ABSTRACT
Eukaryotic translation initiation factors (eIFs) are crucial for initiating protein translation and ensuring the correct assembly of mRNA-ribosomal subunit complexes. In this study, we investigated the effects of deleting six eIFs in the apicomplexan parasite Toxoplasma gondii using the CRISPR-Cas9 system. We determined the subcellular localization of these eIFs using C-terminal endogenous tagging and immunofluorescence analysis. Four eIFs (RH::315150-6HA, RH::286090-6HA, RH::249370-6HA, and RH::211410-6HA) were localized in the cytoplasm, while RH::224235-6HA was localized in the apicoplast. Additionally, RH::272640-6HA was found in both the basal complex and the cytoplasm of T. gondii. Functional characterization of the six RHΔeIFs strains was conducted using plaque assay, cell invasion assay, intracellular growth assay and egress assay in vitro, and virulence assay in mice. Disruption of five eIF genes (RHΔ315150, RHΔ272640, RHΔ249370, RHΔ211410, and RHΔ224235) did not affect the ability of the T. gondii RH strain to invade, replicate, form plaques and egress in vitro, or virulence in Kunming mice (p > 0.05). However, the RHΔ286090 strain showed slightly reduced invasion efficiency and virulence (p < 0.01) compared to the other five RHΔeIFs strains and the wild-type strain. The disruption of the TGGT1_286090 gene significantly impaired the ability of tachyzoites to differentiate into bradyzoites in both type I RH and type II Pru strains. These findings reveal that the eukaryotic translation initiation factor TGGT1_286090 is crucial for T. gondii bradyzoite differentiation and may serve as a potential target for drug development and an attenuated vaccine against T. gondii.
Subject(s)
CRISPR-Cas Systems , Eukaryotic Initiation Factors , Protozoan Proteins , Toxoplasma , Toxoplasma/genetics , Toxoplasma/pathogenicity , Toxoplasma/metabolism , Toxoplasma/growth & development , Animals , Mice , Protozoan Proteins/genetics , Protozoan Proteins/metabolism , Eukaryotic Initiation Factors/genetics , Eukaryotic Initiation Factors/metabolism , Virulence/genetics , Toxoplasmosis/parasitology , Toxoplasmosis/genetics , HumansABSTRACT
As Toxoplasma gondii disseminates through its host, the parasite must sense and adapt to its environment and scavenge nutrients. Oxygen (O2) is one such environmental factor and cytoplasmic prolyl 4-hydroxylases (PHDs) are evolutionarily conserved O2 cellular sensing proteins that regulate responses to changes in O2 availability. Toxoplasma expresses 2 PHDs. One of them, TgPHYa hydroxylates SKP1, a subunit of the SCF-E3 ubiquitin ligase complex. In vitro, TgPHYa is important for growth at low O2 levels. However, studies have yet to examine the role that TgPHYa or any other pathogen-encoded PHD plays in virulence and disease. Using a type II ME49 Toxoplasma TgPHYa knockout, we report that TgPHYa is important for Toxoplasma virulence and brain cyst formation in mice. We further find that while TgPHYa mutant parasites can establish an infection in the gut, they are unable to efficiently disseminate to peripheral tissues because the mutant parasites are unable to survive within recruited immune cells. Since this phenotype was abrogated in IFNγ knockout mice, we studied how TgPHYa mediates survival in IFNγ-treated cells. We find that TgPHYa is not required for release of parasite-encoded effectors into host cells that neutralize anti-parasitic processes induced by IFNγ. In contrast, we find that TgPHYa is required for the parasite to scavenge tryptophan, which is an amino acid whose levels are decreased after IFNγ up-regulates the tryptophan-catabolizing enzyme, indoleamine dioxygenase (IDO). We further find, relative to wild-type mice, that IDO knockout mice display increased morbidity when infected with TgPHYa knockout parasites. Together, these data identify the first parasite mechanism for evading IFNγ-induced nutritional immunity and highlight a novel role that oxygen-sensing proteins play in pathogen growth and virulence.
Subject(s)
Interferon-gamma , Oxygen , Protozoan Proteins , Toxoplasma , Animals , Toxoplasma/pathogenicity , Interferon-gamma/metabolism , Mice , Protozoan Proteins/metabolism , Protozoan Proteins/genetics , Oxygen/metabolism , Mice, Inbred C57BL , Virulence , Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism , Indoleamine-Pyrrole 2,3,-Dioxygenase/genetics , Female , Brain/parasitology , Brain/metabolism , Toxoplasmosis, Animal/immunology , Toxoplasmosis, Animal/metabolism , Toxoplasmosis, Animal/parasitology , Toxoplasmosis/immunology , Toxoplasmosis/metabolism , Toxoplasmosis/parasitologyABSTRACT
Toxoplasma infection in humans is considered due to direct contact with infected cats. Toxoplasma infection (an endemic disease) has the potential to affect various organs and systems (brain, eyes, heart, lungs, liver, and lymph nodes). Bilinear incidence rate and constant population (birth rate is equal to death rate) are used in the literature to explain the dynamics of Toxoplasmosis disease transmission in humans and cats. The goal of this study is to consider the mathematical model of Toxoplasma disease with harmonic mean type incident rate and also consider that the population of humans and cats is not equal (birth rate and the death rate are not equal). In examining Toxoplasma transmission dynamics in humans and cats, harmonic mean incidence rates are better than bilinear incidence rates. The disease dynamics are first schematically illustrated, and then the law of mass action is applied to obtain nonlinear ordinary differential equations (ODEs). Analysis of the boundedness, positivity, and equilibrium points of the system has been analyzed. The reproduction number is calculated using the next-generation matrix technique. The stability of disease-free and endemic equilibrium are analyzed. Sensitivity analysis is also done for reproduction number. Numerical simulation shows that the infection is spread in the population when the contact rate ß h and ß c increases while the infection is reduced when the recovery rate δ h increases. This study investigates the impact of various optimal control strategies, such as vaccinations for the control of disease and the awareness of disease awareness, on the management of disease.
