohen
- Equine Infectious Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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Giguère S, Cohen N, Keith Chaffin M, Hines S, Hondalus M, Prescott J, Slovis N. Rhodococcus equi: Clinical Manifestations, Virulence, and Immunity. J Vet Intern Med 2011; 25:1221-30. [DOI: 10.1111/j.1939-1676.2011.00804.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 08/01/2011] [Accepted: 08/15/2011] [Indexed: 11/27/2022] Open
Affiliation(s)
- S. Giguère
- Department of Large Animal Medicine; University of Georgia; Athens; GA
| | - N.D. Cohen
- Department of Large Animal Clinical Sciences; College of Veterinary Medicine; Texas A&M University; College Station; TX
| | - M. Keith Chaffin
- Department of Large Animal Clinical Sciences; College of Veterinary Medicine; Texas A&M University; College Station; TX
| | - S.A. Hines
- Department of Veterinary Microbiology and Pathology; Washington State University; Pullman; WA
| | - M.K. Hondalus
- Department of Infectious Diseases; University of Georgia; Athens; GA
| | - J.F. Prescott
- Department of Pathobiology; University of Guelph; Guelph; ON; Canada
| | - N.M. Slovis
- Hagyard Equine Medical Institute; Lexington; KY
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Liu C, Betancourt A, Cohen DA, Adams AA, Sun L, Horohov DW. Granzyme B-mRNA expression by equine lymphokine activated killer (LAK) cells is associated with the induction of apoptosis in target cells. Vet Immunol Immunopathol 2011; 143:108-15. [PMID: 21802151 DOI: 10.1016/j.vetimm.2011.06.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 06/20/2011] [Indexed: 11/18/2022]
Abstract
Lymphokine-activated killer (LAK) cells are a subset of cytotoxic cells capable of lysing freshly isolated tumor cells. While LAK activity is typically measured using the (51)Cr-release assay, here we used a non-radioactive flow cytometric method to demonstrate equine LAK activity. Equine peripheral blood mononuclear cells (PBMC) were stimulated in vitro with recombinant human interleukin 2 (hIL-2) to generate LAK cells. An equine tumor cell line, EqT8888, labeled with carboxyfluorescein succinimidyl ester (CFSE) was used as target cells. Following incubation of the targets with different concentrations of LAK cells, Annexin V was added to identify the early apoptotic cells. With increasing effector to target cell ratios, EqT8888 apoptosis was increased. We also measured interferon-gamma, granzyme B and perforin mRNA expression in the LAK cell cultures as possible surrogate markers for cytotoxic cell activity and found granzyme B mRNA expression correlated best with LAK activity. Also, we found that the reduced LAK activity of young horses was associated with decreased granzyme B mRNA expression. Our results indicate that fluorescence-based detection of LAK cell activity provides a suitable non-radioactive alternative to (51)Cr-release assays and mRNA expression of granzyme B can be used as surrogate marker for these cytotoxic cells.
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Affiliation(s)
- C Liu
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY, USA
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Harris SP, Hines MT, Mealey RH, Alperin DC, Hines SA. Early development of cytotoxic T lymphocytes in neonatal foals following oral inoculation with Rhodococcus equi. Vet Immunol Immunopathol 2011; 141:312-6. [PMID: 21481947 DOI: 10.1016/j.vetimm.2011.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 02/28/2011] [Accepted: 03/14/2011] [Indexed: 11/28/2022]
Abstract
Rhodococcus equi is an important respiratory pathogen of young foals for which a vaccine has long been sought. Two major impediments to effective vaccination are the functionally immature type I immune responses of neonatal foals and early exposure to the bacterium via the environment. Despite these obstacles, it appears that under specific circumstances foals can develop a protective immune response. In this study we investigated the protective mechanisms behind oral inoculation of foals with virulent R. equi bacteria. Two foals receiving an oral inoculum demonstrated accelerated development of R. equi specific cytotoxic T lymphocytes (CTL) as evidenced by significant lysis of R. equi infected, ELA-A mismatched cells at 3 weeks of age. As in a previous study, CTL were not detected until 5-6 weeks of age in two control foals. At each time point the ability of foal peripheral blood mononuclear cells (PBMC) to produce IFN-γ following stimulation with live R. equi or extracted cell wall lipids was similar to that of an adult horse control and between foals, regardless of treatment. These results provide a potential mechanism of protection which has previously been shown to occur following oral inoculation, and suggest that the early detection of CTL may be a useful marker for induction of protective immunity.
