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Sabukunze S, Gu H, Zhao L, Jia H, Guo H. Comparison of the performance of SAG2, GRA6, and GRA7 for serological diagnosis of Toxoplasma gondii infection in cats. Front Vet Sci 2024; 11:1423581. [PMID: 38898997 PMCID: PMC11186378 DOI: 10.3389/fvets.2024.1423581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024] Open
Abstract
Toxoplasmosis is an important zoonotic disease caused by Toxoplasma gondii that can infect almost all warm-blooded animals worldwide, including humans. The high prevalence of T. gondii infection and its ability to cause serious harm to humans and animals, especially immunodeficient individuals, make it a key public health issue. Accurate diagnostic tools with high sensitivity are needed for controlling T. gondii infection. In the current study, we compared the performance of recombinant SAG2, GRA6, and GRA7 in ELISA for the serological diagnosis of T. gondii infection in cats. We further investigated the antigenicity of recombinant dense granule protein 3 (rGRA3), rGRA5, rGRA8, and rSRS29A expressed in a plant-based, cell-free expression system for detecting antibodies in T. gondii-infected cats. In summary, our data suggest that GRA7 is more sensitive than the other two antigens for the serodiagnosis of T. gondii infection in cats, and GRA3 expressed in the cell-free system is also a priming antigen in serological tests for detecting T. gondii infection in cats.
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Affiliation(s)
- Serges Sabukunze
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Haorong Gu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Lin Zhao
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Honglin Jia
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
- Heilongjiang Research Center for Veterinary Biopharmaceutical Technology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Huanping Guo
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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Ferra BT, Chyb M, Sołowińska K, Holec-Gąsior L, Skwarecka M, Baranowicz K, Gatkowska J. The Development of Toxoplasma gondii Recombinant Trivalent Chimeric Proteins as an Alternative to Toxoplasma Lysate Antigen (TLA) in Enzyme-Linked Immunosorbent Assay (ELISA) for the Detection of Immunoglobulin G (IgG) in Small Ruminants. Int J Mol Sci 2024; 25:4384. [PMID: 38673969 PMCID: PMC11049947 DOI: 10.3390/ijms25084384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/10/2024] [Accepted: 04/13/2024] [Indexed: 04/28/2024] Open
Abstract
This study presents an evaluation of seventeen newly produced recombinant trivalent chimeric proteins (containing the same immunodominant fragment of SAG1 and SAG2 of Toxoplasma gondii antigens, and an additional immunodominant fragment of one of the parasite antigens, such as AMA1, GRA1, GRA2, GRA5, GRA6, GRA7, GRA9, LDH2, MAG1, MIC1, MIC3, P35, and ROP1) as a potential alternative to the whole-cell tachyzoite lysate (TLA) used in the detection of infection in small ruminants. These recombinant proteins, obtained by genetic engineering and molecular biology methods, were tested for their reactivity with specific anti-Toxoplasma IgG antibodies contained in serum samples of small ruminants (192 samples of sheep serum and 95 samples of goat serum) using an enzyme-linked immunosorbent assay (ELISA). The reactivity of six recombinant trivalent chimeric proteins (SAG1-SAG2-GRA5, SAG1-SAG2-GRA9, SAG1-SAG2-MIC1, SAG1-SAG2-MIC3, SAG1-SAG2-P35, and SAG1-SAG2-ROP1) with IgG antibodies generated during T. gondii invasion was comparable to the sensitivity of TLA-based IgG ELISA (100%). The obtained results show a strong correlation with the results obtained for TLA. This suggests that these protein preparations may be a potential alternative to TLA used in commercial tests and could be used to develop a cheaper test for the detection of parasite infection in small ruminants.
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Affiliation(s)
- Bartłomiej Tomasz Ferra
- Department of Tropical Parasitology, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdańsk, Powstania Styczniowego 9B, 81-519 Gdynia, Poland;
| | - Maciej Chyb
- Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (M.C.); (J.G.)
- Bio-Med-Chem Doctoral School of the University of Lodz and Lodz Institutes of the Polish Academy of Sciences, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland
| | - Karolina Sołowińska
- Department of Molecular Biotechnology and Microbiology, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland; (K.S.); (L.H.-G.)
| | - Lucyna Holec-Gąsior
- Department of Molecular Biotechnology and Microbiology, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland; (K.S.); (L.H.-G.)
| | - Marta Skwarecka
- Institute of Biotechnology and Molecular Medicine, Kampinoska 25, 80-180 Gdansk, Poland;
| | - Karolina Baranowicz
- Department of Tropical Parasitology, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdańsk, Powstania Styczniowego 9B, 81-519 Gdynia, Poland;
| | - Justyna Gatkowska
- Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (M.C.); (J.G.)
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Rahman SU, Akbar H, Shabbir MZ, Ullah U, Rashid MI. Newly optimized ELISA kit and LAT reveal significantly higher seroprevalence in sheep raised in agro-ecological zone as against range-ecological zone, with a significant association of meteorological parameters. PLoS One 2023; 18:e0290374. [PMID: 38051753 DOI: 10.1371/journal.pone.0290374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 08/07/2023] [Indexed: 12/07/2023] Open
Abstract
BACKGROUND Toxoplasma gondii is a zoonotic and foodborne intracellular parasite capable of inducing congenital infections, stillbirths and abortions in humans and animals, globally. The consumption of undercooked or raw mutton is "one of the vital risks" for acquiring toxoplasmosis: an asymptomatic condition in healthy persons, while life-threatening in immunodeficient individuals like "HIV/AIDS" patients. OBJECTIVES The current study has multiple objectives: to optimize a newly ELISA kit for Sheep, to find out the seroprevalence of ovine toxoplasmosis of two ecological zones of the Punjab, Pakistan through LAT and newly Optimized Sheep ELISA kit, to do the comparison of efficacies of various tests (LAT with newly Optimized ELISA kit and newly Optimized ELISA kit with commercial ELISA kit) and to determine the different meteorological parameters as the risk factors for T. gondii infection in sheep. METHODS A cross-sectional study was conducted on 400 sheep sera, 200 were collected from sheep raised on open grazing system by local farmers in the adjoining areas of Civil Veterinary Dispensaries (CVDs) of range-ecological zone i.e. tehsil Kot Chutta (Dera Ghazi khan). Similarly, the remaining 200 were collected from agro-ecological zone i.e. tehsil Sharaqpur (Sheikhupura), to evaluate the comparative efficacy of LAT with optimized ELISA kit and newly optimized ELISA kit with commercial ELISA kit. FINDINGS The newly ELISA kit optimized against a commercial ELISA kit was found to have 100% sensitivity, 97.6% specificity with 98% Positive Predictive Value, 100% Negative Predictive Value, Cut off value = 0.505, 28.28 LR+, 0.0104 LR-, and 2719.23 DOR. Seroprevalence of toxoplasmosis was detected significantly (P < 0.01; χ2) higher in Sharaqpur (44.5% by LAT; 35.5% by ELISA) as compared to that in Kot Chutta (39.5% by LAT; 31% by ELISA). The highest seroprevalence was seen in the sheep of the 1-2 years age group (P < 0.01; χ2), whereas the lowest in the oldest animals (≥ 4 years). Investigation of meteorological data of both the regions reveals that the zone with higher seroprevalence has relatively higher rainfall, higher humidity, lower environmental temperatures, and higher altitude as the critical factors, potentially behind the significant difference seen in seroprevalence level. The partial correlation of both tests (newly optimized ELISA kit and LAT) was 0.991 at maximum temperature in Sharaqpur while it was 0.981 in Kot Chutta. INTERPRETATION A novel significant correlation was found between the meteorological parameters (relative humidity, minimum, maximum, and average temperatures) divided into yearly units of both the ecological zones, and year-wise seroprevalence (birth years of age-wise groups) of the corresponding regions. We hypothesize that such environmental conditions increase the risk of toxoplasmosis in grazing sheep, owing to a more favorable environment for coccidian oocyst survival. The ELISA kit optimized in this study will be helpful for the detection of seroprevalence of ovine toxoplasmosis in other ecological zones of Pakistan as well as of any other country in the world. More studies are recommended involving regions from other ecological zones of Pakistan to further explore the seroprevalence of ovine toxoplasmosis and to ratify the novel correlation of meteorological parameters with seroprevalence.