Subject(s)
Toxoplasmosis , Animals , Humans , Toxoplasmosis/transmission , Toxoplasmosis/epidemiology , Toxoplasmosis/prevention & control , Cats , Incidence , Models, Theoretical , Toxoplasma/pathogenicity , Toxoplasma/physiology , Computer SimulationABSTRACT
Introduction: Toxoplasma gondii is an intracellular parasite of importance to human and veterinary health. The structure and diversity of the genotype population of T. gondii varies considerably with respect to geography, but three lineages, type I, II and III, are distributed globally. Lineage III genotypes are the least well characterized in terms of biology, host immunity and virulence. Once a host is infected with T.gondii, innate immune mechanisms are engaged to reduce the parasite burden in tissues and create a pro-inflammatory environment in which the TH1 response develops to ensure survival. This study investigated the early cellular immune response of Swiss-Webster mice post intraperitoneal infection with 10 tachyzoites of four distinct non-clonal genotypes of lineage III and a local isolate of ToxoDB#1. The virulence phenotype, cumulative mortality (CM) and allele profiles of ROP5, ROP16, ROP18 and GRA15 were published previously. Methods: Parasite dissemination in different tissues was analyzed by real-time PCR and relative expression levels of IFNγ, IL12-p40, IL-10 and TBX21 in the cervical lymph nodes (CLN), brain and spleen were calculated using the ΔΔCt method. Stage conversion was determined by detection of the BAG1 transcript in the brain. Results: Tissue dissemination depends on the virulence phenotype but not CM, while the TBX21 and cytokine levels and kinetics correlate better with CM than virulence phenotype. The earliest detection of BAG1 was seven days post infection. Only infection with the genotype of high CM (69.4%) was associated with high T-bet levels in the CLN 24 h and high systemic IFNγ expression which was sustained over the first week, while infection with genotypes of lower CM (38.8%, 10.7% and 6.8%) is characterized by down-regulation and/or low systemic levels of IFNγ. The response intensity, as assessed by cytokine levels, to the genotype of high CM wanes over time, while it increases gradually to genotypes of lower CM. Discussion: The results point to the conclusion that the immune response is not correlated with the virulence phenotype and/or allele profile, but an early onset, intense pro-inflammatory response is characteristic of genotypes with high CM. Additionally, high IFNγ level in the brain may hamper stage conversion.
Subject(s)
Cytokines , Genotype , Toxoplasma , Toxoplasmosis, Animal , Toxoplasma/pathogenicity , Toxoplasma/genetics , Toxoplasma/immunology , Animals , Mice , Virulence , Cytokines/metabolism , Toxoplasmosis, Animal/immunology , Toxoplasmosis, Animal/parasitology , Phenotype , Female , Spleen/immunology , Spleen/parasitology , Spleen/pathology , Brain/parasitology , Brain/pathology , Brain/immunology , Protozoan Proteins/genetics , Protozoan Proteins/immunology , Disease Models, Animal , Lymph Nodes/parasitology , Interferon-gamma/metabolism , Interferon-gamma/genetics , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism , Immunity, CellularABSTRACT
BACKGROUND: Toxoplasma gondii (T. gondii) is capable of infecting nearly all warm-blooded animals and approximately 30% of the global population. Though most infections are subclinical in immunocompetent individuals, congenital contraction can lead to severe consequences such as spontaneous abortion, stillbirth, and a range of cranio-cerebral and/or ocular abnormalities. Previous studies reported that T. gondii-infected pregnancy mice unveiled a deficit in both the amount and suppressive functions of regulatory T (Treg) cells, accompanied with reduced levels of forkhead box p3 (Foxp3). Recently, accumulative studies have demonstrated that microRNAs (miRNAs) are, to some extent, relevant to T. gondii infection. However, the link between alterations in miRNAs and downregulation of Foxp3 triggered by T. gondii has been only sporadically studied. METHODS: Quantitative reverse transcription polymerase chain reaction (RT-qPCR), protein blotting and immunofluorescence were employed to evaluate the impact of T. gondii infection and antigens on miRNA transcription and Foxp3 expression. Dual-luciferase reporter gene assays were performed to examine the fluorescence activity in EL4 cells, which were transfected with recombinant plasmids containing full-length/truncated/mutant microRNA-142a-3p (miR-142a) promoter sequence or wild type/mutant of Foxp3 3' untranslated region (3' UTR). RESULTS: We found a pronounced increase in miR-142a transcription, concurrent with a decrease in Foxp3 expression in T. gondii-infected mouse placental tissue. Similarly, comparable findings have been experimentally confirmed through the treatment of EL4 cells with T. gondii antigens (TgAg) in vitro. Simultaneously, miR-142a mimics attenuated Foxp3 expression, whereas its inhibitors markedly augmented Foxp3 expression. miR-142a promoter activity was elevated upon the stimulation of T. gondii antigens, which mitigated co-transfection of mutant miR-142a promoter lacking P53 target sites. miR-142a mimics deceased the fluorescence activity of Foxp3 3' untranslated region (3' UTR), but it did not affect the fluorescence activity upon the co-transfection of mutant Foxp3 3' UTR lacking miR-142a target site. CONCLUSION: In both in vivo and in vitro studies, a negative correlation was discovered between Foxp3 expression and miR-142a transcription. TgAg enhanced miR-142a promoter activity to facilitate miR-142a transcription through a P53-dependent mechanism. Furthermore, miR-142a directly targeted Foxp3 3' UTR, resulting in the downregulation of Foxp3 expression. Therefore, harnessing miR-142a may be a possible therapeutic approach for adverse pregnancy caused by immune imbalances, particularly those induced by T. gondii infection.
