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From Signaling Pathways to Distinct Immune Responses: Key Factors for Establishing or Combating Neospora caninum Infection in Different Susceptible Hosts. Pathogens 2020; 9:pathogens9050384. [PMID: 32429367 PMCID: PMC7281608 DOI: 10.3390/pathogens9050384] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 12/12/2022] Open
Abstract
: Neospora caninum is an intracellular protozoan parasite affecting numerous animal species. It induces significant economic losses because of abortion and neonatal abnormalities in cattle. In case of infection, the parasite secretes numerous arsenals to establish a successful infection in the host cell. In the same context but for a different purpose, the host resorts to different strategies to eliminate the invading parasite. During this battle, numerous key factors from both parasite and host sides are produced and interact for the maintaining and vanishing of the infection, respectively. Although several reviews have highlighted the role of different compartments of the immune system against N. caninum infection, each one of them has mostly targeted specific points related to the immune component and animal host. Thus, in the current review, we will focus on effector molecules derived from the host cell or the parasite using a comprehensive survey method from previous reports. According to our knowledge, this is the first review that highlights and discusses immune response at the host cell-parasite molecular interface against N. caninum infection in different susceptible hosts.
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Jiménez-Pelayo L, García-Sánchez M, Vázquez P, Regidor-Cerrillo J, Horcajo P, Collantes-Fernández E, Blanco-Murcia J, Gutiérrez-Expósito D, Román-Trufero A, Osoro K, Benavides J, Ortega-Mora LM. Early Neospora caninum infection dynamics in cattle after inoculation at mid-gestation with high (Nc-Spain7)- or low (Nc-Spain1H)-virulence isolates. Vet Res 2019; 50:72. [PMID: 31551079 PMCID: PMC6760050 DOI: 10.1186/s13567-019-0691-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/05/2019] [Indexed: 01/10/2023] Open
Abstract
Early Neospora caninum infection dynamics were investigated in pregnant heifers intravenously inoculated with PBS (G-Control) or 107 tachyzoites of high (G-NcSpain7)- or low (G-NcSpain1H)-virulence isolates at 110 days of gestation. Serial culling at 10 and 20 days post-infection (dpi) was performed. Fever was detected at 1 dpi in both infected groups (P < 0.0001), and a second peak was detected at 3 dpi only in G-NcSpain7 (P < 0.0001). At 10 dpi, Nc-Spain7 was detected in placental samples from one animal related to focal necrosis, and Nc-Spain7 transmission was observed, although no foetal lesions were associated with this finding. The presence of Nc-Spain1H in the placenta or foetuses, as well as lesions, were not detected at 10 dpi. At 20 dpi, G-NcSpain7 animals showed almost 100% positive placental tissues and severe focal necrosis as well as 100% transmission. Remarkably, foetal mortality was detected in two G-NcSpain7 heifers. Only one animal from G-NcSpain1H presented positive placental samples. No foetal mortality was detected, and lesions and parasite transmission to the foetus were not observed in this group. Finally, 100% of G-NcSpain7 heifers at 20 dpi presented specific antibodies, while only 60% of G-NcSpain1H animals presented specific antibodies at 20 dpi. In addition, earlier seroconversion in G-Nc-Spain7 was observed. In conclusion, tachyzoites from Nc-Spain7 reached the placenta earlier and multiplied, leading to lesion development, transmission to the foetus and foetal mortality, whereas Nc-Spain1H showed delayed infection of the placenta and no lesional development or transmission during early infection.
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Affiliation(s)
- Laura Jiménez-Pelayo
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Marta García-Sánchez
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Patricia Vázquez
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Javier Regidor-Cerrillo
- Saluvet-innova, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Pilar Horcajo
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Esther Collantes-Fernández
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Javier Blanco-Murcia
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
- Department of Animal Medicine and Surgery, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | | | - Alicia Román-Trufero
- Regional Service for Research and Agri-Food Development (SERIDA), 33300 Villaviciosa, Asturias, Spain
| | - Koldo Osoro
- Regional Service for Research and Agri-Food Development (SERIDA), 33300 Villaviciosa, Asturias, Spain
| | - Julio Benavides
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), 24346 León, Spain
| | - Luis Miguel Ortega-Mora
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
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Sánchez-Sánchez R, Ferre I, Re M, Regidor-Cerrillo J, Blanco-Murcia J, Ferrer LM, Navarro T, Pizarro Díaz M, González-Huecas M, Tabanera E, Benavides J, Ortega-Mora LM. Influence of dose and route of administration on the outcome of infection with the virulent Neospora caninum isolate Nc-Spain7 in pregnant sheep at mid-gestation. Vet Res 2018; 49:42. [PMID: 29739449 PMCID: PMC5941812 DOI: 10.1186/s13567-018-0539-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/06/2018] [Indexed: 11/01/2022] Open
Abstract
Experimental infections in pregnant sheep have been focused on studying the effect of the time of challenge on the outcome of N. caninum infection, whereas the impact of the dose and route of challenge has not been studied in depth. Therefore, clinical outcome, immune responses, parasite detection and burden, and lesion severity in placental tissues and foetal brains were investigated in 90-day-pregnant sheep inoculated intravenously with 105 (G1), 104 (G2), 103 (G3), or 102 (G4) tachyzoites or subcutaneously with 104 (G5) tachyzoites of the virulent Nc-Spain7 isolate and an uninfected group (G6). Comparing challenge doses, G1 was the only group that had 100% abortion. Likewise, IFNγ levels in G1 increased earlier than those in other intravenously infected groups, and IgG levels on day 21 post-infection (pi) were higher in G1 than those in other intravenously infected groups. Concerning vertical transmission, G1 shows a higher parasite burden in the foetal brain than did G2 and G3. Comparing routes of administration, no differences in foetal survival rate or parasite load in the foetal brain were found. Although G2 had higher IFNγ levels than G5 on day 10 pi, no differences were found in humoral immune responses. Because the outcome after intravenous infection with 105 tachyzoites was similar to that observed after intravenous infection with 106 tachyzoites used in a previous work (100% abortion and vertical transmission), we conclude that it may be reasonable to use 105 tachyzoites administered by the intravenous route in further experiments when assessing drugs or vaccine candidates.
