RESUMO
BACKGROUND: Toxoplasma gondii infection of Alzheimer's disease model mice decreases amyloid ß plaques. We aimed to determine if there is a brain regional difference in amyloid ß reduction in the brains of T. gondii-infected compared to control mice. METHOD: Three-month-old 5xFAD (AD model) mice were injected with T. gondii or with phosphate-buffered saline as a control. Intact brains were harvested at 6 weeks postinfection, optically cleared using iDISCO+, and brain-wide amyloid burden was visualized using volumetric light-sheet imaging. Amyloid signal was quantified across each brain and computationally mapped to the Allen Institute Brain Reference Atlas to determine amyloid density in each region. RESULTS: A brain-wide analysis of amyloid in control and T. gondii-infected 5xFAD mice revealed that T. gondii infection decreased amyloid burden in the brain globally as well as in the cortex and hippocampus, and many daughter regions. Daughter regions that showed reduced amyloid burden included the prelimbic cortex, visual cortex, and retrosplenial cortex. The olfactory tubercle, a region known to have increased monocytes following T. gondii infection, also showed reduced amyloid after infection. CONCLUSIONS: T. gondii infection of AD mice reduces amyloid burden in a brain region-specific manner that overlaps with known regions of T. gondii infection and peripheral immune cell infiltration.
Assuntos
Doença de Alzheimer , Encéfalo , Modelos Animais de Doenças , Camundongos Transgênicos , Toxoplasma , Animais , Doença de Alzheimer/metabolismo , Doença de Alzheimer/parasitologia , Doença de Alzheimer/patologia , Camundongos , Encéfalo/parasitologia , Encéfalo/metabolismo , Encéfalo/patologia , Peptídeos beta-Amiloides/metabolismo , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Toxoplasmose/metabolismo , FemininoRESUMO
Kidney transplant recipients are at increased risk of opportunistic infections and malignancy, including space-occupying intracranial lesions. Here, we present a case of a patient presenting with multiple intracranial lesions in the context of a distant history of transplantation. MRI findings were consistent with a large subcortical enhancing lesion. Leading differentials included posttransplant lymphoproliferative disorder and cerebral cryptococcoma. Brain biopsy was undertaken along with PCR testing on tissue detected Toxoplasma gondii and Epstein-Barr virus (EBV) DNA. Cerebral toxoplasmosis was diagnosed based on characteristic histology and negative EBV immunohistochemistry. This case demonstrates the difficulties and complexities in reaching a diagnosis in immunocompromised patients and the importance of brain biopsy.
Assuntos
Hospedeiro Imunocomprometido , Transplante de Rim , Toxoplasmose Cerebral , Humanos , Transplante de Rim/efeitos adversos , Toxoplasmose Cerebral/diagnóstico , Masculino , Imageamento por Ressonância Magnética , Toxoplasma/isolamento & purificação , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encéfalo/parasitologia , Pessoa de Meia-Idade , Infecções Oportunistas/diagnóstico , Diagnóstico Diferencial , Biópsia , Herpesvirus Humano 4/isolamento & purificaçãoRESUMO
This study investigates the efficacy of nebivolol (NBV) in experimental models of toxoplasmosis, focusing on parasite burden reduction and neuronal protection. In the acute model of experimental toxoplasmosis, Swiss mice infected with RH strain tachyzoites received oral NBV chlorhydrate doses of 2 mg/kg/day and 4 mg/kg/day for 8 days. Treatment with NBV significantly reduced parasite burden compared to vehicle and standard drug (PYR) groups. In the chronic model of experimental toxoplasmosis, C57/BL6 mice infected with the ME49 strain received NBV chlorhydrate 41 days post-infection and were evaluated after 10 days of treatment. NBV chlorhydrate effectively reduced cyst number and area, as well as bradyzoite burden compared to controls. Histological analysis demonstrated that NBV chlorhydrate preserved neuronal count, with the 4 mg/kg/day dose yielding counts similar to non-infected mice. Statistical analysis confirmed significant differences compared to control groups. Furthermore, immunohistochemical analysis revealed a significant reduction in iNOS labeling in the brains of mice treated with NBV chlorhydrate, indicating a decrease in nitric oxide production compared to control groups. These findings suggest NBV's potential as a promising candidate for toxoplasmosis treatment, highlighting its ability to reduce parasite burden and protect neuronal integrity. Further research is warranted to elucidate NBV's mechanisms of action and its clinical application in managing toxoplasmosis.