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Affiliation(s)
- Sarfraz Ur Rahman
- Faculty of Veterinary Science, Department of Parasitology, Molecular Parasitology Laboratory, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Haroon Akbar
- Faculty of Veterinary Science, Department of Parasitology, Molecular Parasitology Laboratory, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | | | - Ubaid Ullah
- Faculty of Veterinary Science, Department of Parasitology, Molecular Parasitology Laboratory, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Muhammad Imran Rashid
- Faculty of Veterinary Science, Department of Parasitology, Molecular Parasitology Laboratory, University of Veterinary and Animal Sciences, Lahore, Pakistan
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Li X, Yuan W, He T, Guo R, Du X, He Y, Li X, El-Ashram S, Al-Olayan EM, Yang N, Sang X. Boosting Mouse Defense against Lethal Toxoplasma gondii Infection with Full-Length and Soluble SAG1 Recombinant Protein. Vaccines (Basel) 2023; 11:1678. [PMID: 38006011 PMCID: PMC10675489 DOI: 10.3390/vaccines11111678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/23/2023] [Accepted: 10/31/2023] [Indexed: 11/26/2023] Open
Abstract
Toxoplasmosis is a major worldwide protozoan zoonosis. The surface antigen 1 (SAG1) of Toxoplasma gondii (T. gondii) has always been recognized as an ideal vaccine candidate antigen. However, the intact and soluble SAG1 protein is usually difficult to acquire in vitro, which is unfavorable for employing the recombinant protein as a vaccine candidate antigen. In the present study, we obtained the full-length SAG1 recombinant protein in soluble form by Escherichia coli Transetta (DE3) cells under optimized expression conditions. The immunogenicity and protective ability of this recombinant protein against T. gondii acute infection were evaluated in a mouse model. Monitoring changes in serum antibody levels and types, the presence of cytokines, and the rate of lymphocyte proliferation in vaccinated mice were used to assess humoral and cellular immune responses. Additional assessments were performed to determine the protective potency of the recombinant protein in combating T. gondii RH tachyzoites. It was found that the titers of both IgG2a and IgG2b were considerably greater in the immunized mice compared to the titers of IgG1 and IgG3. The levels of Th1-type cytokines (IFN-γ, IL-12p70, IL-2, and TNF-α) and Th2-type cytokines (IL-10) significantly increased when splenocytes from immunological group mice were treated with T. gondii lysate antigen. Compared to the control group, a recombinant protein substantially increased the longevity of infected mice, with an average death time prolonged by 14.50 ± 0.34 days (p < 0.0001). These findings suggest that the full-length and soluble SAG1 recombinant protein produced potent immune responses in mice and could be a preferred subunit vaccine candidate for T. gondii, offering a feasible option for vaccination against acute toxoplasmosis.
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Affiliation(s)
- Xiang Li
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Wei Yuan
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Ting He
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Ruiying Guo
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Xiuxian Du
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Yanhong He
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Xuan Li
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Saeed El-Ashram
- Zoology Department, Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt;
| | - Ebtesam M. Al-Olayan
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Na Yang
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Xiaoyu Sang
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China; (X.L.); (W.Y.); (T.H.); (R.G.); (X.D.); (Y.H.); (X.L.)
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
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Akbar H, Shabbir MZ, Ullah U, Rashid MI. Serological Investigation of Bovine Toxoplasmosis Using Commercial and Indigenous ELISA Kits While Validating Cattle Toxo IgG ELISA Kit. Animals (Basel) 2022; 12:ani12162067. [PMID: 36009657 PMCID: PMC9405383 DOI: 10.3390/ani12162067] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/23/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Toxoplasmosis is a zoonotic disease caused by T. gondii infection. The main aims of this study were to assess the seropositivity to toxoplasmosis of an exotic breed of cattle (n = 400) from different farms using the Latex Agglutination Test, validate the Cattle Toxo IgG ELISA kit with the help of the commercially available ELISA kit and compare the efficacy of the LAT and Cattle Toxo IgG ELISA kit for assessing seropositivity of cattle to toxoplasmosis. Four hundred cattle sera were collected from an exotic breed of cattle in Pakistan. These sera were evaluated through an LAT and Cattle Toxo IgG ELISA kit. Of 400 samples, 90 were elected and screened through a commercially available ELISA kit. The sensitivity and specificity of the Cattle Toxo IgG ELISA kit came out to be 100% and 96.15%, and in LAT, it was found as 26.31% and 61.53%, respectively. The Cattle Toxo IgG ELISA kit revealed 29.75% (119/400) seropositivity, 6% less than that found through LAT. The results of this study show that Cattle Toxo IgG ELISA kit is a highly accurate and reliable serodiagnostic tool to diagnose bovine toxoplasmosis. Abstract Toxoplasma gondii is a protozoan parasite that causes toxoplasmosis in warm-blooded vertebrates, globally. The main aims of this study were to assess the seropositivity to toxoplasmosis of an exotic breed of cattle (n = 400) from different farms using the Latex Agglutination Test and validate Cattle Toxo IgG ELISA kit. Of a total of 400 cattle sera that were evaluated by LAT, 143 (35.75%) were found positive. Based on these data, 90 samples (n = 60 seronegative by LAT; n = 30 seropositive by LAT) were elected for screening through a commercially available ELISA kit. The same 90 samples were screened through a Cattle Toxo IgG ELISA kit for validation purposes. Of 90 samples, 40 were seropositive in the Cattle Toxo IgG ELISA kit (100% sensitivity), and 38 were seropositive in a commercially available ELISA kit. All 50 samples in the Cattle Toxo IgG ELISA kit (96.15% specificity) were also seronegative in the commercially available ELISA kit. Hence, the sensitivity and specificity of the Cattle Toxo IgG ELISA kit came out to be 100% and 96.15%, and in LAT, it was found as 26.31% and 61.53%, respectively. Therefore, the Cattle Toxo IgG ELISA kit is a highly reliable serodiagnostic tool to diagnose bovine toxoplasmosis.
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Affiliation(s)
- Haroon Akbar
- Department of Parasitology, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
- Correspondence: (S.-u.-R.); (H.A.)
| | - Muhammad Zubair Shabbir
- Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
| | - Ubaid Ullah
- Department of Parasitology, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
| | - Muhammad Imran Rashid
- Department of Parasitology, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
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Development of Human Toxo IgG ELISA Kit, and False-Positivity of Latex Agglutination Test for the Diagnosis of Toxoplasmosis. Pathogens 2021; 10:pathogens10091111. [PMID: 34578144 PMCID: PMC8465318 DOI: 10.3390/pathogens10091111] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 12/19/2022] Open
Abstract
Toxoplasma gondii is an intracellular zoonotic parasite that causes infection in a wide range of warm-blooded animals and humans. The main aim of this study was to assess the diagnostic value of the recombinant SAG1 antigen (rSAG1) for T. gondii-IgG screening through the Human Toxo IgG ELISA Kit (K). The rSAG1 was expressed in E. coli (DE3), and it was purified through metal-affinity chromatography. The rSAG1 was confirmed by immunoblotting, and it had a band on 35 kDa. Total of 400 human sera were tested by LAT and K. One hundred and twenty-two (30.5%) sera were found positive by LAT and eighty-nine (22.25%) sera were found positive by K. Out of 400 samples, 80 were selected to evaluate the performance of K through commercial Toxoplasma gondii IgG ELISA Kit (C). Out of 80 human sera, 55 (68.75%) were found positive, 25 (31.25%) were found negative by K and C, respectively. The cut-off value for K was 0.398 and it was calculated through the receiver operator characteristic curve. The ELISA plates were coated at optimized concentration of rSAG1 = 0.125 µg/mL, and the test was performed by diluting the sera at 1:50. The sensitivity and specificity of K were observed to be 98.5% and 100%, respectively. The six sera (K−L+) were found positive through LAT and these human sera were later evaluated by Western blot analysis. These sera did not produce a band equivalent to 35 kDa on WB analysis thus, LAT produced false-positive results.
