1
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Evangelista FF, de Laet Sant'Ana P, Ferreira WC, Ferreira TA, Dos Santos ML, de Souza AH, de Andrade FAL, da Silva DA, de Barros LD, Colli CM, Nogueira-Melo GA, Costa IN, Falavigna-Guilherme AL. The Brazilian Toxoplasma gondii strain BRI caused greater inflammation and impairment in anxiogenic behavior in mice, which was reverted by rosuvastatin treatment. Parasitol Res 2023; 123:64. [PMID: 38117414 DOI: 10.1007/s00436-023-08038-4] [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: 08/14/2023] [Accepted: 11/07/2023] [Indexed: 12/21/2023]
Abstract
This study aimed to investigate the effect of rosuvastatin treatment on anxiety-related behavior and short- and long-term memory impairment in mice infected with acute RH and BRI strains of Toxoplasma gondii. Balb/C mice were infected intraperitoneally and after 2 h, oral treatment with rosuvastatin (40 mg/kg/day) was initiated for 4 days. Behaviors related to anxiety and locomotion were evaluated in the open field (OF), and short- and long-term memory through the novel object recognition test (NOR). At the end of the experiments, peritoneal fluid, brain, liver, and lung were collected for T. gondii DNA quantification and histopathological analysis. Infection with BRI strain reduced the dwell time and central locomotion in the OF (p < 0.05), indicating anxiogenic type behavior, while treatment with rosuvastatin reversed this response (p < 0.05). RH strain infection did not alter any behavior in the OF (p > 0.05) and both strains impaired short- and long-term memory (NOR test), but with no significant treatment effect (p > 0.05). The BRI strain was shown to be more damaging in relation to anxiogenic type behavior when compared to the RH strain (p < 0.05), whereas rosuvastatin reduced this damaging effect in BRI. The treatment reduced the parasite load in the peritoneal lavage, liver, and lung of animals infected with both acute strains; however, it significantly (p < 0.05) attenuated the inflammatory process only in BRI-infected and treated animals, showing that non-archetypal genotypes are more damaging in rodents. This suggests that rosuvastatin may be a drug with great therapeutic potential against T. gondii mainly to reduce damage from virulent strains.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Luiz Daniel de Barros
- Department of Preventive Veterinary Medicine, State University of Londrina (UEL), Londrina, PR, Brazil
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2
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Król G, Fortunka K, Majchrzak M, Piktel E, Paprocka P, Mańkowska A, Lesiak A, Karasiński M, Strzelecka A, Durnaś B, Bucki R. Metallic Nanoparticles and Core-Shell Nanosystems in the Treatment, Diagnosis, and Prevention of Parasitic Diseases. Pathogens 2023; 12:838. [PMID: 37375528 DOI: 10.3390/pathogens12060838] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/05/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
The usage of nanotechnology in the fight against parasitic diseases is in the early stages of development, but it brings hopes that this new field will provide a solution to target the early stages of parasitosis, compensate for the lack of vaccines for most parasitic diseases, and also provide new treatment options for diseases in which parasites show increased resistance to current drugs. The huge physicochemical diversity of nanomaterials developed so far, mainly for antibacterial and anti-cancer therapies, requires additional studies to determine their antiparasitic potential. When designing metallic nanoparticles (MeNPs) and specific nanosystems, such as complexes of MeNPs, with the shell of attached drugs, several physicochemical properties need to be considered. The most important are: size, shape, surface charge, type of surfactants that control their dispersion, and shell molecules that should assure specific molecular interaction with targeted molecules of parasites' cells. Therefore, it can be expected that the development of antiparasitic drugs using strategies provided by nanotechnology and the use of nanomaterials for diagnostic purposes will soon provide new and effective methods of antiparasitic therapy and effective diagnostic tools that will improve the prevention and reduce the morbidity and mortality caused by these diseases.
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Affiliation(s)
- Grzegorz Król
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
| | - Kamila Fortunka
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
| | - Michał Majchrzak
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
| | - Ewelina Piktel
- Independent Laboratory of Nanomedicine, Medical University of Białystok, Mickiewicza 2B, 15-222 Białystok, Poland
| | - Paulina Paprocka
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
| | - Angelika Mańkowska
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
| | - Agata Lesiak
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
| | - Maciej Karasiński
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Mickiewicza 2C, 15-222 Białystok, Poland
| | - Agnieszka Strzelecka
- Department of Public Health , Institute of Health Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
| | - Bonita Durnaś
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
| | - Robert Bucki
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University, IX Wieków Kielc 19A, 25-317 Kielce, Poland
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Mickiewicza 2C, 15-222 Białystok, Poland
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3
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Castaño BL, Silva AA, Hernandez-Velasco LL, Pinheiro APDS, Gibaldi D, Mineo JR, Silva NM, Lannes-Vieira J. Sulfadiazine Plus Pyrimethamine Therapy Reversed Multiple Behavioral and Neurocognitive Changes in Long-Term Chronic Toxoplasmosis by Reducing Brain Cyst Load and Inflammation-Related Alterations. Front Immunol 2022; 13:822567. [PMID: 35572567 PMCID: PMC9091718 DOI: 10.3389/fimmu.2022.822567] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Toxoplasma gondii infects one-third of the world population. For decades, it has been considered a silent lifelong infection. However, chronically T. gondii-infected persons may present psychiatric and neurocognitive changes as anxiety, depression, and memory loss. In a model of long-term chronic infection, behavioral alterations parallel neuroinflammation and systemic high cytokine levels, and may reflect brain cyst load. Recent findings support that in chronic infection an active parasite-host interplay involves an immune-mediated control of tissue cysts. Here, we tested the idea that etiological treatment in chronic phase may add advantage to intrinsic immune-mediated cyst control and impact behavioral changes. Thus, we combined sulfadiazine-plus-pyrimethamine (S+P), the first-choice therapy for toxoplasmosis, to study the association of brain cyst load and biological processes related to the immune response (neuroinflammation, blood-brain barrier -BBB- disruption and serum cytokine levels), with behavioral and neurocognitive changes of long-term chronic infection. Female C57BL/6 mice (H-2b) were infected (5 cysts, ME-49 strain) and treated with S+P from 30 to 60 days postinfection (dpi), compared with vehicle (Veh)-treated and noninfected controls. At endpoints (pre-therapy, 30 dpi; S+P therapy, 60 dpi; after ceased therapy, 90 dpi), independent groups were subjected to behavioral tests, and brain tissues and sera were collected. Multiple behavioral and neurocognitive changes were detected in the early (30 dpi) and long-term (60 and 90 dpi) chronic infection. S+P therapy resolved locomotor alterations, anxiety, and depressive-like behavior, partially or transiently ameliorated hyperactivity and habituation memory loss. Analysis after therapy cessation showed that S+P therapy reduced the number of stimuli required for aversive memory consolidation. S+P therapy resulted in reduced brain cyst load, neuroinflammation and BBB disruption, and lowered systemic Th1-cytokine levels. Correlation analysis revealed association between IFNγ, TNF and MCP-1/CCL2 serum levels, brain cyst load and behavioral and neurocognitive alterations. Moreover, principal-component analysis (PCA-2D and 3D projections) highlighted distinction between clusters (noninfected; Veh-treated and S+P-treated infected). Thus, our data suggest that S+P therapy added gain to intrinsic brain cyst control and, direct or indirectly, ameliorated inflammation-related alterations, traits associated with behavioral and neurocognitive alterations.
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Affiliation(s)
- Barrios Leda Castaño
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Andrea Alice Silva
- Multiuser Laboratory for Research Support in Nephrology and Medical Sciences, Federal University Fluminense, Niterói, Brazil
| | | | | | - Daniel Gibaldi
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - José Roberto Mineo
- Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Brazil
| | - Neide Maria Silva
- Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Brazil
| | - Joseli Lannes-Vieira
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
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Tylvalosin demonstrates anti-parasitic activity and protects mice from acute toxoplasmosis. Life Sci 2022; 294:120373. [DOI: 10.1016/j.lfs.2022.120373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 01/28/2022] [Accepted: 01/29/2022] [Indexed: 11/19/2022]
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Bicyclic azetidines target acute and chronic stages of Toxoplasma gondii by inhibiting parasite phenylalanyl t-RNA synthetase. Nat Commun 2022; 13:459. [PMID: 35075105 PMCID: PMC8786932 DOI: 10.1038/s41467-022-28108-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 01/10/2022] [Indexed: 11/24/2022] Open
Abstract
Toxoplasma gondii commonly infects humans and while most infections are controlled by the immune response, currently approved drugs are not capable of clearing chronic infection in humans. Hence, approximately one third of the world’s human population is at risk of reactivation, potentially leading to severe sequelae. To identify new candidates for treating chronic infection, we investigated a series of compounds derived from diversity-oriented synthesis. Bicyclic azetidines are potent low nanomolar inhibitors of phenylalanine tRNA synthetase (PheRS) in T. gondii, with excellent selectivity. Biochemical and genetic studies validate PheRS as the primary target of bicyclic azetidines in T. gondii, providing a structural basis for rational design of improved analogs. Favorable pharmacokinetic properties of a lead compound provide excellent protection from acute infection and partial protection from chronic infection in an immunocompromised mouse model of toxoplasmosis. Collectively, PheRS inhibitors of the bicyclic azetidine series offer promise for treatment of chronic toxoplasmosis. Current treatments for toxoplasmosis are limited by adverse reactions and inability to cure chronic infections dominated by semi-dormant cyst forms. Here the authors demonstrate the potential of small molecule inhibitors of PheRS for controlling acute and chronic toxoplasmosis.
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Elmehankar MS, Elhenawy AA, Aboukamar WA, Elzoheiry MA, Nabih N. Histopathological and ultrastructural assessment of atovaquone-proguanil hydrochloride combination in chronic murine toxoplasmosis. Ultrastruct Pathol 2021; 45:376-383. [PMID: 34595988 DOI: 10.1080/01913123.2021.1984349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Over one billion people worldwide are expected to have Toxoplasma gondii infection with anonymous health problems. Available therapies are ineffective for persistent chronic toxoplasmosis. So, there is an imperative need for effective therapies to eliminate chronic tissue stage. In this study, we aimed to assess the effect of a drug combination of atovaquone and proguanil hydrochloride in the treatment of experimental chronic toxoplasmosis. Fifty Swiss Webster mice were used in the study. Forty mice were infected with Me49 type II cystogenic Toxoplasma gondii strain and allocated into four groups: infected untreated (vehicle-administered), infected and treated with cotrimoxazole (CTX) 370 mg/kg/day, infected and treated with atovaquone (ATV) 100 mg/kg/day, and infected and treated with atovaquone/proguanil (ATV/PROG) 50 mg/kg/day. An additional group of uninfected mice was used as an uninfected control group. Drug treatment was initiated 8 weeks post-infection and continued for two weeks. All mice were sacrificed 12 weeks post-infection. Parasitological and histopathological parameters were assessed. Toxoplasma gondii cysts recovered from brain tissue homogenates of both infected untreated and ATV/PROG-treated groups were examined by scanning electron microscopy. Combined ATV/PROG treatment demonstrated a significant reduction of Toxoplasma gondii cyst count in brain tissue (a reduction rate of 84.87%) compared to untreated group (P < .001). Brain tissues obtained from ATV/PROG treated group showed reduction of inflammatory infiltrate and marked attenuation and deformation of recovered Toxoplasma gondii cysts. We conclude that ATV/PROG drug combination could offer a potential drug therapy for Toxoplasma gondii chronic cystic stage.