Assuntos
Encéfalo , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Nebivolol , Carga Parasitária , Toxoplasmose Animal , Animais , Nebivolol/farmacologia , Nebivolol/uso terapêutico , Camundongos , Toxoplasmose Animal/tratamento farmacológico , Toxoplasmose Animal/parasitologia , Encéfalo/parasitologia , Encéfalo/patologia , Encéfalo/efeitos dos fármacos , Feminino , Neurônios/efeitos dos fármacos , Neurônios/parasitologia , Etanolaminas/farmacologia , Etanolaminas/uso terapêutico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Antiprotozoários/administração & dosagem , Benzopiranos/farmacologia , Benzopiranos/uso terapêutico , Resultado do Tratamento , Óxido Nítrico/metabolismo , Toxoplasma/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismoRESUMO
Epidemiological studies and meta-analyses have shown a strong association between high seroprevalence of Toxoplasma gondii (T. gondii) and schizophrenia. Schizophrenic patients showed higher levels of anti-Toxoplasma immunoglobulins M and G (IgM and IgG) when compared to healthy controls. Previously, in a rat model, we demonstrated that the progeny of mothers immunized with T. gondii lysates before gestation had behavioral and social impairments during adulthood. Therefore, we suggested that T. gondii infection can trigger autoreactivity by molecularly mimicking host brain proteins. Here, we aimed to identify the occurrence of antigenic mimicry between T. gondii epitopes and host brain proteins. Using a bioinformatic approach, we predicted T. gondii RH-88 B cell epitopes and compared them to human cell-surface proteins involved in brain development and differentiation (BrainS). Five different algorithms for B-cell-epitope prediction were used and compared, resulting in 8584 T. gondii epitopes. We then compared T. gondii predicted epitopes to BrainS proteins by local sequence alignments using BLASTP. T. gondii immunogenic epitopes significantly overlapped with 42 BrainS proteins. Among these overlapping proteins essential for brain development and differentiation, we identified HSP90 and NOTCH receptors as the proteins most likely to be targeted by the maternally generated pathogenic antibodies due to their topological overlap at the extracellular region of their sequence. This analysis highlights the relevance of pregestational clinical surveillance and screening for potential pathogenic anti-T. gondii antibodies. It also identifies potential targets for the design of vaccines that could prevent behavioral and cognitive impairments associated with pre-gestational T. gondii exposure.
Assuntos
Encéfalo , Epitopos de Linfócito B , Mimetismo Molecular , Toxoplasma , Toxoplasma/imunologia , Mimetismo Molecular/imunologia , Humanos , Epitopos de Linfócito B/imunologia , Encéfalo/parasitologia , Encéfalo/imunologia , Encéfalo/metabolismo , Biologia Computacional/métodos , Toxoplasmose/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , RatosRESUMO
The impact of cerebral malaria on the transcriptional profiles of cerebral tissues is difficult to study using noninvasive approaches. We isolated plasma extracellular vesicles (EVs) from patients with cerebral malaria and community controls and sequenced their mRNA content. Deconvolution analysis revealed that EVs from cerebral malaria are enriched in transcripts of brain origin. We ordered the patients with cerebral malaria based on their EV-transcriptional profiles from cross-sectionally collected samples and inferred disease trajectory while using healthy community controls as a starting point. We found that neuronal transcripts in plasma EVs decreased with disease trajectory, whereas transcripts from glial, endothelial, and immune cells increased. Disease trajectory correlated positively with severity indicators like death and was associated with increased VEGFA-VEGFR and glutamatergic signaling, as well as platelet and neutrophil activation. These data suggest that brain tissue responses in cerebral malaria can be studied noninvasively using EVs circulating in peripheral blood.
Assuntos
Encéfalo , Vesículas Extracelulares , Malária Cerebral , RNA Mensageiro , Humanos , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/genética , Malária Cerebral/parasitologia , Malária Cerebral/genética , Malária Cerebral/sangue , Malária Cerebral/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Encéfalo/metabolismo , Encéfalo/parasitologia , Feminino , Masculino , Adulto , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/sangue , Estudos de Casos e ControlesRESUMO
BACKGROUND: Infection with the protozoan parasite Toxoplasma gondii leads to the formation of lifelong cysts in neurons that can have devastating consequences in the immunocompromised. In the immunocompetent individual, anti-parasitic effector mechanisms and a balanced immune response characterized by pro- and anti-inflammatory cytokine production establishes an asymptomatic infection that rarely leads to neurological symptoms. Several mechanisms are known to play a role in this successful immune response in the brain including T cell production of IFNγ and IL-10 and the involvement of CNS resident cells. This limitation of clinical neuropathology during chronic infection suggests a balance between immune response and neuroprotective mechanisms that collectively prevent clinical manifestations of disease. However, how these two vital mechanisms of protection interact during chronic Toxoplasma infection remains poorly understood. MAIN TEXT: This study demonstrates a previously undescribed connection between innate neutrophils found chronically in the brain, termed "chronic brain neutrophils" (CBNeuts), and neuroprotective mechanisms during Toxoplasma infection. Lack of CBNeuts during chronic infection, accomplished via systemic neutrophil depletion, led to enhanced infection and deleterious effects on neuronal regeneration and repair mechanisms in the brain. Phenotypic and transcriptomic analysis of CBNeuts identified them as distinct from peripheral neutrophils and revealed two main subsets of CBNeuts that display heterogeneity towards both classical effector and neuroprotective functions in an age-dependent manner. Further phenotypic profiling defined expression of the neuroprotective molecules NRG-1 andErbB4 by these cells, and the importance of this signaling pathway during chronic infection was demonstrated via NRG-1 treatment studies. CONCLUSIONS: In conclusion, this work identifies CBNeuts as a heterogenous population geared towards both classical immune responses and neuroprotection during chronic Toxoplasma infection and provides the foundation for future mechanistic studies of these cells.