Subject(s)
Forkhead Transcription Factors , MicroRNAs , Toxoplasmosis , Animals , Female , Mice , Pregnancy , 3' Untranslated Regions , Down-Regulation , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Mice, Inbred C57BL , MicroRNAs/genetics , MicroRNAs/metabolism , Pregnancy Outcome , T-Lymphocytes, Regulatory/immunology , Toxoplasma/pathogenicity , Toxoplasmosis/parasitology , Toxoplasmosis/genetics , Toxoplasmosis/metabolismABSTRACT
The present in vitro and in vivo study aimed to fabricate and characterize linalool-zinc oxide nanoparticles (Lin-ZNP) and evaluate their effectiveness against Toxoplasma gondii infection in terms of inflammation, oxidative stress, and pathogenicity. Lin-ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The anti-Toxoplasma and cytotoxicity activities of Lin-ZNP were investigated, along with its effects on nitric oxide (NO) production, caspase-3 activity, and pro-inflammatory genes. After treating T. gondii-infected mice with Lin-ZNP for 14 days, the number and size of tissue cysts, antioxidant potential, pro-inflammatory cytokines, and T. gondii pathogenicity-related genes were evaluated by real-time polymerase chain reaction and Western blot analysis. The Lin-ZNP composite showed a reduced tendency with an average size of 105 nm. Lin-ZNP significantly reduced the viability of tachyzoites. The obtained selectivity index higher than 10, indicating high specificity for parasites with low cytotoxicity to normal cells. The Lin-ZNP significantly (p < 0.05) increased the production of NO, caspase-3 activity, and the expression levels of pro-inflammatory genes. Lin-ZNP significantly (p < 0.001) decreased the size and number of tissue cysts and caused a significant reduction in the level of malondialdehyde and a considerable increase (p < 0.001) in antioxidant enzymes and their expression genes. Lin-ZNP significantly downregulated both mRNA and protein expression of the inflammation-related markers associated with the TLRs/NF-κB pathway. The expression levels of the T. gondii pathogenicity-related genes were significantly downregulated (p < 0.05). The recent survey indicated that Lin-ZNP manages T. gondii infection by its antioxidant activity and inhibiting the TLRs/NF-κB pathway without toxicity in mice.
Subject(s)
Acyclic Monoterpenes , Inflammation , Nanocomposites , Nitric Oxide , Oxidative Stress , Toxoplasma , Zinc Oxide , Animals , Mice , Oxidative Stress/drug effects , Toxoplasma/drug effects , Toxoplasma/pathogenicity , Inflammation/drug therapy , Acyclic Monoterpenes/pharmacology , Zinc Oxide/pharmacology , Zinc Oxide/chemistry , Nitric Oxide/metabolism , Nanocomposites/chemistry , Antioxidants/pharmacology , Cytokines/metabolism , Toxoplasmosis/drug therapy , Toxoplasmosis/parasitology , Caspase 3/metabolism , Caspase 3/genetics , FemaleABSTRACT
Toxoplasma gondii (T. gondii) is a protozoan parasite that infects approximately one-third of the global human population, often leading to chronic infection. While acute T. gondii infection can cause neural damage in the central nervous system and result in toxoplasmic encephalitis, the consequences of T. gondii chronic infection (TCI) are generally asymptomatic. However, emerging evidence suggests that TCI may be linked to behavioral changes or mental disorders in hosts. Astrocyte polarization, particularly the A1 subtype associated with neuronal apoptosis, has been identified in various neurodegenerative diseases. Nevertheless, the role of astrocyte polarization in TCI still needs to be better understood. This study aimed to establish a mouse model of chronic TCI and examine the transcription and expression levels of glial fibrillary acidic protein (GFAP), C3, C1q, IL-1α, and TNF-α in the brain tissues of the mice. Quantitative real-time PCR (qRT-PCR), enzyme-linked immunosorbent assay, and Western blotting were employed to assess these levels. Additionally, the expression level of the A1 astrocyte-specific marker C3 was evaluated using indirect fluorescent assay (IFA). In mice with TCI, the transcriptional and expression levels of the inflammatory factors C1q, IL-1α, and TNF-α followed an up-down-up pattern, although they remained elevated compared to the control group. These findings suggest a potential association between astrocyte polarization towards the A1 subtype and synchronized changes in these three inflammatory mediators. Furthermore, immunofluorescence assay (IFA) revealed a significant increase in the A1 astrocytes (GFAP+C3+) proportion in TCI mice. This study provides evidence that TCI can induce astrocyte polarization, a biological process that may be influenced by changes in the levels of three inflammatory factors: C1q, IL-1α, and TNF-α. Additionally, the release of neurotoxic substances by A1 astrocytes may be associated with the development of TCI.