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Affiliation(s)
- Roberto Sánchez-Sánchez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Ignacio Ferre
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Michela Re
- Department of Animal Medicine and Surgery, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Javier Regidor-Cerrillo
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Javier Blanco-Murcia
- Department of Animal Medicine and Surgery, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Luis Miguel Ferrer
- Departamento de Patología Animal, Facultad de Veterinaria, C/Miguel Servet 177, 50013, Zaragoza, Spain
| | - Teresa Navarro
- Departamento de Patología Animal, Facultad de Veterinaria, C/Miguel Servet 177, 50013, Zaragoza, Spain
| | - Manuel Pizarro Díaz
- Department of Animal Medicine and Surgery, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Marta González-Huecas
- Department of Animal Medicine and Surgery, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Enrique Tabanera
- Department of Animal Medicine and Surgery, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Julio Benavides
- Livestock Health and Production Institute (ULE-CSIC), 24346, León, Spain
| | - Luis Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
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Maternal and foetal cytokine production in dams naturally and experimentally infected with Neospora caninum on gestation day 110. Res Vet Sci 2016; 107:55-61. [DOI: 10.1016/j.rvsc.2016.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 05/07/2016] [Accepted: 05/11/2016] [Indexed: 02/01/2023]
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Horcajo P, Regidor-Cerrillo J, Aguado-Martínez A, Hemphill A, Ortega-Mora LM. Vaccines for bovine neosporosis: current status and key aspects for development. Parasite Immunol 2016; 38:709-723. [DOI: 10.1111/pim.12342] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 06/06/2016] [Indexed: 12/01/2022]
Affiliation(s)
- P. Horcajo
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - J. Regidor-Cerrillo
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - A. Aguado-Martínez
- Institute of Parasitology; Vetsuisse Faculty; University of Bern; Bern Switzerland
| | - A. Hemphill
- Institute of Parasitology; Vetsuisse Faculty; University of Bern; Bern Switzerland
| | - L. M. Ortega-Mora
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
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Experimental ruminant models for bovine neosporosis: what is known and what is needed. Parasitology 2014; 141:1471-88. [PMID: 24926962 DOI: 10.1017/s0031182014000638] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
At present, bovine neosporosis is an important worldwide concern because of its wide geographic distribution and economic impact. Abortion is the main clinical sign of bovine neosporosis in both dairy and beef cattle. Ruminant challenge models are critical to evaluate potential vaccine candidates to help tackle bovine neosporosis and to study pathogenesis and host responses to infection. Several research groups have developed ruminant models of Neospora caninum infection independently of others, resulting in a high degree of variability due to the use of different species of animals, breeds, strains/isolates of N. caninum, doses, routes and times of inoculation. Standardization is greatly needed to advance research in a more collaborative, timely and efficient manner. In the absence of widely accepted international guidelines, this manuscript serves to summarize and discuss the different models and parameters currently in use. Parameters essential for the development of non-pregnant and pregnant ruminant models are outlined and the main knowledge gaps are identified. This information could act as the basis to develop a consensus for international standard guidelines for ruminant models of neosporosis that would be helpful for researchers in this field worldwide.
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Characterization of Immune Cell Infiltration in the Placentome of Water Buffaloes (Bubalus bubalis) Infected with Neospora caninum During Pregnancy. J Comp Pathol 2014; 150:463-8. [DOI: 10.1016/j.jcpa.2013.12.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 10/10/2013] [Accepted: 12/07/2013] [Indexed: 11/23/2022]
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Pathogenicity of Nc-Bahia and Nc-1 strains of Neospora caninum in experimentally infected cows and buffaloes in early pregnancy. Parasitol Res 2014; 113:1521-8. [DOI: 10.1007/s00436-014-3796-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 01/28/2014] [Indexed: 11/26/2022]
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Regidor-Cerrillo J, Arranz-Solís D, Benavides J, Gómez-Bautista M, Castro-Hermida JA, Mezo M, Pérez V, Ortega-Mora LM, González-Warleta M. Neospora caninum infection during early pregnancy in cattle: how the isolate influences infection dynamics, clinical outcome and peripheral and local immune responses. Vet Res 2014; 45:10. [PMID: 24479988 PMCID: PMC3922688 DOI: 10.1186/1297-9716-45-10] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 01/22/2014] [Indexed: 11/10/2022] Open
Abstract
This work studies the influence of Neospora caninum intra-species diversity on abortion outcome, infection dynamics in terms of parasite dissemination and peripheral-local immune responses in pregnant cattle. Animals were intravenously inoculated at day 70 of pregnancy with 10⁷ tachyzoites of two isolates showing marked differences in virulence in vitro and in pregnant mouse models: Nc-Spain7, a high virulence isolate, and Nc-Spain8, a low-to-moderate virulence isolate. After inoculation, pregnancy was monitored, and dams were culled when foetal death was detected. Foetal mortality occurred in all infected heifers between days 24 and 49 post-infection (pi), however, it was detected sooner in Nc-Spain7-infected animals (median day = 34) than those inoculated with Nc-Spain8 (median day = 41) with a trend towards significance (P < 0.11). Similar histological lesions were observed in placentomes and in most of the foetuses from the two infected groups. However, parasites were more frequently detected in the placenta and foetuses by PCR and in the foetal brain by immunohistochemistry in Nc-Spain7-infected animals. Specific antibodies were detected starting at day 13 post-infection in all infected cattle, with higher IgG levels in Nc-Spain7-infected group. IFN-γ and IL-4 profiles also varied between infected groups in PBMC stimulation assays. Infected animals showed significant increases in their cytokine mRNA levels (IFN-γ, IL-4, IL-10, IL-12p40 and TNF-α) in the caruncle at time of foetal death. Differences between the infected groups were also observed for cytokine profiles. These results demonstrate the influence of the N. caninum isolate on foetal death outcome, infection dynamics and immune responses in cattle.
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Affiliation(s)
- Javier Regidor-Cerrillo
- Animal Health Department, SALUVET, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
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Bartley PM, Katzer F, Rocchi MS, Maley SW, Benavides J, Nath M, Pang Y, Cantón G, Thomson J, Chianini F, Innes EA. Development of maternal and foetal immune responses in cattle following experimental challenge with Neospora caninum at day 210 of gestation. Vet Res 2013; 44:91. [PMID: 24090114 PMCID: PMC3851480 DOI: 10.1186/1297-9716-44-91] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 09/24/2013] [Indexed: 11/17/2022] Open
Abstract
This study examined the immunological responses of pregnant cattle and their foetuses following an experimental challenge with live Neospora caninum tachyzoites at day 210 of gestation. Animals were bled prior to and weekly throughout the experiment and sacrificed at 14, 28, 42 and 56 days post inoculation (dpi). At post mortem examination, samples of lymph nodes and spleen were collected from both dam and foetus for immunological analysis. Subcutaneous (sc) inoculation over the left prefemoral (LPF) lymph node of pregnant cattle at day 210 of gestation, led to the vertical transmission of parasites by 14 dpi, however no foetal deaths were observed in the infected animals. Foetuses from infected dams mounted Neospora-specific humoral and cell-mediated immune (CMI) responses by 14 dpi. These responses involved anti-Neospora IgG, antigen-specific lymphocyte proliferation, and the production of the cytokines IFN–γ, interleukin (IL)-4 and IL-10. There was also evidence of innate immunity during the response against Neospora from infected dams, with statistically significant (p < 0.05) increases in mean expression of toll like receptors (TLR)-2 on 56 dpi in maternal spleen, LPF, right prefemoral (RPF), left uterine (LUL) and right uterine (RUL) lymph nodes and TLR-9 in retropharyngeal (RLN), LPF and RPF lymph nodes from 28 dpi. Statistically significant (p < 0.05) increases in mean TLR-9 were detected in spleen samples from foetuses of infected dams, compared to the foetuses from control animals. Our results show that vertical transmission of the parasite occurred in all infected dams, with their foetuses showing effective Neospora-specific cell mediated, humoral and innate immune responses.
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Affiliation(s)
- Paul M Bartley
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, EH26 0PZ, Scotland, United Kingdom.