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Klein S, Stern D, Seeber F. Expression of in vivo biotinylated recombinant antigens SAG1 and SAG2A from Toxoplasma gondii for improved seroepidemiological bead-based multiplex assays. BMC Biotechnol 2020; 20:53. [PMID: 33023547 PMCID: PMC7542104 DOI: 10.1186/s12896-020-00646-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 09/15/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Few bead-based multiplex assays have been described that detect antibodies against the protozoan parasite Toxoplasma gondii in large-scale seroepidemiological surveys. Moreover, each multiplex assay has specific variations or limitations, such as the use of truncated or fusion proteins as antigens, potentially masking important epitopes. Consequently, such an assay must be developed by interested groups as none is commercially available. RESULTS We report the bacterial expression and use of N-terminal fusion-free, soluble, in vivo biotinylated recombinant surface antigens SAG1 and SAG2A for the detection of anti-T. gondii IgG antibodies. The expression system relies on three compatible plasmids. An expression construct produces a fusion of maltose-binding protein with SAG1 (or SAG2A), separated by a TEV protease cleavage site, followed by a peptide sequence recognized by E. coli biotin ligase BirA (AviTag), and a terminal six histidine tag for affinity purification. TEV protease and BirA are encoded on a second plasmid, and their expression leads to proteolytic cleavage of the fusion protein and a single biotinylated lysine within the AviTag by BirA. Correct folding of the parasite proteins is dependent on proper disulfide bonding, which is facilitated by a sulfhydryl oxidase and a protein disulfide isomerase, encoded on the third plasmid. The C-terminal biotinylation allowed the oriented, reproducible coupling of the purified surface antigens to magnetic Luminex beads, requiring only minute amounts of protein per determination. We showed that an N-terminal fusion partner such as maltose-binding protein negatively influenced antibody binding, confirming that access to SAG1's N-terminal epitopes is important for antibody recognition. We validated our bead-based multiplex assay with human sera previously tested with commercial diagnostic assays and found concordance of 98-100% regarding both, sensitivity and specificity, even when only biotinylated SAG1 was used as antigen. CONCLUSIONS Our recombinant in vivo-biotinylated T. gondii antigens offer distinct advantages compared to previously described proteins used in multiplex serological assays for T. gondii. They offer a cheap, specific and sensitive alternative to either parasite lysates or eukaryotic-cell expressed SAG1/SAG2A for BBMA and other formats. The described general expression strategy can also be used for other antigens where oriented immobilization is key for sensitive recognition by antibodies and ligands.
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Affiliation(s)
- Sandra Klein
- FG 16 - Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353, Berlin, Germany
| | - Daniel Stern
- ZBS 3 - Biological Toxins, Robert Koch Institute, 13353, Berlin, Germany
| | - Frank Seeber
- FG 16 - Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353, Berlin, Germany.
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Ybañez RHD, Ybañez AP, Nishikawa Y. Review on the Current Trends of Toxoplasmosis Serodiagnosis in Humans. Front Cell Infect Microbiol 2020; 10:204. [PMID: 32457848 PMCID: PMC7227408 DOI: 10.3389/fcimb.2020.00204] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/16/2020] [Indexed: 12/17/2022] Open
Abstract
Toxoplasmosis is a widely distributed zoonotic infection caused by the obligate intracellular apicomplexan parasite Toxoplasma gondii. It is mainly transmitted through the ingestion of oocysts shed by an infected cat acting as its definitive host. The key to effective control and treatment of toxoplasmosis is prompt and accurate detection of T. gondii infection. Several laboratory diagnostic methods have been established, including the most commonly used serological assays such as the dye test (DT), direct or modified agglutination test (DAT/MAT), indirect hemagglutination test (IHA), latex agglutination test (LAT), indirect immunofluorescent test (IFAT), enzyme-linked immunosorbent assays (ELISA), immunochromatographic tests (ICT), and the western blot. Nonetheless, creating specific and reliable approaches for serodiagnosis of T. gondii infection, and differentiating between acute and chronic phases of infection remains a challenge. This review provides information on the current trends in the serodiagnosis of human toxoplasmosis. It highlights the advantages of the use of recombinant proteins for serological testing and provides insight into the possible future direction of these methods.
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Affiliation(s)
- Rochelle Haidee D. Ybañez
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Adrian P. Ybañez
- Institute of Molecular Parasitology and Protozoan Diseases at Main and College of Veterinary Medicine, Cebu Technological University, Cebu City, Philippines
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
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Holec-Gąsior L, Ferra B, Grąźlewska W. Toxoplasma gondii Tetravalent Chimeric Proteins as Novel Antigens for Detection of Specific Immunoglobulin G in Sera of Small Ruminants. Animals (Basel) 2019; 9:ani9121146. [PMID: 31847285 PMCID: PMC6940879 DOI: 10.3390/ani9121146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/10/2019] [Accepted: 12/10/2019] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Toxoplasma gondii infection leads to large economic losses in the sheep and goat industry worldwide and is considered to be one of the main causes of infectious ovine and caprine abortion. Moreover, in countries where sheep and goat meat are frequently consumed, T. gondii infection in small ruminants may also pose a public health risk. Due to its medical and veterinary importance, it is essential to study the seroprevalence of T. gondii infection among farm animals and humans. This requires the development of new, low-cost diagnostic methods such as enzyme immunoassays based on recombination antigens. Thus, the study aimed to evaluate the reactivity of four different tetravalent chimeric proteins containing immunodominant regions from the AMA1 (apical membrane antigen 1), SAG2 (surface antigen 2), GRA1 (dense granule antigen 1), GRA2 (dense granule antigen 2), and ROP1 (rhoptry antigen 1) T. gondii antigens with specific IgG from the sera of small ruminants. The results demonstrate that an IgG ELISA (enzyme-linked immunosorbent assay) based on one of these chimeric proteins (AMA1-SAG2-GRA1-ROP1) may be a useful test for the determination of T. gondii infection in small ruminants. Abstract The detection of Toxoplasma gondii infection in small ruminants has important significance for public health and veterinary medicine. This study, for the first time, describes the reactivity of four tetravalent chimeric proteins (AMA1N-SAG2-GRA1-ROP1, AMA1C-SAG2-GRA1-ROP1, AMA1-SAG2-GRA1-ROP1, and SAG2-GRA1-ROP1-GRA2) containing immunodominant regions from the AMA1 (apical membrane antigen 1), SAG2 (surface antigen 2), GRA1 (dense granule antigen 1), GRA2 (dense granule antigen 2), and ROP1 (rhoptry antigen 1) with specific IgG antibodies from the sera of small ruminants with the use of an indirect enzyme-linked immunosorbent assay (ELISA). The reactivity of individual chimeric antigens was analyzed in relation to the results obtained in IgG ELISA based on a Toxoplasma lysate antigen (TLA). All chimeric proteins were characterized by high specificity (between 96.39% to 100%), whereas the sensitivity of the IgG ELISAs was variable (between 78.49% and 96.77%). The highest sensitivity was observed in the IgG ELISA test based on the AMA1-SAG2-GRA1-ROP1. These data demonstrate that this chimeric protein can be a promising serodiagnostic tool for T. gondii infection in small ruminants.
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Ferra BT, Holec-Gąsior L, Gatkowska J, Dziadek B, Dzitko K, Grąźlewska W, Lautenbach D. The first study on the usefulness of recombinant tetravalent chimeric proteins containing fragments of SAG2, GRA1, ROP1 and AMA1 antigens in the detection of specific anti-Toxoplasma gondii antibodies in mouse and human sera. PLoS One 2019; 14:e0217866. [PMID: 31170254 PMCID: PMC6553757 DOI: 10.1371/journal.pone.0217866] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/20/2019] [Indexed: 12/22/2022] Open
Abstract
This study presents an evaluation of four tetravalent recombinant chimeric proteins containing fragments of the Toxoplasma gondii antigens, SAG2, GRA1, ROP1 and AMA1, as potential replacements of a the soluble, whole-cell tachyzoite lysate (TLA) used in serological assays. Recombinant chimeric proteins (SAG2-GRA1-ROP1-AMA1N, AMA1N-SAG2-GRA1-ROP1, AMA1C-SAG2-GRA1-ROP1, and AMA1-SAG2-GRA1-ROP1) obtained by genetic engineering were tested for their reactivity with specific IgM and IgG antibodies from sera of experimentally infected mice and humans with T. gondii infection using an enzyme-linked immunosorbent assay (ELISA). In total 192 serum samples from patients with acquired T. gondii infection and 137 sera from seronegative individuals were examined. The reactivity of chimeric antigens with antibodies generated during T. gondii invasion was measured and compared to the results obtained in assays based on whole-cell Toxoplasma antigen. Chimeric proteins proved effective in differentiation between T. gondii-infected and uninfected individuals (100% sensitivity and specificity in the IgG ELISAs) which shows their potential usefulness as a replacements for TLA in standardized commercial tests for the serodiagnosis of toxoplasmosis. In addition, the chimeric proteins were tested for use in avidity determination. Obtained results were comparable to those of the corresponding commercial assays, suggesting the utility of these proteins for avidity assessment. Furthermore, this study demonstrated that the AMA1-SAG2-GRA1-ROP1 chimeric protein has the potential to distinguish specific antibodies from serum samples of individuals with the early and chronic phase of T. gondii infection.