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Affiliation(s)
- Manar S Elmehankar
- Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Abeer A Elhenawy
- Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Wafaa A Aboukamar
- Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Manal A Elzoheiry
- Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Nairmen Nabih
- Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
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Castaño Barrios L, Da Silva Pinheiro AP, Gibaldi D, Silva AA, Machado Rodrigues e Silva P, Roffê E, da Costa Santiago H, Tostes Gazzinelli R, Mineo JR, Silva NM, Lannes-Vieira J. Behavioral alterations in long-term Toxoplasma gondii infection of C57BL/6 mice are associated with neuroinflammation and disruption of the blood brain barrier. PLoS One 2021; 16:e0258199. [PMID: 34610039 PMCID: PMC8491889 DOI: 10.1371/journal.pone.0258199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 09/21/2021] [Indexed: 12/18/2022] Open
Abstract
The Apicomplexa protozoan Toxoplasma gondii is a mandatory intracellular parasite and the causative agent of toxoplasmosis. This illness is of medical importance due to its high prevalence worldwide and may cause neurological alterations in immunocompromised persons. In chronically infected immunocompetent individuals, this parasite forms tissue cysts mainly in the brain. In addition, T. gondii infection has been related to mental illnesses such as schizophrenia, bipolar disorder, depression, obsessive-compulsive disorder, as well as mood, personality, and other behavioral changes. In the present study, we evaluated the kinetics of behavioral alterations in a model of chronic infection, assessing anxiety, depression and exploratory behavior, and their relationship with neuroinflammation and parasite cysts in brain tissue areas, blood-brain-barrier (BBB) integrity, and cytokine status in the brain and serum. Adult female C57BL/6 mice were infected by gavage with 5 cysts of the ME-49 type II T. gondii strain, and analyzed as independent groups at 30, 60 and 90 days postinfection (dpi). Anxiety, depressive-like behavior, and hyperactivity were detected in the early (30 dpi) and long-term (60 and 90 dpi) chronic T. gondii infection, in a direct association with the presence of parasite cysts and neuroinflammation, independently of the brain tissue areas, and linked to BBB disruption. These behavioral alterations paralleled the upregulation of expression of tumor necrosis factor (TNF) and CC-chemokines (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β and CCL5/RANTES) in the brain tissue. In addition, increased levels of interferon-gamma (IFNγ), TNF and CCL2/MCP-1 were detected in the peripheral blood, at 30 and 60 dpi. Our data suggest that the persistence of parasite cysts induces sustained neuroinflammation, and BBB disruption, thus allowing leakage of cytokines of circulating plasma into the brain tissue. Therefore, all these factors may contribute to behavioral changes (anxiety, depressive-like behavior, and hyperactivity) in chronic T. gondii infection.
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Affiliation(s)
- Leda Castaño Barrios
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ana Paula Da Silva Pinheiro
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Daniel Gibaldi
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andrea Alice Silva
- Multiuser Laboratory for Research Support in Nephrology and Medical Sciences, Federal University Fluminense, Niterói, Rio de Janeiro, Brazil
| | | | - Ester Roffê
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Helton da Costa Santiago
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Ricardo Tostes Gazzinelli
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - José Roberto Mineo
- Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Neide Maria Silva
- Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Joseli Lannes-Vieira
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
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8
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Smith NC, Goulart C, Hayward JA, Kupz A, Miller CM, van Dooren GG. Control of human toxoplasmosis. Int J Parasitol 2020; 51:95-121. [PMID: 33347832 DOI: 10.1016/j.ijpara.2020.11.001] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/12/2020] [Accepted: 11/15/2020] [Indexed: 12/21/2022]
Abstract
Toxoplasmosis is caused by Toxoplasma gondii, an apicomplexan parasite that is able to infect any nucleated cell in any warm-blooded animal. Toxoplasma gondii infects around 2 billion people and, whilst only a small percentage of infected people will suffer serious disease, the prevalence of the parasite makes it one of the most damaging zoonotic diseases in the world. Toxoplasmosis is a disease with multiple manifestations: it can cause a fatal encephalitis in immunosuppressed people; if first contracted during pregnancy, it can cause miscarriage or congenital defects in the neonate; and it can cause serious ocular disease, even in immunocompetent people. The disease has a complex epidemiology, being transmitted by ingestion of oocysts that are shed in the faeces of definitive feline hosts and contaminate water, soil and crops, or by consumption of intracellular cysts in undercooked meat from intermediate hosts. In this review we examine current and future approaches to control toxoplasmosis, which encompass a variety of measures that target different components of the life cycle of T. gondii. These include: education programs about the parasite and avoidance of contact with infectious stages; biosecurity and sanitation to ensure food and water safety; chemo- and immunotherapeutics to control active infections and disease; prophylactic options to prevent acquisition of infection by livestock and cyst formation in meat; and vaccines to prevent shedding of oocysts by definitive feline hosts.
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Affiliation(s)
- Nicholas C Smith
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia; Research School of Biology, Australian National University, Canberra, ACT 0200, Australia.
| | - Cibelly Goulart
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia; Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - Jenni A Hayward
- Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - Andreas Kupz
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia
| | - Catherine M Miller
- College of Public Health, Medical and Veterinary Science, James Cook University, Cairns, QLD 4878, Australia
| | - Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
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Gondim BLC, da Silva Catarino J, de Sousa MAD, de Oliveira Silva M, Lemes MR, de Carvalho-Costa TM, de Lima Nascimento TR, Machado JR, Rodrigues V, Oliveira CJF, Cançado Castellano LR, da Silva MV. Nanoparticle-Mediated Drug Delivery: Blood-Brain Barrier as the Main Obstacle to Treating Infectious Diseases in CNS. Curr Pharm Des 2020; 25:3983-3996. [PMID: 31612822 DOI: 10.2174/1381612825666191014171354] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/19/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND Parasitic infections affecting the central nervous system (CNS) present high morbidity and mortality rates and affect millions of people worldwide. The most important parasites affecting the CNS are protozoans (Plasmodium sp., Toxoplasma gondii, Trypanosoma brucei), cestodes (Taenia solium) and free-living amoebae (Acantamoeba spp., Balamuthia mandrillaris and Naegleria fowleri). Current therapeutic regimens include the use of traditional chemicals or natural compounds that have very limited access to the CNS, despite their elevated toxicity to the host. Improvements are needed in drug administration and formulations to treat these infections and to allow the drug to cross the blood-brain barrier (BBB). METHODS This work aims to elucidate the recent advancements in the use of nanoparticles as nanoscaled drug delivery systems (NDDS) for treating and controlling the parasitic infections that affect the CNS, addressing not only the nature and composition of the polymer chosen, but also the mechanisms by which these nanoparticles may cross the BBB and reach the infected tissue. RESULTS There is a strong evidence in the literature demonstrating the potential usefulness of polymeric nanoparticles as functional carriers of drugs to the CNS. Some of them demonstrated the mechanisms by which drugloaded nanoparticles access the CNS and control the infection by using in vivo models, while others only describe the pharmacological ability of these particles to be utilized in in vitro environments. CONCLUSION The scarcity of the studies trying to elucidate the compatibility as well as the exact mechanisms by which NDDS might be entering the CNS infected by parasites reveals new possibilities for further exploratory projects. There is an urgent need for new investments and motivations for applying nanotechnology to control parasitic infectious diseases worldwide.
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Affiliation(s)
- Brenna Louise Cavalcanti Gondim
- Human Immunology Research and Education Group-GEPIH, Technical School of Health, Federal University of Paraiba, Joao Pessoa, Paraiba, Brazil.,Post-Graduation Program in Dentistry, Department of Dentistry, State University of Paraíba, Campina Grande, Paraíba, Brazil
| | - Jonatas da Silva Catarino
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
| | | | - Mariana de Oliveira Silva
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Marcela Rezende Lemes
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
| | | | - Tatiana Rita de Lima Nascimento
- Human Immunology Research and Education Group-GEPIH, Technical School of Health, Federal University of Paraiba, Joao Pessoa, Paraiba, Brazil
| | - Juliana Reis Machado
- Department of Pathology, Genetics and Evolution, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Virmondes Rodrigues
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Carlo José Freire Oliveira
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Lúcio Roberto Cançado Castellano
- Human Immunology Research and Education Group-GEPIH, Technical School of Health, Federal University of Paraiba, Joao Pessoa, Paraiba, Brazil
| | - Marcos Vinicius da Silva
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil
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Janetka JW, Hopper AT, Yang Z, Barks J, Dhason MS, Wang Q, Sibley LD. Optimizing Pyrazolopyrimidine Inhibitors of Calcium Dependent Protein Kinase 1 for Treatment of Acute and Chronic Toxoplasmosis. J Med Chem 2020; 63:6144-6163. [PMID: 32420739 PMCID: PMC7325724 DOI: 10.1021/acs.jmedchem.0c00419] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Calcium dependent protein kinase 1 (CDPK1) is an essential Ser/Thr kinase that controls invasion and egress by the protozoan parasite Toxoplasma gondii. The Gly gatekeeper of CDPK1 makes it exquisitely sensitive to inhibition by small molecule 1H-pyrazolo[3,4-d]pyrimidine-4-amine (PP) compounds that are bulky ATP mimetics. Here we rationally designed, synthesized, and tested a series of novel PP analogs that were evaluated for inhibition of CDPK1 enzyme activity in vitro and parasite growth in cell culture. Optimal substitution on the PP scaffold included 2-pyridyl ethers directed into the hydrophobic pocket and small carbocyclic rings accessing the ribose-binding pocket. Further optimization of the series led to identification of the lead compound 3a that displayed excellent potency, selectivity, safety profile, and efficacy in vivo. The results of these studies provide a foundation for further work to optimize CDPK1 inhibitors for the treatment of acute and chronic toxoplasmosis.
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Affiliation(s)
- James W. Janetka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis. MO 63110
| | | | - Ziping Yang
- Vyera Pharmaceuticals, 600 Third Avenue, New York, NY 10016
| | - Jennifer Barks
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - Mary Savari Dhason
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - Qiuling Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
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11
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Keyhani A, Ziaali N, Shakibaie M, Kareshk AT, Shojaee S, Asadi-Shekaari M, Sepahvand M, Mahmoudvand H. Biogenic selenium nanoparticles target chronic toxoplasmosis with minimal cytotoxicity in a mouse model. J Med Microbiol 2020; 69:104-110. [PMID: 31846412 DOI: 10.1099/jmm.0.001111] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Introduction. Nanoparticles (NPs) have numerous biological benefits due to their large surface-volume ratio and convenient entry into cells compared to other particles. Previous research has shown the antimicrobial properties of biogenic selenium NPs (SeNps) and their effects on cellular immunomodulatory cytokines that play a key role in controlling infections.Aim. This study aimed to evaluate the therapeutic effects of SeNPs against chronic toxoplasmosis in mice.Methodology. Infected mice with Toxoplasma gondii (Tehran strain) were orally treated with SeNPs at doses of 2.5, 5 and 10 mg kg-1 once a day for 14 days. On the fifthteenth day, the mean number of brain-tissue cysts and the mRNA levels of TNF-α, IL-12, IL-10, IFN-γ and inducible nitric oxide synthase (iNOS) in the mice of each group were recorded. Moreover, serum clinical chemistry factors in the treated mice were examined to determine the safety of SeNPs.Results. The mean number of tissue cysts was significantly (P<0.001) decreased in mice treated with SeNPs in a dose-dependent manner compared with the control group. The mRNA levels of inflammatory cytokines were significantly increased in mice treated with SeNPs at a dose of 10 mg kg-1 compared with the control subgroup (P<0.05). No significant variation (P>0.05) observed in clinical chemistry parameters among the mice in the control subgroup compared with those treated with SeNPs.Conclusion. The findings demonstrated the therapeutic effects of SeNPs with no considerable toxicity against latent toxoplasmosis in the mouse model. Nevertheless, further studies are obligatory to reveal the exact anti-Toxoplasma mechanisms of SeNPs.
