β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of <italic toggle="yes">Toxoplasma</italic> and <italic toggle="yes">Eimeria</italic>
ABSTRACT The walls of infectious pathogens, which are essential for transmission, pathogenesis, and diagnosis, contain sugar polymers that are defining structural features, e.g., β-1,3-glucan and chitin in fungi, chitin in Entamoeba cysts, β-1,3-GalNAc in Giardia cysts, and peptidoglycans in bacteri...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Society for Microbiology
2012-11-01
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| Series: | mBio |
| Online Access: | https://journals.asm.org/doi/10.1128/mBio.00258-12 |
| _version_ | 1818427886522073088 |
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| author | G. Guy Bushkin Edwin Motari Paula Magnelli Marc-Jan Gubbels Jitender P. Dubey Katarzyna B. Miska Esther Bullitt Catherine E. Costello Phillips W. Robbins John Samuelson |
| author_facet | G. Guy Bushkin Edwin Motari Paula Magnelli Marc-Jan Gubbels Jitender P. Dubey Katarzyna B. Miska Esther Bullitt Catherine E. Costello Phillips W. Robbins John Samuelson |
| author_sort | G. Guy Bushkin |
| collection | DOAJ |
| description | ABSTRACT The walls of infectious pathogens, which are essential for transmission, pathogenesis, and diagnosis, contain sugar polymers that are defining structural features, e.g., β-1,3-glucan and chitin in fungi, chitin in Entamoeba cysts, β-1,3-GalNAc in Giardia cysts, and peptidoglycans in bacteria. The goal here was to determine in which of three walled forms of Toxoplasma gondii (oocyst, sporocyst, or tissue cyst) is β-1,3-glucan, the product of glucan synthases and glucan hydrolases predicted by whole-genome sequences of the parasite. The three most important discoveries were as follows. (i) β-1,3-glucan is present in oocyst walls of Toxoplasma and Eimeria (a chicken parasite that is a model for intestinal stages of Toxoplasma) but is absent from sporocyst and tissue cyst walls. (ii) Fibrils of β-1,3-glucan are part of a trabecular scaffold in the inner layer of the oocyst wall, which also includes a glucan hydrolase that has a novel glucan-binding domain. (iii) Echinocandins, which target the glucan synthase and kill fungi, arrest development of the Eimeria oocyst wall and prevent release of the parasites into the intestinal lumen. In summary, β-1,3-glucan, which can be targeted by drugs, is an important component of oocyst walls of Toxoplasma but is not a component of sporocyst and tissue cyst walls. IMPORTANCE We show here that walls of Toxoplasma oocysts, the infectious stage shed by cats, contain β-1,3-glucan, a sugar polymer that is a major component of fungal walls. In contrast to fungi, β-1,3-glucan is part of a trabecular scaffold in the inner layer of the oocyst wall that is independent of the permeability barrier formed by the outer layer of the wall. While glucan synthase inhibitors kill fungi, these inhibitors arrest the development of the oocyst walls of Eimeria (an important chicken pathogen that is a surrogate for Toxoplasma) and block release of oocysts into the intestinal lumen. The absence of β-1,3-glucan in tissue cysts of Toxoplasma suggests that drugs targeted at the glucan synthase might be used to treat Eimeria in chickens but not to treat Toxoplasma in people. |
| first_indexed | 2024-12-14T14:52:51Z |
| format | Article |
| id | doaj.art-de73b5bc33504372be351280c253957a |
| institution | Directory Open Access Journal |
| issn | 2150-7511 |
| language | English |
| last_indexed | 2024-12-14T14:52:51Z |
| publishDate | 2012-11-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mBio |
