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Sexual development in Toxoplasma gondii is a multistep process that culminates in the production of oocysts, constituting approximately 50% of human infections. However, the molecular mechanisms governing sexual commitment in this parasite remain poorly understood. Here, we demonstrate that the transcription factors AP2XI-2 and AP2XII-1 act as negative regulators, suppressing merozoite-primed pre-sexual commitment during asexual development. Depletion of AP2XI-2 in type II Pru strain induces merogony and production of mature merozoites in an alkaline medium but not in a neutral medium. In contrast, AP2XII-1-depleted Pru strain undergoes several rounds of merogony and produces merozoites in a neutral medium, with more pronounced effects observed under alkaline conditions. Additionally, we identified two additional AP2XI-2-interacting proteins involved in repressing merozoite programming. These findings underscore the intricate regulation of pre-sexual commitment by a network of factors and suggest that AP2XI-2 or AP2XII-1-depleted Pru parasites can serve as a model for studying merogony in vitro. Wang et al. discovered that AP2XI-2 and AP2XII-1 negatively regulate merozoite-primed pre-sexual commitment in Toxoplasma gondii, and parasites depleted of either AP2XI-2 or AP2XII-1 can serve as a valuable in vitro model for studying merogony.

Protein phosphatases are post-translational regulators of Toxoplasma gondii proliferation, tachyzoite-bradyzoite differentiation and pathogenesis. Here, we identify the putative protein phosphatase 6 (TgPP6) subunits of T . gondii and elucidate their role in the parasite lytic cycle. The putative catalytic subunit TgPP6C and regulatory subunit TgPP6R likely form a complex whereas the predicted structural subunit TgPP6S, with low homology to the human PP6 structural subunit, does not coassemble with TgPP6C and TgPP6R. Functional studies showed that TgPP6C and TgPP6R are essential for parasite growth and replication. The ablation of TgPP6C significantly reduced the synchronous division of the parasite’s daughter cells during endodyogeny, resulting in disordered rosettes. Moreover, the six conserved motifs of TgPP6C were required for efficient endodyogeny. Phosphoproteomic analysis revealed that ablation of TgPP6C predominately altered the phosphorylation status of proteins involved in the regulation of the parasite cell cycle. Deletion of TgPP6C significantly attenuated the parasite virulence in mice. Immunization of mice with TgPP6C-deficient type I RH strain induced protective immunity against challenge with a lethal dose of RH or PYS tachyzoites and Pru cysts. Taken together, the results show that TgPP6C contributes to the cell division, replication and pathogenicity in T . gondii .

Toxoplasma gondii is a significant pathogen in both humans and animals, with disease progression driven by the rapid proliferation of its tachyzoite stage. In this study, we identify the PP2A-2 holoenzyme as a key regulator of daughter cell emergence during parasite division. This holoenzyme, likely composed of the regulatory subunit TgPR48 (PP2A-B2), the catalytic subunit PP2A-C2, and the scaffolding subunit PP2A-A2, is essential for proper cytokinesis. Disruption of any single component severely impairs daughter cell separation and emergence. Phosphoproteomic analysis following PP2A-C2 depletion revealed numerous differentially phosphorylated proteins. Among these, DCS1 and DCS2 were prioritized as potential effectors. While phosphomimetic and non-phosphorylatable mutations in DCS1 and DCS2 did not significantly impair their function, depletion of either protein disrupted TgPR48 localization. Interestingly, TgPR48 overexpression partially rescued the phenotypes associated with DCS2 loss, but not DCS1, indicating divergence in their downstream pathways and implicating additional, yet unidentified, substrates. These findings establish PP2A-2–mediated dephosphorylation as a central mechanism in regulating tachyzoite cytokinesis and highlight a promising regulatory axis for therapeutic intervention against T. gondii .

Toxoplasma gondii undergoes a complex life cycle characterized by alternating developmental stages. The genetic reprogramming mechanisms driving these stage transitions remain largely unknown. In this study, we identified the AP2 factor AP2X-1 as a critical regulator important for T. gondii growth and life cycle progression. Our findings suggest that AP2X-1 functions as a repressor by modulating the function or influencing the association of the HDAC3/MORC complex at the promoters of bradyzoite- and sexual stage-specific genes, leading to chromatin compaction, restricting DNA accessibility and thereby repressing the transcription of genes required for bradyzoite formation and sexual commitment. Deletion of ap2X-1 significantly reduced T. gondii virulence and its ability to form brain cysts. These findings reveal a previously unknown regulatory pathway controlling sexual development in T. gondii , providing new insights into its underlying mechanisms.

