Toxoplasma co-opts host gene expression by injection of a polymorphic kinase homologue

Abstract

Toxoplasma gondii, an obligate intracellular parasite of the phylum Apicomplexa, can cause severe disease in humans with an immature or suppressed immune system. The outcome of Toxoplasma infection is highly dependent on the strain type, as are many of its in vitro growth properties1. Here we use genetic crosses between type II and III lines to show that strain-specific differences in the modulation of host cell transcription are mediated by a putative protein kinase, ROP16. Upon invasion by the parasite, this polymorphic protein is released from the apical organelles known as rhoptries and injected into the host cell, where it ultimately affects the activation of signal transducer and activator of transcription (STAT) signalling pathways and consequent downstream effects on a key host cytokine, interleukin (IL)-12. Our findings provide a new mechanism for how an intracellular eukaryotic pathogen can interact with its host and reveal important differences in how different Toxoplasma lineages have evolved to exploit this interaction.

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Figure 1: Toxoplasma strain-specific regulation of human gene expression.
Figure 2: Genome-wide scans for association of human gene expression with Toxoplasma genetic markers.
Figure 3: Strain-specific activation of STAT3.
Figure 4: ROP16 is secreted from the parasite and localizes to the host cell nucleus.
Figure 5: ROP16 mediates strain-specific activation of STAT3/6 and consequent downstream effects on IL-12.

References

  1. 1

    Saeij, J. P., Boyle, J. P. & Boothroyd, J. C. Differences among the three major strains of Toxoplasma gondii and their specific interactions with the infected host. Trends Parasitol. 21, 476–481 (2005)

    Article  Google Scholar 

  2. 2

    Howe, D. K. & Sibley, L. D. Toxoplasma gondii comprises three clonal lineages: correlation of parasite genotype with human disease. J. Infect. Dis. 172, 1561–1566 (1995)

    CAS  Article  Google Scholar 

  3. 3

    Darde, M. L., Bouteille, B. & Pestre-Alexandre, M. Isoenzyme analysis of 35 Toxoplasma gondii isolates and the biological and epidemiological implications. J. Parasitol. 78, 786–794 (1992)

    CAS  Article  Google Scholar 

  4. 4

    Grigg, M. E., Ganatra, J., Boothroyd, J. C. & Margolis, T. P. Unusual abundance of atypical strains associated with human ocular toxoplasmosis. J. Infect. Dis. 184, 633–639 (2001)

    CAS  Article  Google Scholar 

  5. 5

    Howe, D. K., Honore, S., Derouin, F. & Sibley, L. D. Determination of genotypes of Toxoplasma gondii strains isolated from patients with toxoplasmosis. J. Clin. Microbiol. 35, 1411–1414 (1997)

    CAS  PubMed  PubMed Central  Google Scholar 

  6. 6

    Fuentes, I., Rubio, J. M., Ramirez, C. & Alvar, J. Genotypic characterization of Toxoplasma gondii strains associated with human toxoplasmosis in Spain: direct analysis from clinical samples. J. Clin. Microbiol. 39, 1566–1570 (2001)

    CAS  Article  Google Scholar 

  7. 7

    Khan, A. et al. Genotyping of Toxoplasma gondii strains from immunocompromised patients reveals high prevalence of type I strains. J. Clin. Microbiol. 43, 5881–5887 (2005)

    CAS  Article  Google Scholar 

  8. 8

    Darde, M. L., Villena, I., Pinon, J. M. & Beguinot, I. Severe toxoplasmosis caused by a Toxoplasma gondii strain with a new isoenzyme type acquired in French Guyana. J. Clin. Microbiol. 36, 324 (1998)

    CAS  PubMed  PubMed Central  Google Scholar 

  9. 9

    Carme, B. et al. Severe acquired toxoplasmosis in immunocompetent adult patients in French Guiana. J. Clin. Microbiol. 40, 4037–4044 (2002)

    CAS  Article  Google Scholar 

  10. 10

    Tusher, V. G., Tibshirani, R. & Chu, G. Significance analysis of microarrays applied to the ionizing radiation response. Proc. Natl Acad. Sci. USA 98, 5116–5121 (2001)

    ADS  CAS  Article  Google Scholar 

  11. 11

    Khan, A. et al. Composite genome map and recombination parameters derived from three archetypal lineages of Toxoplasma gondii. Nucleic Acids Res. 33, 2980–2992 (2005)

    CAS  Article  Google Scholar 

  12. 12

    Broman, K. W., Wu, H., Sen, S. & Churchill, G. A. R/qtl: QTL mapping in experimental crosses. Bioinformatics 19, 889–890 (2003)

    CAS  Article  Google Scholar 

  13. 13

    Ihle, J. N. The Stat family in cytokine signaling. Curr. Opin. Cell Biol. 13, 211–217 (2001)

    CAS  Article  Google Scholar 

  14. 14

    Bradley, P. J. et al. Proteomic analysis of rhoptry organelles reveals many novel constituents for host-parasite interactions in Toxoplasma gondii. J. Biol. Chem. 280, 34245–34258 (2005)

    CAS  Article  Google Scholar 

  15. 15

    Hakansson, S., Charron, A. J. & Sibley, L. D. Toxoplasma evacuoles: a two-step process of secretion and fusion forms the parasitophorous vacuole. EMBO J. 20, 3132–3144 (2001)

    CAS  Article  Google Scholar 

  16. 16

    Gilbert, L. A., Ravindran, S., Turetzky, J. M., Boothroyd, J. C. & Bradley, P. J. Toxoplasma gondii targets a protein phosphatase 2C to the nucleus of infected host cells. Eukaryot. Cell (published online 3 November 2006; doi:10.1128/EC/00309-06).

