Toxoplasma gondii: Cytokine responses in mice reinfected with atypical strains

Background: A high correlation is observed between specific clonal lineages and host types in toxoplasmosis. The main objectives of this study were comparing polymorphism and evolutionary analysis of the B1 and ROP8 genes, as well as the evaluation of phylogenic and Toxoplasma gondii isolates obtained from different hosts and regions. Methods: Overall 96 brain/ diaphragm tissue samples of livestock and poultry from three provinces of Iran (cows: 9 from Yazd, 9 from Qom; sheep: 19 from Yazd, 7 from Qom; goats: 7 from Yazd, 4 from Qom; one camel from Yazd and 37 chickens, 2 roosters and one duck from Golestan) were tested during 2018-19. A nested PCR and PCR-PCR methods were developed with the B1 and ROP8 genes. Evaluation of genetic proximity, genetic diversity and evolutionary analysis were done using MEGA-X and DnaSP5 software. Thirty samples of both genes were sequenced (18 B1 and 12 ROP8 genes), and submitted to the GenBank (MN275903-MN275932). Results: Tajima's D index analyses showed that both genes were in the negative direction of evolution. The B1 gene was more sensitive than the ROP8 gene. The ROP8 gene showed better and more acceptable results in terms of the relationship between the host and the genotyping of the samples. Conclusion: The B1 gene was only an attractive target for rapid detection of T. gondii parasites, whereas the ROP8 gene due to a high level of polymorphism was able to isolate the three clonal lineages (type I, II and III), inter-types and even atypical strains from different isolates of T. gondii.

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Polymorphisms in Toxoplasma gondii: role of atypical strains in unusual clinical manifestations of toxoplasmosis

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/0037-8682-0216-2016 ◽

2017 ◽

Vol 50 (4) ◽

pp. 578-579 ◽

Cited By ~ 1

Author(s):

Claudio Bruno Silva de Oliveira

Keyword(s):

Toxoplasma Gondii ◽

Clinical Manifestations ◽

Atypical Strains

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Non-archetypal Type II-like and atypical strains of Toxoplasma gondii infecting marsupials of Australia

International Journal for Parasitology ◽

10.1016/j.ijpara.2010.02.008 ◽

2010 ◽

Vol 40 (6) ◽

pp. 635-640 ◽

Cited By ~ 34

Author(s):

N. Parameswaran ◽

R.C.A. Thompson ◽

N. Sundar ◽

S. Pan ◽

M. Johnson ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Type Ii ◽

Atypical Strains

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Selection of Polymorphic Peptides from GRA6 and GRA7 Sequences of Toxoplasma gondii Strains To Be Used in Serotyping

Clinical and Vaccine Immunology ◽

10.1128/cvi.00092-09 ◽

2009 ◽

Vol 16 (8) ◽

pp. 1158-1169 ◽

Cited By ~ 24

Author(s):

Susana Sousa ◽

Daniel Ajzenberg ◽

Maggy Marle ◽

Dominique Aubert ◽

Isabelle Villena ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Amino Acid Sequences ◽

Type I ◽

Serum Samples ◽

Coding Regions ◽

Polymorphic Genes ◽

Low Sensitivity ◽

Reference Strains ◽

Selection Of ◽

Atypical Strains

ABSTRACT The evaluation of Toxoplasma gondii isolates obtained from geographical environments other than Europe and North America revealed the existence of atypical strains that are not included in the three archetypal clonal lineages (lineages I, II, and III). GRA6 and GRA7 are polymorphic genes that have been used for the genotyping of Toxoplasma. The coding regions of GRA6 and GRA7 from 49 nonarchetypal strains were sequenced and compared with the sequences of type I, II, and III reference strains. Eighteen and 10 different amino acid sequences were found for GRA6 and GRA7, respectively. The polymorphisms found between the different sequences were analyzed, with the objective of defining peptides to be used for the serotyping of Toxoplasma infections. Two peptides specific for clonal lineages I and III (peptides GRA7I and GRA7III, respectively) were selected from the GRA7 locus. Three peptides specific for some atypical strains (peptides Am6, Af6, and Am7) were selected from both the GRA6 and the GRA7 loci. Serum samples from humans infected with Toxoplasma strains of known genotypes were serotyped with the selected peptides. Peptide GRA7III seems to be a good candidate for the serotyping of infections caused by type III strains. Peptide GRA7I had a very low sensitivity. Peptides Am6 and Af6 had low specificities, since they reacted with serum samples from patients infected with strains belonging to the three archetypal lineages. Although peptide Am7 was specific, it had low sensitivity.

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Strains of Toxoplasma gondii used for tachyzoite antigens to stimulate spleen cells of infected mice in vitro affect cytokine responses of the cells in the culture

Parasitology Research ◽

10.1007/s00436-005-1416-5 ◽

2005 ◽

Vol 97 (4) ◽

pp. 332-335 ◽

Cited By ~ 10

Author(s):

Laurel Rodgers ◽

Xisheng Wang ◽

Xiangshu Wen ◽

Bradley Dunford ◽

Renee Miller ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Spleen Cells ◽

Cytokine Responses

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Role of CD4+Foxp3+Regulatory T Cells in Protection Induced by a Live Attenuated, Replicating Type I Vaccine Strain of Toxoplasma gondii

Infection and Immunity ◽

10.1128/iai.00217-15 ◽

2015 ◽

Vol 83 (9) ◽

pp. 3601-3611 ◽

Cited By ~ 8

Author(s):

Haroon Akbar ◽

Isabelle Dimier-Poisson ◽

Nathalie Moiré

Keyword(s):

T Cells ◽

Toxoplasma Gondii ◽

Regulatory T Cells ◽

T Regulatory Cells ◽

Interleukin 2 ◽

Type I ◽

Content Type ◽

Effector Cells ◽

Cytokine Responses

Vaccination with the live attenuatedToxoplasma gondiiMic1.3KO strain induced long-lasting immunity against challenge withToxoplasma gondiitype I and type II strains. The involvement of regulatory T cells (Tregs) in the protection mechanism was investigated. Intraperitoneal injection of Mic1.3KO induced a weak and transient influx of CD4+Foxp3+T regulatory cells followed by recruitment/expansion of CD4+Foxp3−CD25+effector cells and control of the parasite at the site of infection. The local and systemic cytokine responses associated with this recruitment of Tregs were of the TH1/Treg-like type. In contrast, injection of RH, the wild-type strain from which the vaccinal strain is derived, induced a low CD4+Foxp3+cell influx and uncontrolled multiplication of the parasites at this local site, followed by death of the mice. The associated local and systemic cytokine responses were of the TH1/TH17-like type. In addition,in vivoTreg induction in RH-infected mice with interleukin-2 (IL-2)/anti-IL-2 complexes induced control of the parasite and a TH1/Treg cytokine response similar to the response after Mic1.3KO vaccination. These results suggest that Tregs may contribute to the protective response after vaccination with Mic1.3KO.

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