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Affiliation(s)
- Amir Keyhani
- Department of Disease Prevention, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Naser Ziaali
- Research Center of Tropical and Infectious Diseases, Kerman University of Medical Sciences, Kerman, Iran
| | - Mojtaba Shakibaie
- Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Amir Tavakoli Kareshk
- Infectious Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Saeedeh Shojaee
- Department of Medical Parasitology & Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Majid Asadi-Shekaari
- Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Maryam Sepahvand
- Student Research Committee, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Hossein Mahmoudvand
- Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran
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12
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French T, Düsedau HP, Steffen J, Biswas A, Ahmed N, Hartmann S, Schüler T, Schott BH, Dunay IR. Neuronal impairment following chronic Toxoplasma gondii infection is aggravated by intestinal nematode challenge in an IFN-γ-dependent manner. J Neuroinflammation 2019; 16:159. [PMID: 31352901 PMCID: PMC6661741 DOI: 10.1186/s12974-019-1539-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/09/2019] [Indexed: 02/06/2023] Open
Abstract
Background It has become increasingly evident that the immune and nervous systems are closely intertwined, relying on one another during regular homeostatic conditions. Prolonged states of imbalance between neural and immune homeostasis, such as chronic neuroinflammation, are associated with a higher risk for neural damage. Toxoplasma gondii is a highly successful neurotropic parasite causing persistent subclinical neuroinflammation, which is associated with psychiatric and neurodegenerative disorders. Little is known, however, by what means neuroinflammation and the associated neural impairment can be modulated by peripheral inflammatory processes. Methods Expression of immune and synapse-associated genes was assessed via quantitative real-time PCR to investigate how T. gondii infection-induced chronic neuroinflammation and associated neuronal alterations can be reshaped by a subsequent acute intestinal nematode co-infection. Immune cell subsets were characterized via flow cytometry in the brain of infected mice. Sulfadiazine and interferon-γ-neutralizing antibody were applied to subdue neuroinflammation. Results Neuroinflammation induced by T. gondii infection of mice was associated with increased microglia activation, recruitment of immune cells into the brain exhibiting Th1 effector functions, and enhanced production of Th1 and pro-inflammatory molecules (IFN-γ, iNOS, IL-12, TNF, IL-6, and IL-1β) following co-infection with Heligmosomoides polygyrus. The accelerated cerebral Th1 immune response resulted in enhanced T. gondii removal but exacerbated the inflammation-related decrease of synapse-associated gene expression. Synaptic proteins EAAT2 and GABAAα1, which are involved in the excitation/inhibition balance in the CNS, were affected in particular. These synaptic alterations were partially recovered by reducing neuroinflammation indirectly via antiparasitic treatment and especially by application of IFN-γ-neutralizing antibody. Impaired iNOS expression following IFN-γ neutralization directly affected EAAT2 and GABAAα1 signaling, thus contributing to the microglial regulation of neurons. Besides, reduced CD36, TREM2, and C1qa gene expression points toward inflammation induced synaptic pruning as a fundamental mechanism. Conclusion Our results suggest that neuroimmune responses following chronic T. gondii infection can be modulated by acute enteric nematode co-infection. While consecutive co-infection promotes parasite elimination in the CNS, it also adversely affects gene expression of synaptic proteins, via an IFN-γ-dependent manner. Electronic supplementary material The online version of this article (10.1186/s12974-019-1539-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Timothy French
- Institute of Inflammation and Neurodegeneration, Medizinische Fakultät, Otto-von-Guericke-University Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Henning Peter Düsedau
- Institute of Inflammation and Neurodegeneration, Medizinische Fakultät, Otto-von-Guericke-University Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Johannes Steffen
- Institute of Inflammation and Neurodegeneration, Medizinische Fakultät, Otto-von-Guericke-University Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Aindrila Biswas
- Institute of Inflammation and Neurodegeneration, Medizinische Fakultät, Otto-von-Guericke-University Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Norus Ahmed
- Department of Veterinary Medicine, Institute of Immunology, Free University Berlin, Berlin, Germany
| | - Susanne Hartmann
- Department of Veterinary Medicine, Institute of Immunology, Free University Berlin, Berlin, Germany
| | - Thomas Schüler
- Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Björn H Schott
- Leibniz Institute of Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Department of Psychiatry and Psychotherapy, University Medicine Göttingen, Göttingen, Germany
| | - Ildiko Rita Dunay
- Institute of Inflammation and Neurodegeneration, Medizinische Fakultät, Otto-von-Guericke-University Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany. .,Center for Behavioral Brain Sciences, Magdeburg, Germany.
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13
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Sánchez-Sánchez R, Vázquez P, Ferre I, Ortega-Mora LM. Treatment of Toxoplasmosis and Neosporosis in Farm Ruminants: State of Knowledge and Future Trends. Curr Top Med Chem 2019; 18:1304-1323. [PMID: 30277158 PMCID: PMC6340160 DOI: 10.2174/1568026618666181002113617] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/03/2018] [Accepted: 09/13/2018] [Indexed: 12/17/2022]
Abstract
Toxoplasmosis and neosporosis are closely related protozoan diseases that lead to important economic impacts in farm ruminants. Toxoplasma gondii infection mainly causes reproductive failure in small ruminants and is a widespread zoonosis, whereas Neospora caninum infection is one of the most important causes of abortion in cattle worldwide. Vaccination has been considered the most economic measure for controlling these diseases. However, despite vaccine development efforts, only a live-attenuated T. gondii vaccine has been licensed for veterinary use, and no promising vaccines against ne-osporosis have been developed; therefore, vaccine development remains a key goal. Additionally, drug therapy could be a valuable strategy for disease control in farm ruminants, as several drugs that limit T. gondii and N. caninum proliferation and dissemination have been evaluated. This approach may also be relevant to performing an initial drug screening for potential human therapy for zoonotic parasites. Treat-ments can be applied against infections in adult ruminants to minimize the outcomes of a primo-infection or the reactivation of a chronic infection during gestation or in newborn ruminants to avoid infection chronification. In this review, the current status of drug development against toxoplasmosis and neosporo-sis in farm ruminants is presented, and in an effort to promote additional treatment options, prospective drugs that have shown efficacy in vitro and in laboratory animal models of toxoplasmosis and neosporosis are examined
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Affiliation(s)
- Roberto Sánchez-Sánchez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Patricia Vázquez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Ignacio Ferre
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Luis Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
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14
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Azami SJ, Teimouri A, Keshavarz H, Amani A, Esmaeili F, Hasanpour H, Elikaee S, Salehiniya H, Shojaee S. Curcumin nanoemulsion as a novel chemical for the treatment of acute and chronic toxoplasmosis in mice. Int J Nanomedicine 2018; 13:7363-7374. [PMID: 30519020 PMCID: PMC6233476 DOI: 10.2147/ijn.s181896] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background The aim of this study was to prepare curcumin nanoemulsion (CR-NE) to solve the problems associated with poor water solubility and low bioavailability of CR and to test its efficiency in the treatment of acute and chronic toxoplasmosis in mouse models. Materials and methods CR-NE 1% was prepared using spontaneous emulsification by soybean as oil phase; a mixture of Tween 80 and Tween 85 as surfactant; ethanol as cosurfactant and distilled water. Particle size and zeta potential of NE were assessed using Nano-ZS90 dynamic light scattering. Stability testing of NE was assessed after storage for 2 months at room temperature. In vivo experiments were carried out using 50 BALB/c mice inoculated with virulent RH strain (type I) and 50 BALB/c mice inoculated with avirulent Tehran strain (type II) of Toxoplasma gondii and treated with CR-NE (1% w/v), CR suspension (CR-S, 1% w/v), and NE without CR (NE-no CR). Results The mean particle size and zeta potential of CR-NE included 215.66±16.8 nm and −29.46±2.65 mV, respectively, and were stable in particle size after a three freeze–thaw cycle. In acute phase experiment, the survival time of mice infected with RH strain of T. gondii and treated with CR-NE extended from 8 to 10 days postinoculation. The differences were statistically significant between the survival time of mice in CR-NE-treated group compared with negative control group (P<0.001). Furthermore, CR-NE significantly decreased the mean counts of peritoneum tachyzoites from 5,962.5±666 in negative control group to 627.5±73 in CR-NE-treated mice (P<0.001). Growth inhibition rates of tachyzoites in peritoneum of mice receiving CR-NE, CR-S, and NE-no CR included 90%, 21%, and 11%, respectively, compared with negative control group. In chronic phase experiment, the average number and size of tissue cysts significantly decreased to 17.2±15.6 and 31.5±6.26 µm, respectively, in mice inoculated with bradyzoites of T. gondii Tehran strain and treated with CR-NE compared with that in negative control group (P<0.001). Decrease of cyst numbers was verified by downregulation of BAG1 in treatment groups compared with negative control group with a minimum relative expression in CR-NE (1.12±0.28), CR-S (11.76±0.87), and NE-no CR (14.67±0.77), respectively, (P<0.001). Conclusion Results from the current study showed the potential of CR-S and CR-NE in treatment of acute and chronic toxoplasmosis in mouse models for the first time. However, CR-NE was more efficient than CR-S, and it seems that CR-NE has a potential formula for the treatment of acute and chronic toxoplasmosis, especially in those with latent bradyzoites in brain.
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Affiliation(s)
- Sanaz Jafarpour Azami
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,
| | - Aref Teimouri
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran, .,Students Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Keshavarz
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,
| | - Amir Amani
- Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Natural Products and Medicinal Plants Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Fariba Esmaeili
- Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Hasanpour
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran, .,Department of Medical Parasitology and Mycology, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran
| | - Samira Elikaee
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,
| | - Hamid Salehiniya
- Department of Public Health, School of Health, Zabol University of Medical Sciences, Zabol, Iran
| | - Saeedeh Shojaee
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,
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15
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Treatment of Toxoplasmosis: Historical Perspective, Animal Models, and Current Clinical Practice. Clin Microbiol Rev 2018; 31:31/4/e00057-17. [PMID: 30209035 DOI: 10.1128/cmr.00057-17] [Citation(s) in RCA: 240] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Primary Toxoplasma gondii infection is usually subclinical, but cervical lymphadenopathy or ocular disease can be present in some patients. Active infection is characterized by tachyzoites, while tissue cysts characterize latent disease. Infection in the fetus and in immunocompromised patients can cause devastating disease. The combination of pyrimethamine and sulfadiazine (pyr-sulf), targeting the active stage of the infection, is the current gold standard for treating toxoplasmosis, but failure rates remain significant. Although other regimens are available, including pyrimethamine in combination with clindamycin, atovaquone, clarithromycin, or azithromycin or monotherapy with trimethoprim-sulfamethoxazole (TMP-SMX) or atovaquone, none have been found to be superior to pyr-sulf, and no regimen is active against the latent stage of the infection. Furthermore, the efficacy of these regimens against ocular disease remains uncertain. In multiple studies, systematic screening for Toxoplasma infection during gestation, followed by treatment with spiramycin for acute maternal infections and with pyr-sulf for those with established fetal infection, has been shown to be effective at preventing vertical transmission and minimizing the severity of congenital toxoplasmosis (CT). Despite significant progress in treating human disease, there is a strong impetus to develop novel therapeutics for both the acute and latent forms of the infection. Here we present an overview of toxoplasmosis treatment in humans and in animal models. Additional research is needed to identify novel drugs by use of innovative high-throughput screening technologies and to improve experimental models to reflect human disease. Such advances will pave the way for lead candidates to be tested in thoroughly designed clinical trials in defined patient populations.
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16
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Radke JB, Burrows JN, Goldberg DE, Sibley LD. Evaluation of Current and Emerging Antimalarial Medicines for Inhibition of Toxoplasma gondii Growth in Vitro. ACS Infect Dis 2018; 4:1264-1274. [PMID: 29998728 PMCID: PMC6093624 DOI: 10.1021/acsinfecdis.8b00113] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Toxoplasma gondii is a common zoonotic infection of humans, and estimates indicate that 1-2 billion people are chronically infected. Although largely asymptomatic, chronic infection poses risk of serious disease due to reactivation should immunity decline. Current therapies for toxoplasmosis only control acute infection caused by actively proliferating tachyzoites but do not eradicate the chronic tissue cyst stages. As well, there are considerable adverse side effects of the most commonly used therapy of combined sulfadiazine and pyrimethamine. Targeting the folate pathway is also an effective treatment for malaria, caused by the related parasites Plasmodium spp., suggesting common agents might be used to treat both infections. Here, we evaluated currently approved and newly emerging medicines for malaria to determine if such compounds might also prove useful for treating toxoplasmosis. Surprisingly, the majority of antimalarial compounds being used currently or in development for treatment of malaria were only modestly effective at inhibiting in vitro growth of T. gondii tachyzoites. These findings suggest that many essential processes in P. falciparum that are targeted by antimalarial compounds are either divergent or nonessential in T. gondii, thus limiting options for repurposing of current antimalarial medicines for toxoplasmosis.