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Affiliation(s)
- Seth P Harris
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, PO Box 647040, Pullman, WA 99164-7040, USA
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Demas GE, Zysling DA, Beechler BR, Muehlenbein MP, French SS. Beyond phytohaemagglutinin: assessing vertebrate immune function across ecological contexts. J Anim Ecol 2011; 80:710-30. [DOI: 10.1111/j.1365-2656.2011.01813.x] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Equine neonates have attenuated humoral and cell-mediated immune responses to a killed adjuvanted vaccine compared to adult horses. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:1896-902. [PMID: 20943883 DOI: 10.1128/cvi.00328-10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The objectives of this study were to compare relative vaccine-specific serum immunoglobulin concentrations, vaccine-specific lymphoproliferative responses, and cytokine profiles of proliferating lymphocytes between 3-day-old foals, 3-month-old foals, and adult horses after vaccination with a killed adjuvanted vaccine. Horses were vaccinated intramuscularly twice at 3-week intervals with a vaccine containing antigens from bovine viral respiratory pathogens to avoid interference from maternal antibody. Both groups of foals and adult horses responded to the vaccine with a significant increase in vaccine-specific IgGa and IgG(T) concentrations. In contrast, only adult horses and 3-month-old foals mounted significant vaccine-specific total IgG, IgGb, and IgM responses. Vaccine-specific concentrations of IgM and IgG(T) were significantly different between all groups, with the highest concentrations occurring in adult horses, followed by 3-month-old foals and, finally, 3-day-old foals. Only the adult horses mounted significant vaccine-specific lymphoproliferative responses. Baseline gamma interferon (IFN-γ) and interleukin-4 (IL-4) concentrations were significantly lower in 3-day-old foals than in adult horses. Vaccination resulted in a significant decrease in IFN-γ concentrations in adult horses and a significant decrease in IL-4 concentrations in 3-day-old foals. After vaccination, the ratio of IFN-γ/IL-4 in both groups of foals was significantly higher than that in adult horses. The results of this study indicate that the humoral and lymphoproliferative immune responses to this killed adjuvanted vaccine are modest in newborn foals. Although immune responses improve with age, 3-month-old foals do not respond with the same magnitude as adult horses.
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Passler NH, Chan HM, Stewart AJ, Duran SH, Welles EG, Lin HC, Ravis WR. Distribution of voriconazole in seven body fluids of adult horses after repeated oral dosing. J Vet Pharmacol Ther 2010; 33:35-41. [PMID: 20444023 DOI: 10.1111/j.1365-2885.2009.01099.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to assess safety and alterations in body fluid concentrations of voriconazole in normal horses on days 7 and 14 following once daily dose of 4 mg/kg of voriconazole orally for 14 days. Body fluid drug concentrations were determined by the use of high performance liquid chromatography (HPLC). On day 7, mean voriconazole concentrations of plasma, peritoneal, synovial and cerebrospinal fluids, aqueous humor, epithelial lining fluid (ELF), and urine were 1.47 +/- 0.63, 0.61 +/- 0.22, 0.70 +/- 0.20, 0.62 +/- 0.26, 0.55 +/- 0.32, 79.45 +/- 69.4, and 1.83 +/- 0.44 microg/mL respectively. Mean voriconazole concentrations in the plasma, peritoneal, synovial and cerebrospinal fluids, aqueous humor, ELF and urine on day 14 were 1.60 +/- 0.37, 1.02 +/- 0.27, 0.86 +/- 0.25, 0.64 +/- 0.21, 0.68 +/- 0.13, 47.76 +/- 45.4 and 3.34 +/- 2.17 respectively. Voriconazole concentrations in the bronchoalveolar cell pellet were below the limit of detection. There was no statistically significant difference between voriconazole concentrations of body fluids when comparing days 7 and 14. Results indicated that voriconazole distributes widely into body fluids.