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Cantón GJ, Katzer F, Benavides-Silván J, Maley SW, Palarea-Albaladejo J, Pang Y, Smith S, Bartley PM, Rocchi M, Innes EA, Chianini F. Phenotypic characterisation of the cellular immune infiltrate in placentas of cattle following experimental inoculation with Neospora caninum in late gestation. Vet Res 2013; 44:60. [PMID: 23876124 PMCID: PMC3726360 DOI: 10.1186/1297-9716-44-60] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 07/08/2013] [Indexed: 11/17/2022] Open
Abstract
Despite Neospora caninum being a major cause of bovine abortion worldwide, its pathogenesis is not completely understood. Neospora infection stimulates host cell-mediated immune responses, which may be responsible for the placental damage leading to abortion. The aim of the current study was to characterize the placental immune response following an experimental inoculation of pregnant cattle with N. caninum tachyzoites at day 210 of gestation. Cows were culled at 14, 28, 42 and 56 days post inoculation (dpi). Placentomes were examined by immunohistochemistry using antibodies against macrophages, T-cell subsets (CD4, CD8 and γδ), NK cells and B cells. Macrophages were detected mainly at 14 days post inoculation. Inflammation was generally mild and mainly characterized by CD3+, CD4+ and γδ T-cells; whereas CD8+ and NK cells were less numerous. The immune cell repertoire observed in this study was similar to those seen in pregnant cattle challenged with N. caninum at early gestation. However, cellular infiltrates were less severe than those seen during first trimester Neospora infections. This may explain the milder clinical outcome observed when animals are infected late in gestation.
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Commensal microbiome effects on mucosal immune system development in the ruminant gastrointestinal tract. Anim Health Res Rev 2013; 13:129-41. [PMID: 22853940 DOI: 10.1017/s1466252312000096] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Commensal microflora play many roles within the mammalian gastrointestinal tract (GIT) that benefit host physiology by way of direct or indirect interactions with mucosal surfaces. Commensal flora comprises members across all microbial phyla, although predominantly bacterial, with population dynamics varying with host species, genotype, and environmental factors. Little is known, however, about the complex mechanisms regulating host-commensal interactions that underlie this mutually beneficial relationship and how alterations in the microbiome may influence host development and susceptibility to infection. Research into the gut microbiome has intensified as it becomes increasingly evident that symbiont-host interactions have a significant impact on mucosal immunity and health. Furthermore, evidence that microbial populations vary significantly throughout the GIT suggest that regional differences in the microbiome may also influence immune function within distinct compartments of the GIT. Postpartum colonization of the GIT has been shown to have a direct effect on mucosal immune system development, but information is limited regarding regional effects of the microbiome on the development, activation, and maturation of the mucosal immune system. This review discusses factors influencing the colonization and establishment of the microbiome throughout the GIT of newborn calves and the evidence that regional differences in the microbiome influence mucosal immune system development and maturation. The implications of this complex interaction are also discussed in terms of possible effects on responses to enteric pathogens and vaccines.
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Benavides J, Katzer F, Maley SW, Bartley PM, Cantón G, Palarea-Albaladejo J, Purslow CA, Pang Y, Rocchi MS, Chianini F, Buxton D, Innes EA. High rate of transplacental infection and transmission of Neospora caninum following experimental challenge of cattle at day 210 of gestation. Vet Res 2012; 43:83. [PMID: 23228067 PMCID: PMC3567967 DOI: 10.1186/1297-9716-43-83] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 11/21/2012] [Indexed: 11/10/2022] Open
Abstract
In order to investigate the pathogenesis of neosporosis following a primary infection in late pregnancy, cattle were subcutaneously challenged with 5 × 108Neospora caninum (NC1 isolate) tachyzoites at day 210 of gestation and serial necropsies were then carried out at 14, 28, 42 and 56 days post-infection (dpi). No abortions occurred and all the foetuses were viable at the time of euthanasia. There was a high rate of vertical transmission, as parasites were detected by immunohistochemical labelling and PCR in all the foetuses from 28 dpi. Focal necrotic lesions were observed in the placentomes of the placenta from 28 dpi and showed resolution during later time points, denoted by infiltration of inflammatory cells at 42 dpi and fibrosis at 56 dpi. Foetuses at 28 and 42 dpi showed scarce and isolated lesions which are unlikely to represent a threat to foetal viability. No lesions were observed in the foetuses at 14 or 56 dpi suggesting control of the infection and resolution of the lesions by maternal and foetal immune responses. Once infection was established, it could not be cleared from the host and vertical transmission of the parasite occurred in all infected hosts. Parasite was detected in the placenta at 28 dpi, while in previous experimental infections of cattle at day 70 and 140 of gestation using the same challenge model, it was already present at day 14 post infection. This suggests that a change in the maternal immune response plays a crucial role in limiting the initial infection during the last term of pregnancy.
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Affiliation(s)
- Julio Benavides
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ, United Kingdom.
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Orozco MA, Morales E, Salmerón F. Characterization of the inflammatory response in the uteri of cows infected naturally by Neospora caninum. J Comp Pathol 2012; 148:148-56. [PMID: 22784781 DOI: 10.1016/j.jcpa.2012.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/13/2012] [Accepted: 05/10/2012] [Indexed: 10/28/2022]
Abstract
Bovine neosporosis manifests during gestation, when the fetus may be vulnerable to pathogens. Experimental studies of Neospora caninum-infected cattle have been performed, but little is known about the in-utero inflammatory response. The aim of this study was to characterize the inflammatory response in the uteri of pregnant and non-pregnant cows infected naturally with N. caninum. Four groups of seven animals were studied. Two groups consisted of N. caninum-seropositive pregnant and non-pregnant cows and the other two groups contained N. caninum-seronegative pregnant and non-pregnant cows. Uterine and placental samples were subjected to immunohistochemistry using antibodies specific for N. caninum, CD4, CD8, CD14 and CD21. The non-pregnant seropositive and seronegative groups did not show a difference (P >0.05) in the types of cells present. There were more lymphocytes in the uteri of the seropositive pregnant animals (P <0.05) than in the seronegative pregnant animals, but this was not considered to be consistent with an inflammatory process. N. caninum cysts were detected in eight seropositive cows; five were non-pregnant and three were pregnant. CD4(+) T cells were distributed in the endometrium and myometrium of the non-pregnant cows and were sparse in the placentomes of pregnant cows. CD8(+) T cells were distributed in a similar manner, but were present in smaller number. There were no cells expressing CD14 or CD21. The results of the study suggest that there is no consistent uterine inflammatory response against N. caninum in naturally infected animals.
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Affiliation(s)
- M A Orozco
- Departamento de Patología Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad Universitaria, Avenida Universidad 3000, México, Mexico
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Bartley PM, Wright SE, Maley SW, Macaldowie CN, Nath M, Hamilton CM, Katzer F, Buxton D, Innes EA. Maternal and foetal immune responses of cattle following an experimental challenge with Neospora caninum at day 70 of gestation. Vet Res 2012; 43:38. [PMID: 22536795 PMCID: PMC3416710 DOI: 10.1186/1297-9716-43-38] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 04/26/2012] [Indexed: 02/06/2023] Open
Abstract
The immune responses of pregnant cattle and their foetuses were examined following inoculation on day 70 of gestation either intravenously (iv) (group 1) or subcutaneously (sc) (group 2) with live NC1 strain tachyzoites or with Vero cells (control) (group 3). Peripheral blood mononuclear cell (PBMC) responses to Neospora antigen and foetal viability were assessed throughout the experiment. Two animals from each group were sacrificed at 14, 28, 42 and 56 days post inoculation (pi). At post mortem, maternal lymph nodes, spleen and PBMC and when possible foetal spleen, thymus and PBMC samples were collected for analysis. Inoculation with NC1 (iv and sc) lead to foetal deaths in all group 1 dams (6/6) and in 3/6 group 2 dams from day 28pi; statistically significant (p ≤ 0.05) increases in cell-mediated immune (CMI) responses including antigen-specific cell proliferation and IFN-γ production as well as increased levels of IL-4, IL-10 and IL-12 were observed in challenged dams compared to the group 3 animals. Lymph node samples from the group 2 animals carrying live foetuses showed greater levels of cellular proliferation as well as significantly (p ≤ 0.05) higher levels of IFN-γ compared to the dams in group 2 carrying dead foetuses. Foetal spleen, thymus and PBMC samples demonstrated cellular proliferation as well as IFN-γ, IL-4, IL-10 and IL-12 production following mitogenic stimulation with Con A from day 14pi (day 84 gestation) onwards. This study shows that the generation of robust peripheral and local maternal CMI responses (lymphoproliferation, IFN-γ) may inhibit the vertical transmission of the parasite.