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Affiliation(s)
- Joshua B. Radke
- Department of Molecular Microbiology, Washington University Sch. Med., 600 S. Euclid Ave., St Louis, MO 63110
| | - Jeremy N. Burrows
- Medicines for Malaria Venture, ICC, Route de Pré3Bois 20, 1215 Geneva, Switzerland
| | - Daniel E. Goldberg
- Departments of Medicine and Molecular Microbiology, Washington University Sch. Med., 660 S. Euclid Ave., St Louis, MO 63110
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University Sch. Med., 600 S. Euclid Ave., St Louis, MO 63110
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17
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Liu J, Huang S, Lu F. Galectin-3 and Galectin-9 May Differently Regulate the Expressions of Microglial M1/M2 Markers and T Helper 1/Th2 Cytokines in the Brains of Genetically Susceptible C57BL/6 and Resistant BALB/c Mice Following Peroral Infection With Toxoplasma gondii. Front Immunol 2018; 9:1648. [PMID: 30108583 PMCID: PMC6080610 DOI: 10.3389/fimmu.2018.01648] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 07/04/2018] [Indexed: 11/13/2022] Open
Abstract
Toxoplasmic encephalitis (TE), an opportunistic infection, is a severe health problem in immunocompromised patients. Previous studies have revealed that C57BL/6 mice are susceptible and BALB/c mice are resistant to TE. To investigate the mechanisms involved in the immunopathogenesis of TE in susceptible C57BL/6 and resistant BALB/c mice, both strains of mice were perorally infected with the Prugniuad (Pru) strain of Toxoplasma gondii. Our results showed that compared with BALB/c mice, C57BL/6 mice infected with T. gondii Pru strain had more severe brain histopathological damage, and higher mRNA expression levels of tachyzoite-specific surface antigen 1, bradyzoite-specific antigen 1, interferon gamma (IFNγ), interleukin (IL)-10, arginase1 (Arg1) (M2 marker), galectin (Gal)-3, Gal-9, T. gondii microneme protein 1 (TgMIC1), TgMIC4, and TgMIC6 during the course of infection by using quantitative real-time reverse transcription-polymerase chain reaction. Further analysis displayed that BALB/c mice showed higher numbers of microglial cells and higher levels of IL-1β, inducible nitric oxide synthase (iNOS) (M1 marker), and chitinase-3-like protein 3 (Ym1) (M2 marker) in the early infective stage [at day 14 or 35 post infection (p.i.)] compared with C57BL/6 mice, whereas C57BL/6 mice showed higher numbers of microglial cells and higher levels of IL-10, iNOS (M1 marker), and Ym1 (M2 marker) at days 35, 50, or 70 p.i. compared with BALB/c mice. Correlation analysis showed that significant positive correlations existed between Gal-3 and IL-4/IL-10/iNOS/Ym1 and between Gal-9 and IL-4/Ym1 in C57BL/6 mice; between Gal-3 and IFNγ/Arg1 and between Gal-9 and IFNγ/Arg1 in BALB/c mice. Together, our data demonstrated that different Gal-3 and Gal-9 expressions as well as different positive correlations were found between Gal-3 and T helper 1 (Th1)/Th2/M1/M2 cytokines or between Gal-9 and Th1/Th2/M2 cytokines in the brains of T. gondii Pru strain-infected C57BL/6 and BALB/c mice.
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Affiliation(s)
- Jinfeng Liu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou, China
| | - Shiguang Huang
- School of Stomatology, Jinan University, Guangzhou, China
| | - Fangli Lu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou, China
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18
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A Repurposed Drug for Brain Cancer: Enhanced Atovaquone Amorphous Solid Dispersion by Combining a Spontaneously Emulsifying Component with a Polymer Carrier. Pharmaceutics 2018; 10:pharmaceutics10020060. [PMID: 29783757 PMCID: PMC6027483 DOI: 10.3390/pharmaceutics10020060] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/14/2018] [Accepted: 05/16/2018] [Indexed: 01/01/2023] Open
Abstract
Glioblastoma multiforme (GBM) is the most common and lethal central nervous system tumor. Recently, atovaquone has shown inhibition of signal transducer and activator transcription 3, a promising target for GBM therapy. However, it is currently unable to achieve therapeutic drug concentrations in the brain with the currently reported and marketed formulations. The present study sought to explore the efficacy of atovaquone against GBM as well as develop a formulation of atovaquone that would improve oral bioavailability, resulting in higher amounts of drug delivered to the brain. Atovaquone was formulated as an amorphous solid dispersion using an optimized formulation containing a polymer and a spontaneously emulsifying component (SEC) with greatly improved wetting, disintegration, dispersibility, and dissolution properties. Atovaquone demonstrated cytotoxicity against GBM cell lines as well as provided a confirmed target for atovaquone brain concentrations in in vitro cell viability studies. This new formulation approach was then assessed in a proof-of-concept in vivo exposure study. Based on these results, the enhanced amorphous solid dispersion is promising for providing therapeutically effective brain levels of atovaquone for the treatment of GBM.
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19
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Abstract
Toxoplasmosis is one of the most important causes of foodborne illnesses and inflammatory complications, as well as congenital disorders. Promiscuous Toxoplasma is transmitted by contaminated food and animal produce, water, vegetations, fruits and sexually through semen. Toxoplasma infects nucleated cells with a unique tropism for muscles and central nervous system and a mind bugging malicious effect. Pregnant women with acute or reactivated toxoplasmosis can transmit Toxoplasma via transplacental to the fetus. The severity of congenital toxoplasmosis depends on the gestation period, as infection in early pregnancy causes more severe consequences. Congenital toxoplasmosis complications include miscarriage, encephalitis, neurological retardation, mental illnesses, auditory and visual inflammatory disorders, cardiovascular abnormalities, and pains. Current therapies are inefficient for congenital and chronic toxoplasmosis or have severe side effects with life threatening complications. There is an urgent need for effective and safe therapeutic modalities to treat complications of toxoplasmosis and effective vaccines to eliminate the infectious agent. This investigation will discuss pathogenesis of feto-maternal, congenital and pediatric toxoplasmosis, the current available therapies in practice, and explore those therapeutic modalities in experimental stages for promising future trials.
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Affiliation(s)
- Helieh S. Oz
- Address for correspondence: Helieh S. Oz, DVM, PhD, AGAF, Department of Physiology and Internal Medicine, University of Kentucky Medical Center, Lexington, KY, United States ()
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20
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Rutaganira FU, Barks J, Dhason MS, Wang Q, Lopez MS, Long S, Radke JB, Jones NG, Maddirala AR, Janetka JW, El Bakkouri M, Hui R, Shokat KM, Sibley LD. Inhibition of Calcium Dependent Protein Kinase 1 (CDPK1) by Pyrazolopyrimidine Analogs Decreases Establishment and Reoccurrence of Central Nervous System Disease by Toxoplasma gondii. J Med Chem 2017; 60:9976-9989. [PMID: 28933846 DOI: 10.1021/acs.jmedchem.7b01192] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Calcium dependent protein kinase 1 (CDPK1) is an essential enzyme in the opportunistic pathogen Toxoplasma gondii. CDPK1 controls multiple processes that are critical to the intracellular replicative cycle of T. gondii including secretion of adhesins, motility, invasion, and egress. Remarkably, CDPK1 contains a small glycine gatekeeper residue in the ATP binding pocket making it sensitive to ATP-competitive inhibitors with bulky substituents that complement this expanded binding pocket. Here we explored structure-activity relationships of a series of pyrazolopyrimidine inhibitors of CDPK1 with the goal of increasing selectivity over host enzymes, improving antiparasite potency, and improving metabolic stability. The resulting lead compound 24 exhibited excellent enzyme inhibition and selectivity for CDPK1 and potently inhibited parasite growth in vitro. Compound 24 was also effective at treating acute toxoplasmosis in the mouse, reducing dissemination to the central nervous system, and decreasing reactivation of chronic infection in severely immunocompromised mice. These findings provide proof of concept for the development of small molecule inhibitors of CDPK1 for treatment of CNS toxoplasmosis.
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Affiliation(s)
- Florentine U Rutaganira
- Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco , San Francisco, California 94158, United States
| | - Jennifer Barks
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Mary Savari Dhason
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Qiuling Wang
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Michael S Lopez
- Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco , San Francisco, California 94158, United States
| | - Shaojun Long
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Joshua B Radke
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Amarendar R Maddirala
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - James W Janetka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine , St. Louis, Missouri 63130, United States
| | - Majida El Bakkouri
- Structural Genomics Consortium, University of Toronto , MaRS South Tower, 101 College St, Toronto, ON M5G 1L7, Canada
| | - Raymond Hui
- Structural Genomics Consortium, University of Toronto , MaRS South Tower, 101 College St, Toronto, ON M5G 1L7, Canada.,Toronto General Hospital Research Institute , 200 Elizabeth St., Toronto, ON M5G 2C4, Canada
| | - Kevan M Shokat
- Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco , San Francisco, California 94158, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63130, United States
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21
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Assolini JP, Concato VM, Gonçalves MD, Carloto ACM, Conchon-Costa I, Pavanelli WR, Melanda FN, Costa IN. Nanomedicine advances in toxoplasmosis: diagnostic, treatment, and vaccine applications. Parasitol Res 2017; 116:1603-1615. [PMID: 28477099 DOI: 10.1007/s00436-017-5458-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 04/24/2017] [Indexed: 12/16/2022]
Abstract
Toxoplasmosis is an infectious disease caused by the intracellular parasite Toxoplasma gondii that affects about one third of the world's population. The diagnosis of this disease is carried out by parasite isolation and host antibodies detection. However, the diagnosis presents problems in regard to test sensitivity and specificity. Currently, the most effective T. gondii treatment is a combination of pyrimethamine and sulfadiazine, although both drugs are toxic to the host. In addition to the problems that compromise the effective diagnosis and treatment of toxoplasmosis, there are no reports or indications of any vaccine capable of fully protecting against this infection. Nanomaterials, smaller than 1000 nm, are currently being investigated as an alternative tool in the management of T. gondii infection. This article reviews how recent nanotechnology advances indicate the utility of nanomaterials in toxoplasmosis diagnosis, treatment, and vaccine development.
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Affiliation(s)
- João Paulo Assolini
- Departamento de Ciências Patológicas, Laboratório de Parasitologia, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Virginia Márcia Concato
- Departamento de Ciências Patológicas, Laboratório de Parasitologia, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Manoela Daiele Gonçalves
- Departamento de Ciências Patológicas, Laboratório de Parasitologia, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | | | - Ivete Conchon-Costa
- Departamento de Ciências Patológicas, Laboratório de Parasitologia, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Wander Rogério Pavanelli
- Departamento de Ciências Patológicas, Laboratório de Parasitologia, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Francine Nesello Melanda
- Departamento de Ciências Patológicas, Laboratório de Parasitologia, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Idessania Nazareth Costa
- Departamento de Ciências Patológicas, Laboratório de Parasitologia, Universidade Estadual de Londrina, Londrina, PR, Brazil. .,Departamento de Ciências Patológicas - Laboratório de Parasitologia, Universidade Estadual de Londrina-UEL, Rodovia Celso Garcia Cid, Campus Universitário, Cx. Postal 6001, Londrina, PR, 86051-990, Brazil.
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Blanchard N, Dunay IR, Schlüter D. Persistence of Toxoplasma gondii in the central nervous system: a fine-tuned balance between the parasite, the brain and the immune system. Parasite Immunol 2015; 37:150-8. [PMID: 25573476 DOI: 10.1111/pim.12173] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 12/30/2014] [Indexed: 02/04/2023]
Abstract
Upon infection of humans and animals with Toxoplasma gondii, the parasites persist as intraneuronal cysts that are controlled, but not eliminated by the immune system. In particular, intracerebral T cells are crucial in the control of T. gondii infection and are supported by essential functions from other leukocyte populations. Additionally, brain-resident cells including astrocytes, microglia and neurons contribute to the intracerebral immune response by the production of cytokines, chemokines and expression of immunoregulatory cell surface molecules, such as major histocompatibility (MHC) antigens. However, the in vivo behaviour of these individual cell populations, specifically their interaction during cerebral toxoplasmosis, remains to be elucidated. We discuss here what is known about the function of T cells, recruited myeloid cells and brain-resident cells, with particular emphasis on the potential cross-regulation of these cell populations, in governing cerebral toxoplasmosis.
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Affiliation(s)
- N Blanchard
- Inserm U1043, Toulouse, France; CNRS U5282, Toulouse, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UPS, Toulouse, France
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Zeng YB, Zhu SH, Dong H, Han HY, Jiang LL, Wang Q, Cheng J, Zhao QP, Ma WJ, Huang B. Great efficacy of sulfachloropyrazine-sodium against acute murine toxoplasmosis. Asian Pac J Trop Biomed 2015; 2:70-5. [PMID: 23569838 DOI: 10.1016/s2221-1691(11)60193-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Revised: 06/27/2011] [Accepted: 07/15/2011] [Indexed: 10/14/2022] Open
Abstract
OBJECTIVE To identify more effective and less toxic drugs to treat animal toxoplasmosis. METHODS Efficacy of seven kinds of sulfonamides against Toxoplasma gondii (T. gondii) in an acute murine model was evaluated. The mice used throughout the study were randomly assigned to many groups (10 mice each), which either remained uninfected or were infected intraperitoneally with tachyzoites of T. gondii (strains RH and CN). All groups were then treated with different sulfonamides and the optimal treatment protocol was determined candidates. Sulfadiazine-sodium (SD) was used for comparison. RESULTS The optimal therapy involved gavaging mice twice per day with 250 mg/kg bw of sulfachloropyrazine-sodium (SPZ) for five days. Using this protocol, the average survival time and the time-point of 50% fatalities were prolonged significantly compared with SD treatment. Treatment with SPZ protected 40% of mice from death, and the heart and kidney tissue of these animals was parasite-free, as determined by nested-PCR. SPZ showed excellent therapeutic effects in the treatment of T. gondii in an acute murine model and is therefore a promising drug candidate for the treatment and prevention of T. gondii in animals. CONCLUSIONS It can be concluded that the effective drug sulfachloropyrazine may be the new therapeutic options against animal toxoplasmosis.
