In Vitro Induction of
            <i>Neospora caninum</i>
            Bradyzoites in Vero Cells Reveals Differential Antigen Expression, Localization, and Host-Cell Recognition of Tachyzoites and Bradyzoites

Vonlaufen, Nathalie; Guetg, Nicole; Naguleswaran, Arunasalam; Müller, Norbert; Björkman, Camilla; Schares, Gereon; Blumroeder, Daniela von; Ellis, John; Hemphill, Andrew

doi:10.1128/iai.72.1.576-583.2004

Cited by 72 publications

(78 citation statements)

References 59 publications

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“…However, major antigenic differences do exist between the different stages of N. caninum i.e. the tachyzoite, the bradyzoite and the oocyst [48,49]. These three stages can be observed in the dog.…”

Section: Discussionmentioning

confidence: 99%

First epidemiological study on exposure to Neospora caninum in different canine populations in the Algiers District (Algeria)

Ghalmi

China

Kaidi

et al. 2009

Parasitology International

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Neospora caninum is an important cause of abortion in cattle worldwide. Dogs act as final hosts shedding oocysts in the environment. They can also harbour the extraintestinal stage of the parasite and this may be associated with a fairly rare neuromuscular condition. The sera of 781 dogs from the Algiers District were screened by IFAT for the presence of anti-N. caninum antibodies. These dogs were distributed into four populations: local stray dogs, police dogs, dogs from breeding kennels and farm dogs. The overall seroprevalence was 21.90%. Significant differences were observed between the different populations, the highest prevalence being observed in farm (44.44%) and stray dogs (22.55%). Additionally, the highest titres were observed in farm dogs. Among studied epidemiological parameters, breed, dog origin, season and vaccination status were significantly associated with IFAT results. Additionally, a recently described real time PCR was used on the blood of 100 pound dogs and the results were compared with the serological data. A higher proportion of dogs was found to be positive by PCR when compared to the IFAT results. There was only a fairly low agreement between PCR and IFAT results which suggests that these techniques measured different aspects of the host-parasite relationship. This study indicates that the level of exposure of the canine population of Algiers area to N. caninum is very high. This would indicate a potentially high risk for N. caninum induced abortion in cattle in this region and in Algeria.

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Section: Discussionmentioning

confidence: 99%

First epidemiological study on exposure to Neospora caninum in different canine populations in the Algiers District (Algeria)

Ghalmi

China

Kaidi

et al. 2009

Parasitology International

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“…BAG1, a classical bradyzoite-specific marker (McAllister et al 1996;Vonlaufen et al 2002Vonlaufen et al , 2004, was used to monitor the conversion efficiency. For this purpose, parasites were purified from SNP-treated cells and the expression levels of BAG1 and BAG1 mRNA were compared with those of tachyzoites by immunofluorescence (IF) and quantitative RT-PCR (qRT-PCR), respectively ( Fig.…”

Section: Cell and Parasite Culturesmentioning

confidence: 99%

Molecular cloning and characterization ofNcROP2Fam-1, a member of the ROP2 family of rhoptry proteins inNeospora caninumthat is targeted by antibodies neutralizing host cell invasionin vitro

et al. 2013

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S U M M A R YRecent publications demonstrated that a fragment of a Neospora caninum ROP2 family member antigen represents a promising vaccine candidate. We here report on the cloning of the cDNA encoding this protein, N. caninum ROP2 family member 1 (NcROP2Fam-1), its molecular characterization and localization. The protein possesses the hallmarks of ROP2 family members and is apparently devoid of catalytic activity. NcROP2Fam-1 is synthesized as a pre-pro-protein that is matured to 2 proteins of 49 and 55 kDa that localize to rhoptry bulbs. Upon invasion the protein is associated with the nascent parasitophorous vacuole membrane (PVM), evacuoles surrounding the host cell nucleus and, in some instances, the surface of intracellular parasites. Staining was also observed within the cyst wall of 'cysts' produced in vitro. Interestingly, NcROP2Fam-1 was also detected on the surface of extracellular parasites entering the host cells and antibodies directed against NcROP2Fam-1-specific peptides partially neutralized invasion in vitro. We conclude that, in spite of the general belief that ROP2 family proteins are intracellular antigens, NcROP2Fam-1 can also be considered as an extracellular antigen, a property that should be taken into account in further experiments employing ROP2 family proteins as vaccines.