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Affiliation(s)
- Bartłomiej Tomasz Ferra
- Department of Molecular Biotechnology and Microbiology, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk, Poland
- * E-mail:
| | - Lucyna Holec-Gąsior
- Department of Molecular Biotechnology and Microbiology, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk, Poland
| | - Justyna Gatkowska
- Department of Immunoparasitology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Bożena Dziadek
- Department of Immunoparasitology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Katarzyna Dzitko
- Department of Immunoparasitology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Weronika Grąźlewska
- Department of Molecular Biotechnology and Microbiology, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk, Poland
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Rostami A, Karanis P, Fallahi S. Advances in serological, imaging techniques and molecular diagnosis of Toxoplasma gondii infection. Infection 2018; 46:303-315. [PMID: 29330674 DOI: 10.1007/s15010-017-1111-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 12/22/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Toxoplasmosis is worldwide distributed zoonotic infection disease with medical importance in immunocompromised patients, pregnant women and congenitally infected newborns. Having basic information on the traditional and new developed methods is essential for general physicians and infectious disease specialists for choosing a suitable diagnostic approach for rapid and accurate diagnosis of the disease and, consequently, timely and effective treatment. METHODS We conducted English literature searches in PubMed from 1989 to 2016 using relevant keywords and summarized the recent advances in diagnosis of toxoplasmosis. RESULTS Enzyme-linked immunosorbent assay (ELISA) was most used method in past century. Recently advanced ELISA-based methods including chemiluminescence assays (CLIA), enzyme-linked fluorescence assay (ELFA), immunochromatographic test (ICT), serum IgG avidity test and immunosorbent agglutination assays (ISAGA) have shown high sensitivity and specificity. Recent studies using recombinant or chimeric antigens and multiepitope peptides method demonstrated very promising results to development of new strategies capable of discriminating recently acquired infections from chronic infection. Real-time PCR and loop-mediated isothermal amplification (LAMP) are two recently developed PCR-based methods with high sensitivity and specificity and could be useful to early diagnosis of infection. Computed tomography, magnetic resonance imaging, nuclear imaging and ultrasonography could be useful, although their results might be not specific alone. CONCLUSION This review provides a summary of recent developed methods and also attempts to improve their sensitivity for diagnosis of toxoplasmosis. Serology, molecular and imaging technologies each has their own advantages and limitations which can certainly achieve definitive diagnosis of toxoplasmosis by combining these diagnostic techniques.
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Affiliation(s)
- Ali Rostami
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Panagiotis Karanis
- Qinghai Academy of Animal Science and Veterinary Medicine, Qinghai University, Xining, China
| | - Shirzad Fallahi
- Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran. .,Department of Medical Parasitology and Mycology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran.
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Toxoplasma gondii : Immunological response of sheep to injections of recombinant SAG1, SAG2, GRA1 proteins coupled to the non-toxic microparticle muramyl dipeptide. Small Rumin Res 2017. [DOI: 10.1016/j.smallrumres.2017.03.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Sudan V, Tewari AK, Singh H. Serodiagnosis of Toxoplasma gondii infection in bovines from Kerala, India using a recombinant surface antigen 1 ELISA. Biologicals 2015; 43:250-5. [DOI: 10.1016/j.biologicals.2015.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/03/2015] [Accepted: 04/08/2015] [Indexed: 11/25/2022] Open
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Ferra B, Holec-Gąsior L, Kur J. A new Toxoplasma gondii chimeric antigen containing fragments of SAG2, GRA1, and ROP1 proteins-impact of immunodominant sequences size on its diagnostic usefulness. Parasitol Res 2015; 114:3291-9. [PMID: 26055987 PMCID: PMC4537703 DOI: 10.1007/s00436-015-4552-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 05/21/2015] [Indexed: 11/28/2022]
Abstract
This study presents the first evaluation of new Toxoplasma gondii recombinant chimeric antigens containing three immunodominant regions of SAG2, GRA1, and one of two ROP1 fragments differing in length for the serodiagnosis of human toxoplasmosis. The recombinant chimeric antigens SAG2-GRA1-ROP1L (with large fragment of ROP1, 85–396 amino acid residues) and SAG2-GRA1-ROP1S (with a small fragment of ROP1, 85–250 amino acid residues) were obtained as fusion proteins containing His6-tags at both ends using an Escherichia coli expression system. The diagnostic utility of these chimeric antigens was determined using the enzyme-linked immunosorbent assay (ELISA) for the detection of specific anti-T. gondii immunoglobulin G (IgG). The IgG ELISA results obtained for the chimeric antigens were compared to those obtained for the use of Toxoplasma lysate antigen (TLA) and for a mixture of recombinant antigens containing rSAG2, rGRA1, and rROP1. The sensitivity of the IgG ELISA was similar for the SAG2-GRA1-ROP1L chimeric antigen (100 %), the mixture of three proteins (99.4 %) and the TLA (97.1 %), whereas the sensitivity of IgG ELISA with the SAG2-GRA1-ROP1S chimeric antigen was definitely lower, reaching 88.4 %. In conclusion, this study shows that SAG2-GRA1-ROP1L chimeric antigen can be useful for serodiagnosis of human toxoplasmosis with the use of the IgG ELISA assay. Therefore, the importance of proper selection of protein fragments for the construction of chimeric antigen with the highest reactivity in ELISA test is demonstrated.
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Affiliation(s)
- Bartłomiej Ferra
- Department of Molecular Biotechnology and Microbiology, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233, Gdańsk, Poland
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Ferra B, Holec-Gąsior L, Kur J. Serodiagnosis of Toxoplasma gondii infection in farm animals (horses, swine, and sheep) by enzyme-linked immunosorbent assay using chimeric antigens. Parasitol Int 2015; 64:288-94. [PMID: 25817245 DOI: 10.1016/j.parint.2015.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/16/2015] [Accepted: 03/17/2015] [Indexed: 10/23/2022]
Abstract
Toxoplasma gondii infects all warm-blooded animals including humans, causing serious public health problems and great economic loss in the animal husbandry. Commonly used serological tests for diagnosis of toxoplasmosis involve preparation of whole Toxoplasma lysate antigen (TLA) from tachyzoites. The production of this antigen is associated with high costs and lengthy preparation and the possibility of staff infection. There are also some difficulties in the standardization of such tests. One approach in order to improve the diagnosis of T. gondii infection is to use recombinant chimeric antigens in place of the TLA, which was confirmed by studies in the serodiagnosis of toxoplasmosis in humans. In this paper, we assess, for the first time, the diagnostic utility of five T. gondii recombinant chimeric antigens (MIC1-MAG1-SAG1S, SAG1L-MIC1-MAG1, SAG2-GRA1-ROP1S, SAG2-GRA1-ROP1L, and GRA1-GRA2-GRA6) in immunoglobulin G (IgG) enzyme-linked immunosorbent assays (IgG ELISAs) with sera from three different groups of livestock animals (horses, pigs, and sheep). The reactivity of individual chimeric antigens was analyzed in relation to the results obtained in IgG ELISAs based on a mixture of three antigens (M1: rSAG1+rMIC1+rMAG1, M2: rSAG2+rGRA1+rROP1, and M3: rGRA1+rGRA2+rGRA6) and referenced to TLA. All chimeric antigens were characterized by high specificity (100%), and the sensitivity of the IgG ELISAs based on chimeric antigens was variable (between 28.4% and 100%) and mainly dependent on the animal species. The chimeric antigens were generally more reactive than mixtures of three antigens. The most effective for the diagnosis of toxoplasmosis was SAG2-GRA1-ROP1L, which can detect specific anti-T. gondii antibodies in 100%, 93.8%, and 100% of positive serum samples from horses, pigs, and sheep, respectively. The present study shows that recombinant chimeric antigens can be successfully used to diagnose T. gondii infection in farm animals, and can replace the commonly used TLA.