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Affiliation(s)
- N H Passler
- Department of Clinical Sciences, College of Veterinary Medicine, JT Vaughan Large Animal Teaching Hospital, Auburn University, AL 36849-2900, USA.
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Harris SP, Fujiwara N, Mealey RH, Alperin DC, Naka T, Goda R, Hines SA. Identification of Rhodococcus equi lipids recognized by host cytotoxic T lymphocytes. MICROBIOLOGY-SGM 2010; 156:1836-1847. [PMID: 20299405 DOI: 10.1099/mic.0.035915-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Immune adult horses have CD8(+) cytotoxic T lymphocytes (CTLs) that recognize and lyse Rhodococcus equi-infected cells in an equine lymphocyte alloantigen (ELA)-A [classical major histocompatibility complex (MHC) class I]-unrestricted fashion. As protein antigens are MHC class I-restricted, the lack of restriction suggests that the bacterial antigens being recognized by the host are not proteins. The goals of this study were to test the hypothesis that these CTLs recognize unique R. equi cell-wall lipids related to mycobacterial lipids. Initial experiments showed that treatment of soluble R. equi antigen with broadly reactive proteases did not significantly diminish the ability of the antigen to stimulate R. equi-specific CTLs. R. equi-specific CTLs were also shown to lyse target cells (equine macrophages) pulsed with an R. equi lipid extract. Analysis of the R. equi lipid by TLC and MS (MALDI-TOF and ES) indicated that the extracted antigen consisted of three primary fractions: trehalose monomycolate (TMM), trehalose dimycolate (TDM) and cardiolipin (CL). ELA-A-mismatched cells pulsed with purified TMM and CL, but not the TDM fraction, were recognized and lysed by R. equi-specific CTLs. Because of their role in immune clearance and pathogenesis, transcription of the cytokines gamma interferon (IFN-gamma) and interleukin-4 (IL-4) was also measured in response to R. equi lipids by using real-time PCR; elevated IFN-gamma, but not IL-4, was associated with host clearance of the bacteria. The whole-cell R. equi lipid and all three R. equi lipid fractions resulted in marked increases in IFN-gamma transcription, but no increase in IL-4 transcription. Together, these data support the hypothesis that immune recognition of unique lipids in the bacterial cell wall is an important component of the protective immune response to R. equi. The results also identify potential lipid antigens not previously shown to be recognized by CTLs in an important, naturally occurring actinomycete bacterial pathogen.
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Affiliation(s)
- Seth P Harris
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, PO Box 647040, Pullman, WA 99164-7040, USA
| | - Nagatoshi Fujiwara
- Department of Bacteriology, Osaka City University, Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585, Japan
| | - Robert H Mealey
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, PO Box 647040, Pullman, WA 99164-7040, USA
| | - Debra C Alperin
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, PO Box 647040, Pullman, WA 99164-7040, USA
| | - Takashi Naka
- Department of Bacteriology, Osaka City University, Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585, Japan
| | - Reina Goda
- Department of Bacteriology, Osaka City University, Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585, Japan
| | - Stephen A Hines
- Department of Veterinary Microbiology and Pathology, Washington State University, College of Veterinary Medicine, PO Box 647040, Pullman, WA 99164-7040, USA
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16
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Dawson TRMY, Horohov DW, Meijer WG, Muscatello G. Current understanding of the equine immune response to Rhodococcus equi. An immunological review of R. equi pneumonia. Vet Immunol Immunopathol 2009; 135:1-11. [PMID: 20064668 DOI: 10.1016/j.vetimm.2009.12.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Revised: 12/11/2009] [Accepted: 12/16/2009] [Indexed: 10/20/2022]
Abstract
Rhodococcus equi is recognised to cause chronic purulent bronchopneumonia in foals of less than 6 months of age. Virulent strains of the bacteria possess a large 80-90 kb plasmid encoding several virulence-associated proteins, including virulence-associated protein A (VapA), which is associated with disease. R. equi pneumonia can represent significant costs and wastage to the equine breeding industry, especially on stud farms where the disease is endemic. This article reviews knowledge of the equine immune response, both in the immune adult and susceptible neonate, with respect to this pathogen. Humoral immune responses are addressed, with a discussion on the use of hyperimmune and normal adult equine plasma as prophylactic tools. The role that innate immune mechanisms play in the susceptibility of some foals to R. equi infection is also highlighted. Likewise, cell-mediated immune components are reviewed, with particular attention directed towards research undertaken to develop an effective vaccine for foals. It is possible that the implementation of a single immunoprophylaxis strategy to prevent R. equi infection on farms will yield disappointing results. Combined prophylactic protocols that address husbandry practices, environmental and aerosol contamination levels, enhancement of innate immunity, good quality hyperimmune plasma for the neonate, and vaccinal efficacy in the developing foal may be required.
