Detection of immunogenic parasite and host‐specific proteins in the sera of active and chronic individuals infected with Toxoplasma gondii

Abstract

Toxoplasma gondii infection in pregnant women may result in abortion and foetal abnormalities, and may be life-threatening in immunocompromised hosts. To identify the potential infection markers of this disease, 2-DE and Western blot methods were employed to study the parasite circulating antigens and host-specific proteins in the sera of T. gondii-infected individuals. The comparisons were made between serum protein profiles of infected (n=31) and normal (n=10) subjects. Antigenic proteins were identified by immunoblotting using pooled sera and monoclonal anti-human IgM-HRP. Selected protein spots were characterised using mass spectrometry. Prominent differences were observed when serum samples of T. gondii-infected individuals and normal controls were compared. A significant up-regulation of host-specific proteins, α(2)-HS glycoprotein and α(1)-B glycoprotein, was also observed in the silver-stained gels of both active and chronic infections. However, only α(2)-HS glycoprotein and α(1)-B glycoprotein in the active infection showed immunoreactivity in Western blots. In addition, three spots of T. gondii proteins were detected, namely (i) hypothetical protein chrXII: 3984434-3 TGME 49, (ii) dual specificity protein phosphatase, catalytic domain TGME 49 and (iii) NADPH-cytochrome p450 reductase TGME 49. Thus, 2-DE approach followed by Western blotting has enabled the identification of five potential infection markers for the diagnosis of toxoplasmosis: three are parasite-specific proteins and two are host-specific proteins.

Identification of Host-Immune Response Protein Candidates in the Sera of Human Oral Squamous Cell Carcinoma Patients

“…In addition, five non-host factors were detected, including proteins from A. lwoffii, B. multivorans, M. xanthus, L. hongkogenisis , and S. salivarius . As previously suggested [88] , combined proteomic and serological approaches, such as the one used in the present study, can reflect numerous events occurring in vivo simultaneously due to the fact that patient serum is complex and consists of many proteins. Our data indicate that immunoproteomics approach could be a promising application for biomarker discovery and disease progression.…”

Identification of circulating biomarkers in sera of Plasmodium knowlesi-infected malaria patients – comparison against Plasmodium vivax infection

“…Proteomic analysis by 2-DE has been widely used to identify specific bacterial or viral antigens during vaccine and/or serodiagnostic test development [ 23 ]. Nevertheless, there have been few proteomic studies focused at elucidating pathogenic mechanisms or identifying potential diagnostic markers in malaria [ 24 - 26 ].…”

Characterization of Soluble and Membrane-Bound Proteins of Toxoplasma gondii as Diagnostic Markers of Infection

“…In order to select proteins that present strong similarity with T. gondii sequences and in the same time the lowest similarity with any non-T. gondii sequences, we used a ToxoDB database search with MASCOT followed by a NCBI non-redundant protein database to deduce sequence homology of these 7 proteins against their closest relatives (Hammondia, Neospora, and Eimeria) and other organisms including humans [14,22].…”

“…Immunoproteomics combining one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D-SDS-PAGE) followed by immunoblot and nano-liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) analysis is a powerful tool for the identification of proteins with diagnostic value [6,[12][13][14].…”