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Affiliation(s)
- Bartłomiej Ferra
- Faculty of Chemistry, Department of Molecular Biotechnology and Microbiology, Gdańsk University of Technology, Narutowicza 11/12 Street, Gdańsk 80-233, Poland
| | - Lucyna Holec-Gąsior
- Faculty of Chemistry, Department of Molecular Biotechnology and Microbiology, Gdańsk University of Technology, Narutowicza 11/12 Street, Gdańsk 80-233, Poland
| | - Józef Kur
- Faculty of Chemistry, Department of Molecular Biotechnology and Microbiology, Gdańsk University of Technology, Narutowicza 11/12 Street, Gdańsk 80-233, Poland.
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The optimal mixture of Toxoplasma gondii recombinant antigens (GRA1, P22, ROP1) for diagnosis of ovine toxoplasmosis. Vet Parasitol 2014; 206:146-52. [DOI: 10.1016/j.vetpar.2014.09.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 09/13/2014] [Accepted: 09/20/2014] [Indexed: 11/16/2022]
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Allahyari M, Mohabati R, Babaie J, Amiri S, Siavashani ZJ, Zare M, Sadeghiani G, Golkar M. Production of in-vitro refolded and highly antigenic SAG1 for development of a sensitive and specific Toxoplasma IgG ELISA. J Immunol Methods 2014; 416:157-66. [PMID: 25437069 DOI: 10.1016/j.jim.2014.11.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 10/20/2014] [Accepted: 11/21/2014] [Indexed: 01/23/2023]
Abstract
Recombinant antigens are increasingly applied to replace native antigens in serological tests. Surface antigen 1 (SAG1) is a highly immunogenic antigen and probably represents the most explored and used antigen of Toxoplasma gondii for development of serological test kits. The presence of six disulfide bridges in its structure makes SAG1 a highly conformational protein. In fact, antigenicity of SAG1 is greatly dependent on proper disulfide bonding and folding. In-vitro refolding of SAG1 inclusion bodies, produced in Escherichia coli, was reported to result in soluble and antigenic protein. We produced SAG1 in E. coli and highly purified it by a single denaturing immobilized metal affinity chromatography. Refolding of denatured SAG1 was performed by (a) dialysis in the presence of reduced/oxidized glutathione, (b) drop-wise dilution and (c) drop-wise dilution in the presence of CuSo4. Refolding in the presence of oxido-shuffling reagent was much more efficient in producing presumably correctly-folded and highly antigenic SAG1 as demonstrated by non-reducing SDS-gel electrophoresis, ELISA, Western blotting and reversed-phase HPLC. An IgG ELISA developed using SAG1 refolded in the presence of oxido-shuffling reagent displayed high sensitivity and specificity for detection of Toxoplasma IgG antibodies in pregnant women.
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Affiliation(s)
- Mojgan Allahyari
- Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran; Recombinant Protein Production Department, Research and Production Complex, Pasteur Institute of Iran, Karaj, Iran
| | - Reyhaneh Mohabati
- Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Jalal Babaie
- Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Samira Amiri
- Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Zahra Jafari Siavashani
- Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Mehrak Zare
- Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Ghazaleh Sadeghiani
- Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Majid Golkar
- Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran.
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Yang Z, Ahn HJ, Nam HW. High expression of water-soluble recombinant antigenic domains of Toxoplasma gondii secretory organelles. THE KOREAN JOURNAL OF PARASITOLOGY 2014; 52:367-76. [PMID: 25246715 PMCID: PMC4170032 DOI: 10.3347/kjp.2014.52.4.367] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/10/2014] [Accepted: 06/15/2014] [Indexed: 12/05/2022]
Abstract
Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with GRA225-105, GRA339-138, ROP2324-561, and MIC21-284 domains had respectively higher value of IgG avidity. The rGST-GRA225-105 and rGST-GRA339-138 were soluble, while rGST-ROP2324-561 and rGST-MIC21-284 were not. GRA231-71, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The rGST-GRA231-71-ROP2324-561, a chimeric protein, appeared to be soluble. Moreover, rGST-GRA231-71-MIC21-284 was also soluble and had higher IgG avidity comparing to rGST-MIC21-284. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1.
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Affiliation(s)
- Zhaoshou Yang
- Department of Parasitology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
| | - Hye-Jin Ahn
- Department of Parasitology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
| | - Ho-Woo Nam
- Department of Parasitology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
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Toxoplasma gondii recombinant antigens as tools for serodiagnosis of human toxoplasmosis: current status of studies. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1343-51. [PMID: 23784855 DOI: 10.1128/cvi.00117-13] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Toxoplasma gondii is a parasitic protozoan which is the cause of toxoplasmosis. Although human toxoplasmosis in healthy adults is usually asymptomatic, serious disease can occur in the case of congenital infections and immunocompromised individuals. Furthermore, despite the exact recognition of its etiology, it still presents a diagnostic problem. Diagnosis of toxoplasmosis is mainly based on the results of serological tests detecting anti-T. gondii-specific antibodies in the patient's serum sample. The specificities and sensitivities of serology tests depend mostly on the diagnostic antigen(s) used. Most of the commercial serological kits currently available are based on Toxoplasma lysate antigens (TLAs). In recent years, many studies showed that recombinant antigenic proteins of T. gondii may be an alternative source of antigens which are very useful for the serodiagnosis of toxoplasmosis. This article presents a review of current studies on the application and usefulness of different T. gondii recombinant antigens in serological tests for the diagnosis of human toxoplasmosis.
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MIC1-MAG1-SAG1 chimeric protein, a most effective antigen for detection of human toxoplasmosis. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1977-9. [PMID: 23035174 DOI: 10.1128/cvi.00452-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study describes a Toxoplasma gondii IgG enzyme-linked immunosorbent assay based on a new chimeric antigen containing three immunodominant regions from the MIC1, MAG1, and SAG1 proteins of the parasite and shows that this test is useful for diagnostic purposes and may replace the lysed and whole-cell antigens.
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Selseleh M, Keshavarz H, Mohebali M, Shojaee S, Selseleh M, Eshragian MR, Mansouri F, Modarressi MH. Production and evaluation of Toxoplasma gondii recombinant GRA7 for serodiagnosis of human infections. THE KOREAN JOURNAL OF PARASITOLOGY 2012; 50:233-8. [PMID: 22949752 PMCID: PMC3428570 DOI: 10.3347/kjp.2012.50.3.233] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/13/2012] [Accepted: 04/14/2012] [Indexed: 11/23/2022]
Abstract
The precise diagnosis of the acute toxoplasmosis in pregnant women and immunocompromsied patients has critical importance. Most of the commercially available assays use the whole Toxoplasma soluble extract as the antigen. However, the assays currently available for the detection of specific anti-Toxoplasma antibodies may vary in their abilities to detect serum immunoglobulins, due to the lack of a purified standardized antigen. The aim of this study was production and evaluation of the usefulness of the recombinant Toxoplasma gondii GRA7 antigen for the serodiagnosis of Toxoplasma gondii IgM and IgG by ELISA. A total of 70 T. gondii IgM positive sera, 74 T. gondii IgG positive sera, and 60 sera from subjects who were not infected with T. gondii were examined. These sera were shown different absorbance values in ELISA test. To control the specificity of the rGRA7 other parasitic diseases, for example, echinococcosis, malaria, leishmaniasis, fascioliasis, and strongyloidiasis were tested of which none showed positive results. Sensitivity and specificity of the generated recombinant IgG ELISA in comparison with commercial ELISA (com ELISA) were 89% and 90%, and the sensitivity and specificity of the generated recombinant IgM ELISA were 96% and 90%, respectively. The results obtained here show that this antigen is useful for diagnostic purposes.