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Affiliation(s)
- Tamsin R M Y Dawson
- The Faculty of Applied Sciences, University of Sunderland, Fleming Building, Wharncliffe Street, Sunderland SR1 3SD, UK.
| | - David W Horohov
- Department of Veterinary Science, University of Kentucky, UK
| | - Wim G Meijer
- School of Biomolecular and Biomedical Science, University College Dublin, Ireland
| | - Gary Muscatello
- Faculty of Veterinary Science, The University of Sydney, Australia
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17
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The influence of age and Rhodococcus equi infection on CD1 expression by equine antigen presenting cells. Vet Immunol Immunopathol 2009; 130:197-209. [DOI: 10.1016/j.vetimm.2009.02.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 01/13/2009] [Accepted: 02/06/2009] [Indexed: 11/21/2022]
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18
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Foal monocyte-derived dendritic cells become activated upon Rhodococcus equi infection. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 16:176-83. [PMID: 19109450 DOI: 10.1128/cvi.00336-08] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Susceptibility of foals to Rhodococcus equi pneumonia is exclusive to the first few months of life. The objective of this study was to investigate the immediate immunologic response of foal and adult horse antigen-presenting cells (APCs) upon infection with R. equi. We measured the activation of the antigen-presenting major histocompatibility complex (MHC) class II molecule, costimulatory molecules CD40 and CD86, the cytokine interleukin-12 (IL-12), and the transcriptional factor interferon regulatory factor 1 (IRF-1) in monocyte-derived macrophages (mMOs) and dendritic cells (mDCs) of adult horses and foals of different ages (from birth to 3 months of age) infected with virulent R. equi or its avirulent, plasmid-cured derivative. Infection with virulent or avirulent R. equi induced (P <or= 0.01) the expression of IL-12p35 and IL-12p40 mRNAs in foal mMOs and mDCs at different ages. This response was likely mediated by the higher (P=0.008) expression of IRF-1 in foal mDCs at birth than in adult horse mDCs. R. equi infection promoted comparable expression of costimulatory molecules CD86 and CD40 in foal and adult horse cells. The cytokine and costimulatory response by foal mDCs was not accompanied by robust MHC class II molecule expression. These data suggest that foal APCs detect the presence of R. equi and respond with the expression of the Th1-inducing cytokine IL-12. Nevertheless, there seems to be a limitation to MHC class II molecule expression which we hypothesize may compromise the efficient priming of naïve effector cells in early life.
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19
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Krewer C, Costa M, Schrank I, Vargas A. RHODOCOCCUS EQUI. ARQUIVOS DO INSTITUTO BIOLÓGICO 2008. [DOI: 10.1590/1808-1657v75p5332008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
RESUMO Rhodococcus equi é uma importante causa de broncopneumonia em potros com menos de seis meses de idade, sendo responsável pela mortalidade de eqüinos no mundo inteiro. É um microrganismo intracelular capaz de sobreviver e se multiplicar no interior de macrófagos. Apresenta três níveis de virulência de acordo com os diferentes antígenos expressos em sua superfície. Cepas virulentas apresentam um plasmídeo que codifica a proteína de superfície VapA e são isoladas principalmente de potros com pneumonia e de alguns pacientes humanos. Cepas com virulência intermediária expressam a proteína VapB e predominam em suínos e humanos com AIDS. Cepas avirulentas não expressam antígenos de superfície e são encontradas principalmente no ambiente e em pacientes humanos. Um dos fatores responsáveis pela ampla distribuição da enfermidade em potros é a imaturidade do sistema imunológico dos animais acometidos pela infecção, que pode se tornar endêmica em alguns criatórios. Em humanos, as formas de infecção são ainda desconhecidas, mas o contato com eqüinos é relatado em um terço dos casos. Devido à importância clínica da doença, são necessários métodos diagnósticos que promovam sua identificação precoce, facilitando e aumentando as chances de sucesso com o tratamento. Os métodos mais utilizados atualmente são o cultivo microbiológico, testes sorológicos para detecção de anticorpos séricos nos animais e técnicas de PCR que detectam a região 16S do rDNA e o fragmento do gene vapA do microrganismo.