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Affiliation(s)
- Yan-Bo Zeng
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory for Animal Parasitology of Ministry of Agriculture, Shanghai 200241
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Heimesaat MM, Dunay IR, Alutis M, Fischer A, Möhle L, Göbel UB, Kühl AA, Bereswill S. Nucleotide-oligomerization-domain-2 affects commensal gut microbiota composition and intracerebral immunopathology in acute Toxoplasma gondii induced murine ileitis. PLoS One 2014; 9:e105120. [PMID: 25141224 PMCID: PMC4139296 DOI: 10.1371/journal.pone.0105120] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 07/18/2014] [Indexed: 01/01/2023] Open
Abstract
Background Within one week following peroral high dose infection with Toxoplasma (T.) gondii, susceptible mice develop non-selflimiting acute ileitis due to an underlying Th1-type immunopathology. The role of the innate immune receptor nucleotide-oligomerization-domain-2 (NOD2) in mediating potential extra-intestinal inflammatory sequelae including the brain, however, has not been investigated so far. Methodology/Principal Findings Following peroral infection with 100 cysts of T. gondii strain ME49, NOD2-/- mice displayed more severe ileitis and higher small intestinal parasitic loads as compared to wildtype (WT) mice. However, systemic (i.e. splenic) levels of pro-inflammatory cytokines such as TNF-α and IFN-γ were lower in NOD2-/- mice versus WT controls at day 7 p.i. Given that the immunopathological outcome might be influenced by the intestinal microbiota composition, which is shaped by NOD2, we performed a quantitative survey of main intestinal bacterial groups by 16S rRNA analysis. Interestingly, Bifidobacteria were virtually absent in NOD2-/- but not WT mice, whereas differences in remaining bacterial species were rather subtle. Interestingly, more distinct intestinal inflammation was accompanied by higher bacterial translocation rates to extra-intestinal tissue sites such as liver, spleen, and kidneys in T. gondii infected NOD2-/- mice. Strikingly, intracerebral inflammatory foci could be observed as early as seven days following T. gondii infection irrespective of the genotype of animals, whereas NOD2-/- mice exhibited higher intracerebral parasitic loads, higher F4/80 positive macrophage and microglia numbers as well as higher IFN-γ mRNA expression levels as compared to WT control animals. Conclusion/Significance NOD2 signaling is involved in protection of mice from T. gondii induced acute ileitis. The parasite-induced Th1-type immunopathology at intestinal as well as extra-intestinal sites including the brain is modulated in a NOD2-dependent manner.
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Affiliation(s)
- Markus M. Heimesaat
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Berlin, Germany
- * E-mail:
| | - Ildiko R. Dunay
- Department of Microbiology and Hygiene, University of Magdeburg, Magdeburg, Germany
| | - Marie Alutis
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Berlin, Germany
| | - André Fischer
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Berlin, Germany
| | - Luisa Möhle
- Department of Microbiology and Hygiene, University of Magdeburg, Magdeburg, Germany
| | - Ulf B. Göbel
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Berlin, Germany
| | - Anja A. Kühl
- Department of Internal Medicine, Rheumatology and Clinical Immunology/Research Center ImmunoSciences (RCIS), Charité - University Medicine Berlin, Berlin, Germany
| | - Stefan Bereswill
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Berlin, Germany
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Oz HS. Maternal and congenital toxoplasmosis, currently available and novel therapies in horizon. Front Microbiol 2014; 5:385. [PMID: 25104952 PMCID: PMC4109466 DOI: 10.3389/fmicb.2014.00385] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 07/10/2014] [Indexed: 12/24/2022] Open
Abstract
Over one billion people worldwide are predicted to harbor Toxoplasma infection frequently with unknown lifelong health consequences. Toxoplasmosis is an important cause of foodborne, inflammatory illnesses, as well as congenital abnormalities. Ubiquitous Toxoplasma has a unique tropism for central nervous system with a mind-bugging effect and is transmitted sexually through semen. Currently available therapies are ineffective for persistent chronic disease and congenital toxoplasmosis or have severe side effects which may result in life-threatening complications. There is an urgent need for safe and effective therapies to eliminate or treat this cosmopolitan infectious and inflammatory disease. This investigation discusses pathogenesis of maternal and congenital toxoplasmosis, the currently available therapies in practice, and the experimental therapeutic modalities for promising future trials.
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Affiliation(s)
- Helieh S Oz
- Department of Medicine, University of Kentucky Medical Center Lexington, KY, USA
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26
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Brown KM, Suvorova E, Farrell A, McLain A, Dittmar A, Wiley GB, Marth G, Gaffney PM, Gubbels MJ, White M, Blader IJ. Forward genetic screening identifies a small molecule that blocks Toxoplasma gondii growth by inhibiting both host- and parasite-encoded kinases. PLoS Pathog 2014; 10:e1004180. [PMID: 24945800 PMCID: PMC4055737 DOI: 10.1371/journal.ppat.1004180] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 04/28/2014] [Indexed: 02/02/2023] Open
Abstract
The simultaneous targeting of host and pathogen processes represents an untapped approach for the treatment of intracellular infections. Hypoxia-inducible factor-1 (HIF-1) is a host cell transcription factor that is activated by and required for the growth of the intracellular protozoan parasite Toxoplasma gondii at physiological oxygen levels. Parasite activation of HIF-1 is blocked by inhibiting the family of closely related Activin-Like Kinase (ALK) host cell receptors ALK4, ALK5, and ALK7, which was determined in part by use of an ALK4,5,7 inhibitor named SB505124. Besides inhibiting HIF-1 activation, SB505124 also potently blocks parasite replication under normoxic conditions. To determine whether SB505124 inhibition of parasite growth was exclusively due to inhibition of ALK4,5,7 or because the drug inhibited a second kinase, SB505124-resistant parasites were isolated by chemical mutagenesis. Whole-genome sequencing of these mutants revealed mutations in the Toxoplasma MAP kinase, TgMAPK1. Allelic replacement of mutant TgMAPK1 alleles into wild-type parasites was sufficient to confer SB505124 resistance. SB505124 independently impacts TgMAPK1 and ALK4,5,7 signaling since drug resistant parasites could not activate HIF-1 in the presence of SB505124 or grow in HIF-1 deficient cells. In addition, TgMAPK1 kinase activity is inhibited by SB505124. Finally, mice treated with SB505124 had significantly lower tissue burdens following Toxoplasma infection. These data therefore identify SB505124 as a novel small molecule inhibitor that acts by inhibiting two distinct targets, host HIF-1 and TgMAPK1. Understanding how a compound blocks growth of an intracellular pathogen is important not only for developing these compounds into drugs that can be prescribed to patients, but also because these data will likely provide novel insight into the biology of these pathogens. Forward genetic screens are one established approach towards defining these mechanisms. But performing these screens with intracellular parasites has been limited not only because of technical limitations but also because the compounds may have off-target effects in either the host or parasite. Here, we report the first compound that kills a pathogen by simultaneously inhibiting distinct host- and parasite-encoded targets. Because developing drug resistance simultaneously to two targets is less likely, this work may highlight a new approach to antimicrobial drug discovery.
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Affiliation(s)
- Kevin M Brown
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Elena Suvorova
- Departments of Molecular Medicine & Global Health, University of South Florida, Tampa, Florida, United States of America
| | - Andrew Farrell
- Department of Biology, Boston College, Chestnut Hill, Massachusetts, United States of America
| | - Aaron McLain
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York, United States of America
| | - Ashley Dittmar
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York, United States of America
| | - Graham B Wiley
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Gabor Marth
- Department of Biology, Boston College, Chestnut Hill, Massachusetts, United States of America
| | - Patrick M Gaffney
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Marc Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, Massachusetts, United States of America
| | - Michael White
- Departments of Molecular Medicine & Global Health, University of South Florida, Tampa, Florida, United States of America
| | - Ira J Blader
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America; Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York, United States of America
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Bereswill S, Kühl AA, Alutis M, Fischer A, Möhle L, Struck D, Liesenfeld O, Göbel UB, Dunay IR, Heimesaat MM. The impact of Toll-like-receptor-9 on intestinal microbiota composition and extra-intestinal sequelae in experimental Toxoplasma gondii induced ileitis. Gut Pathog 2014; 6:19. [PMID: 24932221 PMCID: PMC4057803 DOI: 10.1186/1757-4749-6-19] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 05/26/2014] [Indexed: 01/01/2023] Open
Abstract
Background Following peroral Toxoplasma (T.) gondii infection, susceptible mice develop acute ileitis due to a microbiota-dependent Th1 type immunopathology. Toll-like-receptor (TLR)-9 is known to recognize bacterial DNA and mediates intestinal inflammation, but its impact on intestinal microbiota composition and extra-intestinal sequelae following T. gondii infection has not yet been elucidated. Methods and results Seven days following peroral infection (p.i.) with 100 cysts of T. gondii ME49 strain, TLR-9-/- and wildtype (WT) mice suffered from comparable ileitis, whereas ileal parasitic loads as well as IFN-γ and nitric oxide levels were higher in TLR-9-/- compared to WT mice. Locally, TLR-9-/- mice exhibited increased ileal CD3+, but not FOXP3+ cell numbers at day 7 p.i.; in mesenteric lymph nodes IFN-γ-producing CD4+ cell numbers and TNF-α and IFN-γ concentrations were also increased in TLR-9-/- compared to WT mice. T. gondii DNA levels, however, did not differ in mice of either genotype. Differences in intestinal microbiota were rather subtle except for bifidobacteria that were virtually absent in both, naïve and T. gondii infected TLR-9-/-, but not WT mice. Extra-intestinally, TLR-9-/- mice displayed less distinct systemic immune responses as indicated by lower serum IL-6, and splenic TNF-α and IFN-γ levels as compared to WT mice despite higher translocation rates of intestinal bacteria to extra-intestinal compartments such as liver, spleen, kidney, and cardiac blood. Most importantly, brains were also affected in this inflammatory scenario as early as day 7 p.i. Remarkably, TLR-9-/- mice exhibited more pronounced inflammatory infiltrates with higher numbers of F4/80+ macrophages and microglia in the cortex and meninges as compared to WT mice, whereas T. gondii DNA levels did not differ. Conclusion We here show that TLR-9 is not required for the development of T. gondii induced ileitis but mediates distinct inflammatory changes in intestinal and extra-intestinal compartments including the brain.