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Affiliation(s)
- Mina Selseleh
- Department of Medical Parasitology and Mycology, School of Public Health (Affiliation Center), Tehran University of Medical Sciences, Tehran, Iran.
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Maksimov P, Zerweck J, Maksimov A, Hotop A, Groß U, Spekker K, Däubener W, Werdermann S, Niederstrasser O, Petri E, Mertens M, Ulrich RG, Conraths FJ, Schares G. Analysis of clonal type-specific antibody reactions in Toxoplasma gondii seropositive humans from Germany by peptide-microarray. PLoS One 2012; 7:e34212. [PMID: 22470537 PMCID: PMC3314601 DOI: 10.1371/journal.pone.0034212] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 02/28/2012] [Indexed: 11/18/2022] Open
Abstract
Background Different clonal types of Toxoplasma gondii are thought to be associated with distinct clinical manifestations of infections. Serotyping is a novel technique which may allow to determine the clonal type of T. gondii humans are infected with and to extend typing studies to larger populations which include infected but non-diseased individuals. Methodology A peptide-microarray test for T. gondii serotyping was established with 54 previously published synthetic peptides, which mimic clonal type-specific epitopes. The test was applied to human sera (n = 174) collected from individuals with an acute T. gondii infection (n = 21), a latent T. gondii infection (n = 53) and from T. gondii-seropositive forest workers (n = 100). Findings The majority (n = 124; 71%) of all T. gondii seropositive human sera showed reactions against synthetic peptides with sequences specific for clonal type II (type II peptides). Type I and type III peptides were recognized by 42% (n = 73) or 16% (n = 28) of the human sera, respectively, while type II–III, type I–III or type I–II peptides were recognized by 49% (n = 85), 36% (n = 62) or 14% (n = 25) of the sera, respectively. Highest reaction intensities were observed with synthetic peptides mimicking type II-specific epitopes. A proportion of the sera (n = 22; 13%) showed no reaction with type-specific peptides. Individuals with acute toxoplasmosis reacted with a statistically significantly higher number of peptides as compared to individuals with latent T. gondii infection or seropositive forest workers. Conclusions Type II-specific reactions were overrepresented and higher in intensity in the study population, which was in accord with genotyping studies on T. gondii oocysts previously conducted in the same area. There were also individuals with type I- or type III-specific reactions. Well-characterized reference sera and further specific peptide markers are needed to establish and to perform future serotyping approaches with higher resolution.
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Affiliation(s)
- Pavlo Maksimov
- Federal Research Institute for Animal Health, Institute of Epidemiology, Friedrich-Loeffler-Institut, Wusterhausen, Germany
- * E-mail: (PM); (GS)
| | | | - Aline Maksimov
- Federal Research Institute for Animal Health, Institute of Epidemiology, Friedrich-Loeffler-Institut, Wusterhausen, Germany
| | - Andrea Hotop
- German National Consulting Laboratory for Toxoplasmosis, Department of Medical Microbiology, University Medical Center Göttingen, Göttingen, Germany
| | - Uwe Groß
- German National Consulting Laboratory for Toxoplasmosis, Department of Medical Microbiology, University Medical Center Göttingen, Göttingen, Germany
| | - Katrin Spekker
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Walter Däubener
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | | | | | | | - Marc Mertens
- Federal Research Institute for Animal Health, Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Rainer G. Ulrich
- Federal Research Institute for Animal Health, Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Franz J. Conraths
- Federal Research Institute for Animal Health, Institute of Epidemiology, Friedrich-Loeffler-Institut, Wusterhausen, Germany
| | - Gereon Schares
- Federal Research Institute for Animal Health, Institute of Epidemiology, Friedrich-Loeffler-Institut, Wusterhausen, Germany
- * E-mail: (PM); (GS)
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Hiszczyńska-Sawicka E, Li H, Xu JB, Holec-Gąsior L, Kur J, Sedcole R, Bickerstaffe R, Stankiewicz M. Modulation of immune response to Toxoplasma gondii in sheep by immunization with a DNA vaccine encoding ROP1 antigen as a fusion protein with ovine CD154. Vet Parasitol 2011; 183:72-8. [DOI: 10.1016/j.vetpar.2011.06.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 05/31/2011] [Accepted: 06/07/2011] [Indexed: 11/15/2022]
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Hiszczyńska-Sawicka E, Olędzka G, Holec-Gąsior L, Li H, Xu JB, Sedcole R, Kur J, Bickerstaffe R, Stankiewicz M. Evaluation of immune responses in sheep induced by DNA immunization with genes encoding GRA1, GRA4, GRA6 and GRA7 antigens of Toxoplasma gondii. Vet Parasitol 2010; 177:281-9. [PMID: 21251760 DOI: 10.1016/j.vetpar.2010.11.047] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Revised: 11/23/2010] [Accepted: 11/29/2010] [Indexed: 11/18/2022]
Abstract
The dense granule proteins of Toxoplasma gondii are investigated as possible vaccine candidates against the parasite. The aim of this research was to evaluate the immune responses of sheep injected twice, intramuscularly, with DNA plasmids encoding T. gondii dense granule antigens GRA1, GRA4, GRA6 and GRA7 formulated into liposomes. Control sheep were injected with an empty vector or received no injections. The injection of sheep with DNA plasmids encoding for GRA1, GRA4, GRA6 or GRA7 elicited an immune response after the first and the second injections as indicated by the moderate to high antibody responses. The injection of pGRA7 induced a significant level of anti-GRA7 IgG2 antibody and IFN-γ responses indicating a Th1-like immune response whereas injection with pGRA1, pGRA4 and pGRA6 stimulated a IgG1 type antibody response with a limited, if any, IFN-γ response. The results demonstrate that the intramuscular injection of sheep with a DNA liposome formulated plasmid coding for GRA proteins is an effective system that induces a significant immune response against T. gondii.
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Abstract
Toxoplasma gondii is an important human pathogen with a worldwide distribution. It is primarily of medical importance for pregnant women and immunocompromised patients. Primary infection of the former is often associated with fetal infection, which can lead to abortion or severe neonatal malformation. Immunocompromised patients are at risk of contracting the severe form of the disease that may be fatal. Thus, detection of T. gondii infection with high sensitivity and specificity is crucial in the management of the disease. Toxoplasmosis is generally diagnosed by demonstrating specific immunoglobulin M (IgM) and IgG antibodies to toxoplasma antigens in the patient's serum sample. Most of the commercially available tests use T. gondii native antigens and display wide variations in test accuracy. Recombinant antigens have great potential as diagnostic reagents for use in assays to detect toxoplasmosis. Thus in this review, we address recent advances in the use of Toxoplasma recombinant proteins for serodiagnosis of toxoplasmosis.
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Affiliation(s)
- Dupadahalli Kotresha
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang, Malaysia
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Emelia O, Zeehaida M, Sulaiman O, Rohela M, Saadatnia G, Yeng C, Rahmah N. An assay for selection of sera with circulating Toxoplasma gondii antigens. J Immunoassay Immunochem 2010; 31:79-91. [PMID: 20391020 DOI: 10.1080/15321810903405134] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We have developed an ELISA that employs monoclonal anti-Toxoplasma SAG1 (p30) as the capture antibody to detect T. gondii circulating antigens in patients' serum samples. Using serum spiked with Toxoplasma soluble and with SAG1 recombinant proteins, the detection limits were 31.25 ng/mL and 62.50 ng/mL, respectively. We obtained positive results in 28% (21/75) and 11% (23/206) of probable active and chronic toxoplasmosis serum samples, respectively. Western blot analysis on pooled antigen-positive serum samples showed antigenic bands of molecular weights 25 and 75 kDa from sera of probable active infection and five antigenic bands ranging in size from 26 to 33 kDa from chronic infection sera. This assay would be useful as an initial serum selection step in developing a Toxoplasma antigen detection test and for characterization studies.