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Affiliation(s)
| | - M.M. Costa
- Universidade Federal do Vale do São Francisco, Brasil
| | - I. Schrank
- Universidade Federal do Rio Grande do Sul, Brasil
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20
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Zhang YW, Davis EG, Blecha F, Wilkerson MJ. Molecular cloning and characterization of equine Toll-like receptor 9. Vet Immunol Immunopathol 2008; 124:209-19. [DOI: 10.1016/j.vetimm.2008.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 03/13/2008] [Accepted: 03/14/2008] [Indexed: 11/17/2022]
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21
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Liu T, Nerren J, Murrell J, Juillard V, El Garch H, Martens R, Cohen N. CpG-Induced Stimulation of Cytokine Expression by Peripheral Blood Mononuclear Cells of Foals and Their Dams. J Equine Vet Sci 2008. [DOI: 10.1016/j.jevs.2008.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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22
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Phumoonna T, Barton MD, Vanniasinkam T, Heuzenroeder MW. Chimeric vapA/groEL2 DNA vaccines enhance clearance of Rhodococcus equi in aerosol challenged C3H/He mice. Vaccine 2008; 26:2457-65. [DOI: 10.1016/j.vaccine.2008.03.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 01/31/2008] [Accepted: 03/12/2008] [Indexed: 10/22/2022]
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23
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Lopez A, Townsend H, Allen A, Hondalus M. Safety and immunogenicity of a live-attenuated auxotrophic candidate vaccine against the intracellular pathogen Rhodococcus equi. Vaccine 2008; 26:998-1009. [DOI: 10.1016/j.vaccine.2007.10.069] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Revised: 10/26/2007] [Accepted: 10/30/2007] [Indexed: 11/15/2022]
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24
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Muscatello G, Leadon DP, Klayt M, Ocampo-Sosa A, Lewis DA, Fogarty U, Buckley T, Gilkerson JR, Meijer WG, Vazquez-Boland JA. Rhodococcus equi infection in foals: the science of 'rattles'. Equine Vet J 2007; 39:470-8. [PMID: 17910275 DOI: 10.2746/042516407x209217] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Infection with Rhodococcus (Corynebacterium) equi is a well-recognised condition in foals that represents a consistent and serious risk worldwide. The condition manifests itself primarily as one of pulmonary abscessation and bronchitis, hence the terminology of 'rattles' derived from its most obvious clinical sign, frequently terminal when first identified. This review addresses the clinical manifestation, bacteriology and pathogenesis of the condition together with recent developments providing knowledge of the organism in terms of virulence, epidemiology, transmission and immune responses. Enhanced understanding of R. equi virulence mechanisms and biology derived from the recently available genome sequence may facilitate the rational development of a vaccine and the improvement of farm management practices used to control R. equi on stud farms in the future. Reliance on vaccines alone, in the absence of management strategies to control the on-farm challenge is likely to be disappointing.