Subject(s)
Astrocytes , Brain , Toxoplasma , Animals , Astrocytes/metabolism , Astrocytes/parasitology , Astrocytes/pathology , Mice , Toxoplasma/pathogenicity , Toxoplasma/physiology , Brain/parasitology , Brain/metabolism , Brain/pathology , Disease Models, Animal , Female , Chronic Disease , Cell Polarity , Glial Fibrillary Acidic Protein/metabolism , Glial Fibrillary Acidic Protein/genetics , Toxoplasmosis/metabolism , Toxoplasmosis/parasitology , Toxoplasmosis/pathology , Tumor Necrosis Factor-alpha/metabolism , Toxoplasmosis, Cerebral/parasitology , Toxoplasmosis, Cerebral/pathology , Toxoplasmosis, Cerebral/metabolismABSTRACT
The placenta is a selective maternal-fetal barrier that provides nourishment and protection from infections. However, certain pathogens can attach to and even cross the placenta, causing pregnancy complications with potential lifelong impacts on the child's health. Here, we profiled at the single-cell level the placental responses to three pathogens associated with intrauterine complications-Plasmodium falciparum, Listeria monocytogenes, and Toxoplasma gondii. We found that upon exposure to the pathogens, all placental lineages trigger inflammatory responses that may compromise placental function. Additionally, we characterized the responses of fetal macrophages known as Hofbauer cells (HBCs) to each pathogen and propose that they are the probable niche for T. gondii. Finally, we revealed how P. falciparum adapts to the placental microenvironment by modulating protein export into the host erythrocyte and nutrient uptake pathways. Altogether, we have defined the cellular networks and signaling pathways mediating acute placental inflammatory responses that could contribute to pregnancy complications.
Subject(s)
Placenta , Single-Cell Analysis , Humans , Female , Pregnancy , Placenta/microbiology , Placenta/immunology , Single-Cell Analysis/methods , Plasmodium falciparum , Listeria monocytogenes/pathogenicity , Listeria monocytogenes/physiology , Toxoplasma/pathogenicity , Macrophages/microbiology , Macrophages/immunology , Macrophages/metabolism , Toxoplasmosis/immunology , Toxoplasmosis/metabolism , InflammationABSTRACT
BACKGROUND: Toxoplasma gondii, an obligate intracellular parasitic protozoa, infects approximately 30% of the global population. Contracting T. gondii at the primary infection of the mother can result in neonatal microcephaly, chorioretinitis, hydrocephalus, or mortality. Our previous study indicated that pregnant mice infected with T. gondii displayed a decrease in both the number and the suppressive ability of regulatory T cells, accompanied by the reduced Forkhead box P3 (Foxp3). Numerous studies have proved that microRNAs (miRNAs) are implicated in T. gondii infection, but there is meager evidence on the relationship between alterations of miRNAs and downregulation of Foxp3 induced by T. gondii. METHODS: Quantitative reverse transcription polymerase chain reaction was utilized to detect the transcriptions of miRNAs and Foxp3. Protein blotting and immunofluorescence were used to detect the expressions of Foxp3 and related transcription factors. The structure of mouse placenta was observed by hematoxylin and eosin (HE) staining. To examine the activity of miR-7b promoter and whether miR-7b-5p targets Sp1 to suppress Foxp3 expression, we constructed recombinant plasmids containing the full-length/truncated/mutant miR-7b promoter sequence or wildtype/mutant of Sp1 3' untranslated region (3' UTR) to detect the fluorescence activity in EL4 cells. RESULTS: In T. gondii-infected mice, miR-7b transcription was significantly elevated, while Foxp3 expression was decreased in the placenta. In vitro, miR-7b mimics downregulated Foxp3 expression, whereas its inhibitors significantly upregulated Foxp3 expression. miR-7b promoter activity was elevated upon the stimulation of T. gondii antigens, which was mitigated by co-transfection of mutant miR-7b promoter lacking peroxisome proliferator-activated receptor γ (PPARγ) target sites. Additionally, miR-7b mimics diminished Sp1 expression, while miR-7b inhibitors elevated its expression. miR-7b mimics deceased the fluorescence activity of Sp1 3' untranslated region (3' UTR), but it failed to impact the fluorescence activity upon the co-transfection of mutant Sp1 3' UTR lacking miR-7b target site. CONCLUSIONS: T. gondii infection and antigens promote miR-7b transcription but inhibit Foxp3 protein and gene levels. T. gondii antigens promote miR-7b promoter activity by a PPARγ-dependent mechanism. miR-7b directly binds to Sp1 3' UTR to repress Sp1 expression. Understanding the regulatory functions by which T. gondii-induced miR-7b suppresses Foxp3 expression can provide new perspectives for the possible therapeutic avenue of T. gondii-induced adverse pregnancy outcomes.