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Affiliation(s)
- O Emelia
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Minden, Penang, Malaysia
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Comparison of immune response in sheep immunized with DNA vaccine encoding Toxoplasma gondii GRA7 antigen in different adjuvant formulations. Exp Parasitol 2010; 124:365-72. [DOI: 10.1016/j.exppara.2009.11.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 10/27/2009] [Accepted: 11/25/2009] [Indexed: 11/21/2022]
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28
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Holec-Gasior L, Kur J. Toxoplasma gondii: Recombinant GRA5 antigen for detection of immunoglobulin G antibodies using enzyme-linked immunosorbent assay. Exp Parasitol 2009; 124:272-8. [PMID: 19874823 DOI: 10.1016/j.exppara.2009.10.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 09/23/2009] [Accepted: 10/21/2009] [Indexed: 01/12/2023]
Abstract
In this study, for the first time, the evaluation of Toxoplasma gondii full-length recombinant GRA5 antigen for the serodiagnosis of human toxoplasmosis is shown. The recombinant GRA5 antigen as a fusion protein containing His-tag at both terminals was obtained using an Escherichia coli expression system. The usefulness of rGRA5 for the diagnosis of toxoplasmosis in an ELISA was tested on a total of 189 sera from patients with different stages of the infection and 31 sera from sero-negative individuals, obtained during routine diagnostic tests. Anti-GRA5 IgG antibodies were detected in 70.9% of all seropositive serum samples. This result was comparable to ELISA using a Toxoplasma lysate antigen (TLA) and six combinations of recombinant antigens. The sensitivity of IgG ELISA calculated from all positive serum samples was similar for TLA (94.2%), rMAG1+rSAG1+rGRA5 (92.6%), rGRA2+rSAG1+rGRA5 (93.1%) and rROP1+rSAG1+rGRA5 (94.2%) cocktails, whereas the sensitivity of cocktails without rGRA5 antigens was lower giving 82.0%, 86.2% and 87.8%, respectively. Thus, the present study showed that the full-length rGRA5 is suitable for use as a component of an antigen cocktail for the detection of anti-T. gondii IgG antibodies.
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Affiliation(s)
- Lucyna Holec-Gasior
- Gdańsk University of Technology, Chemical Faculty, Department of Microbiology, Narutowicza 11/12 Str., 80-233 Gdańsk, Poland
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29
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GRA2 and ROP1 recombinant antigens as potential markers for detection of Toxoplasma gondii-specific immunoglobulin G in humans with acute toxoplasmosis. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2009; 16:510-4. [PMID: 19225074 DOI: 10.1128/cvi.00341-08] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A goal of the current study was to evaluate serological applications of Toxoplasma gondii GRA2 and rhoptry protein 1 (ROP1) antigens. Soluble recombinant GRA2 and ROP1 antigens as fusion proteins containing six histidyl residues at the N and C terminals were obtained using an Escherichia coli expression system. Purification by one-step metal affinity chromatography allowed recovery of milligram amounts of pure recombinant proteins per liter of culture. The usefulness of these antigens for diagnosis of human infections was tested on 167 serum samples obtained during routine diagnostic tests. A panel of 37 serum samples from patients with acute toxoplasmosis was compared to a panel of 90 serum samples from individuals with past infection. The results indicated that both GRA2 and ROP1 recombinant antigens detected antibodies more frequently in samples from individuals with acute infections (100% and 94.6%, respectively) than in samples from individuals with chronic infections (22.5% and 15.5%, respectively). These results suggest that immunoglobulin G antibodies against GRA2 and ROP1 antigens are produced during the acute stage of toxoplasmosis but are uncommon in the chronic phase of the infection. Hence, these recombinant proteins can be used as specific molecular markers to differentiate between acute and chronic infections.
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30
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Extracellular secretion of Pseudoalteromonas sp. cold-adapted esterase in Escherichia coli in the presence of Pseudoalteromonas sp. components of ABC transport system. Protein Expr Purif 2008; 62:179-84. [PMID: 18700165 DOI: 10.1016/j.pep.2008.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 07/15/2008] [Accepted: 07/16/2008] [Indexed: 11/21/2022]
Abstract
Recently we described identification and characterization of GDSL esterase EstA from psychrotrophic bacterium Pseudoalteromonas sp. 643A. Attempts to obtain heterologous overexpression of this enzyme in Escherichia coli system were not satisfactory. The EstA protein was expressed as inclusion bodies, most of that were inactive after purification step, and the recovery of esterolytic activity was very low after refolding. Based on the sequence analysis we found that the esterase EstA gene is clustered with three genes encoding components of ABC transport system. These genes, designated abc1, abc2, and abc3 encode an ATP-binding protein (ABC1) and two permease proteins (ABC2 and ABC3). In present study, to obtain larger amounts of the active cold-adapted EstA esterase from Pseudoalteromonas sp. 643A, we designed a two-plasmid E. coli expression system where the gene encoding EstA enzyme was cloned into pET30b(+) expression vector and three genes encoding components of ABC transport system were cloned into pACYC-pBAD vector. It was shown that the created expression system was useful for extracellular production of active EstA enzyme which was purified from the culture medium. In the presence of all the three transporter proteins the secretion of EstA was at the highest level. When one or two of these components were missing, EstA secretion was also possible, but not so effective. It indicates that ABC2 and ABC3 proteins of Pseudoalteromonas sp. 643A could be replaced with their homologous proteins of E. coli.
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Velmurugan GV, Tewari AK, Rao JR, Baidya S, Kumar MU, Mishra AK. High-level expression of SAG1 and GRA7 gene of Toxoplasma gondii (Izatnagar isolate) and their application in serodiagnosis of goat toxoplasmosis. Vet Parasitol 2008; 154:185-92. [DOI: 10.1016/j.vetpar.2008.03.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Revised: 03/27/2008] [Accepted: 03/31/2008] [Indexed: 11/27/2022]
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32
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Gatkowska J, Gasior A, Kur J, Dlugonska H. Toxoplasma gondii: Chimeric Dr fimbriae as a recombinant vaccine against toxoplasmosis. Exp Parasitol 2008; 118:266-70. [PMID: 17825290 DOI: 10.1016/j.exppara.2007.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 07/10/2007] [Accepted: 07/16/2007] [Indexed: 10/23/2022]
Abstract
Toxoplasma gondii is responsible for fetopathy in farm animals and humans and severe disease in immunocompromised individuals (i.e. AIDS patients). Effective vaccines, inducing protective and long-lasting immunity to this global parasite, are still desired. In the work, we evaluated the immunogenic and immunoprotective activity of Escherichia coli chimeric Dr fimbriae bearing selected antigenic epitopes of three T. gondii antigens (SAG1, GRA1 and MAG1), in comparison with conventional recombinant antigens obtained in E. coli expression system. Our data demonstrate a very high protective efficacy of recombinant antigens supplemented with Freund's adjuvants, whereas chimeric Dr fimbriae as a vaccine proved non-protective. The recombinant antigen vaccine induced a strong specific antibody response and prevented the brain cysts formation by 89%. The results are promising and should be confirmed in further study on farm animals by use of less aggressive than Freund's adjuvant preparations.
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Affiliation(s)
- Justyna Gatkowska
- Department of Immunoparasitology, University of Lodz, Banacha Str. 12/16, 90-237 Lodz, Poland.
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33
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Golkar M, Azadmanesh K, Khalili G, Khoshkholgh-Sima B, Babaie J, Mercier C, Brenier-Pinchart MP, Fricker-Hidalgo H, Pelloux H, Cesbron-Delauw MF. Serodiagnosis of recently acquired Toxoplasma gondii infection in pregnant women using enzyme-linked immunosorbent assays with a recombinant dense granule GRA6 protein. Diagn Microbiol Infect Dis 2008; 61:31-9. [PMID: 18249081 DOI: 10.1016/j.diagmicrobio.2007.09.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 08/21/2007] [Accepted: 09/04/2007] [Indexed: 10/22/2022]
Abstract
Indirect immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assays (ELISAs) with a recombinant GRA6 protein of Toxoplasma gondii were developed and evaluated for accurate diagnosis of recently acquired infection in pregnant women. According to the results from Toxoplasma serodiagnostic tests, women were classified into 3 groups representing acute (group I), chronic (group II), or no Toxoplasma infection (group III). To discriminate group I from group II sera, the GRA6-IgG-ELISA reached sensitivity and specificity of 87.5% and 94.1%, respectively. Although 22 (91.7%) of 24 group I sera were positive by the GRA6-IgM-ELISA, only 1 (2.9%) of 34 group II sera scored positive. The GRA6-IgM-ELISA displayed a meaningful correlation with Vidas Toxo IgM and exhibited higher specificity (97.1%) than Euroimmun IgM ELISA (88.2%) (Euroimmun, Lübeck, Germany) for detection of recent infection. These results demonstrate that IgG and IgM ELISA with rGRA6 are useful to identify and discriminate recent from past Toxoplasma infection in pregnant women.