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Affiliation(s)
- Stefan Bereswill
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Centrum 5, Campus Benjamin Franklin, Hindenburgdamm 27, D-12203 Berlin, Germany
| | - Anja A Kühl
- Department of Internal Medicine, Rheumatology and Clinical Immunology/Research Center ImmunoSciences (RCIS), Charité - University Medicine Berlin, Berlin, Germany
| | - Marie Alutis
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Centrum 5, Campus Benjamin Franklin, Hindenburgdamm 27, D-12203 Berlin, Germany
| | - André Fischer
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Centrum 5, Campus Benjamin Franklin, Hindenburgdamm 27, D-12203 Berlin, Germany
| | - Luisa Möhle
- Department of Microbiology and Hygiene, University of Magdeburg, Magdeburg, Germany
| | - Daniela Struck
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Centrum 5, Campus Benjamin Franklin, Hindenburgdamm 27, D-12203 Berlin, Germany
| | - Oliver Liesenfeld
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Centrum 5, Campus Benjamin Franklin, Hindenburgdamm 27, D-12203 Berlin, Germany
| | - Ulf B Göbel
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Centrum 5, Campus Benjamin Franklin, Hindenburgdamm 27, D-12203 Berlin, Germany
| | - Ildikò R Dunay
- Department of Microbiology and Hygiene, University of Magdeburg, Magdeburg, Germany
| | - Markus M Heimesaat
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin, Centrum 5, Campus Benjamin Franklin, Hindenburgdamm 27, D-12203 Berlin, Germany
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Yan J, Wu B, Huang B, Huang S, Jiang S, Lu F. Dectin-1-CD37 association regulates IL-6 expression during Toxoplasma gondii infection. Parasitol Res 2014; 113:2851-60. [PMID: 24870248 DOI: 10.1007/s00436-014-3946-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Accepted: 05/05/2014] [Indexed: 12/21/2022]
Abstract
Toxoplasma gondii can establish chronic infection and is characterized by the formation of tissue cysts in the brain. Although T. gondii can infect any kind of nucleated cells, macrophages and related mononuclear phagocytes are its preferred targets in vivo. Microglial cells are the resident macrophages in the central nervous system. It has been reported that CD37, a tetraspanin molecule, is expressed exclusively in the immune system; Dectin-1, an important pattern-recognition receptor, is expressed on the surface of murine primary microglia. The Dectin-1-CD37 association can affect Dectin-1-mediated IL-6 secretion. However, there is no report concerning the relationship among the expressions of Dectin-1, IL-6, and CD37 during T. gondii infection. In the present study, Kunming outbred mice were infected with Prugniaud (Pru), a type II strain of T. gondii by oral gavage, and BV-2 murine microglial cells were cocultured with RH tachyzoites of T. gondii. By H&E and immunohistochemical staining, the results showed that marked inflammation and a significantly increased activation of Iba1-positive microglial cells were observed in the brain tissues of mice infected with T. gondii Pru strain at 5 weeks postinfection (p.i.) in comparison of uninfected controls. Using quantitative real-time PCR detection, Dectin-1 messenger RNA (mRNA) expressions were significantly upregulated in both brains at 3 (P < 0.01), 5 (P < 0.01), 7 (P < 0.01), and 9 (P < 0.05) weeks p.i. and spleens at 3, 5, 7, and 9 weeks p.i. (P < 0.01). IL-6 expressions showed similar dynamic tendency as that of Dectin-1 in both the brains and spleens at the same times in comparison of uninfected controls; CD37 expressions were significantly increased in the brain tissues at all the times (P < 0.01) and no significant differences in the spleens at 3 weeks p.i. but significantly downregulated in the spleens at 5, 7, and 9 weeks p.i. (P < 0.01). In vitro study showed that compared with uninfected controls, the mRNA expressions of Dectin-1 at 2, 4, 8, and 10 h (P < 0.01); IL-6 at 8 and 10 h (P < 0.01); and CD37 at 4 (P < 0.05), 8 (P < 0.01), and 10 h (P < 0.01) were significantly upregulated in BV-2 murine microglial cells stimulated with RH tachyzoites of T. gondii. Our data suggested that the expression of Dectin-1 was positively correlated with that of IL-6 in toxoplasmic encephalitis (TE) mouse model; Dectin-1 interaction with tetraspanin CD37 regulated IL-6 expression in both the brain tissues of TE mouse model and in the T. gongdii-infected BV-2 murine microglial cells.
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Affiliation(s)
- Junping Yan
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, Guangdong, China
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Gaafar MR, Mady RF, Diab RG, Shalaby TI. Chitosan and silver nanoparticles: promising anti-toxoplasma agents. Exp Parasitol 2014; 143:30-8. [PMID: 24852215 DOI: 10.1016/j.exppara.2014.05.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 04/13/2014] [Accepted: 05/12/2014] [Indexed: 01/21/2023]
Abstract
Toxoplasmosis is a worldwide infection caused by obligate intracellular protozoan parasite which is Toxoplasma gondii. Chitosan and silver nanoparticles were synthesized to be evaluated singly or combined for their anti-toxoplasma effects as prophylaxis and as treatment in the experimental animals. Results were assessed through studying the parasite density and the ultrastructural parasite changes, and estimation of serum gamma interferon. Weight of tissue silver was assessed in different organs. Results showed that silver nanoparticles used singly or combined with chitosan have promising anti-toxoplasma potentials. The animals that received these compounds showed statistically significant decrease in the mean number of the parasite count in the liver and the spleen, when compared to the corresponding control group. Light microscopic examination of the peritoneal exudates of animals receiving these compounds showed stoppage of movement and deformity in shape of the tachyzoites, whereas, by scanning electron microscope, the organisms were mutilated. Moreover, gamma interferon was increased in the serum of animals receiving these compounds. All values of silver detected in different tissues were within the safe range. Thus, these nanoparticles proved their effectiveness against the experimental Toxoplasma infection.
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Affiliation(s)
- M R Gaafar
- Department of Parasitology, Faculty of Medicine, Alexandria University, Egypt.
| | - R F Mady
- Department of Parasitology, Faculty of Medicine, Alexandria University, Egypt
| | - R G Diab
- Department of Parasitology, Faculty of Medicine, Alexandria University, Egypt
| | - Th I Shalaby
- Department of Medical Biophysics, Medical Research Institute, Alexandria University, Egypt
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Borhade V, Pathak S, Sharma S, Patravale V. Formulation and characterization of atovaquone nanosuspension for improved oral delivery in the treatment of malaria. Nanomedicine (Lond) 2014; 9:649-66. [DOI: 10.2217/nnm.13.61] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: The objective of the present study was to develop an atovaquone (ATQ) nanosuspension and evaluate its ability to improve the pharmacokinetic and therapeutic efficacy on oral administration. Materials & methods: The ATQ nanosuspension was prepared by a combination of microprecipitation and high-pressure homogenization. It was freeze dried and characterized for various physiochemical properties. In vivo pharmacokinetics was performed in rats whereas antimalarial efficacy was assessed in mice using a 4-day suppressive test. Results: The ATQ nanosuspension stabilized with Solutol® HS 15 (BASF India Ltd, Mumbai, India) and Capryol™ 90 (Gattefosse, Mumbai, India) exhibited a z-average diameter of 371.50 nm and a polydispersity index of 0.19. X-ray diffraction and differential scanning calorimetry analysis indicated no substantial changes in the crystalline state of ATQ nanocrystals. The aqueous solubility and in vitro dissolution rate were significantly increased by reducing the particle size. An in vivo pharmacokinetics study of the nanosuspension compared with a drug suspension and Malarone® (GlaxoSmithKline, Brentford, UK) exhibited an approximately 4.6–3.2-fold improvement in area under plasma concentration. A significant increase in Cmax and decrease in time to reach peak plasma concentration after administration was also observed. ATQ in nanosized form, even at one-quarter lower doses, exhibited greater reduction in parasitemia and prolonged survival compared with its reference formulations. Conclusion: Results of this pilot study highlight the potential of nanosuspension as an efficient and commercially viable strategy for improving delivery of ATQ for malaria treatment. Original submitted 1 August 2011; Revised submitted 2 February 2013
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Affiliation(s)
- Vivek Borhade
- Department of Pharmaceutical Sciences & Technology, Institute of Chemical Technology, N.P. Marg, Matunga, Mumbai 400019, Maharashtra, India
| | - Sulabha Pathak
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, Maharashtra, India
| | - Shobhona Sharma
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, Maharashtra, India
| | - Vandana Patravale
- Department of Pharmaceutical Sciences & Technology, Institute of Chemical Technology, N.P. Marg, Matunga, Mumbai 400019, Maharashtra, India
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Wu B, Fu X, Huang B, Tong X, Zheng H, Huang S, Lu F. Comparison of dynamic expressions of Tim-3 and PD-1 in the brains between toxoplasmic encephalitis-resistant BALB/c and -susceptible C57BL/6 mice. Parasitol Res 2014; 113:1261-7. [PMID: 24481903 DOI: 10.1007/s00436-014-3764-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 01/10/2014] [Indexed: 01/07/2023]
Abstract
T cells and IFN-γ are essential for controlling the reactivation of toxoplasmic encephalitis (TE), regardless of whether mice are susceptible or resistant to TE. It has been demonstrated that CD8(+) T cells exhausted in chronic Toxoplasma gondii infection result in TE reactivation in C57BL/6 mice. However, this phenomenon had not been reported in genetically TE-resistant BALB/c mice. To explore the immune mechanism of TE in different backgrounds of mice, the dynamic expressions of Tim-3, programmed cell death 1 (PD-1), and their ligands (galectin-9, PD-L1, PD-L2) in brain tissues were compared between TE-resistant BALB/c and -susceptible C57BL/6 mice infected with Prugniaud (Pru, a type II strain) of T. gondii in this study. Compared with infected BALB/c mice, there were remarkable pathological changes with significantly higher histological scores in the brains of C57BL/6 mice at 14, 35, 50, and 70 days postinfection (p.i., P < 0.01); significantly increased mRNA expressions of Tim-3 at 35 (P < 0.05) and 70 (P < 0.01) days p.i.; and significantly increased PD-1 at all the times p.i. (P < 0.01) in the brains of infected C57BL/6 mice. Furthermore, there were significantly increased mRNA expressions of PD-L1 in the brain of C57BL/6 mice than that in BALB/c mice at all the times p.i. (P < 0.01). Although the mRNA expressions of galectin-9 (ligand of Tim-3) were increased in the brains of both lineages of mice at all the times p.i., it showed no differences between the two lineages of mice. Our data suggest that the differences of Tim-3 and PD-1/PD-L1 expressions may contribute to the different immune responses between TE-resistant BALB/c and -susceptible C57BL/6 mice infected with Pru strain of T. gondii.
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Affiliation(s)
- Bin Wu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, Guangdong, China
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Wu B, Huang B, Chen Y, Li S, Yan J, Zheng H, Huang S, Shen J, Lun ZR, Wang Y, Kasper LH, Lu F. Upregulated expression of Tim-3 involved in the process of toxoplasmic encephalitis in mouse model. Parasitol Res 2013; 112:2511-21. [PMID: 23595213 DOI: 10.1007/s00436-013-3416-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/02/2013] [Indexed: 12/28/2022]
Abstract
Toxoplasma gondii can establish chronic infection and is characterized by the formation of tissue cysts in the brain. The cysts may remain throughout the life of the host but can reactivate and cause life-threatening toxoplasmic encephalitis (TE) in immunocompromised patients. T cell-mediated immune responses are essential for preventing the reactivation of chronic infection of T. gondii in the brain. The immunoinhibitory receptor T cell immunoglobulin and mucin domain (Tim)-1 and Tim-3 are expressed on terminally differentiated T helper (Th) 2 and Th1 cells, respectively, participating in the regulation of Th immune response. However, there is no report concerning the role of Tim genes in TE. In this study, Kunming outbred mice were infected with Prugniaud (Pru), a type II strain of T. gondii by oral gavage. Compared with the uninfected controls, there were mild brain inflammations at 3 weeks postinfection (p.i.), moderate brain inflammations at 5 weeks p.i., and aggravated brain inflammations and necrosis at 7 and 9 weeks p.i. The expressions of tachyzoite stage-specific genes in brains were consistent with the severity of brain histopathology of TE at 5 and 7 weeks p.i., while the expressions of bradyzoite stage-specific genes in brains were significantly increased at 7 and 9 weeks p.i. Using quantitative real-time PCR detection and immunohistochemistry staining, our results showed that the expressions of Tim-3 were significantly upregulated in both brains and spleens at 5 weeks p.i. and in spleens at 9 weeks p.i., which showed the similar dynamic tendency as that of interferon-γ expressions in both brains and spleens at the same times. In contrast, the Th2-specific marker Tim-1 expressions were significantly downregulated in both brains and spleens at 3 weeks p.i. and upregulated in both brains and spleens at 7 and 9 weeks p.i., which showed the similar dynamic tendency as that of interleukin-4 expressions in both brains and spleens at the same time. Our data indicate that Tim-3 may involve in the process of TE in mice infected with T. gondii Pru strain.