Assuntos
Neutrófilos , Toxoplasmose , Animais , Neutrófilos/imunologia , Neutrófilos/metabolismo , Camundongos , Toxoplasmose/imunologia , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Neurônios/imunologia , Toxoplasma/imunologia , Feminino , Neuroproteção/fisiologia , Masculino , Encéfalo/imunologia , Encéfalo/patologia , Encéfalo/parasitologiaRESUMO
The dynamic properties of neural systems throughout life can be hijacked by so-called manipulative parasites. This study investigated changes in the brain chemistry of the amphipod Gammarus fossarum in response to infection with two trophically-transmitted helminth parasites known to induce distinct behavioral alterations: the bird acanthocephalan Polymorphus minutus and the fish acanthocephalan Pomphorhynchus tereticollis. We quantified brain antioxidant capacity as a common marker of homeostasis and neuroprotection, and brain total protein, on 72 pools of six brains. We analyzed the concentration of serotonin (5HT), dopamine (DA) and tyramine in 52 pools of six brains, by using ultrafast high performance liquid chromatography with electrochemical detection (UHPLC-ECD). Brain total protein concentration scaled hypo-allometrically to dry body weight, and was increased in infected gammarids compared to uninfected ones. The brain of gammarids infected with P. minutus had significantly lower total antioxidant capacity relative to total proteins. Infection with P. tereticollis impacted DA level compared to uninfected ones, and in opposite direction between spring and summer. Brain 5HT level was higher in summer compared to spring independently of infection status, and was decreased by infection after correcting for brain total protein concentration estimated from dry whole-body weight. The potential implication of 5HT/DA balance in parasite manipulation, as a major modulator of the reward-punishment axis, is discussed. Taken together, these findings highlight the need to consider both brain homeostatic and/or structural changes (antioxidant and total protein content) together with neurotransmission balance and flexibility, in studies investigating the impact of parasites on brain and behavior.
Assuntos
Acantocéfalos , Anfípodes , Química Encefálica , Encéfalo , Serotonina , Animais , Acantocéfalos/fisiologia , Serotonina/análise , Serotonina/metabolismo , Encéfalo/parasitologia , Encéfalo/metabolismo , Anfípodes/parasitologia , Anfípodes/fisiologia , Estações do Ano , Dopamina/análise , Dopamina/metabolismo , Cromatografia Líquida de Alta Pressão , Antioxidantes/análise , Antioxidantes/metabolismoRESUMO
Delivering macromolecules across biological barriers such as the blood-brain barrier limits their application in vivo. Previous work has demonstrated that Toxoplasma gondii, a parasite that naturally travels from the human gut to the central nervous system (CNS), can deliver proteins to host cells. Here we engineered T. gondii's endogenous secretion systems, the rhoptries and dense granules, to deliver multiple large (>100 kDa) therapeutic proteins into neurons via translational fusions to toxofilin and GRA16. We demonstrate delivery in cultured cells, brain organoids and in vivo, and probe protein activity using imaging, pull-down assays, scRNA-seq and fluorescent reporters. We demonstrate robust delivery after intraperitoneal administration in mice and characterize 3D distribution throughout the brain. As proof of concept, we demonstrate GRA16-mediated brain delivery of the MeCP2 protein, a putative therapeutic target for Rett syndrome. By characterizing the potential and current limitations of the system, we aim to guide future improvements that will be required for broader application.
