Identification of a human immunodominant B-cell epitope within the GRA1 antigen of Toxoplasma gondii by phage display of cDNA libraries

Beghetto, Elisa; Pucci, Andrea; Minenkova, Olga; Spadoni, Andrea; Bruno, Luca; Buffolano, Wilma; Soldati, Dominique; Felici, Franco; Gargano, Nicola

doi:10.1016/s0020-7519(01)00288-0

Cited by 51 publications

(53 citation statements)

References 28 publications

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“…This antigen produces a strong antibody response in the acute phase of infection and is found in the parasitophorous vacuole and the cytoplasm of the tachyzoite-infected host cell, leading to immune recognition due to constant rupture of the 67 cyst cells 16 . The granule-dense 1 antigen (GRA-1) reacts strongly with serum samples from pregnant women infected with T. gondii 3 and, as we found here, with sera from chronic and acute/recent toxoplasmosis, as in reported 16 data. The present study was undertaken since the exact composition and conformation of T. gondii ESA antigens to be used to detect IgG and IgM antibodies in an immunoassay remained an open question.…”

Section: Discussionsupporting

confidence: 87%

“…However, some problems can be observed in laboratory practice, such as false negative results after treatment with anti-toxoplasma drugs, low and focal distribution of parasites in the tissues or the presence of non-viable parasites in autolyzed tissue. Excreted and secreted antigen (ESA) of T. gondii has been used in detection of specific antibodies for the diagnosis of acute toxoplasmosis 1,2,3,4,6,7,15,27 . As previously mentioned, circulating antigens in infected humans are constituted by T. gondii ESA, and are one of the first targets of the host immune response 26 .…”

Section: Discussionmentioning

confidence: 99%

“…In addition, positivity observed in these same groups of patients, by means of the above referred to assays, did not permit discrimination of acute/recent toxoplasmosis from other phases of the infection (Table 1). The IgG-ELISA using independently the peptides GRA-1 and GRA-7, although showing good sensitivities for chronic toxoplasmosis, cannot be helpful as confirmatory assays, as referred to JACOBS et al(1999) 17 and BEGHETTO et al (2001) 3 . Maximum specificity was observed in the control groups (IV and V) including clinically healthy individuals and others with unrelated pathologies.…”

Section: Discussionmentioning

confidence: 99%

“…The Fmoc protecting group was removed by using a mild base treatment with 2% piperidine 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) in dimethyl sulfoxide-70% domethylformamide with in situ activation. The peptide sequence chosen for SAG-1 is based in KATO et al 19 ; for GRA-1 in BEGHETTO et al 3 ; and for GRA-7 in SOUSA et al 31 .…”

Section: Pagementioning

confidence: 99%

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High diagnostic efficiency of IgM-ELISA with the use of multiple antigen peptides (MAP1) from T. gondii ESA (SAG-1, GRA-1 and GRA-7), in acute toxoplasmosis

Araújo

Ferreira

2010

Rev. Inst. Med. trop. S. Paulo

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SUMMARYThe main serological marker for the diagnosis of recent toxoplasmosis is the specific IgM antibody, along with IgG antibodies of low avidity. However, in some patients these antibodies may persist long after the acute/recent phase, contributing to misdiagnosis in suspected cases of toxoplasmosis. In the present study, the diagnostic efficiency of ELISA was evaluated, with the use of peptides derived from T. gondii ESA antigens, named SAG-1, GRA-1 and GRA-7. In the assay referred to, we studied each of these peptides individually, as well as in four different combinations, as Multiple Antigen Peptides (MAP), aiming to establish a reliable profile for the acute/recent toxoplasmosis with only one patient serum sample. The diagnostic performance of the assay using MAP1, with the combination of SAG-1, GRA-1 and GRA-7 peptides, demonstrated better discrimination of the acute/recent phase from non acute/ recent phase of toxoplasmosis. Our results show that IgM antibodies to MAP1 may be useful as a serological marker, enhancing the diagnostic efficiency of the assay for acute/recent phase of toxoplasmosis.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Pagementioning

confidence: 99%

See 2 more Smart Citations

High diagnostic efficiency of IgM-ELISA with the use of multiple antigen peptides (MAP1) from T. gondii ESA (SAG-1, GRA-1 and GRA-7), in acute toxoplasmosis

Araújo

Ferreira

2010

Rev. Inst. Med. trop. S. Paulo

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“…The involvement of GRA1 immunodominant B cell epitope in inducing antibody production by the human immune system was previously identified [58], whereas the immunodominant epitope on GRA1 was also located and accessed using pig sera. The result indicates high immunoreactivity as well as the capability of the peptide to improve the toxoplasmosis serodiagnostic tests [56].…”

Section: Epitope-based Antigenmentioning

confidence: 97%

Effective Diagnostic Marker for Serodiagnosis of Toxoplasma gondii Infection: New Developments and Perspectives

Mohamed¹,

Hajissa²

2017

Toxoplasmosis

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Toxoplasmosis is a prevalent parasitic infection caused by an obligate intracellular parasite Toxoplasma gondii. Various methods have been established in the laboratory diagnosis of toxoplasmosis. Among these methods, serological tests are common and provide satisfactory results. However, producing reliable reagents and standard antigen remains difficult and expensive. Replacing native antigens in all current diagnostic kits with standard and reliable reagents are speculated to achieve more sensitive and specific detection that can significantly improve the assay performance. This review provides updated data on toxoplasmosis serodiagnosis. It focuses on the recent trends of producing reliable and standard antigens that have been used in the serological tests of toxoplasmosis, as well as the future direction in this field.

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The Use of Phage Display in Neurobiology

Bradbury

2010

CP Neuroscience

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Phage display has been extensively used to study protein-protein interactions, receptor- and antibody-binding sites, and immune responses, to modify protein properties, and to select antibodies against a wide range of different antigens. In the format most often used, a polypeptide is displayed on the surface of a filamentous phage by genetic fusion to one of the coat proteins, creating a chimeric coat protein, and coupling phenotype (the protein) to genotype (the gene within). As the gene encoding the chimeric coat protein is packaged within the phage, selection of the phage on the basis of the binding properties of the polypeptide displayed on the surface simultaneously results in the isolation of the gene encoding the polypeptide. This unit describes the background to the technique, and illustrates how it has been applied to a number of different problems, each of which has its neurobiological counterparts. Although this overview concentrates on the use of filamentous phage, which is the most popular platform, other systems are also described.

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Identification of a human immunodominant B-cell epitope within the GRA1 antigen of Toxoplasma gondii by phage display of cDNA libraries

Cited by 51 publications

References 28 publications

High diagnostic efficiency of IgM-ELISA with the use of multiple antigen peptides (MAP1) from T. gondii ESA (SAG-1, GRA-1 and GRA-7), in acute toxoplasmosis

High diagnostic efficiency of IgM-ELISA with the use of multiple antigen peptides (MAP1) from T. gondii ESA (SAG-1, GRA-1 and GRA-7), in acute toxoplasmosis

Effective Diagnostic Marker for Serodiagnosis of Toxoplasma gondii Infection: New Developments and Perspectives

The Use of Phage Display in Neurobiology

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