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Affiliation(s)
- Paul M Bartley
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, EH26 0PZ, Scotland, United Kingdom.
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16
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Rocchi MS, Bartley PM, Inglis NF, Collantes-Fernandez E, Entrican G, Katzer F, Innes EA. Selection of Neospora caninum antigens stimulating bovine CD4+ve T cell responses through immuno-potency screening and proteomic approaches. Vet Res 2011; 42:91. [PMID: 21813001 PMCID: PMC3167765 DOI: 10.1186/1297-9716-42-91] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 08/03/2011] [Indexed: 11/23/2022] Open
Abstract
Neospora caninum is recognised worldwide as a major cause of bovine infectious abortion. There is a real need to develop effective strategies to control infection during pregnancy which may lead to either abortion or congenital transmission. Due to the intracellular nature of the parasite, cell-mediated immune (CMI) responses involving CD4+ve, CD8+ve, γ/δ TCR+ve T cells and NK cells, as well as production of IFN-γ, are thought to be important for protective immunity. In this study we applied a combination of proteomic and immunological approaches to identify antigens of N. caninum that are recognized by CD4+ve T cell lines derived from infected cattle. Initially, N. caninum tachyzoite Water Soluble Antigens (NcWSA) were fractionated by size-exclusion HPLC and then screened for immune-potency using CD4+ve T cell lines. LC-ESI-MS/MS (liquid chromatography electrospray ionisation tandem mass spectrometry) was employed to catalogue and identify the proteins comprising three immunologically selected fractions and led to the identification of six N. caninum target proteins as well as sixteen functional orthologues of Toxoplasma gondii. This approach allows the screening of biologically reactive antigenic fractions by the immune cells responsible for protection (such as bovine CD4+ve cells) and the subsequent identification of the stimulating components using tandem mass spectrometry.
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Affiliation(s)
- Mara S Rocchi
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, EH26 0PZ, UK.
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17
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Rosbottom A, Gibney H, Kaiser P, Hartley C, Smith RF, Robinson R, Kipar A, Williams DJL. Up regulation of the maternal immune response in the placenta of cattle naturally infected with Neospora caninum. PLoS One 2011; 6:e15799. [PMID: 21283810 PMCID: PMC3023762 DOI: 10.1371/journal.pone.0015799] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 11/24/2010] [Indexed: 12/21/2022] Open
Abstract
Neospora caninum is an intracellular protozoan parasite which is a major cause of abortion in cattle worldwide. It forms persistent infections which recrudesce during pregnancy leading to foetal infection and in a proportion of cases, abortion. The mechanisms underlying abortion are not understood. In this study, recrudescence of a persistent infection in eight naturally infected cows occurred between 20 and 33 weeks of gestation. Animals were killed at the time of recrudescence and parasites were detected in the placentae and foetuses. An active maternal immune response consisting of an infiltration of CD4+ and CD8+ T cells and a 46–49 fold increase in interferon-γ and interleukin-4 mRNA was detected. Other cytokines, notably interleukin-12 p40, interleukin-10 and tumour necrosis factor-α were also significantly increased and Major Histocompatibility Class II antigen was expressed on maternal and foetal epithelial and stromal fibroblastoid cells. Significantly, despite the presence of an active maternal immune response in the placenta, all the foetuses were alive at the time of maternal euthanasia. There was evidence of parasites within foetal tissues; their distribution was restricted to the central nervous system and skeletal muscle and their presence was associated with tissue necrosis and a non-suppurative inflammatory response involving lymphocytes and macrophages, irrespective of the gestational age of the foetus. Whilst an active maternal immune response to a pathogen in the placenta is generally considered to be damaging to the foetal trophoblast, our findings suggest that the presence of a parasite-induced maternal immune response in the placenta is not detrimental to foetal survival but may contribute to the control of placental parasitosis.
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Affiliation(s)
- Anne Rosbottom
- Department of Veterinary Pathology, School of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Helen Gibney
- Department of Veterinary Pathology, School of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Peter Kaiser
- Institute for Animal Health, Compton, Berkshire, United Kingdom
| | - Catherine Hartley
- Department of Veterinary Pathology, School of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Robert F. Smith
- Department of Veterinary Clinical Science, Veterinary Teaching Hospital, Leahurst, Neston, United Kingdom
| | - Rebecca Robinson
- Department of Veterinary Pathology, School of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Anja Kipar
- Department of Veterinary Pathology, School of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Diana J. L. Williams
- Department of Veterinary Pathology, School of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
- * E-mail:
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18
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Transplacental transmission in cattle: is Toxoplasma gondii less potent than Neospora caninum? Parasitol Res 2011; 108:1235-41. [PMID: 21203773 DOI: 10.1007/s00436-010-2172-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 11/12/2010] [Indexed: 10/18/2022]
Abstract
We compared the transplacental-transmission ability of Toxoplasma gondii and Neospora caninum in cattle. One uninfected pregnant heifer served as control, while three were inoculated with N. caninum K9WA strain and four with T. gondii RH strain at their midgestational period. Both infected groups showed clinical signs and antibodies either to N. caninum or T. gondii, while the control animal was normal. Two (50%) Toxoplasma dams aborted on days 6 and 11 postinoculation. T. gondii tachyzoites were found in various organs of those dams that had abortions but not in their fetuses. Two Neospora dams did not abort but gave birth to subclinically infected calves. The remaining two Toxoplasma dams and one from Neospora group became recumbent. Those two dams and their fetuses showed disseminated Toxoplasma DNA, but no Neospora DNA was found. Our findings suggest that maternal toxoplasmosis could be a cause of abortion and congenital toxoplasmosis in cattle, especially when they are infected by virulent strains.
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19
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Cadore GC, Vogel FS, Sangioni LA, Pena HF, Gennari SM. IgM e IgG como marcadores da infecção transplacentária por Neospora caninum em fetos bovinos. PESQUISA VETERINARIA BRASILEIRA 2010. [DOI: 10.1590/s0100-736x2010000700007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
O objetivo deste estudo foi determinar a ocorrência de anticorpos anti-Neospora caninum em 260 amostras de soro coletadas de fetos bovinos de julho de 2007 a março de 2008, em abatedouro do município de Santa Maria, Rio Grande do Sul, Brasil. Para detecção de anticorpos anti-N. caninum, a técnica de imunofluorescência indireta foi utilizada tanto para a detecção de imunoglobulinas G e M. Amostras com títulos e" 25 foram consideradas positivas. Das 260 amostras testadas, 15% (39/260) foram positivas para anticorpos anti-N. caninum. Destas, em 38 (97,4%) foi detectada a presença de IgG anti-N. caninum e em seis (15,4%) de IgM. Em cinco amostras (12,8%) detectaram-se ambos, IgG e IgM. Os resultados reafirmam a habilidade do N. caninum em determinar infecção fetal. A pesquisa de IgM foi de limitada importância na detecção da infecção via transplacentária em soro fetal bovino.