Assuntos
Encéfalo , Neurônios , Proteínas de Protozoários , Toxoplasma , Toxoplasma/genética , Toxoplasma/metabolismo , Animais , Neurônios/metabolismo , Neurônios/parasitologia , Camundongos , Humanos , Encéfalo/metabolismo , Encéfalo/parasitologia , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/genética , Proteína 2 de Ligação a Metil-CpG/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , Sistemas de Liberação de MedicamentosRESUMO
BACKGROUND: Cerebral echinococcosis is relatively rare, and it is important to distinguish cerebral cystic echinococcosis (CCE) from cerebral alveolar echinococcosis (CAE) in terms of pathological diagnosis. We aim to describe the different clinicopathological features among patients with CCE and CAE. METHODS: We collected 27 cases of cerebral echinococcosis which were diagnosed in the Department of Pathology of the First Affiliated Hospital of Xinjiang Medical University from January 1, 2012, to June 30, 2023. We compared the patients' clinical characteristics, MRI features, and pathologic manifestations of CCE and CAE. RESULTS: Among 27 cases of cerebral echinococcosis, 23 cases were CAE and 4 cases were CCE. The clinical manifestations of both CCE and CAE patients mainly included headache (21 patients, 77.78%), limb movement disorders (6 patients, 22.22%), epileptic seizures (4 patients, 14.81%) and visual disturbances (2 patients, 7.41%). The average onset age of CAE cases was 34.96 ± 11.11 years, which was 9.00 ± 7.26 years in CCE cases. All CAE patients presented with multiple involvements in the brain and extracranial organs while all CCE patients observed a solitary lesion in the brain and 3 CCE cases had no extracranial involvement. Lesions of CCE in MRI showed a single isolated circular, which was well demarcated from the surrounding tissues and with no obvious edema around the lesions, whereas CAE lesions presented as multiple intracranial lesions, with blurred edges and edema around the lesions, and multiple small vesicles could be observed in the lesions. The edge of CAE lesions could be enhanced, while CCE lesions have no obvious enhancement. CCE foci were clear cysts with a wall of about 0.1 cm. Microscopically, the walls of the cysts were characterized by an eosinophilic keratin layer, which was flanked on one side by basophilic germinal lamina cells, which were sometimes visible as protocephalic nodes. While the CAE lesion was a nodular structure with a rough and uneven nodule surface, and the cut section was cystic and solid; microscopically, the CAE lesion had areas of coagulative necrosis, and the proto-cephalic nodes were barely visible. Inflammatory cell areas consisting of macrophages, lymphocytes, epithelioid cells, plasma cells, eosinophils, and fibroblasts can be seen around the lesion. Brain tissues in the vicinity of the inflammatory cell areas may show apoptosis, degeneration, necrosis, and cellular edema, while brain tissues a little farther away from the lesion show a normal morphology. CONCLUSIONS: With the low incidence of brain echinococcosis, the diagnosis of echinococcosis and the differential diagnosis of CAE and CCE are challenging for pathologists. Grasping the different clinical pathology characteristics of CAE and CCE is helpful for pathologists to make accurate diagnoses.
Assuntos
Equinococose , Humanos , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , China/epidemiologia , Equinococose/patologia , Adulto Jovem , Imageamento por Ressonância Magnética , Diagnóstico Diferencial , Encefalopatias/parasitologia , Encefalopatias/patologia , Adolescente , Encéfalo/patologia , Encéfalo/parasitologiaRESUMO
Despite being the initial choice for treating toxoplasmosis, sulfadiazine and pyrimethamine have limited effectiveness in eliminating the infection and were linked to a variety of adverse effects. Therefore, the search for new effective therapeutic strategies against toxoplasmosis is still required. The current work is the first research to assess the efficacy of spiramycin-loaded maltodextrin nanoparticles (SPM-loaded MNPs) as a novel alternative drug therapy against toxoplasmosis in a murine model. Fifty laboratory-bred Swiss albino mice were divided into five groups: normal control group (GI, n = 10), positive control group (GII, n = 10), orally treated with spiramycin (SPM) alone (GIII, n = 10), intranasal treated with SPM-loaded MNPs (GIV, n = 10), and orally treated with SPM-loaded MNPs (GV, n = 10). Cysts of Toxoplasma gondii ME-49 strain were used to infect the mice. Tested drugs were administered 2 months after the infection. Drug efficacy was assessed by counting brain cysts, histopathological examination, and measures of serum CD19 by flow cytometer. The orally treated group with SPM-loaded MNPs (GV) showed a marked reduction of brain cyst count (88.7%), histopathological improvement changes, and an increasing mean level of CD19 (80.2%) with significant differences. SPM-loaded MNPs showed potent therapeutic effects against chronic toxoplasmosis. Further research should be conducted to assess it in the treatment of human toxoplasmosis, especially during pregnancy.