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Affiliation(s)
- G Muscatello
- Equine Infectious Disease Laboratory, School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia
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25
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Paillot R, Kydd JH, MacRae S, Minke JM, Hannant D, Daly JM. New assays to measure equine influenza virus-specific Type 1 immunity in horses. Vaccine 2007; 25:7385-98. [PMID: 17881098 DOI: 10.1016/j.vaccine.2007.08.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/01/2007] [Accepted: 08/07/2007] [Indexed: 11/28/2022]
Abstract
Equine influenza virus (EIV) is a leading cause of respiratory disease in horses. Equine influenza infection induces a long-term immunity to re-infection. Recent strategies of vaccination aim to mimic this immunity by stimulating both antibody and cellular immune responses. Cell-mediated immunity (CMI) to influenza is well defined in man, but little has been done to characterise the responses in the horse. Additionally, the development of reliable assays for the measurement of equine CMI has lagged behind serological methods and vaccine development. In this study, two methods of measuring EIV-specific T lymphocyte responses have been developed. An EIV 'bulk' cytotoxic T lymphocytes (CTL) assay using equine dermal fibroblasts as target cells has been adapted from a method used in the 1980s. This method was also complemented with a new EIV-specific IFNgamma synthesis assay. When compared with the measurement of EIV-specific IFNgamma synthesis previously described, this method required the amplification of EIV-specific lymphocytes by culture and was sensitive enough to detect stimulation of EIV-specific T lymphocytes induced by experimental infection with EIV or vaccination with recombinant canarypox viruses coding for EIV-HA molecules. This study provides the tools to characterise the stimulation of CMI by the new generation of vaccines against equine influenza.
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Affiliation(s)
- R Paillot
- Animal Health Trust, Centre for Preventive Medicine, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK.
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26
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Mealey R, Stone D, Hines M, Alperin D, Littke M, Leib S, Leach S, Hines S. Experimental Rhodococcus equi and equine infectious anemia virus DNA vaccination in adult and neonatal horses: effect of IL-12, dose, and route. Vaccine 2007; 25:7582-97. [PMID: 17889970 PMCID: PMC3342688 DOI: 10.1016/j.vaccine.2007.07.055] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2007] [Revised: 07/24/2007] [Accepted: 07/28/2007] [Indexed: 11/15/2022]
Abstract
Improving the ability of DNA-based vaccines to induce potent Type1/Th1 responses against intracellular pathogens in large outbred species is essential. Rhodoccocus equi and equine infectious anemia virus (EIAV) are two naturally occurring equine pathogens that also serve as important large animal models of neonatal immunity and lentiviral immune control. Neonates present a unique challenge for immunization due to their diminished immunologic capabilities and apparent Th2 bias. In an effort to augment R. equi- and EIAV-specific Th1 responses induced by DNA vaccination, we hypothesized that a dual promoter plasmid encoding recombinant equine IL-12 (rEqIL-12) would function as a molecular adjuvant. In adult horses, DNA vaccines induced R. equi- and EIAV-specific antibody and lymphoproliferative responses, and EIAV-specific CTL and tetramer-positive CD8+ T lymphocytes. These responses were not enhanced by the rEqIL-12 plasmid. In neonatal foals, DNA immunization induced EIAV-specific antibody and lymphoproliferative responses, but not CTL. The R. equi vapA vaccine was poorly immunogenic in foals even when co-administered with the IL-12 plasmid. It was concluded that DNA immunization was capable of inducing Th1 responses in horses; dose and route were significant variables, but rEqIL-12 was not an effective molecular adjuvant. Additional work is needed to optimize DNA vaccine-induced Th1 responses in horses, especially in neonates.