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20
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King JS, Slapeta J, Jenkins DJ, Al-Qassab SE, Ellis JT, Windsor PA. Australian dingoes are definitive hosts of Neospora caninum. Int J Parasitol 2010; 40:945-50. [PMID: 20149793 DOI: 10.1016/j.ijpara.2010.01.008] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/20/2010] [Accepted: 01/21/2010] [Indexed: 11/18/2022]
Abstract
To provide objective data on the potential role of dingoes (Canis lupus dingo) in the life cycle of Neospora caninum in Australia, the production of N. caninum oocysts by experimentally infected canids was investigated. Three dingo pups raised in captivity and three domestic dogs were fed tissue from calves infected with an Australian isolate of N. caninum, Nc-Nowra. Oocysts of N. caninum, confirmed by species-specific PCR, were shed in low numbers by one dingo pup at 12-14 days p.i. The remaining animals did not shed oocysts. Furthermore, the blood from two out of three dingoes tested positive for DNA of N. caninum using PCR tests at 14 and 28 days p.i. Oocyst shedding from the intestinal tract of a dingo demonstrates that dingoes are definitive hosts of N. caninum and horizontal transmission of N. caninum from dingoes to farm animals and wildlife may occur in Australia.
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Affiliation(s)
- Jessica S King
- Faculty of Veterinary Science, University of Sydney, NSW, Australia.
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21
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Almería S, Araujo R, Tuo W, López-Gatius F, Dubey JP, Gasbarre LC. Fetal death in cows experimentally infected with Neospora caninum at 110 days of gestation. Vet Parasitol 2010; 169:304-11. [PMID: 20089361 DOI: 10.1016/j.vetpar.2009.12.044] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 12/16/2009] [Accepted: 12/30/2009] [Indexed: 11/16/2022]
Abstract
Neospora caninum is a major cause of abortion in cattle, but the reasons why some animals abort and not others remain unclear. Most of the N. caninum experimental primary infections in cattle late in gestation, after 120 days of pregnancy, result in birth of full-term congenitally infected fetuses. In the present study, the distribution of parasites and pathogenesis of infection in both dams and fetuses after inoculation with 10(7) culture derived tachyzoites of N. caninum NC-Illinois cattle strain at 110 days of gestation were analyzed at 3 weeks, 6 weeks and 9 weeks after infection (WAI) in eight Angus heifers. One dam from the group euthanized at 6 WAI had a dead fetus at necropsy. Extensive lesions were observed in the placenta and tachyzoites were detected in both the placenta and the fetus. The fetus was seropositive and had high IFN-gamma g production in fetal fluids. Another fetus, still alive when euthanized at 3 WAI, had severe lesions and high IFN-gamma production and a similar fate could have been expected if the experimental period would have been longer. Lesions in the placenta of the remaining six dams that had live fetuses at necropsy were mild. In those dams, the fetal and maternal placentas had not separated and contained focal areas of placentitis at the materno-fetal junction. Transplacental infection took place on all fetuses based on detection of parasitic DNA in fetal tissues. The present study shows that experimental N. caninum infection of naïve dams after 110 days of pregnancy can lead to fetal death. The results suggest that the severity of placental lesions and the strong IFN-gamma response in some fetuses, possibly as part of the immune response trying to control the high parasitemia, might, in fact, be the cause of their death.
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Affiliation(s)
- S Almería
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, and Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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22
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Rojo-Montejo S, Collantes-Fernández E, Blanco-Murcia J, Rodríguez-Bertos A, Risco-Castillo V, Ortega-Mora LM. Experimental infection with a low virulence isolate of Neospora caninum at 70 days gestation in cattle did not result in foetopathy. Vet Res 2009; 40:49. [PMID: 19497257 PMCID: PMC2704335 DOI: 10.1051/vetres/2009032] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 06/03/2009] [Indexed: 11/28/2022] Open
Abstract
The Nc-Spain 1H isolate of Neospora caninum, which was newly obtained from the brain of a congenitally asymptomatic infected calf, demonstrated a reduced in vitro tachyzoite yield and viability rate, as well as low virulence in mouse models. The objective of the present study was to determine the ability of this isolate to induce foetal death in a pregnant bovine model. For this purpose, 13 naïve pregnant heifers were divided into three groups and were experimentally challenged with either 107 tachyzoites of Nc-1 (group 1, n = 5), Nc-Spain 1H (group 2, n = 5) isolates or phosphate-buffered saline (group 3, n = 3) intravenously at 70 days of gestation. After inoculation, pregnancy was monitored and dams were sacrificed when foetal death was detected. The remaining animals were slaughtered at 45 days post-infection. Maternal and foetal samples were collected for examination by histology and parasite DNA detection. Parasitaemia, specific anti-N. caninum IgG and interferon γ responses were also studied. At 3–4 weeks after infection, foetal death was detected in 3 out of 5 Nc-1-infected dams. However, no evidence of foetal death was observed in either Nc-Spain 1H-infected or control groups during the period studied. The most severe histopathological lesions were observed in the placenta and foetal organs from Nc-1-infected cattle that exhibited foetal death. It was in these animals that N. caninum DNA was more frequently detected. Parasitaemia was observed in all Nc-1-infected dams and in only 3 out of 5 Nc-Spain 1H-infected animals. The magnitude of the immune response was significantly higher in the Nc-1-inoculated group than in the group inoculated with the Nc-Spain 1H isolate. These data reveal the reduced virulence of the Nc-Spain 1H isolate in cattle.
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Affiliation(s)
- Silvia Rojo-Montejo
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
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23
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Influence of Neospora caninum infection in BALB/c mice during pregnancy in post-natal development. Vet Parasitol 2008; 155:175-83. [DOI: 10.1016/j.vetpar.2008.05.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 04/30/2008] [Accepted: 05/15/2008] [Indexed: 11/21/2022]
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24
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Abstract
The protozoan parasite Neospora caninum is an important cause of reproductive disease in cattle worldwide. The dog is a definitive host for the parasite and the oocyst stage, shed in the faeces, is a source of infection for cattle through consumption of contaminated feed or water. In addition, transplacental transmission of N. caninum is a very efficient means of the parasite infecting a new host and this can occur in successive pregnancies and over several generations. Neospora parasites may cause disease during pregnancy resulting in death of the foetus or birth of live congenitally infected calves that may show some neurological clinical signs at birth. The stage of pregnancy at which infection/parasitaemia occurs is an important factor in determining disease severity. Neospora infection in the first trimester of pregnancy may have more severe consequences for the foetus compared with infection occurring in the final trimester. The host-parasite relationship during pregnancy is a fascinating interaction and research in this area will improve understanding of disease pathogenesis and the various consequences of the host immune response, being host-protective, parasite protective and contributing to disease pathology. Pregnancy poses an interesting problem for the immune system of the dam as she is essentially carrying a semi-allogeneic tissue graft (the foetus) without immunological rejection taking place. To facilitate the pregnancy the cytokine environment in the placenta favours the regulatory Th-2-type cytokines, whose role is to counteract the pro-inflammatory Th1-type immune responses. Protective immunity to N. caninum, similar to many other intracellular parasites, involves Th1-type immune responses, which may pose problems for the dam trying to control a Neospora infection during pregnancy. This paper will discuss the host-parasite relationship at different stages of gestation in pregnant cattle and review the implications of this research for our understanding of disease pathogenesis, parasite transmission and host protection.