Assuntos
Modelos Animais de Doenças , Nanopartículas , Polissacarídeos , Espiramicina , Toxoplasmose Animal , Animais , Espiramicina/uso terapêutico , Espiramicina/administração & dosagem , Camundongos , Polissacarídeos/administração & dosagem , Polissacarídeos/uso terapêutico , Polissacarídeos/farmacologia , Nanopartículas/química , Toxoplasmose Animal/tratamento farmacológico , Toxoplasma/efeitos dos fármacos , Feminino , Encéfalo/parasitologia , Encéfalo/patologia , Antiprotozoários/administração & dosagem , Antiprotozoários/uso terapêutico , Toxoplasmose/tratamento farmacológico , Toxoplasmose/parasitologia , Portadores de FármacosRESUMO
Toxoplasma gondii, a widespread parasite, has the ability to infect nearly any nucleated cell in warm-blooded vertebrates. It is estimated that around 2 billion people globally have been infected by this pathogen. Although most healthy individuals can effectively control parasite replication, certain parasites may evade the immune response, establishing cysts in the brain that are refractory to the immune system and resistant to available drugs. For its chronic persistence in the brain, the parasite relies on host cells' nutrients, particularly amino acids and lipids. Therefore, understanding how latent parasites persist in the brain is crucial for identifying potential drug targets against chronic forms. While shielded within parasitophorous vacuoles (PVs) or cysts, Toxoplasma exploits the host endoplasmic reticulum (ER) metabolism to sustain its persistence in the brain, resulting in host neurological alterations. In this study, we demonstrate that T. gondii disrupts the host ER homeostasis, resulting in the accumulation of unfolded protein within the host ER. The host counters this stress by initiating an autophagic pathway known as ER-phagy, which breaks down unfolded proteins into amino acids, promoting their recycling. Our findings unveil the underlying mechanisms employed by T. gondii to exploit host ER and lysosomal pathways, enhancing nutrient levels during infection. These insights provide new strategies for the treatment of toxoplasmosis. IMPORTANCE: Intracellular parasites employ several mechanisms to manipulate the cellular environment, enabling them to persist in the host. Toxoplasma gondii, a single-celled parasite, possesses the ability to infect virtually any nucleated cell of warm-blooded vertebrates, including nearly 2 billion people worldwide. Unfortunately, existing treatments and immune responses are not entirely effective in eliminating the chronic persisting forms of the parasite. This study reveals that T. gondii induces the host's autophagic pathway to boost amino acid levels in infected cells. The depletion of amino acids, in turn, influences the persistence of the parasite's chronic forms. Significantly, our investigation establishes the crucial role of host endoplasmic reticulum (ER)-phagy in the parasite's persistence within the host during latent infection.
Assuntos
Aminoácidos , Autofagia , Retículo Endoplasmático , Toxoplasma , Toxoplasma/fisiologia , Aminoácidos/metabolismo , Animais , Retículo Endoplasmático/metabolismo , Camundongos , Toxoplasmose/parasitologia , Toxoplasmose/metabolismo , Humanos , Encéfalo/parasitologia , Interações Hospedeiro-ParasitaRESUMO
OBJECTIVE: To investigate the development and dynamic changes of cysts in the brain of mice following infection with different forms of Toxoplasma gondii, so as to provide insights into for toxoplasmosis prevention and control. METHODS: ICR mice at ages of 6 to 8 weeks, each weighing 20 to 25 g, were intraperitoneally injected with tachyzoites of the T. gondii PRU strain at a dose of 1 × 105 tachyzoites per mouse, orally administered with cysts at a dose of 20 oocysts per mouse or oocysts at a dose of 200 oocysts per mouse for modeling chronic T. gondii infection in mice, and the clinical symptoms and survival of mice were observed post-infection. Mice were orally infected with T. gondii cysts at doses of 10 (low-dose group), 20 (medium-dose group), 40 cysts per mouse (high-dose group), and the effect of different doses of T. gondii infections on the number of cysts was examined in the mouse brain. Mice were orally administered with T. gondii cysts at a dose of 20 cysts per mouse, and grouped according to gender (female and male) and time points of infections (20, 30, 60, 90, 120, 150, 180 days post-infection), and the effects of gender and time points of infections on the number of cysts was examined in the mouse brain. In addition, mice were divided into the tachyzoite group (Group T), the first-generation cyst group (Group C1), the second-generation cyst group (Group C2), the third-generation cyst (Group C3) and the fourth-generation cyst group (Group C4). Mice in the Group T were intraperitoneally injected