Subject(s)
Forkhead Transcription Factors , MicroRNAs , Toxoplasma , Animals , Female , Mice , Pregnancy , 3' Untranslated Regions , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , MicroRNAs/genetics , Placenta/metabolism , Placenta/parasitology , Placenta/pathology , PPAR gamma/genetics , PPAR gamma/metabolism , Signal Transduction , Toxoplasma/pathogenicity , Sp1 Transcription Factor/genetics , Sp1 Transcription Factor/metabolism , Toxoplasmosis/genetics , Toxoplasmosis/metabolism , Toxoplasmosis/parasitologyABSTRACT
Toxoplasma gondii has at least 318 genotypes distributed worldwide, and tropical regions usually have greater genetic diversity. Campeche is a state located in the southeastern region of México and has favourable climate conditions for the replication and dissemination of this protozoan, similar to those in South American countries where broad genetic diversity has been described. Thus, in this study, 4 T. gondii isolates were obtained from tissues of stray dogs and free-range chickens in Campeche, México, and were genotyped by Mn-PCR-RFLP with 10 typing markers (SAG1, altSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) and 5 virulence markers (CS3, ROP16, ROP17, ROP18 and ROP5) to provide new information about the distribution and virulence prediction of T. gondii genotypes. Two isolates of T. gondii genotype #116 and 2 of genotype #38 were obtained from stray dogs and chickens, respectively. The parasite load found in these species was between <50 and more than 35 000 tachyzoites per mg of tissue. Virulence marker genotyping revealed a recombinant 1&3 ROP5 RFLP pattern in 2 ToxoDB #116 isolates with no prediction of virulence in a murine model, while in the 2 ToxoDB #38 isolates, the ROP18/ROP5 combination predicted high virulence. Considering all the typed markers, there is a predominance of type I and III alleles, as constantly reported for the isolates characterized in various regions of México. It is crucial to determine their phenotype to corroborate the genetic virulence profile of the T. gondii isolates obtained in this study.
Subject(s)
Chickens , Genotype , Poultry Diseases , Protozoan Proteins , Toxoplasma , Toxoplasmosis, Animal , Animals , Mexico/epidemiology , Toxoplasma/genetics , Toxoplasma/pathogenicity , Toxoplasma/classification , Toxoplasma/isolation & purification , Chickens/parasitology , Toxoplasmosis, Animal/parasitology , Virulence , Dogs , Protozoan Proteins/genetics , Mice , Poultry Diseases/parasitology , Polymorphism, Restriction Fragment Length , Dog Diseases/parasitology , AllelesABSTRACT
A Neospora caninum e a Toxoplasma gondii são os agentes etiológicos que causam a Neosporose e a Toxoplasmose, respectivamente. Estas duas doenças são consideradas de grande importância econômica e de distribuição mundial, que acometem tanto animais de produção quanto animais domésticos. Apresentam sinais clínicos inespecíficos, sendo a Neosporose frequentemente associada ao abortamento em fêmeas. Ambas enfermidades costumavam ser confundidas, dificultando o diagnóstico. São causadas por protozoários cosmopolitas de ciclos biológicos heteróxenos. O Toxoplasma gondii é responsável por doença clínica em cães e gatos, enquanto o Neospora caninum acomete somente cães. Além disso, não há, até o momento, relatos de Neosporose em humanos, diferente da Toxoplasmose. Ocasionalmente esta pode ocorrer em coiotes, suínos, ovinos, caprinos, equinos, cervídeos e bubalinos. Anticorpos contra Neospora tem sido descrito em raposas, camelos e felídeos. O objetivo da presente revisão, é elucidar a forma de transmissão, sinais clínicos, diagnóstico, tratamento e controle de ambas as doenças, mostrando suas semelhanças, afim de que se possa diagnosticá-las corretamente.(AU)
Neospora caninum and toxoplasma gondii are agents of great economic importance and worldwide distribution that affect production and domestic animals. They present nonspecific clinical signs, and neosporosis is a disease that frequently causes abortion in females, which is considered current, because both used to be confused, making diagnosis difficult. They are protozoan, cosmopolitan, of heterogeneous biological cycles. Toxoplasma gondii is responsible for clinical disease in dogs and cats, while Neospora caninum affects only dogs. Furthermore, there are no reports to date of neosporosis in humans, other than toxoplasmosis. Occasionally it may occur in coyotes, pigs, sheep, goats, horses, deer, and bubaline. Antibodies to Neospora have been described in foxes, camels, and felids. This review aims to elucidate the transmission, clinical signs, diagnosis, treatment, and control of both diseases, showing their similarities, so that they can be correctly diagnosed.(AU)