| spelling | doaj.art-de73b5bc33504372be351280c253957a2022-12-21T22:57:06ZengAmerican Society for MicrobiologymBio2150-75112012-11-013510.1128/mBio.00258-12β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of <italic toggle="yes">Toxoplasma</italic> and <italic toggle="yes">Eimeria</italic>G. Guy Bushkin0Edwin Motari1Paula Magnelli2Marc-Jan Gubbels3Jitender P. Dubey4Katarzyna B. Miska5Esther Bullitt6Catherine E. Costello7Phillips W. Robbins8John Samuelson9Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USADepartment of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USADepartment of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USADepartment of Biology, Boston College, Chestnut Hill, Massachusetts, USAAnimal Parasitic Diseases Laboratory, Animal Natural Resources Institute, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland, USAAnimal Parasitic Diseases Laboratory, Animal Natural Resources Institute, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland, USADepartment of Physiology and Biophysics, Boston University School of Medicine, Massachusetts, USAMass Spectrometry Resource and Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USADepartment of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USADepartment of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USAABSTRACT The walls of infectious pathogens, which are essential for transmission, pathogenesis, and diagnosis, contain sugar polymers that are defining structural features, e.g., β-1,3-glucan and chitin in fungi, chitin in Entamoeba cysts, β-1,3-GalNAc in Giardia cysts, and peptidoglycans in bacteria. The goal here was to determine in which of three walled forms of Toxoplasma gondii (oocyst, sporocyst, or tissue cyst) is β-1,3-glucan, the product of glucan synthases and glucan hydrolases predicted by whole-genome sequences of the parasite. The three most important discoveries were as follows. (i) β-1,3-glucan is present in oocyst walls of Toxoplasma and Eimeria (a chicken parasite that is a model for intestinal stages of Toxoplasma) but is absent from sporocyst and tissue cyst walls. (ii) Fibrils of β-1,3-glucan are part of a trabecular scaffold in the inner layer of the oocyst wall, which also includes a glucan hydrolase that has a novel glucan-binding domain. (iii) Echinocandins, which target the glucan synthase and kill fungi, arrest development of the Eimeria oocyst wall and prevent release of the parasites into the intestinal lumen. In summary, β-1,3-glucan, which can be targeted by drugs, is an important component of oocyst walls of Toxoplasma but is not a component of sporocyst and tissue cyst walls. IMPORTANCE We show here that walls of Toxoplasma oocysts, the infectious stage shed by cats, contain β-1,3-glucan, a sugar polymer that is a major component of fungal walls. In contrast to fungi, β-1,3-glucan is part of a trabecular scaffold in the inner layer of the oocyst wall that is independent of the permeability barrier formed by the outer layer of the wall. While glucan synthase inhibitors kill fungi, these inhibitors arrest the development of the oocyst walls of Eimeria (an important chicken pathogen that is a surrogate for Toxoplasma) and block release of oocysts into the intestinal lumen. The absence of β-1,3-glucan in tissue cysts of Toxoplasma suggests that drugs targeted at the glucan synthase might be used to treat Eimeria in chickens but not to treat Toxoplasma in people.https://journals.asm.org/doi/10.1128/mBio.00258-12 |
| spellingShingle | G. Guy Bushkin Edwin Motari Paula Magnelli Marc-Jan Gubbels Jitender P. Dubey Katarzyna B. Miska Esther Bullitt Catherine E. Costello Phillips W. Robbins John Samuelson β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of <italic toggle="yes">Toxoplasma</italic> and <italic toggle="yes">Eimeria</italic> mBio |
| title | β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of <italic toggle="yes">Toxoplasma</italic> and <italic toggle="yes">Eimeria</italic> |
| title_full | β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of <italic toggle="yes">Toxoplasma</italic> and <italic toggle="yes">Eimeria</italic> |
| title_fullStr | β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of <italic toggle="yes">Toxoplasma</italic> and <italic toggle="yes">Eimeria</italic> |
| title_full_unstemmed | β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of <italic toggle="yes">Toxoplasma</italic> and <italic toggle="yes">Eimeria</italic> |
| title_short | β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of <italic toggle="yes">Toxoplasma</italic> and <italic toggle="yes">Eimeria</italic> |
| title_sort | β 1 3 glucan which can be targeted by drugs forms a trabecular scaffold in the oocyst walls of italic toggle yes toxoplasma italic and italic toggle yes eimeria italic |
| url | https://journals.asm.org/doi/10.1128/mBio.00258-12 |
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