with T. gondii tachyzoites at a dose of 1 × 105 tachyzoites per mouse, and the cysts were collected from the mouse brain tissues 30 days post-infection, while mice in the Group C1 were orally infected with the collected cysts at a dose of 30 cysts per mouse. Continuous passage was performed by oral administration with cysts produced by the previous generation in mice, and the effect of continuous passage on the number of cysts was examined in the mouse brain. RESULTS: Following infection with T. gondii tachyzoites, cysts and oocysts in mice, obvious clinical symptoms were observed on days 6 to 13 and mice frequently died on days 7 to 12. The survival rates of mice were 67.0%, 87.0% and 53.0%, and the mean numbers of cysts were (516.0 ± 257.2), (1 203.0 ± 502.0) and (581.0 ± 183.1) in the mouse brain (F = 11.94, P < 0.01) on day 30 post-infection with T. gondii tachyzoites, cysts and oocysts, respectively, and the numbers of cysts in the brain tissues were significantly lower in mice infected with T. gondii tachyzoites and oocysts than in those infected with cysts (all P values < 0.01). The survival rates of mice were 87.0%, 87.0% and 60.0%, and the mean numbers of cysts were (953.0 ± 355.5), (1 084.0 ± 474.3) and (1 113.0 ± 546.0) in the mouse brain in the low-, medium- and high-dose groups on day 30 post-infection, respectively (F = 0.42, P > 0.05). The survival rates of male and female mice were 73.0% and 80.0%, and the mean numbers of cysts were (946.4 ± 411.4) and (932.1 ± 322.4) in the brain tissues of male and female mice, respectively (F = 1.63, P > 0.05). Following continuous passage, the mean numbers of cysts were (516.0 ± 257.2), (1 203.0 ± 502.0), (896.8 ± 332.3), (782.5 ± 423.9) and (829.2 ± 306.0) in the brain tissues of mice in the T, C1, C2, C3 and C4 groups, respectively (F = 4.82, P < 0.01), and the number of cysts was higher in the mouse brain in Group 1 than in Group T (P < 0.01). Following oral administration of 20 T. gondii cysts in mice, cysts were found in the moues brain for the first time on day 20 post-infection, and the number of cysts gradually increased over time, peaked on days 30 and 90 post-infection and then gradually decreased; however, the cysts were still found in the mouse brain on day 180 post-infection. CONCLUSIONS: There is a higher possibility of developing chronic T. gondii infection in mice following infection with cysts than with oocysts or tachyzoites and the most severe chronic infection is seen following infection with cysts. The number of cysts does not correlate with the severity of chronic T. gondii infection, and the number of cysts peaks in the mouse brain on days 30 and 90 post-infection.
Assuntos
Encéfalo , Camundongos Endogâmicos ICR , Toxoplasma , Toxoplasmose Animal , Animais , Camundongos , Feminino , Masculino , Encéfalo/parasitologia , Doença Crônica , Toxoplasmose Animal/parasitologia , Toxoplasma/fisiologia , Toxoplasmose/parasitologia , Modelos Animais de DoençasRESUMO
Toxoplasma gondii is a successful parasite capable of infecting a wide range of warm-blooded animals, including people, livestock, and wildlife. In individuals with intact immune function, T. gondii can invade the host brain tissue by altering the blood-brain barrier permeability, leading to chronic infection. Proteins play crucial regulatory roles in disease progression. By monitoring changes in proteins, a deeper understanding of the molecular mechanisms underlying host resistance to infection and the potential pathogenic mechanisms of pathogens can be gained. This study analyzed differential protein expression and associated signaling pathways in mouse brain tissues during acute and chronic T. gondii infection using proteomic and bioinformatics methods. The results showed that during acute and chronic T. gondii infection stages, 74 and 498 differentially expressed proteins (DEPs) were identified in mouse brain tissue, respectively. Among them, 45 and 309 were up-regulated, while 29 and 189 were down-regulated. GO and KEGG analyses revealed that some of these DEPs were implicated in host immunity, pathogen immune evasion, and T. gondii invasion of the central nervous system, particularly interleukin production and secretion, complement system activation, and alterations in tight junction pathways. Notably, the upregulation of Rab13 was identified as a potential molecular mechanism for T. gondii to regulate blood-brain barrier permeability and facilitate central nervous system invasion. Our findings provided fundamental data for understanding host control of Toxoplasmosis infection and offered new insights into parasite immune evasion and invasion mechanisms within the central nervous system. These insights are crucial for developing strategies to prevent the establishment of chronic T. gondii infection.