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25
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Upregulation of cytokines is detected in the placentas of cattle infected with Neospora caninum and is more marked early in gestation when fetal death is observed. Infect Immun 2008; 76:2352-61. [PMID: 18362132 DOI: 10.1128/iai.01780-06] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The protozoan parasite Neospora caninum causes fetal death after experimental infection of pregnant cattle in early gestation, but the fetus survives a similar infection in late gestation. An increase in Th1-type cytokines in the placenta in response to the presence of the parasite has been implicated as a contributory factor to fetal death due to immune-mediated pathological alterations. We measured, using real-time reverse transcription-PCR and enzyme-linked immunosorbent assay, the levels of cytokines in the placentas of cattle experimentally infected with N. caninum in early and late gestation. After infection in early gestation, fetal death occurred, and the levels of mRNA of both Th1 and Th2 cytokines, including interleukin-2 (IL-2), gamma interferon (IFN-gamma), IL-12p40, tumor necrosis factor alpha (TNF-alpha), IL-18, IL-10, and IL-4, were significantly (P < 0.01) increased by up to 1,000-fold. There was extensive placental necrosis and a corresponding infiltration of CD4(+) T cells and macrophages. IFN-gamma protein expression was also highly increased, and a modest increase in transforming growth factor beta was detected. A much smaller increase in the same cytokines and IFN-gamma protein expression, with minimal placental necrosis and inflammatory infiltration, occurred after N. caninum infection in late gestation when the fetuses survived. Comparison of cytokine mRNA levels in separated maternal and fetal placental tissue that showed maternal tissue was the major source of all cytokine mRNA except for IL-10 and TNF-alpha, which were similar in both maternal and fetal tissues. These results suggest that the magnitude of the cytokine response correlates with but is not necessarily the cause of fetal death and demonstrate that a polarized Th1 response was not evident in the placentas of N. caninum-infected cattle.
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26
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Gibney EH, Kipar A, Rosbottom A, Guy CS, Smith RF, Hetzel U, Trees AJ, Williams DJL. The extent of parasite-associated necrosis in the placenta and foetal tissues of cattle following Neospora caninum infection in early and late gestation correlates with foetal death. Int J Parasitol 2007; 38:579-88. [PMID: 18021783 DOI: 10.1016/j.ijpara.2007.09.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/31/2007] [Accepted: 09/04/2007] [Indexed: 11/19/2022]
Abstract
The protozoan parasite Neospora caninum is the most frequently diagnosed abortifacient in the UK and a leading cause of abortion worldwide but the mechanisms leading to abortion are not fully understood. The distribution of parasites and the histopathological changes in the placenta and foetus were compared in 12 cows following experimental infection of cattle with N. caninum in early (n=6) and late (n=6) gestation, by PCR, immunohistology, light microscopy and transmission electron microscopy. Twelve uninfected pregnant cattle were used as controls. Infection in early gestation led to foetal death. In the placentae of cattle immediately following foetal death, N. caninum DNA was detected and there was evidence of widespread parasite dissemination. This was associated with extensive focal epithelial necrosis, serum leakage and moderate maternal interstitial mononuclear cell infiltration. In the foetuses, parasites were evident in all tissues examined and were associated with necrosis. In the placenta of cattle infected in late gestation, N. caninum DNA was detected sporadically but parasites were not evident immunohistologically. Small foci of necrosis were seen associated with mild interstitial mononuclear cell infiltration. Detection of N. caninum DNA in the foetuses was sporadic and parasites were demonstrated immunohistologically in brain and spinal cord only, with an associated mononuclear cell infiltration. This data is consistent with uncontrolled parasite spread in an immunologically immature foetus and could, via multiparenchymal necrosis of foetal tissues or the widespread necrosis and inflammation observed in the placenta, be the cause of Neospora-associated abortions.
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Affiliation(s)
- E Helen Gibney
- Veterinary Parasitology, Liverpool School of Tropical Medicine/Faculty of Veterinary Science, Pembroke Place, Liverpool L3 5QA, UK
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27
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Innes EA, Bartley PM, Maley SW, Wright SE, Buxton D. Comparative host–parasite relationships in ovine toxoplasmosis and bovine neosporosis and strategies for vaccination. Vaccine 2007; 25:5495-503. [PMID: 17367899 DOI: 10.1016/j.vaccine.2007.02.044] [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: 09/22/2006] [Revised: 01/24/2007] [Accepted: 02/07/2007] [Indexed: 10/23/2022]
Abstract
Toxoplasma gondii and Neospora caninum are important causes of reproductive loss in ruminant species worldwide. Both parasites cause disease during pregnancy that may result in foetal death or birth of live congenitally infected offspring. T. gondii is also an important human pathogen with the main risk groups including pregnant women and immuno-compromised individuals, although clinical disease has also been observed in outbreaks among immuno-competent people. While the two parasites are closely related there are distinct differences between the two in their interactions with different host species and subsequent clinical outcome. This paper discusses the respective host-parasite relationships in ovine toxoplasmosis and bovine neosporosis and how the immune response may be host-protective, parasite-protective or contribute to disease pathogenesis, and how this knowledge may help in the development of more effective and targeted vaccination strategies.
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Affiliation(s)
- Elisabeth A Innes
- Moredun Research Institute, Pentlands Science Park, Edinburgh EH26 OPZ, United Kingdom.
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28
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Rosbottom A, Guy CS, Gibney EH, Smith RF, Valarcher JF, Taylor G, Williams DJL. Peripheral immune responses in pregnant cattle following Neospora caninum infection. Parasite Immunol 2007; 29:219-28. [PMID: 17371459 DOI: 10.1111/j.1365-3024.2007.00936.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Experimental infection of cattle with Neospora caninum in early gestation causes foetal death, but the foetus survives infection in late gestation. An immunological mechanism of abortion has been suggested; therefore changes in the maternal immune response during pregnancy could account for these differences. We have investigated the peripheral immune responses of pregnant cattle following an intravenous inoculation with 10(7) N. caninum tachyzoites in early and late gestation. Percentages of CD2+ and CD4+ T-cells in peripheral blood mononuclear cells (PBMC) increased 1-2 weeks after infection in both early (day 70) and late (day 210) gestation, and percentages of CD8+ T-cells increased 1-2 weeks after infection at day 70. Interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) mRNA expression in PBMC increased 1-2 weeks after infection at day 210 and IL-4 increased 1-2 weeks after infection at day 70. Immunomagnetic isolation of CD4+ cells from PBMC showed that they were a major source of IL-4 and IFN-gamma, and expression of both cytokines increased in CD4+ cells after infection in early and late gestation. These results suggest that CD4+ cells proliferate and express IL-4 and IFN-gamma in response to N. caninum irrespective of the stage of gestation when infection occurs.
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Affiliation(s)
- A Rosbottom
- Veterinary Parasitology, Liverpool School of Tropical Medicine/Faculty of Veterinary Science, University of Liverpool, Liverpool, UK.