Echinococcus granulosus sensu stricto ( s.s. ) is the primary cause of cystic echinococcosis (CE), a parasitic disease affecting humans and livestock with significant health and economic impacts. Previous studies on this parasite relied on mitochondrial DNA to classify its genotypes and understand its genetic diversity. However, these studies cannot capture the full complexity of its evolutionary dynamics and adaptation strategies. Our research employs comprehensive genome-wide sequencing, offering a more nuanced view of its genetic landscape. We discovered that cross-fertilization appears to be a prevalent reproductive strategy in the hermaphroditic E. granulosus , underpinning the observed deep mitochondrial divergence between genotypes G1 and G3, as well as gene flow among populations. The transmission history of E. granulosus s.s. in China and its widespread genetic mixing were likely facilitated by the migrations of nomadic peoples. Furthermore, we identified genes under balancing selection, including the gene involved in the uptake of host bile acids, which play a crucial role in the parasite’s survival and development, potentially offering new targets for intervention. Our research advances the understanding of the genetic diversity and evolutionary strategies of E. granulosus , laying the foundation for improved control measures of CE.

Toxoplasma gondii is a widely spread opportunistic pathogen that can infect nearly all warm-blooded vertebrates and cause serious toxoplasmosis in immunosuppressed animals and patients. However, the relationship between the host’s innate immune system and effector proteins is poorly understood, particularly with regard to how effectors antagonize cGAS-STING signaling during T. gondii infection. In this study, the ROP5 from the PRU strain of T. gondii was found to promote cGAS-STING-mediated immune responses. Mechanistically, ROP5 interacted with STING through predicted domain 2 and modulated cGAS-STING signaling in a predicted domain 3-dependent manner. Additionally, ROP5 strengthened cGAS-STING signaling by enhancing the K63-linked ubiquitination of STING. Consistently, ROP5 deficient PRU (PRUΔROP5) induced fewer type I IFN-related immune responses and replicated faster than the parental strain in RAW264.7 cells. Taken together, this study provides new insights into the mechanism by which ROP5 regulates T. gondii infection and provides new clues for strategies to prevent and control toxoplasmosis.

Background Cystic echinococcosis (CE) is a serious tapeworm infection caused by Echinococcus granulosus ( sensu lato ) which infects a wide range of animals and humans worldwide. Despite the millions of livestock heads reared in Pakistan, only a few reports on CE prevalence and even fewer on the genetic diversity are available for the country. Meanwhile, the available reports on the genetic diversity are predominantly based on short sequences of the cox 1 gene. Methods To close this knowledge gap, this study was designed to investigate the genetic diversity and population structure of Echinococcus spp. in Pakistan using the complete mitochondrial cytochrome c oxidase subunit 1 ( cox 1) and NADH dehydrogenase subunit 1 ( nad 1) genes. Results Based on BLAST searches of the generated cox 1 and nad 1 gene sequences from a total of 60 hydatid cysts collected from cattle ( n  = 40) and buffalo ( n  = 20), 52 isolates were identified as E . granulosus ( s.s. ) (G1, G3) and 8 as E . ortleppi (G5). The detection of the G5 genotype represents the first in Pakistan. The phylogeny inferred by the Bayesian method using nucleotide sequences of cox 1 -nad 1 further confirmed their identity. The diversity indices indicated a high haplotype diversity and a low nucleotide diversity. The negative values of Tajima’s D and Fu’s Fs test demonstrated deviation from neutrality suggesting a recent population expansion. Conclusions To the best of our knowledge, this report described the genetic variation of E. granulosus population for the first time in Pakistan using the complete cox 1 and nad 1 mitochondrial genes and confirms E. ortleppi as one of the causative agents of CE among livestock in Pakistan. While this report will contribute to baseline information for CE control, more studies considering species diversity and distribution in different hosts across unstudied regions of Pakistan are highly needed.