Assuntos
Barreira Hematoencefálica , Encéfalo , Proteômica , Toxoplasma , Animais , Toxoplasma/imunologia , Camundongos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/parasitologia , Barreira Hematoencefálica/imunologia , Encéfalo/parasitologia , Encéfalo/metabolismo , Encéfalo/imunologia , Feminino , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/parasitologia , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab de Ligação ao GTP/genética , Transdução de SinaisRESUMO
Toxoplasmosis is a pervasive parasitic infection possessing a chief impact on both public health and veterinary medicine. Unfortunately, the commercially-available anti-Toxoplasma agents have either serious side effects or diminished efficiency, specifically on the Toxoplasma tissue cysts. In the present study, metformin (The first-line treatment for type 2 diabetes mellitus) was investigated for the first time against chronic cerebral toxoplasmosis in mice model experimentally-infected with ME49 strain versus spiramycin. Two metformin regimens were applied; starting one week before the infection and four weeks PI. Parasitological, ultrastructural, histopathological, immunohistochemical, immunological, and biochemical assessments were performed. The anti-parasitic effect of metformin was granted by the statistically-significant reduction in tissue-cyst burden in both treatment regimens. This was accompanied by markedly-mutilated ultrastructure and profound amelioration of the cerebral histopathology with remarkable decline in the brain CD4+ and CD8+ T cell count. Besides, diminution of anti-Toxoplasma IgG and brain GSH levels was evident. Ultimately, the present findings highlighted the powerful promising therapeutic role of metformin in the management of chronic toxoplasmosis on a basis of anti-parasitic, anti-inflammatory, and anti-oxidant possessions.
Assuntos
Encéfalo , Modelos Animais de Doenças , Metformina , Toxoplasma , Animais , Metformina/farmacologia , Metformina/uso terapêutico , Metformina/administração & dosagem , Camundongos , Encéfalo/parasitologia , Encéfalo/patologia , Encéfalo/efeitos dos fármacos , Toxoplasma/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Toxoplasmose Cerebral/tratamento farmacológico , Toxoplasmose Cerebral/parasitologia , Feminino , Toxoplasmose Animal/tratamento farmacológico , Anticorpos Antiprotozoários/sangue , Resultado do Tratamento , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Antiprotozoários/uso terapêutico , Antiprotozoários/farmacologia , Antiprotozoários/administração & dosagem , Doença Crônica , Espiramicina/uso terapêutico , Espiramicina/farmacologia , Imunoglobulina G/sangueRESUMO
Toxoplasma gondii (T. gondii) is an obligate intracellular parasite of warm-blooded vertebrates. At present, High-throughput RNA sequencing analysis have made it possible to determine the role of effective genes in host immune response. The aim of the present study is to global transcriptome analysis of the brain of mice infected with T. gondii Tehran strain for the first time and also to evaluate the expression of effective genes in the chronic form of infection. RNA was extracted from the samples and the library was prepared and sequenced using the IlluminaNovaSeq 6000 system. After analyzing gene expression changes, the results were confirmed by real-time method. We found 125 genes that were significantly differentially expressed between infected and non-infected samples (p < 0.0005). Gene ontology analysis revealed that the expression of many genes is critical for pathways such as T cell receptor signaling pathway, Natural Killer cell mediated cytotoxicity, Lysosome and Apoptosis of the host. As infection with Tehran strain leads to chronic infection in mice, therefore, we investigated the genes effective in creating the chronic form of Toxoplasma infection. The comparative analysis of genes showed increases in the expression of genes ctla4, ccl4, cd3e, c3, lcn2, gbp5, usp18, cyba, tap1 and samhd1 in the in the infected sample, which highlights their role in causing chronic infection. RNA-seq provides a valuable tool for analyzing host transcriptomes, better understanding the parasite-host interaction, and developing future drug and vaccine targets.
Assuntos
Encéfalo , Toxoplasma , Toxoplasmose Animal , Animais , Toxoplasma/genética , Toxoplasma/imunologia , Camundongos , Encéfalo/parasitologia , Encéfalo/metabolismo , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/parasitologia , RNA-Seq , Feminino , Perfilação da Expressão Gênica , Transcriptoma , Expressão GênicaRESUMO
Sarcocystis spp. cause pigeon protozoan encephalitis, a neuronal disease. A female pigeon exhibiting torticollis had a necrotic area in the cerebral hemisphere surrounded by lesions with perivascular cuffing, gliosis, granulomatous foci, and meningitis. Non-necrotic lesions were also observed in the brainstem. Intact and degenerative schizonts were observed within the neuropils and neurons in the lesions. Deoxyribonucleic acid (DNA) was extracted from paraffin-embedded brain tissues and genetically analyzed after gel electrophoresis to determine Sarcocystis spp. using specific primer sets for 28S ribosomal ribonucleic acid and internal transcribed spacer region-1. DNA sequencing confirmed a significant homology with S. calchasi. This is the first report of meningoencephalitis with malacia caused by S. calchasi in a rock pigeon in Japan.