Neospora caninum y Toxoplasma gondii son los agentes etiológicos que causan Neosporosis y Toxoplasmosis, respectivamente. Estas dos enfermedades se consideran de gran importancia económica y de distribución mundial, afectando tanto al ganado como a los animales domésticos. Presentan signos clínicos inespecíficos y la neosporosis se asocia con frecuencia al aborto en mujeres. Ambas dolencias solían ser erróneas, lo que hacía difícil el diagnóstico. Son causados por protozoos cosmopolitas de ciclos biológicos heterogéneos. Toxoplasma gondii es responsable de enfermedades clínicas en perros y gatos, mientras que Neospora caninum sólo ataca a perros. Además, no se han notificado casos de Neosporosis en humanos hasta el momento, diferente de Toxoplasmosis. Ocasionalmente esto puede ocurrir en coyotes, cerdos, ovejas, cabras, caballos, ciervos y bubalinos. Se han notificado anticuerpos contra la Neospora en zorros, camellos y felinos. El propósito de esta revisión es dilucidar la forma de transmisión, los signos clínicos, el diagnóstico, el tratamiento y el control de ambas enfermedades, mostrando sus similitudes, de manera que puedan ser diagnosticadas correctamente.(AU)
Subject(s)
Animals , Toxoplasmosis/diagnosis , Toxoplasmosis/etiology , Coccidiosis/diagnosis , Coccidiosis/etiology , Toxoplasma/pathogenicity , Neospora/pathogenicityABSTRACT
BACKGROUND: Toxoplasma gondii is known as the most successful parasite, which can regulate the host immune response through a variety of ways to achieve immune escape. We previously reported that a novel gene wx2 of T. gondii may be a virulence-related molecule. The objective of this study was to explore the mechanism of wx2 regulating host immune response. METHODS: The wx2 knockout strain (RHwx2-/- strain) and complementary strain (RHwx2+/+ strain) were constructed by the CRISPR/Cas9 technique, and the virulence of the wx2 gene was detected and changes in pyroptosis-related molecules were observed. RESULTS: Compared with the wild RH and RHwx2+/+ strain groups, the survival time for mice infected with the RHwx2-/- strain was prolonged to a certain extent. The mRNA levels of pyroptosis-related molecules of caspase-1, NLRP3, and GSDMD and et al. in mouse lymphocytes in vivo and RAW267.4 cells in vitro infected with RHwx2-/- strain increased to different degrees, compared with infected with wild RH strain and RHwx2+/+ strain. As with the mRNA level, the protein level of caspase-1, caspase-1 p20, IL-1ß, NLRP3, GSDMD-FL, GSDMD-N, and phosphorylation level of NF-κB (p65) were also significantly increased. These data suggest that wx2 may regulate the host immune response through the pyroptosis pathway. In infected RAW264.7 cells at 48 h post-infection, the levels of Th1-type cytokines of IFN-γ, Th2-type cytokines such as IL-13, Th17-type cytokine of IL-17 in cells infected with RHwx2-/- were significantly higher than those of RH and RHwx2+/+ strains, suggesting that the wx2 may inhibit the host's immune response. CONCLUSION: wx2 is a virulence related gene of T. gondii, and may be involved in host immune regulation by inhibiting the pyroptosis pathway.
Subject(s)
Host-Parasite Interactions , Pyroptosis , Toxoplasma , Animals , Mice , Caspase 1/metabolism , Cytokines/genetics , Cytokines/metabolism , Immunity , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , RNA, Messenger/metabolism , Toxoplasma/genetics , Toxoplasma/pathogenicity , Virulence , Host-Parasite Interactions/immunologyABSTRACT
Toxoplasma gondii is able to manipulate the host immune system to establish a persistent and efficient infection, contributing to the development of brain abnormalities with behavioral repercussions. In this context, this work aimed to evaluate the effects of T. gondii infection on the systemic inflammatory response and structure of the primary somatosensory cortex (PSC). C57BL/6 and BALB/c mice were infected with T. gondii ME49 strain tissue cysts and accompanied for 30 days. After this period, levels of cytokines IFN-γ, IL-12, TNF-α and TGF-ß were measured. After blood collection, mice were perfused and the brains were submitted to immunohistochemistry for perineuronal net (PNN) evaluation and cyst quantification. The results showed that C57BL/6 mice presented higher levels of TNF-α and IL-12, while the levels of TGF-ß were similar between the two mouse lineages, associated with the elevated number of tissue cysts, with a higher occurrence of cysts in the posterior area of the PSC when compared to BALB/c mice, which presented a more homogeneous cyst distribution. Immunohistochemistry analysis revealed a greater loss of PNN labeling in C57BL/6 animals compared to BALB/c. These data raised a discussion about the ability of T. gondii to stimulate a systemic inflammatory response capable of indirectly interfering in the brain structure and function.