spp., are amongst the most widespread parasitic nematodes, primarily live in the muscles of a wide range of vertebrate animals and humans. Human infection occurs by ingestion of raw or undercooked meat containing larvae. Accurate diagnosis of spp. infection in domestic animals is crucial for the effective prevention and control of human trichinellosis. In the present study, a simple, rapid and accurate diagnostic assay was developed combining recombinase polymerase amplification and a lateral flow strip (LF-RPA) to detect spp. infection. The LF-RPA assay targets spp. mitochondrial small-subunit ribosomal RNA ( ) gene and can detect as low as 100 fg DNA of strains, which was approximately 10 times more sensitive than a conventional PCR assay. The LF-RPA assay can be performed within 10-25 min, at a wide range of temperatures (25-45°C) and showed no cross-reactivity with DNA of other parasites and related host species of . The performance of the LF-RPA assay in the presence of high concentration of PCR inhibitor was better than that of a conventional PCR assay. Results obtained by LF-RPA assay for the detection of experimentally infected mice were comparable to the results obtained by using a conventional PCR, achieving 100% specificity and high sensitivity. These results present the developed LF-RPA assay as a new simple, specific, sensitive, rapid and convenient method for the detection of infection in domestic animals.

Echinococcosis is a serious public health issue that affects people and livestock all over the world. Many synthetic and natural products have been examined in vitro and in vivo on Echinococcus species but only a few are used clinically, however, they may cause some complications and side effects. To overcome these limitations, new horizons of herbal drugs to cure echinococcosis are opening with every passing day. To summarize the developments during the last 21 years, we conducted this review of the literature to identify medicinal herbs utilized throughout the world that have anti-Echinococcus activity. From 2000 to 2021, data were carefully obtained from four English databases: Science Direct, PubMed, Scopus, and OpenGrey. Botanical name, extraction technique, extract quantities, efficacy, duration of treatment, year of publication, and half-maximal inhibitory concentration (IC50) values were all well noted. Ninety-one published papers, with 78 in vitro and 15 in vivo, fulfilled our selection criteria. Fifty-eight different plant species were thoroughly tested against Echinococcus granulosus. Zataria multiflora, Nigella sativa, Berberis vulgaris, Zingiber officinale (ginger), and Allium sativum were the most often utilized anti-Echinococcus herbs and the leaves of the herbs were extensively used. The pooled value of IC50 was 61 (95% CI 60–61.9) according to the random effect model and a large degree of diversity among studies was observed. The current systematic study described the medicinal plants with anti-Echinococcus activity, which could be investigated in future experimental and clinical studies to identify their in vivo efficacy, lethal effects, and mechanisms of action.

infection can induce macrophages into the alternatively activated phenotype, which is primarily associated with the development of a polarized Th2 immune response. In the present study, we examined the immunomodulatory effect of thioredoxin peroxidase-2 (TsTPX2), a protein derived from ES products, in the regulation of Th2 response through direct activation of macrophages. The location of TsTPX2 was detected by immunohistochemistry and immunofluorescence analyses. The immune response induced by rTsTPX2 was characterized by analyzing the Th2 cytokines and Th1 cytokines in the peripheral blood. The rTsTPX2-activated macrophages (M ) were tested for polarization, their ability to evoke naïve CD4 T cells, and resistance to the larval infection after adoptive transfer in BALB/c mice. The immunolocalization analysis showed TsTPX2 in cuticles and stichosome of ML. The immunostaining was detected in cuticles and stichosome of Ad3 and ML, as well as in tissue-dwellings around ML after the intestines and muscle tissues of infected mice were incubated with anti-rTsTPX2 antibody. Immunization of BALB/c mice with rTsTPX2 could induce a Th1-suppressing mixed immune response given the increased levels of Th2 cytokines (IL-4 and IL-10) production along with the decreased levels of Th1 cytokines (IFN-γ, IL-12, and TNF-α). studies showed that rTsTPX2 could directly drive RAW264.7 and peritoneal macrophages to the M2 phenotype. Moreover, M could promote CD4 T cells polarized into Th2 type . Adoptive transfer of M into mice suppressed Th1 responses by enhancing Th2 responses and exhibited a 44.7% reduction in adult worm burden following challenge with infective larval, suggesting that the TsTPX2 is a potential vaccine candidate against trichinosis. Our study showed that TsTPX2 would be at least one of the molecules to switch macrophages into the M2 phenotype during infection, which provides a new therapeutic approach to various inflammatory disorders like allergies or autoimmune diseases.