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Affiliation(s)
- Bin Wu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, Guangdong, China
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Oz HS, Tobin T. Atovaquone ameliorate gastrointestinal toxoplasmosis complications in a pregnancy model. Med Sci Monit 2013; 18:BR337-45. [PMID: 22936182 PMCID: PMC3560658 DOI: 10.12659/msm.883342] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Toxoplasma is an important source of foodborne hospitalization with no safe and effective therapy against chronic or congenital Toxopalsmosis. Atovaquone is a drug of choice but not approved for use in congenital Toxoplasmosis. We hypothesized atovaquone to be safe and effective against feto-maternal Toxoplasmosis. Material/Methods Programmed pregnant mice were i.p. infected with 50–2400 Tachyzoites from Type II strain (clone PTG). Dams were treated daily with atovaquone or sham and monitored for pain, and complications. Results Dams developed pain related abdominal hypersensitivity (allodynia) to mechanical stimuli in a Tachyzoites dose dependent manner. Infected dams were anemic and exhibited ascities and severe hepatitis (score 3.6±0.01 on scale 0 – normal to 4 – severe) with influx of inflammatory and plasma cells, multinucleated dysplastic hepatocytes and necrosis. In addition, dams expressed mild to severe pancreatitis with mononuclear cell invasion, loss of islets and necrosis. This was consistent with splenomegaly (X3 Fold), and massive infiltration of epithelioid cells and loss of germinal structure. Colon became significantly shortened in length (p<0.01) with semi-normal content. Pathological manifestation included, shortening of crypts with numerous microabscess formations, infiltration of lymphocytes, and macrophages. The severe clinical complications led to abortion (50%), early birth (25%) or still birth (25%) consistent with the high dose of Tachyzoites inoculation. Atovaquone treatment partially but significantly protected the dams from the severity of hepatitis, splenomegaly, colitis, myocarditis, and pain related responses as well as fetal demise. Conclusions This is a valuable model for therapeutic evaluation of feto-maternal Toxoplasmosis and gastrointestinal complications. Atovaquone protects dams and their fetuses against some infectious/inflammatory aspects of the disease.
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Affiliation(s)
- Helieh S Oz
- Department of Physiology, College of Medicine, University of Kentucky Medical Center, Lexington, KY 40536, USA.
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Wahajuddin, Raju KSR, Taneja I. Bioanalysis of antimalarials using liquid chromatography. Trends Analyt Chem 2013. [DOI: 10.1016/j.trac.2012.09.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Significant reduction of brain cysts caused by Toxoplasma gondii after treatment with spiramycin coadministered with metronidazole in a mouse model of chronic toxoplasmosis. Antimicrob Agents Chemother 2012; 56:1762-8. [PMID: 22271863 DOI: 10.1128/aac.05183-11] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Toxoplasma gondii is a parasite that generates latent cysts in the brain; reactivation of these cysts may lead to fatal toxoplasmic encephalitis, for which treatment remains unsuccessful. We assessed spiramycin pharmacokinetics coadministered with metronidazole, the eradication of brain cysts and the in vitro reactivation. Male BALB/c mice were fed 1,000 tachyzoites orally to develop chronic toxoplasmosis. Four weeks later, infected mice underwent different treatments: (i) infected untreated mice (n = 9), which received vehicle only; (ii) a spiramycin-only group (n = 9), 400 mg/kg daily for 7 days; (iii) a metronidazole-only group (n = 9), 500 mg/kg daily for 7 days; and (iv) a combination group (n = 9), which received both spiramycin (400 mg/kg) and metronidazole (500 mg/kg) daily for 7 days. An uninfected control group (n = 10) was administered vehicle only. After treatment, the brain cysts were counted, brain homogenates were cultured in confluent Vero cells, and cysts and tachyzoites were counted after 1 week. Separately, pharmacokinetic profiles (plasma and brain) were assessed after a single dose of spiramycin (400 mg/kg), metronidazole (500 mg/kg), or both. Metronidazole treatment increased the brain spiramycin area under the concentration-time curve from 0 h to ∞ (AUC(0-∞)) by 67% without affecting its plasma disposition. Metronidazole plasma and brain AUC(0-∞) values were reduced 9 and 62%, respectively, after spiramycin coadministration. Enhanced spiramycin brain exposure after coadministration reduced brain cysts 15-fold (79 ± 23 for the combination treatment versus 1,198 ± 153 for the untreated control group [P < 0.05]) and 10-fold versus the spiramycin-only group (768 ± 125). Metronidazole alone showed no effect (1,028 ± 149). Tachyzoites were absent in the brain. Spiramycin reduced in vitro reactivation. Metronidazole increased spiramycin brain penetration, causing a significant reduction of T. gondii brain cysts, with potential clinical translatability for chronic toxoplasmosis treatment.
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Chew WK, Wah MJ, Ambu S, Segarra I. Toxoplasma gondii: determination of the onset of chronic infection in mice and the in vitro reactivation of brain cysts. Exp Parasitol 2011; 130:22-5. [PMID: 22027550 DOI: 10.1016/j.exppara.2011.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/25/2011] [Accepted: 10/06/2011] [Indexed: 11/15/2022]
Abstract
Toxoplasma gondii is an intra-cellular parasite that infects humans through vertical and horizontal transmission. The cysts remain dormant in the brain of infected humans and can reactivate in immunocompromised hosts resulting in acute toxoplasmic encephalitis which may be fatal. We determined the onset and progression of brain cysts generation in a mouse model following acute toxoplasmosis as well as the ability of brain cysts to reactivate in vitro. Male Balb/c mice, (uninfected control group, n = 10) were infected orally (study group, n = 50) with 1000 tachyzoites of T. gondii (ME49 strain) and euthanized at 1, 2, 4, 8 and 16 weeks post infection. Brain tissue was harvested, homogenized, stained and the number of brain cysts counted. Aliquots of brain homogenate with cysts were cultured in vitro with confluent Vero cells and the number of cysts and tachyzoites counted after 1 week. Brain cysts but not tachyzoites were detected at week 2 post infection and reached a plateau by week 4. In vitro Vero cells culture showed similar pattern for cysts and tachyzoites and reactivation of cyst in vitro was not influenced by the age of the brain cysts.
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Affiliation(s)
- Wai Kit Chew
- Department of Human Biology, School of Medicine, International Medical University, No 126 Jalan 19/155B, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.
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Alvarado-Esquivel C, Niewiadomski A, Schweickert B, Liesenfeld O. Antiparasitic treatment suppresses production and avidity of Toxoplasma gondii-specific antibodies in a murine model of acute infection*. Eur J Microbiol Immunol (Bp) 2011; 1:249-55. [PMID: 24516731 DOI: 10.1556/eujmi.1.2011.3.9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 07/14/2011] [Indexed: 01/04/2023] Open
Abstract
Infection with Toxoplasma gondii during pregnancy may result in congenital transmission of the parasite. Infection is commonly diagnosed using serological tests for IgG, IgM and IgA antibodies. Avidity of IgG antibodies is used to exclude acute infection. Few studies have investigated the impact of antiparasitic treatment on the production of anti-T. gondii antibody and the avidity of IgG antibodies. We therefore investigated the production of IgG, IgM, and IgA antibodies and IgG avidity in a murine model of acute infection with 10 cysts of T. gondii. All antibody classes increased following infection. Treatment of mice with pyrimethamine/sulfadiazine but not with spiramycin or azithromycin at dosages equivalent to those used in patients resulted in a significant decrease in the concentration of T. gondii-specific IgG and IgM antibodies postinfection. IgG and IgM antibody decreases were paralleled by a significant reduction in cyst numbers in brains of mice treated with pyrimethamine/sulfadiazine but not with other drugs. In contrast, treatment with atovaquone did significantly reduce the concentrations of IgM antibodies and resulted in reduced IgG avidity indices. T. gondii-specific DNA was not detected in blood between days 1 and 3. In conclusion, antiparasitic treatment with pyrimethamine/sulfadiazine and atovaquone appears to impact the generation of antibody responses against T. gondii. Future studies will have to determine the specific impact of antiparasitic treatment on antibody responses and the consequences for the management of patients infected with T. gondii.
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Affiliation(s)
- C Alvarado-Esquivel
- Department of Microbiology and Hygiene, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin Berlin Germany
| | - A Niewiadomski
- Department of Microbiology and Hygiene, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin Berlin Germany
| | - B Schweickert
- Department of Microbiology and Hygiene, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin Berlin Germany
| | - O Liesenfeld
- Department of Microbiology and Hygiene, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin Berlin Germany
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The IFN-γ-inducible GTPase, Irga6, protects mice against Toxoplasma gondii but not against Plasmodium berghei and some other intracellular pathogens. PLoS One 2011; 6:e20568. [PMID: 21698150 PMCID: PMC3117789 DOI: 10.1371/journal.pone.0020568] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 05/03/2011] [Indexed: 11/24/2022] Open
Abstract
Clearance of infection with intracellular pathogens in mice involves interferon-regulated GTPases of the IRG protein family. Experiments with mice genetically deficient in members of this family such as Irgm1(LRG-47), Irgm3(IGTP), and Irgd(IRG-47) has revealed a critical role in microbial clearance, especially for Toxoplasma gondii. The in vivo role of another member of this family, Irga6 (IIGP, IIGP1) has been studied in less detail. We investigated the susceptibility of two independently generated mouse strains deficient in Irga6 to in vivo infection with T. gondii, Mycobacterium tuberculosis, Leishmania mexicana, L. major, Listeria monocytogenes, Anaplasma phagocytophilum and Plasmodium berghei. Compared with wild-type mice, mice deficient in Irga6 showed increased susceptibility to oral and intraperitoneal infection with T. gondii but not to infection with the other organisms. Surprisingly, infection of Irga6-deficient mice with the related apicomplexan parasite, P. berghei, did not result in increased replication in the liver stage and no Irga6 (or any other IRG protein) was detected at the parasitophorous vacuole membrane in IFN-γ-induced wild-type cells infected with P. berghei in vitro. Susceptibility to infection with T. gondii was associated with increased mortality and reduced time to death, increased numbers of inflammatory foci in the brains and elevated parasite loads in brains of infected Irga6-deficient mice. In vitro, Irga6-deficient macrophages and fibroblasts stimulated with IFN-γ were defective in controlling parasite replication. Taken together, our results implicate Irga6 in the control of infection with T. gondii and further highlight the importance of the IRG system for resistance to this pathogen.
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Abstract
Toxoplasma gondii is an obligate intracellular parasite. Following oral infection the parasite crosses the intestinal epithelial barrier to disseminate throughout the body and establish latent infection in central nervous tissues. The clinical presentation ranges from asymptomatic to severe neurological disorders in immunocompromised individuals. Since the clinical presentation is diverse and depends, among other factors, on the immune status of the host, in the present review, we introduce parasitological, epidemiological, clinical, and molecular biological aspects of infection with T. gondii to set the stage for an in-depth discussion of host immune responses. Since immune responses in humans have not been investigated in detail the present review is exclusively referring to immune responses in experimental models of infection. Systemic and local immune responses in different models of infection are discussed, and a separate chapter introduces commonly used animal models of infection.
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Affiliation(s)
- Melba Munoz
- Charite Medical School Berlin - Microbiology and Hygiene, Berlin, Germany
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Gurule S, Goswami D, Khuroo AH, Monif T. LC-APCI mass spectrometric method development and validation for the determination of atovaquone in human plasma. Biomed Chromatogr 2010; 24:497-505. [PMID: 19711297 DOI: 10.1002/bmc.1317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A newly developed LC-APCI mass spectrometric method is described for human plasma determination of atovaquone using lapachol internal standard. A single-step protein precipitation technique for plasma extraction of atovaquone achieving mean recovery of 94.17% (CV 8%) without compromising sensitivity (limit of quantitation 50.3 ng/mL) or linearity (50.3 ng/mL-23924.6 ng/mL) is delineated in this paper. Heated nebulizer in negative multiple reaction monitoring mode was employed with transitions m/z 365.2 --> m/z 337.1 and m/z 240.9 --> m/z 185.7 for atovaquone and lapachol respectively in this liquid chromatographic-tandem mass spectrometric method. Excellent chromatographic separation on a Synergi 4 micro Polar-RP 80A (150 x 2.0 mm) column, using 100 microL of plasma extraction volume along with 10 microL of injection load, completing analysis run-time within 2.5 min, highlights this simple yet unique bioanalytical method. The developed method can be successfully applied to pharmacokinetic studies on atovaquone suspension administered in healthy volunteers or HIV-infected patients. Moreover full method validation results not published before are presented and discussed in detail for the first time in this article.