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29
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Innes EA, Vermeulen AN. Vaccination as a control strategy against the coccidial parasitesEimeria,ToxoplasmaandNeospora. Parasitology 2007; 133 Suppl:S145-68. [PMID: 17274844 DOI: 10.1017/s0031182006001855] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The protozoan parasitesEimeriaspp.Toxoplasma gondiiandNeospora caninumare significant causes of disease in livestock worldwide andT. gondiiis also an important human pathogen. Drugs have been used with varying success to help control aspects of these diseases and commercial vaccines are available for all three groups of parasites. However, there are issues with increasing development of resistance to many of the anti-coccidial drugs used to help control avian eimeriosis and public concerns about the use of drugs in food animals. In addition there are no drugs available that can act against the tissue cyst stage of eitherT. gondiiorN. caninumand thus cure animals or people of infection. All three groups of parasites multiply within the cells of their host species and therefore cell mediated immune mechanisms are thought to be an important component of host protective immunity. Successful vaccination strategies for bothEimeriaandToxoplasmahave relied on using a live vaccination approach using attenuated parasites which allows correct processing and presentation of antigen to the host immune system to stimulate appropriate cell mediated immune responses. However, live vaccines can have problems with safety, short shelf-life and large-scale production; therefore there is continued interest in devising new vaccines using defined recombinant antigens. The major challenges in devising novel vaccines are to select relevant antigens and then present them to the immune system in an appropriate manner to enable the induction of protective immune responses. With all three groups of parasites, vaccine preparations comprising antigens from the different life cycle stages may also be advantageous. In the case ofEimeriaparasites there are also problems with strain-specific immunity therefore a cocktail of antigens from different parasite strains may be required. Improving our knowledge of the different parasite transmission routes, host-parasite relationships, disease pathogenesis and determining the various roles of the host immune response being at times host-protective, parasite protective and in causing immunopathology will help to tailor a vaccination strategy against a particular disease target. This paper discusses current vaccination strategies to help combat infections withEimeria,ToxoplasmaandNeosporaand recent research looking towards developing new vaccine targets and approaches.
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Affiliation(s)
- E A Innes
- Moredun Research Institute, Pentlands Science Park, Edinburgh EH26 OPZ, UK.
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30
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Maley SW, Buxton D, Macaldowie CN, Anderson IE, Wright SE, Bartley PM, Esteban-Redondo I, Hamilton CM, Storset AK, Innes EA. Characterization of the immune response in the placenta of cattle experimentally infected with Neospora caninum in early gestation. J Comp Pathol 2006; 135:130-141. [PMID: 16997005 DOI: 10.1016/j.jcpa.2006.07.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Accepted: 07/05/2006] [Indexed: 11/30/2022]
Abstract
A serial examination of three groups of cattle infected intravenously (iv) (Group 1, n=8) or subcutaneously (sc) (Group 2, n=8) with live Neospora caninum tachyzoites or with VERO cells (Group 3, n=8) at 70 days' gestation was carried out and the nature of the inflammatory responses in the placenta and the presence of parasite antigen were analysed. Immune cells expressing CD3, CD4, CD8, gamma delta (gammadelta) T-cell receptors (TCR), CD79alpha cytoplasmic (cy) (B cells) and NKp46 [natural killer (NK) cells] antigens were identified immunohistochemically and cells expressing mRNA for interferon-gamma (IFN-gamma) were labelled by in-situ hybridization. Intravenous inoculation caused mortality in all fetuses from 28 days post-inoculation (dpi) onwards. Subcutaneous inoculation caused mortality in 50% of the animals by 28dpi. Pathological changes in the placenta consisted of necrosis of fetal placental villi, necrosis and inflammation in adjacent areas of the maternal septum and inflammation at the base of the maternal caruncle. The inflammatory infiltrate consisted mainly of CD3(+) lymphocytes, dominated by CD4(+) and gammadelta TCR(+) cells, with CD8(+) cells present to a lesser extent. The results from the control group indicated fewer NK cells than those occurring in the placenta of human beings or mice. Infiltration of CD4(+) cells and NKp46(+) cells was observed in the caruncular base and septa 14 days after infection, whereas infiltration of gammadelta TCR(+) cells was observed from 28 dpi onwards. To our knowledge this is the first report on the presence and distribution of NK cells in the bovine placenta. Maternal inflammatory cells expressing mRNA for IFN-gamma were identified in animals inoculated with parasites iv or sc at 14 and 28 dpi, respectively. In the sc-inoculated dams with live fetuses at 28, 42 and 56dpi, there was no evidence of parasite antigen, infiltration of immune cells or production of IFN-gamma, suggesting that the parasite had not reached the placenta. The exact cause of fetal death was not established. Tissue destruction by the parasite may have occurred; in addition, there may have been a T helper 1 (Th-1) immune response to the neospora infection at the materno-fetal interface, resulting in infiltrations of CD4T cells, gammadelta T cells and NK cells and the subsequent production of IFN-gamma. It is possible that a pro-inflammatory Th-1 response early in gestation protects the dam by eliminating the parasite; however, it may lead to destruction of the placental tissues themselves and thus be incompatible with fetal survival.
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MESH Headings
- Animals
- CD3 Complex/genetics
- CD3 Complex/metabolism
- CD4-Positive T-Lymphocytes/metabolism
- CD4-Positive T-Lymphocytes/pathology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/pathology
- Cattle
- Cattle Diseases/immunology
- Cattle Diseases/metabolism
- Cattle Diseases/parasitology
- Cattle Diseases/pathology
- Coccidiosis/immunology
- Coccidiosis/pathology
- Coccidiosis/veterinary
- Female
- Fetal Death
- Interferon-gamma/genetics
- Interferon-gamma/metabolism
- Neospora/immunology
- Neospora/pathogenicity
- Placenta/immunology
- Placenta/metabolism
- Placenta/parasitology
- Placenta/pathology
- Pregnancy
- Pregnancy, Animal/immunology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- T-Lymphocytes/pathology
- Th1 Cells/immunology
- Th1 Cells/metabolism
- Th1 Cells/pathology
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Affiliation(s)
- S W Maley
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ.
| | - D Buxton
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ
| | - C N Macaldowie
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ
| | - I E Anderson
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ
| | - S E Wright
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ
| | - P M Bartley
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ
| | - I Esteban-Redondo
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ
| | - C M Hamilton
- Department of Zoology, Trinity College, Dublin 2, Ireland
| | - A K Storset
- Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, PO Box 8146, dep., N-0033, Oslo, Norway
| | - E A Innes
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ
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31
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McInnes LM, Ryan UM, O'Handley R, Sager H, Forshaw D, Palmer DG. Diagnostic significance of Neospora caninum DNA detected by PCR in cattle serum. Vet Parasitol 2006; 142:207-13. [PMID: 16934934 DOI: 10.1016/j.vetpar.2006.07.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 07/13/2006] [Accepted: 07/18/2006] [Indexed: 11/29/2022]
Abstract
A nested PCR that successfully detected Neospora caninum DNA in serum of cattle was used for investigation of selected abortion cases and in a study of healthy pregnant cows at an abattoir. N. caninum DNA was not detected in serum from antibody positive dams that aborted due to N. caninum, but was present in serum of some antibody negative dams that aborted due to other causes. N. caninum DNA was also found in the serum of about half of the animals that aborted of undetermined cause, but was not detected in cow sera from two beef cattle herds in Western Australia with no recent history of abortion. In the abattoir study of 79 dams and their foetuses N. caninum DNA was found in serum of 3 dams and in material from 11 foetuses. The majority of the cows and all foetuses were antibody negative. Our findings suggest that there is no obvious relationship between the presence or absence of N. caninum DNA in serum and the presence of antibodies to N. caninum in dams, the presence of N. caninum DNA in foetuses or abortion due to N. caninum. This is the first report of the detection of N. caninum DNA in serum of cattle rather than the white blood cell fraction. It indicates the presence of free tachyzoites and/or parasite DNA in circulation. The results suggest that persistent infection in the absence of antibodies is a possible outcome of N. caninum infection. Infection of foetuses in the absence of antibodies supports the possibility of persistent infection due to immunotolerance to an early in utero infection. It is therefore important to test for N. caninum DNA as well as antibodies for the detection of exposed and/or infected animals. However, the presence or absence of N. caninum antibodies or DNA did not support nor exclude N. caninum as the cause of abortion. Additional criteria are required for a positive diagnosis of abortion caused by N. caninum.