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“…The relevant role of GRA proteins in the closely related T. gondii is well known: GRA proteins constitute a highly immunogenic group which are excreted/secreted by dense granules to the parasitophorous vacuole during parasite intracellular development (Cesbron-Delauw 1994). In particular, GRA7 is a highly immunogenic, dense granule protein in both T. gondii and N. caninum (Lally et al 1997, Fischer et al 1998, Vonlaufen et al 2004, which has been effectively employed as a diagnostic tool (Aguado-Martínez et al 2008). Moreover, although GRA proteins appear to be related to intracellular parasite development, previous studies Characterisation of Neospora caninum NcGRA7 and NcSAG4 proteins 305 revealed that NcGRA7 might be involved in the initial host cell invasion process of N. caninum (Augustine et al 1999, Cho et al 2005.…”

Section: Introductionmentioning

confidence: 99%

Characterisation of NcGRA7 and NcSAG4 proteins: Immunolocalisation and their role in the host cell invasion by Neospora caninum tachyzoites

Aguado‐Martínez

Álvarez‐García

Schares

et al. 2010

Acta Parasitologica

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Neospora caninum negatively impacts bovine reproductive performance around the world. Addressing this problem requires a greater understanding of the parasite's molecular biology. In this study, monoclonal antibodies against recombinant proteins were successfully developed and employed to characterise two different proteins of N. caninum: the acute phase-associated NcGRA7 and the chronic phase-associated NcSAG4. Immunofluorescence with the anti-rNcGRA7 monoclonal antibody suggested that NcGRA7 trafficks from tachyzoite dense granules to the matrix of the parasitophorous vacuole and parasite's surroundings. Furthermore, NcGRA7 is also expressed in the bradyzoite stage and localised on the matrix of bradyzoite-positive vacuoles. NcGRA7 appears to be partially involved in the tachyzoite-invasion mechanisms, as an anti-rNcGRA7 monoclonal antibody partially inhibited in vitro tachyzoite-invasion. A monoclonal antibody specific for NcSAG4 confirmed this protein's bradyzoitespecific expression both by western blot and immunofluorescence. However, some bradyzoite-positive vacuoles only weakly expressed NcSAG4, if it was expressed at all. The specificity of the anti-rNcSAG4 monoclonal antibody was confirmed by the recognition of the NcSAG4 in the membrane surface of Nc-1SAG4 c transgenic tachyzoites, which constitutively expresses NcSAG4. Blocking NcSAG4 of Nc-1SAG4 c tachyzoites with the monoclonal antibody did not affect host cell invasion. However, its implication on the host cell adhesion or host immune evasion should not be discarded.

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In Vitro Induction of Neospora caninum Bradyzoites in Vero Cells Reveals Differential Antigen Expression, Localization, and Host-Cell Recognition of Tachyzoites and Bradyzoites

Cited by 72 publications

References 59 publications

First epidemiological study on exposure to Neospora caninum in different canine populations in the Algiers District (Algeria)

First epidemiological study on exposure to Neospora caninum in different canine populations in the Algiers District (Algeria)

Molecular cloning and characterization ofNcROP2Fam-1, a member of the ROP2 family of rhoptry proteins inNeospora caninumthat is targeted by antibodies neutralizing host cell invasionin vitro

Characterisation of NcGRA7 and NcSAG4 proteins: Immunolocalisation and their role in the host cell invasion by Neospora caninum tachyzoites

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