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Affiliation(s)
- R.H. Mealey
- Department of Veterinary Microbiology & Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, United States
| | - D.M. Stone
- Department of Veterinary Microbiology & Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, United States
| | - M.T. Hines
- Department of Veterinary Clinical Sciences, Washington State University, College of Veterinary Medicine, P.O. Box 646010, Pullman, WA 99164-6010, United States
| | - D.C. Alperin
- Department of Veterinary Microbiology & Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, United States
| | - M.H. Littke
- Department of Veterinary Microbiology & Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, United States
| | - S.R. Leib
- Department of Veterinary Microbiology & Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, United States
| | - S.E. Leach
- Department of Veterinary Microbiology & Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, United States
| | - S.A. Hines
- Department of Veterinary Microbiology & Pathology, Washington State University, College of Veterinary Medicine, P.O. Box 647040, Pullman, WA 99164-7040, United States
- Corresponding author. Tel.: +1 509 335 6030; fax: +1 509 335 8529. (S.A. Hines)
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27
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Mealey RH, Littke MH, Leib SR, Davis WC, McGuire TC. Cloning and large-scale expansion of epitope-specific equine cytotoxic T lymphocytes using an anti-equine CD3 monoclonal antibody and human recombinant IL-2. Vet Immunol Immunopathol 2007; 118:121-8. [PMID: 17498813 PMCID: PMC2002571 DOI: 10.1016/j.vetimm.2007.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2007] [Revised: 03/20/2007] [Accepted: 04/05/2007] [Indexed: 11/20/2022]
Abstract
Cytotoxic T lymphocytes are involved in controlling intracellular pathogens in many species, including horses. Particularly, CTL are critical for the control of equine infectious anemia virus (EIAV), a lentivirus that infects horses world-wide. In humans and animal models, CTL clones are valuable for evaluating the fine specificity of epitope recognition, and for adoptive immunotherapy against infectious and neoplastic diseases. Cloned CTL would be equally useful for similar studies in the horse. Here we present the first analysis of a method to generate equine CTL clones. Peripheral blood mononuclear cells were obtained from an EIAV-infected horse and stimulated with the EIAV Rev-QW11 peptide. Sorted CD8+ T cells were cloned by limiting dilution, and expanded without further antigen addition using irradiated PBMC, anti-equine CD3, and human recombinant IL-2. Clones could be frozen and thawed without detrimental effects, and could be subsequently expanded to numbers exceeding 2 x 10(9)cells. Flow cytometry of expanded clones confirmed the CD3+/CD8+ phenotype, and chromium release assays confirmed CTL activity. Finally, sequencing TCR beta chain genes confirmed clonality. Our results provide a reliable means to generate large numbers of epitope-specific equine CTL clones that are suitable for use in downstream applications, including functional assays and adoptive transfer studies.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal/immunology
- CD3 Complex/immunology
- Clone Cells/cytology
- Clone Cells/drug effects
- Epitopes, T-Lymphocyte/immunology
- Horses/immunology
- Humans
- Interleukin-2/immunology
- Interleukin-2/pharmacology
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Recombinant Proteins
- T-Lymphocytes, Cytotoxic/cytology
- T-Lymphocytes, Cytotoxic/drug effects
- T-Lymphocytes, Cytotoxic/immunology
- Time Factors
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Affiliation(s)
- Robert H Mealey
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA.
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28
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Breathnach CC, Sturgill-Wright T, Stiltner JL, Adams AA, Lunn DP, Horohov DW. Foals are interferon gamma-deficient at birth. Vet Immunol Immunopathol 2006; 112:199-209. [PMID: 16621024 DOI: 10.1016/j.vetimm.2006.02.010] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 02/17/2006] [Accepted: 02/20/2006] [Indexed: 11/23/2022]
Abstract
The increased vulnerability of foals to specific pathogens such as Rhodococcus equi is believed to reflect an innate immunodeficiency, the nature of which remains poorly understood. Previous studies have demonstrated that neonates of many species fail to mount potent Th1 responses. The current research investigates the ability of circulating and pulmonary lymphocytes of developing foals to produce interferon gamma (IFNgamma). Peripheral blood mononuclear cells (PBMC) were prepared from up to 10 horse foals at regular intervals throughout the first 6 months of life. Bronchoalveolar lavage (BAL) samples were collected at 1, 3 or 6 months of age from three groups of five foals. The PBMC and BAL cells were stimulated in vitro and IFNgamma production was measured by intracellular staining. In addition, RNA was extracted from freshly isolated and in vitro stimulated PBMC and BAL cells for quantitation of IFNgamma gene expression by real time PCR. Newborn foals exhibited a marked inability to express the IFNgamma gene and produce IFNgamma protein. This deficiency was observed in both circulating and pulmonary lymphocytes. However, IFNgamma gene expression and protein production increased steadily throughout the first 6 months of life, reaching adult levels within the first year of life. These findings suggest that foals are born with an inherent inability to mount a Th1-based cell mediated immune response which may contribute to their susceptibility to intracellular pathogens.
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Affiliation(s)
- C C Breathnach
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, USA
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