Subject(s)
Somatosensory Cortex , Systemic Inflammatory Response Syndrome , Toxoplasma , Toxoplasmosis , Animals , Mice , Interleukin-12/metabolism , Mice, Inbred BALB C , Mice, Inbred C57BL , Somatosensory Cortex/immunology , Somatosensory Cortex/parasitology , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/parasitology , Toxoplasma/pathogenicity , Toxoplasmosis/immunology , Toxoplasmosis/parasitology , Transforming Growth Factor beta/metabolism , Tumor Necrosis Factor-alpha/metabolismABSTRACT
AIMS: Toxoplasmosis, caused by Toxoplasma gondii (Tg), is one of the most prevalent zoonotic diseases worldwide. Currently, safe and efficient therapeutic options for this disease are still being developed, and are urgently needed. Tylvalosin (Tyl), a broad-spectrum third-generation macrolide, exhibits anti-bacterial, anti-viral, and anti-inflammatory properties. The present study aims to explore the anti-parasitic and immunomodulation activities of Tyl against Tg, and the underlying mechanism. MAIN METHODS: Adhesion, invasion, replication, proliferation, plaque, reversibility, immunofluorescence assays and transmission electron microscopy were utilized to determine the anti-Toxoplasma effect of Tyl. With acute toxoplasmosis model and rabies virus-induced brain inflammation model, the anti-toxoplasmosis and immunomodulation activities of Tyl were assessed by colorimetric assay, histopathological and Oil red O staining, and real-time quantitative PCR. The involved molecular mechanisms were investigated by western blotting and immunohistochemical staining. KEY FINDINGS: Tyl (5 and 10 µg/ml) can inhibit Tg propagation, and damage its ultrastructure irreversibly. The combination of Tyl and Pyrimethamine (Pyr) exhibits a better synergistic effect. Tyl (50 and 100 mg/kg) treatment intraperitoneally can delay mice death and improve survival rate, accompanying the reduced histopathological score and parasite load in the indicated tissues, espically for ileum, liver, spleen, lung and brain. Furthermore, Tg can modulate host phospho-p38 MAPK (pp38), subtilisin/kexin-isozyme-1 (SKI-1)-sterol regulatory element binding protein-1 (SREBP-1) (SKI-1-SREBP-1) pathway and peroxisome proliferators-activated receptor δ (PPARδ), while Tyl is able to reverse these signal pathways close to normal levels. SIGNIFICANCE: Our findings indicate that Tyl exhibits anti-Toxoplasma activity and protects mice from acute toxoplasmosis.
Subject(s)
Acute Lung Injury/drug therapy , Antiparasitic Agents/pharmacology , Brain Diseases/drug therapy , Toxoplasma/pathogenicity , Toxoplasmosis/drug therapy , Tylosin/analogs & derivatives , Acute Lung Injury/immunology , Acute Lung Injury/parasitology , Animals , Brain Diseases/immunology , Brain Diseases/parasitology , Female , Male , Mice , Mice, Inbred C57BL , Toxoplasmosis/immunology , Toxoplasmosis/parasitology , Tylosin/pharmacologySubject(s)
Mitochondria/physiology , Mitochondria/parasitology , Animals , Host-Parasite Interactions/physiology , Mitochondrial Membranes/parasitology , Mitochondrial Membranes/physiology , Models, Biological , Protozoan Proteins/physiology , Stress, Physiological , Toxoplasma/pathogenicity , Toxoplasmosis/parasitology , Toxoplasmosis/physiopathologyABSTRACT
BACKGROUND: Toxoplasma gondii, one of the most common parasites, causes toxoplasmosis, one of the most frequent zoonotic diseases worldwide. T. gondii infects about one-third of the world's population. T. gondii infection is generally considered a major risk for spontaneous abortion, prematurity and low birth weight in the animal sphere. Less commonly, a toxoplasma serological profile is correlated with the particular data of delivery. Acute T. gondii infection during pregnancy often leads to spontaneous abortion and/or a severe injury of the eyes, brain, and other structures of the foetus. Latent T. gondii infection of pregnant women could lead to less obvious but important changes during pregnancy, including the end product of pregnancy and the timing of labour. This study aimed to contribute to the current knowledge by comparing serological T. gondii profiles of pregnant women with prematurity and low birth weights of newborns. MATERIAL AND METHODS: A retrospective study design was adopted. The study participants included a cohort of 1733 pregnant women who consecutively gave birth to their children and underwent regular antenatal biochemical screening between the 14th and 16th weeks of pregnancy. Prematurity was defined as the liveborn preterm delivery in gestational age of pregnancy <37 weeks. Low birth weight was defined as weight at birth of ≤2499 grams. The complement-fixation test (CFT) provided serological profiles for toxoplasmosis that expresses the overall levels of toxoplasma immunoglobulins of all classes. Enzyme-linked immunosorbent assay (ELISA) tests for IgG and IgM were used simultaneously. IgM positivity helped to differentiate acute from the latent stage of toxoplasmosis. Birth data, especially the week of delivery and fetal weight, were evaluated accordingly. RESULTS: Of the 1733 pregnant women, 25% were diagnosed as latent toxoplasma positive, and 75% as toxoplasma negative. There were 87 premature deliveries versus 1646 timely births. We observed 88 low birth weights and 1645 normal fetal weights. We found a statistically significant association between latent toxoplasmosis and prematurity, χ2(1) = 5.471, p = .019 and between latent toxoplasmosis and low birth weight of newborns, χ2(1) = 7.663, p = .006. There was a 1.707 times higher risk of prematurity for toxoplasma-positive women, while the risk for low birth weight was 1.861 times higher. The strength of both tests of association was mild. We tested the correlation between the levels of CFT titres and week of delivery and weight of newborns. No association was found between the level of latent toxoplasmosis and the week of delivery and fetal weight. CONCLUSION: Latent toxoplasmosis was associated with premature birth rate and lower birth weight of newborns. The odds of premature delivery was 1.7 and low birth weight 1.9 times higher in women with latent toxoplasmosis compared to toxoplasma negative women. Even though the strength of the association in our large sample is relatively mild, the combination of latent toxoplasmosis with other adverse factors could cause serious harm. Whole CFT and specific IgG levels of latent toxoplasmosis are not linked to the severity of prematurity or low birth weight in newborns.