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Affiliation(s)
- Linda M McInnes
- Division of Health Sciences, School of Veterinary and Biomedical Science, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
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32
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Dubey JP, Schares G. Diagnosis of bovine neosporosis. Vet Parasitol 2006; 140:1-34. [PMID: 16730126 DOI: 10.1016/j.vetpar.2006.03.035] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 03/17/2006] [Accepted: 03/22/2006] [Indexed: 10/24/2022]
Abstract
The protozoan parasite Neospora caninum is a major cause of abortion in cattle. The diagnosis of neosporosis-associated mortality and abortion in cattle is difficult. In the present paper we review histologic, serologic, immunohistochemical, and molecular methods for dignosis of bovine neosporosis. Although not a routine method of diagnosis, methods to isolate viable N. caninum from bovine tissues are also reviewed.
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Affiliation(s)
- J P Dubey
- Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, United States Department of Agricultural, Beltsville, MD 20705, USA.
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33
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Dubey JP, Buxton D, Wouda W. Pathogenesis of bovine neosporosis. J Comp Pathol 2006; 134:267-89. [PMID: 16712863 DOI: 10.1016/j.jcpa.2005.11.004] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Accepted: 11/28/2005] [Indexed: 11/29/2022]
Abstract
The protozoan parasite Neospora caninum is a major pathogen of cattle and dogs, being a significant cause of abortion in cattle in many countries. It is one of the most efficiently transmitted parasites, with up to 90% of cattle infected in some herds. The pathogenesis of abortion due to Neospora is complex and only partially understood. Losses occur after a primary infection during pregnancy but more commonly as the result of recrudescence of a persistent infection during pregnancy. Parasitaemia is followed by invasion of the placenta and fetus. It is suggested that abortion occurs when primary parasite-induced placental damage jeopardises fetal survival directly or causes release of maternal prostaglandins that in turn cause luteolysis and abortion. Fetal damage may also occur due to primary tissue damage caused by the multiplication of N. caninum in the fetus or due to insufficient oxygen/nutrition, secondary to placental damage. In addition, maternal immune expulsion of the fetus may occur associated with maternal placental inflammation and the release of maternal pro-inflammatory cytokines in the placenta. Thus N. caninum is a primary pathogen capable of causing abortion either through maternal placental inflammation, maternal and fetal placental necrosis, fetal damage, or a combination of all three. The question of how N. caninum kills the fetus exposes the complex and finely balanced biological processes that have evolved to permit bovine and other mammalian pregnancies to occur. Defining these immunological mechanisms will shed light on potential methods of control of bovine neosporosis and enrich our understanding of the continuity of mammalian and protozoal survival.
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Affiliation(s)
- J P Dubey
- Animal Parasitic Diseases Laboratory, United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, BARC-East, Building 1001, 10300 Baltimore Avenue, Beltsville, MD 20705-2350, USA
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34
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Staubli D, Sager H, Haerdi C, Haessig M, Gottstein B. Precolostral serology in calves born from Neospora-seropositive mothers. Parasitol Res 2006; 99:398-404. [PMID: 16572335 DOI: 10.1007/s00436-006-0170-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Accepted: 02/10/2006] [Indexed: 11/29/2022]
Abstract
The present study was designed to exploratively determine (a) how many healthy calves, born from seropositive mothers, were also precolostrally seropositive; (b) how many precolostrally negative calves became postcolostrally positive; and (c) in these calves, how the IgG1/IgG2 situation developed pre- and postcolostrally. All calves were born from mothers that were determined to be seropositive in a conventional Neospora caninum-ELISA and by immunoblotting. When the diagnostic performance of the conventional ELISA was compared with that of immunoblotting and an IgG1/IgG2-ELISA in the calves, the latter two exhibited a higher sensitivity: From a total of 15 precolostral calf sera, 7 were positive in the conventional ELISA (diagnostic sensitivity 47%) compared to 15 that were positive by immunoblotting (diagnostic sensitivity 100%) and 12 that were positive by the IgG1/IgG2-ELISA (diagnostic sensitivity 80%). With regard to IgG1/IgG2 findings in the dams, IgG2 appeared as the dominant subclass in the humoral immune response of adult cattle, while in calves, IgG1 appeared as the main prenatally/precolostrally reactive antibody isotype. Provided that precolostral seropositivity reflects postnatal persistent infection with N. caninum, we then postulate that, basically, all of our study calves born form N. caninum-seropositive mothers were prenatally infected with the parasite, and may, thus, all become members of the next transmitting generation.
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Affiliation(s)
- Daniela Staubli
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Laenggass-Strasse 122, CH-3012, Bern, Switzerland
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35
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Innes EA, Wright S, Bartley P, Maley S, Macaldowie C, Esteban-Redondo I, Buxton D. The host–parasite relationship in bovine neosporosis. Vet Immunol Immunopathol 2005; 108:29-36. [PMID: 16098610 DOI: 10.1016/j.vetimm.2005.07.004] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Infection with the protozoan parasite Neospora caninum is thought to be a major cause of reproductive failure in cattle worldwide. Cattle infected with the parasite are three to seven times more likely to abort compared to uninfected cattle. The parasite may be transmitted to cattle through the ingestion of oocysts that are shed in the faeces of acutely infected dogs (definitive host of N. caninum) or by congenital infection from mother to foetus via the placenta. Interestingly, transplacental transmission can occur over consecutive pregnancies and congenitally infected heifers can transmit the parasite to their own offspring. This repeated vertical transmission observed in naturally infected cattle suggests that cattle do not easily develop effective immunity to the parasite, presenting a significant challenge to the development of a control strategy based on vaccination. Neosporosis is a disease of pregnancy and studying the bovine maternal and foetal immune responses during pregnancy will help us to understand the change in the balance between the parasite and the host that may result in disease of the foetus. Studies in non-pregnant cattle and in murine models of infection have shown the importance of T-helper 1-type immune responses involving pro-inflammatory cytokines, such as IFNgamma and IL-12, in limiting intracellular multiplication of the parasite. During pregnancy, changes occur in the immune system allowing the mother to accept the foetal allograft. Research in other species has stressed the crucial role of T-helper 2-type cytokines at the materno-foetal interface in maintaining the pregnancy and regulating the potentially damaging effect of Th-1 responses. Studies in cattle have shown that cell proliferation and IFNgamma responses may be significantly down-regulated around mid-gestation. This may mean that cattle are less able to cope with N. caninum infection at this time and are more likely to transmit the parasite to the foetus. Another important factor is the gestational age and hence immuno-competence of the foetus at the time of infection. Early in gestation, N. caninum infection of the placenta and subsequently the foetus usually proves fatal, whereas infection occurring in mid to late pregnancy may result in the birth of a congenitally infected but otherwise healthy calf. Studies of foetal immune responses have shown that at 14 weeks of gestation, lymphocytes only respond to mitogen, while by 24 weeks (mid-gestation), they respond to antigen by proliferating and releasing IFNgamma. Clearly, there are several factors influencing the outcome of N. caninum infection in pregnancy: the timing, quantity and duration of parasitaemia, the effectiveness of the maternal immune response and the ability of the foetus to mount an immune response against the parasite. The challenge is to design a vaccine that will prevent foetal infection by N. caninum. This is likely to involve a fine balancing act with the immune system that will allow intervention in a manner that will tip the host-parasite balance in favour of the host without compromising the pregnancy.
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Affiliation(s)
- Elisabeth A Innes
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh EH26 OPZ, UK. lee.innes.@moredun.ac.uk
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