  17. 17

    Robben, P. M. et al. Production of IL-12 by macrophages infected with Toxoplasma gondii depends on the parasite genotype. J. Immunol. 172, 3686–3694 (2004)

    CAS  Article  Google Scholar 

  18. 18

    Butcher, B. A. et al. IL-10-independent STAT3 activation by Toxoplasma gondii mediates suppression of IL-12 and TNF-alpha in host macrophages. J. Immunol. 174, 3148–3152 (2005)

    CAS  Article  Google Scholar 

  19. 19

    Remaut, H. & Waksman, G. Structural biology of bacterial pathogenesis. Curr. Opin. Struct. Biol. 14, 161–170 (2004)

    CAS  Article  Google Scholar 

  20. 20

    Suss-Toby, E., Zimmerberg, J. & Ward, G. E. Toxoplasma invasion: The parasitophorous vacuole is formed from host cell pasma membrane and pinches off via a fission pore. Proc. Natl Acad. Sci. USA 93, 8413–8418 (1996)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Limnander, A. et al. v-Abl signaling disrupts SOCS-1 function in transformed pre-B cells. Mol. Cell 15, 329–341 (2004)

    CAS  Article  Google Scholar 

  22. 22

    Burg, J. L., Perelman, D., Kasper, L. H., Ware, P. L. & Boothroyd, J. C. Molecular analysis of the gene encoding the major surface antigen of Toxoplasma gondii. J. Immunol. 141, 3584–3591 (1988)

    CAS  PubMed  Google Scholar 

  23. 23

    Chan, S. M. et al. Protein microarrays for multiplex analysis of signal transduction pathways. Nature Med. 10, 1390–1396 (2004)

    CAS  Article  Google Scholar 

  24. 24

    Mital, J. et al. Conditional expression of Toxoplasma gondii apical membrane antigen-1 (TgAMA1) demonstrates that TgAMA1 plays a critical role in host cell invasion. Mol. Biol. Cell 16, 4341–4349 (2005)

    CAS  Article  Google Scholar 

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Acknowledgements

This work was supported by grants from the NIH (to J.C.B., J.P.B. and M.W.W.), the Ellison Medical Foundation (to J.C.B.), the USDS (to M.W.W.) and the California Universitywide AIDS Research Program (to J.P.J.S. and S.C.). We thank K. Broman for help with R/qtl and the Stanford Functional Genomics Facility for the human cDNA microarrays used for this study.

Author Contributions J.P.J.S. and S.C. contributed equally to this work. J.P.J.S. performed the microarrays and pathway analyses. S.C. and J.P.J.S. performed the experiments in Fig. 3. S.C. performed the experiments in Fig. 4 and Fig 5. J.P.B., M.E.J. and M.W.W. performed the genetic crosses that produced the progeny D3X1 and JD4. J.P.B. genotyped D3X1 and JD4. J.P.J.S., S.C., J.P.B. and J.C.B. wrote the paper. All authors discussed the results and commented on the manuscript.

The microarray data have been deposited in ArrayExpress with the accession number E-MEXP-783.

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Correspondence to J. C. Boothroyd.

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Supplementary information

Supplementary Figures

This file contains Supplementary Figures 1-6 with legends, Supplementary Methods and additional references. (PDF 1410 kb)

Supplementary Data 1

This file contains Supplementary Data 1 with the array data (Log2 of Cy5/Cy3 normalized ratio (median)) for the genes indicated in Figure 1 (XLS 58 kb)

Supplementary Data 2

This file contains Supplementary Data 2 with the raw array data (Log2 of Cy5/Cy3 normalized ratio (median)) for all cDNAs. For the cDNAs that mapped significantly to a Toxoplasma genetic marker the LOD-score value at each genetic marker is indicated. (XLS 26202 kb)

Supplementary Data 3

This file contains Supplementary Data 3 with the array data for comparing HFFs infected with type II vs. type II:ROP16I strains. (XLS 24327 kb)

Supplementary legends

This file contains legends for Supplementary Data 1-3 (DOC 24 kb)

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Saeij, J., Coller, S., Boyle, J. et al. Toxoplasma co-opts host gene expression by injection of a polymorphic kinase homologue. Nature 445, 324–327 (2007). https://doi.org/10.1038/nature05395

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