Assuntos
Doenças das Aves , Columbidae , Meningoencefalite , Sarcocystis , Sarcocistose , Animais , Sarcocystis/isolamento & purificação , Sarcocystis/genética , Columbidae/parasitologia , Sarcocistose/veterinária , Sarcocistose/parasitologia , Sarcocistose/patologia , Feminino , Japão , Doenças das Aves/parasitologia , Doenças das Aves/patologia , Meningoencefalite/veterinária , Meningoencefalite/parasitologia , Meningoencefalite/patologia , Encéfalo/patologia , Encéfalo/parasitologiaRESUMO
BACKGROUND: The interplay between Toxoplasma gondii infection and tumor development is intriguing and not yet fully understood. Some studies showed that T. gondii reversed tumor immune suppression, while some reported the opposite, stating that T. gondii infection promoted tumor growth. METHODS: We created three mouse models to investigate the interplay between T. gondii and tumor. Model I aimed to study the effect of tumor growth on T. gondii infection by measuring cyst number and size. Models II and III were used to investigate the effect of different stages of T. gondii infection on tumor development via flow cytometry and bioluminescent imaging. Mouse strains (Kunming, BALB/c, and C57BL/6J) with varying susceptibilities to tumors were used in the study. RESULTS: The size and number of brain cysts in the tumor-infected group were significantly higher, indicating that tumor presence promotes T. gondii growth in the brain. Acute T. gondii infection, before or after tumor cell introduction, decreased tumor growth manifested by reduced bioluminescent signal and tumor size and weight. In the tumor microenvironment, CD4+ and CD8+ T cell number, including their subpopulations (cytotoxic CD8+ T cells and Th1 cells) had a time-dependent increase in the group with acute T. gondii infection compared with the group without infection. However, in the peripheral blood, the increase of T cells, including cytotoxic CD8+ T cells and Th1 cells, persisted 25 days after Lewis lung carcinoma (LLC) cell injection in the group with acute T. gondii. Chronic T. gondii infection enhanced tumor growth as reflected by increase in tumor size and weight. The LLC group with chronic T. gondii infection exhibited decreased percentages of cytotoxic CD8+ T cells and Th1 cells 25 days post-LLC injection as compared with the LLC group without T. gondii infection. At week 4 post-LLC injection, chronic T. gondii infection increased tumor formation rate [odds ratio (OR) 1.71] in both KM and BALB/c mice. CONCLUSIONS: Our research elucidates the dynamics between T. gondii infection and tumorigenesis. Tumor-induced immune suppression promoted T. gondii replication in the brain. Acute and chronic T. gondii infection had opposing effects on tumor development.
Assuntos
Modelos Animais de Doenças , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Toxoplasma , Animais , Camundongos , Toxoplasma/imunologia , Toxoplasmose/imunologia , Toxoplasmose/parasitologia , Feminino , Linfócitos T CD8-Positivos/imunologia , Encéfalo/parasitologia , Encéfalo/patologia , Doença Crônica , Microambiente Tumoral , Neoplasias/parasitologia , Doença AgudaRESUMO
Naegleria fowleri invades the brain and causes a fatal primary amoebic meningoencephalitis (PAM). Despite its high mortality rate of approximately 97%, an effective therapeutic drug for PAM has not been developed. Approaches with miltefosine, amphotericin B, and other antimicrobials have been clinically attempted to treat PAM, but their therapeutic efficacy remains unclear. The development of an effective and safe therapeutic drug for PAM is urgently needed. In this study, we investigated the anti-amoebic activity of Pinus densiflora leaf extract (PLE) against N. fowleri. PLE induced significant morphological changes in N. fowleri trophozoites, resulting in the death of the amoeba. The IC50 of PLE on N. fowleri was 62.3±0.95 µg/ml. Alternatively, PLE did not significantly affect the viability of the rat glial cell line C6. Transcriptome analysis revealed differentially expressed genes (DEGs) between PLE-treated and non-treated amoebae. A total of 5,846 DEGs were identified, of which 2,189 were upregulated, and 3,657 were downregulated in the PLE-treated amoebae. The DEGs were categorized into biological process (1,742 genes), cellular component (1,237 genes), and molecular function (846 genes) based on the gene ontology analysis, indicating that PLE may have dramatically altered the biological and cellular functions of the amoeba and contributed to their death. These results suggest that PLE has anti-N. fowleri activity and may be considered as a potential candidate for the development of therapeutic drugs for PAM. It may also be used as a supplement compound to enhance the therapeutic efficacy of drugs currently used to treat PAM.