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Affiliation(s)
- Majid Golkar
- Molecular Parasitology Laboratory, Parasitology Department, Pasteur Institute of Iran, Tehran 1316943551, Iran.
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34
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Holec L, Gasior A, Brillowska-Dabrowska A, Kur J. Toxoplasma gondii: enzyme-linked immunosorbent assay using different fragments of recombinant microneme protein 1 (MIC1) for detection of immunoglobulin G antibodies. Exp Parasitol 2008; 119:1-6. [PMID: 18207143 DOI: 10.1016/j.exppara.2007.12.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 10/17/2007] [Accepted: 12/10/2007] [Indexed: 11/28/2022]
Abstract
Three different fragments of microneme 1 protein termed, r-MIC1ex2, r-MIC1ex34 and r-MIC1 of Toxoplasma gondii, were expressed in Escherichia coli as fusion proteins containing six histidyl residues at N- and C-terminal. After purification by metal affinity chromatography, these recombinant proteins were tested for their usefulness as antigens in an enzyme-linked immunosorbent assay for the detection of immunoglobulin G. Ninety-eight sera from patients with different stages of invasion and 24 sera from seronegative patients were examined. There was no significant difference observed in the antigenicity for human serum samples from patients with acute toxoplasmosis between three recombinant types of MIC1 antigen (96.1% for r-MIC1ex2 antigen and 100% for both r-MIC1ex34 and r-MIC1 proteins). Sera from chronic infections (with low titers of IgG antibody) showed significant lower sensitivity, especially for r-MIC1ex34 and r-MIC1 antigens (75%, 52.7% and 36.1% for r-MIC1ex2, r-MIC1ex34 and r-MIC1, respectively). These results indicate that the strongest antigenic region of the MIC1 is encoding by the second exon of mic1 gene. When r-MIC1ex2 (N-terminal fragment of protein) was combined with MAG1 (matrix antigen) and MIC3 (microneme 3 protein), the sensitivity increased to 88.9%. This result was comparable to an ELISA using a Toxoplasma lysate antigen (TLA) and two combinations of recombinant antigens: M1 (GRA1+GRA7+SAG1) and M2 (P35+SAG2+GRA6) with the sensitivity for serum samples tested 94.4%, 88.9% and 94.4%, respectively.
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Affiliation(s)
- Lucyna Holec
- Gdańsk University of Technology, Chemical Faculty, Department of Microbiology, ul. Narutowicza 11/12, 80-952 Gdańsk, Poland
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35
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Döşkaya M, Kalantari-Dehaghi M, Walsh CM, Hiszczyńska-Sawicka E, Davies DH, Felgner PL, Larsen LSZ, Lathrop RH, Hatfield GW, Schulz JR, Gürüz Y, Jurnak F. GRA1 protein vaccine confers better immune response compared to codon-optimized GRA1 DNA vaccine. Vaccine 2007; 25:1824-37. [PMID: 17234306 DOI: 10.1016/j.vaccine.2006.10.060] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 10/26/2006] [Accepted: 10/30/2006] [Indexed: 01/15/2023]
Abstract
The present study evaluates immunogenicity and protection potency of a codon-optimized GRA1 DNA vaccine, wild type GRA1 DNA vaccine and an adjuvanted recombinant GRA1 protein vaccine candidate in BALB/c mice against lethal toxoplasmosis. Of the three GRA1 vaccines tested, the recombinant GRA1 protein vaccine results reveal significant increase in immune response and prolonged survival against acute toxoplasmosis compared to DNA vaccinations. Immune response and protection conferred by codon-optimized GRA1 DNA vaccine was slightly better than wild type GRA1 DNA vaccine.
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Affiliation(s)
- Mert Döşkaya
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
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36
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Holec L, Hiszczyńska-Sawicka E, Gasior A, Brillowska-Dabrowska A, Kur J. Use of MAG1 recombinant antigen for diagnosis of Toxoplasma gondii infection in humans. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2007; 14:220-5. [PMID: 17202305 PMCID: PMC1828848 DOI: 10.1128/cvi.00419-06] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This paper describes the cloning, purification, and serological applications of matrix antigen MAG1 of Toxoplasma gondii. The expression system used allows the production of a large amount of T. gondii recombinant protein, which was assessed for its potential use in an enzyme-linked immunosorbent assay (ELISA) for detection of T. gondii infection in humans. Serum samples from 117 patients with different stages of infection, along with 10 serum samples from seronegative patients obtained for routine diagnostic tests, were used. The results were compared with those of an ELISA that uses a native T. gondii antigen extract. The MAG1 antigen detected antibodies more frequently from the acute stage (97.3%) than from the chronic stage (7.5%) of toxoplasmosis. Hence, this antigen may be used as a tool for detection of T. gondii immunoglobulin G antibodies in persons with acute toxoplasmosis.
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Affiliation(s)
- Lucyna Holec
- Gdańsk University of Technology, Department of Microbiology, ul. Narutowicza 11/12, 80-952 Gdańsk, Poland.
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37
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Gatkowska J, Hiszczynska-Sawicka E, Kur J, Holec L, Dlugonska H. Toxoplasma gondii: An evaluation of diagnostic value of recombinant antigens in a murine model. Exp Parasitol 2006; 114:220-7. [DOI: 10.1016/j.exppara.2006.03.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 03/15/2006] [Accepted: 03/25/2006] [Indexed: 11/16/2022]
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Pietkiewicz H, Hiszczyńska-Sawicka E, Kur J, Petersen E, Nielsen HV, Paul M, Stankiewicz M, Myjak P. Usefulness of Toxoplasma gondii recombinant antigens (GRA1, GRA7 and SAG1) in an immunoglobulin G avidity test for the serodiagnosis of toxoplasmosis. Parasitol Res 2006; 100:333-7. [PMID: 16896649 DOI: 10.1007/s00436-006-0265-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Accepted: 06/02/2006] [Indexed: 10/24/2022]
Abstract
The precise diagnosis of an acute and recent Toxoplasma infection in pregnant women and the newborn child is important before treatment. This study describes a new Toxoplasma gondii IgG avidity test based on a combination of recombinant GRA1, GRA7 and SAG1 antigens and shows that this test is useful for diagnostic purposes and may replace the lysed, whole-cell antigens. Although more sera need to be tested, the results obtained here suggest that the IgG avidity test performed with rec-antigens correlated more with the stage of a T. gondii infection than the IgG avidity results obtained with the lysed, whole-cell antigen test, the VIDAS Toxo IgG avidity (bioMérieux).
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Affiliation(s)
- H Pietkiewicz
- Department of Tropical Parasitology, Inter-Faculty Institute of Maritime and Tropical Medicine, Medical University of Gdańsk, ul. Powstania Styczniowego 9b, Gdynia, Poland
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39
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Pietkiewicz H, Hiszczyńska-Sawicka E, Kur J, Petersen E, Nielsen HV, Stankiewicz M, Andrzejewska I, Myjak P. Usefulness of Toxoplasma gondii-specific recombinant antigens in serodiagnosis of human toxoplasmosis. J Clin Microbiol 2004; 42:1779-81. [PMID: 15071048 PMCID: PMC387576 DOI: 10.1128/jcm.42.4.1779-1781.2004] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii SAG1, GRA1, and GRA7 recombinant antigens may be regarded as tools for the detection of T. gondii immunoglobulin G antibodies in persons with chronic and acute toxoplasmosis. GRA7 is more correlated with acute toxoplasmosis. A combination of these antigens will increase the sensitivity of enzyme-linked immunosorbent assays.
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Affiliation(s)
- H Pietkiewicz
- Department of Tropical Parasitology, Interfaculty Institute of Maritime and Tropical Medicine, Medical University of Gdańsk
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