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Affiliation(s)
- Sanjay Gurule
- Department of Clinical Pharmacology and Pharmacokinetics, Ranbaxy Laboratories Ltd, Gurgaon, Haryana, India
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41
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Shubar HM, Lachenmaier S, Heimesaat MM, Lohman U, Mauludin R, Mueller RH, Fitzner R, Borner K, Liesenfeld O. SDS-coated atovaquone nanosuspensions show improved therapeutic efficacy against experimental acquired and reactivated toxoplasmosis by improving passage of gastrointestinal and blood-brain barriers. J Drug Target 2010; 19:114-24. [PMID: 20367080 DOI: 10.3109/10611861003733995] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Toxoplasmic encephalitis (TE) is the most common clinical manifestation of reactivated infection with Toxoplasma gondii in immunocompromised patients that is lethal if untreated. The combination of pyrimethamine plus sulfadiazine or clindamycin is the standard therapy for the treatment of TE, but these combinations are associated with hematologic toxicity and/or life-threatening allergic reactions. Therefore, alternative treatment options are needed. Atovaquone is safe and highly effective against T. gondii in vitro, but the oral micronized solution shows poor bioavailability. We synthesized atovaquone nanosuspensions (ANSs) coated with poloxamer 188 (P188) and sodium dodecyl sulfate (SDS) to improve oral bioavailability and passage through the blood-brain barrier (BBB). Coating of ANSs with SDS resulted in enhanced oral bioavailability and enhanced brain uptake of atovaquone compared to Wellvone(®) in murine models of acute and reactivated toxoplasmosis as measured by high performance liquid chromatography (HPLC). Parasite loads and inflammatory changes in brains of mice treated with SDS-coated ANS were significantly reduced compared to untreated controls and to Wellvone(®)-treated mice. In conclusion, nanosuspensions coated with SDS may ultimately lead to improvements in the treatment of TE and other cerebral diseases.
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Affiliation(s)
- Hend M Shubar
- Institute of Microbiology and Hygiene, Campus Benjamin Franklin, Charité-University Medicine Berlin, Berlin, Germany
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Zhao Q, Zhang M, Hong L, Zhou K, Lin Y. Evaluation of drug effects on Toxoplasma gondii nuclear and plastid DNA replication using real-time PCR. Parasitol Res 2010; 106:1257-62. [PMID: 20186551 DOI: 10.1007/s00436-010-1792-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 02/03/2010] [Indexed: 01/07/2023]
Abstract
Toxoplasma gondii Nicolle and Manceaux, 1908 is a unicellular protozoan that can infect a broad spectrum of organisms including humans. In addition to a nuclear genome, it also carries a circular DNA within a plastid-like organelle (apicoplast) and a linear genome within its mitochondria. The plastid organelle has been shown to be the target of various anti-parasitic drugs or antibiotics. To evaluate the effects of agents on the DNA replication of T. gondii, we tested six drugs (ciprofloxacin, acetylspiramycin, clindamycin, azithromycin, artemether, and sulfadiazine) on the parasite cultured in Hela cells. After drug treatment for 48 h, the parasite growth and DNA replication were evaluated and quantitated using TaqMan real-time quantitative PCR with oligonucleotide primers synthesized based on a gene from the apicoplast genome (ycf24, Genbank accession no. U87145) and a gene from the nuclear genome (uprt, Genbank accession no. U10246). Our results showed that ciprofloxacin was the most effective in inhibiting the replication of the plastid DNA after 48 h drug treatment, with a reduction of 22% in the copy number of the plastid DNA. Artemether was the most effective drug in suppressing the proliferation of tachyzoites. This study also demonstrates that real-time quantitative PCR is a simple and useful technique for monitoring parasite growth and DNA replication.
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Affiliation(s)
- Qing Zhao
- School of Life Sciences, Xiamen University, Xiamen, Fujian, China.
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In vitro and in vivo activities of 1-hydroxy-2-alkyl-4(1H)quinolone derivatives against Toxoplasma gondii. Antimicrob Agents Chemother 2009; 54:517-21. [PMID: 19884369 DOI: 10.1128/aac.01001-09] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
1-Hydroxy-2-dodecyl-4(1H)quinolone (HDQ) was recently identified as a Toxoplasma gondii inhibitor. We describe here two novel 1-hydroxyquinolones, which displayed 50% inhibitory concentrations 10- and 5-fold lower than that of HDQ. In a mouse model of acute toxoplasmosis, these two compounds and HDQ reduced the percentages of infected peritoneal cells and decreased the parasite loads in lungs and livers. Compound B showed a tendency toward lowering parasite loads in brains in a mouse model of toxoplasmic encephalitis.
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Hülsermann U, Hoffmann MM, Massing U, Fricker G. Uptake of apolipoprotein E fragment coupled liposomes by cultured brain microvessel endothelial cells and intact brain capillaries. J Drug Target 2009; 17:610-8. [PMID: 19694613 DOI: 10.1080/10611860903105986] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The suitability of surface modified liposomes as drug carriers for brain-specific targeting was investigated using apolipoprotein E fragments as brain-directed vectors. Liposomes coated with polyethylene glycol-2000 (sterically stabilized, PEGylated liposomes) were prepared from hydrogenated egg phosphatidylcholine, cholesterol, and a PEG-derivatized phospholipid. Liposomes were covalently coupled to a peptide of 26 amino acids length, derived from the binding site of human apolipoprotein E4 (ApoE4) and a peptide of random amino acid sequence, respectively. Rhodamine-labeled dipalmitoylphosphatidylethanolamine was incorporated into the lipid bilayer in order to visualize the liposomal interaction with brain capillary endothelial cell monolayers. The interaction of the liposomes with monolayers of porcine brain capillary endothelial cells (BCEC), the rodent cell line RBE4, and freshly isolated porcine brain capillaries was studied by means of confocal laser scanning fluorescence microscopy. In contrast to random peptide coupled liposomes, the ApoE4-fragment coupled liposomes were rapidly taken up by cultured BCECs and RBE4 cells. Uptake could be inhibited by ApoE4, free peptide, and antibodies against the LDL receptor in a concentration-dependent manner. The results indicate that the liposomes are internalized via the LDL receptor, which is expressed at the blood-brain barrier. In conclusion, liposomes coupled to ApoE4 fragments are taken up into brain endothelium via an endocytotic pathway and may therefore be a suitable carrier for drug delivery to the brain.
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Affiliation(s)
- Uta Hülsermann
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht-Karls-University, Heidelberg, Germany
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Artemisone and artemiside control acute and reactivated toxoplasmosis in a murine model. Antimicrob Agents Chemother 2009; 53:4450-6. [PMID: 19635951 DOI: 10.1128/aac.00502-09] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immunocompromised patients are at risk of developing toxoplasmosis, and although chemotherapy is available, standard treatments are often complicated by severe side effects. Artemisinin is a new highly potent antimalarial drug that has activity against Toxoplasma gondii in vitro. However, artemisinin derivatives have previously been ineffective in vivo using a rat model of toxoplasmosis. In the present study, the efficacy of several new artemisinin derivates was investigated for treatment of mice infected with the parasite Toxoplasma gondii. Artemiside and artemisone displayed better inhibition than either artemisinin or artesunate against the parasite in vitro. Artemiside and artemisone treatment controlled parasite replication in vivo, and mice survived the acute infection. In a murine model of reactivated toxoplasmosis, both drugs increased survival, although artemiside was more effective. These results indicate that these newer derivatives of artemisinin may have potential for treatment of toxoplasmosis.
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Pingale SG, Nerurkar KK, Padgaonkar AM, Pawar UD, Mangaonkar KV. Determination of Atovaquone in Human Plasma by LC-MS-MS and Its Application to a Bioequivalence Study. Chromatographia 2009. [DOI: 10.1365/s10337-009-1220-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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47
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Shubar HM, Dunay IR, Lachenmaier S, Dathe M, Bushrab FN, Mauludin R, Müller RH, Fitzner R, Borner K, Liesenfeld O. The role of apolipoprotein E in uptake of atovaquone into the brain in murine acute and reactivated toxoplasmosis. J Drug Target 2009; 17:257-67. [DOI: 10.1080/10611860902718680] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Megged O, Shalit I, Yaniv I, Stein J, Fisher S, Levy I. Breakthrough cerebral toxoplasmosis in a patient receiving atovaquone prophylaxis after a hematopoietic stem cell transplantation. Pediatr Transplant 2008; 12:902-5. [PMID: 18194354 DOI: 10.1111/j.1399-3046.2007.00891.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe a case of breakthrough cerebral toxoplasmosis during atovaquone therapy in a child who was intolerant of conventional prophylactic regimens after hematopoietic stem cell transplantation. The available data on the efficacy of atovaquone prophylaxis in Toxoplasma sero-positive stem cell transplant recipients remain limited, and other strategies, such as preemptive strategy using toxoplasma PCR or TMP-SMX desensitization should be considered in this setting.
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Affiliation(s)
- Orli Megged
- Infectious Diseases Unit, Schneider Children's Medical Center of Israel, Petah Tiqwa, Israel
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Madigan WP, Raymond WR, Wroblewski KJ, Thebpatiphat N, Birdsong RH, Jaafar MS. A review of pediatric uveitis: Part I. Infectious causes and the masquerade syndromes. J Pediatr Ophthalmol Strabismus 2008; 45:140-9. [PMID: 18524191 DOI: 10.3928/01913913-20080501-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Uveitis is a manifestation of complex processes that can represent an infectious or a purely immune system modulated condition and may have grave effects on the eye. Much of the morbidity in these conditions is the result of the immune response to these stimuli. These infectious diseases may be successfully treated by addressing the inciting organism with recognized interventions. Treatment of the immune response to the organism often must be pursued simultaneously to minimize long-term complications caused by structural changes within the eye. Assisting the individual's immune response to eliminate the organism while minimizing the immune response's damaging effects remains a unique challenge drawing on both the science and the art of medicine. Several non-infectious conditions that are not autoimmune diseases may commonly masquerade as uveitis, leading to delays in appropriate treatment.
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Jost C, Reiter-Owona I, Liesenfeld O. The timing of sulfadiazine therapy impacts the reactivation of latent Toxoplasma infection in IRF-8−/− mice. Parasitol Res 2007; 101:1603-9. [PMID: 17846793 DOI: 10.1007/s00436-007-0700-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2007] [Accepted: 07/23/2007] [Indexed: 10/22/2022]
Abstract
The process of reactivation of latent infection with Toxoplasma gondii in immunosuppressed hosts is yet not fully understood. In the past, a number of murine models of reactivation in immunocompromised mice have been described using sulfadiazine to establish latent infection before withdrawal and subsequent reactivation. We studied the process of reactivation in brains of mice with a targeted mutation in the interferon-regulatory factor (IRF)-8 gene after withdrawal of sulfadiazine therapy. IRF-8(-/-) mice were orally infected with five cysts of the ME 49 strain of T. gondii. To allow establishment of latent infection with cyst formation, mice were treated with sulfadiazine starting either 3, 5, 6, or 7 days postinfection. Sulfadiazine was withdrawn after 14-21 days to allow reactivation. We observed that timing of sulfadiazine therapy had a marked impact on the course of infection and reactivation. Mice treated late after infection (days 5-7) showed increased mortality and decreased time to death compared to mice treated early after infection (group A). In the blood of mice with late (days 5-7) but not early (day 3) initiation of treatment, T. gondii-specific deoxyribonucleic acid was detected by polymerase chain reaction. Using double staining with stage-specific antibodies, tachyzoites were detectable in brains of mice with late initiation of sulfadiazine treatment but rarely within cysts thus indicating continued invasion of parasites across the blood-brain barrier. Intracerebral cyst rupture or bradyzoite-tachyzoite conversion was not detectable in IRF-8(-/-) mice when sulfadiazine therapy was initiated late after infection. These results indicate that continued invasion of tachyzoites rather than reactivation of latent cerebral infection impacts the course of infection in this model of reactivated toxoplasmosis. In conclusion, the timing of sulfadiazine therapy is of utmost importance for the course of infection in immunocompromised mice.
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MESH Headings
- Animals
- Antiprotozoal Agents/administration & dosage
- Antiprotozoal Agents/therapeutic use
- Brain/parasitology
- Brain/pathology
- Disease Models, Animal
- Drug Administration Schedule
- Humans
- Interferon Regulatory Factors/genetics
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Sulfadiazine/administration & dosage
- Sulfadiazine/therapeutic use
- Toxoplasma/drug effects
- Toxoplasma/growth & development
- Toxoplasma/pathogenicity
- Toxoplasma/physiology
- Toxoplasmosis, Animal/drug therapy
- Toxoplasmosis, Animal/mortality
- Toxoplasmosis, Animal/parasitology
- Toxoplasmosis, Animal/pathology
- Toxoplasmosis, Cerebral/drug therapy
- Toxoplasmosis, Cerebral/mortality
- Toxoplasmosis, Cerebral/parasitology
- Toxoplasmosis, Cerebral/pathology
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Affiliation(s)
- Christian Jost
- Institut für Medizinische Mikrobiologie, Immunologie und Parasitologie, Universität Bonn, Sigmund-Freud Str. 25, 53105 Bonn, Germany
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