Subject(s)
Infant, Low Birth Weight/metabolism , Premature Birth/etiology , Toxoplasmosis/embryology , Adult , Female , Humans , Infant , Infant, Newborn , Infant, Newborn, Diseases/epidemiology , Infant, Premature, Diseases/epidemiology , Pregnancy , Pregnancy Complications, Parasitic/epidemiology , Pregnant Women , Premature Birth/physiopathology , Prevalence , Retrospective Studies , Risk Factors , Seroepidemiologic Studies , Serologic Tests , Toxoplasma/pathogenicity , Toxoplasmosis/epidemiologyABSTRACT
Coenzyme A (CoA) is an essential molecule acting in metabolism, post-translational modification, and regulation of gene expression. While all organisms synthesize CoA, many, including humans, are unable to produce its precursor, pantothenate. Intriguingly, like most plants, fungi and bacteria, parasites of the coccidian subgroup of Apicomplexa, including the human pathogen Toxoplasma gondii, possess all the enzymes required for de novo synthesis of pantothenate. Here, the importance of CoA and pantothenate biosynthesis for the acute and chronic stages of T. gondii infection is dissected through genetic, biochemical and metabolomic approaches, revealing that CoA synthesis is essential for T. gondii tachyzoites, due to the parasite's inability to salvage CoA or intermediates of the pathway. In contrast, pantothenate synthesis is only partially active in T. gondii tachyzoites, making the parasite reliant on its uptake. However, pantothenate synthesis is crucial for the establishment of chronic infection, offering a promising target for intervention against the persistent stage of T. gondii.
Subject(s)
Pantothenic Acid/biosynthesis , Parasites/pathogenicity , Persistent Infection/parasitology , Toxoplasma/pathogenicity , Toxoplasmosis/parasitology , Animals , Biosynthetic Pathways , Cell Differentiation , Cell Membrane/metabolism , Coenzyme A/biosynthesis , Coenzyme A/chemistry , Coenzyme A/metabolism , Cytoplasm/metabolism , Female , Life Cycle Stages , Mice , Pantothenic Acid/chemistry , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Protein Multimerization , Toxoplasma/growth & developmentSubject(s)
Blindness/parasitology , Career Choice , Microscopy, Confocal , Parasites/pathogenicity , Research Personnel , Toxoplasma/pathogenicity , Animals , Blindness/congenital , Female , Humans , Infant, Newborn , Parasites/cytology , Pregnancy , Sheep , Sheep Diseases/parasitology , Toxoplasma/cytology , Toxoplasmosis/parasitology , VirulenceABSTRACT
Signalling by IFN-y and CD40 is known to trigger anti-microbial activity in macrophages infected with Toxoplasma gondii, but their effects on infected neurons are less well known. Here, we compared how stimulation with IFN-y and an agonistic anti-CD40 mAb impacts infection and cyst formation in the mouse neuroblastoma cell line Neuro-2a relative to bone marrow-derived macrophages. Both IFN-y and CD40 mAb decreased cyst emergence in Neuro-2a cells. In macrophages, these stimuli decreased infection, but had no impact on infection in the neuroblastoma cell line. Resistance to killing in Neuro-2a cells may explain why neurons preferentially harbour parasites during chronic infection in the brain.
Subject(s)
CD40 Antigens , Interferon-gamma , Toxoplasma , Animals , CD40 Antigens/metabolism , Cell Line, Tumor , Interferon-gamma/metabolism , Mice , Neuroblastoma , Toxoplasma/pathogenicityABSTRACT
Protozoan parasites with complex life cycles have high mortality rates affecting billions of human lives. Available anti-parasitic drugs are inadequate due to variable efficacy, toxicity, poor patient compliance and drug-resistance. Hence, there is an urgent need for the development of safer and better chemotherapeutics. Mitogen Activated Protein Kinases (MAPKs) have drawn much attention as potential drug targets. This review summarizes unique structural and functional features of MAP kinases and their possible role in pathogenesis of obligate intracellular protozoan parasites namely, Leishmania, Trypanosoma, Plasmodium and Toxoplasma. It also provides an overview of available knowledge concerning the target proteins of parasite MAPKs and the need to understand and unravel unknown interaction network(s) of MAPK(s).