Discovery of new Toxoplasma gondii antigenic proteins using a high throughput protein microarray approach screening sera of murine model infected orally with oocysts and tissue cysts

Mert Döşkaya,Aarti Jain,Sultan Gülçe İz,Hüseyin Can,Aysu Değirmenci Döşkaya,Li Liang,David Huw Davies,Adnan Yüksel Gürüz,Philip Louis Felgner

doi:10.1186/s13071-018-2934-1

Mert Döşkaya, Aarti Jain + Show 7 more

Open Access

https://doi.org/10.1186/s13071-018-2934-1

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Abstract

BackgroundToxoplasma gondii is an obligate intracellular protozoan parasite that causes congenital toxoplasmosis, as well as other serious clinical presentations in immune compromised humans. The parasite has also been recently linked to behavioral diseases in humans and other mammalian hosts. New antigens are being evaluated to develop a diagnostic kit for the diagnosis of acute infection or a protective vaccine.MethodsIn this study, we have focused on the discovery of new antigenic proteins from T. gondii genomic data using a high throughput protein microarray screening. To date, microarrays containing > 2870 candidate exon products of T. gondii have been probed with sera collected from patients with toxoplasmosis. Here, the protein microarrays are probed with well-characterized serum samples from animal models administered orally with oocysts or tissue cysts. The aim was to discover the antigens that overlap in the mouse profile with human antibody profiles published previously. For this, a reactive antigen list of 240 antigens recognized by murine IgG and IgM was identified using pooled sera from orally infected mice.ResultsAnalyses of screening data have identified plenty of antigens and showed strong immunogenicity in both mouse and human antibody profiles. Among them, ROP1, GRA2, GRA3, GRA4, GRA5, GRA6, GRA7, GRA8, GRA14, MIC1, MIC2 and MAG1 have shown strong immunogenicity and used as antigen in development of vaccines or serological diagnostic assays in previous studies.ConclusionIn addition to the above findings, ROP6, MIC12, SRS29A and SRS13 have shown strong immunogenicity but have not been tested in development of a diagnostic assay or a vaccine model yet.

Highlights

Toxoplasma gondii is an obligate intracellular protozoan parasite that causes congenital toxoplasmosis, as well as other serious clinical presentations in immune compromised humans
Our approach has revealed that ROP6, MIC12, SRS29A and SRS13 have shown strong immunogenicity and at the same time not tested in development of a diagnostic assay or a vaccine model yet
It seems that GRA3 and GRA8 can be a good vaccine candidate that has not been tested in an animal model yet

Summary

Introduction

Toxoplasma gondii is an obligate intracellular protozoan parasite that causes congenital toxoplasmosis, as well as other serious clinical presentations in immune compromised humans. Toxoplasma gondii is a protozoan parasite that has a widespread distribution worldwide among humans and animals [1] The importance of this intracellular parasite comes from the clinical presentations formed in the fetus and in immune compromised patients. Infection of women early in pregnancy is associated with an increased risk of congenital toxoplasmosis in utero and may become lethal by dissemination to vital organs such as brain, heart or lungs. This may occur in immunocompromised adults by therapeutic immunosuppression, such as in cancer chemotherapy or organ transplantation [1]. As well as other intermediate hosts, are often infected via domestic cats, but can become infected by ingestion of tissue cysts in raw or under-cooked meat prepared from infected hosts

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