This investigation seeks to determine their potential efficacy in reducing parasite load and mitigating disease progression in immunocompromised hosts. The green synthesis of copper nanoparticles (CNPs) was performed using an extract from Rumex vesicarius. The chronic toxoplasmosis model was developed using the ME49 strain of Toxoplasma gondii. RT in the mice was achieved using dexamethasone (0.25 mg/kg) for 30 days. Then, mice were randomly assigned to 10 distinct groups, which were orally treated with CNP alone (10 and 20 mg/kg) and in combination with pyrimethamine (PM, 5 mg/kg) for 28 days. Next, parasite burden, spleen cell proliferation, and cytokine analysis, molecular analysis of inflammatory and apoptosis gene expression, oxidative/antioxidative biomarkers, and biochemical analysis were evaluated. CNP exhibits a uniform distribution and spherical morphology with an average diameter of 40 nm. CNP, mainly in combination with PM, significantly enhanced the survival rate in RT mice (P < 0.001), whereas it markedly yielded the most substantial reduction in parasite burden across all organs assessed (P < 0.001). The CNP 20 mg/kg + PM 5 mg/kg group demonstrated the highest increases in the gene expression of immune factors (3.78- to 5.79-fold change) (P < 0.001), whereas it reduced the expression of pro-apoptotic markers (P < 0.01). CNP + PM indicated a synergistic interaction in mitigating liver and kidney damage associated with reactivated toxoplasmosis. The combined administration of CNP and PM significantly decreased the parasitic load in cases of reactivated toxoplasmosis, concurrently augmenting antioxidant capacity and innate immune function. These results indicate that CNP holds potential as a valuable adjunctive therapy to enhance treatment efficacy in reactivated toxoplasmosis.

Long-term protective efficacy and distinct immune responses of live and inactivated vaccines against cryptocaryoniasis in orange-spotted grouper (Epinephelus coioides).

Host adenosine deaminase reprograms purinergic immunoregulation in Leishmania braziliensis infection.

Canine leishmaniosis, caused by Leishmania infantum, is a chronic vector-borne zoonosis with variable clinical manifestations, which complicates its diagnosis and monitoring. Although quantitative serology is the primary indirect diagnostic approach, polymerase chain reaction (PCR) is the most sensitive direct diagnostic method for confirming the infection by detecting Leishmania DNA in biological samples, but its performance varies according to the analysed tissue and molecular assay. This study aimed to validate a duplex real-time PCR assay and compare its diagnostic performance with a nested PCR in six different canine tissues, as well as to define the diagnostic value of non-invasive samples in clinical staging and monitoring in naturally infected dogs before and after specific treatment. Leishmania nested PCR and quantitative PCR targeting the small subunit (SSU) ribosomal RNA (rRNA) gene were performed on lymph node, blood, oral and conjunctival swabs, urine and hair samples from 66 dogs (20 non-infected, 15 clinically healthy infected and 31 naturally infected sick dogs classified according to LeishVet clinical staging). Sick dogs classified as stage II-III were re-evaluated 30days after therapy to assess clinical improvement and changes in parasite load during follow-up. Lymph node samples showed the highest sensitivity and parasite loads, correlating well with clinical severity, IFAT titres and albumin/globulin ratio. Among non-invasive samples, oral swabs showed the best performance, particularly in dogs with clinically relevant disease, while conjunctival swabs showed moderate sensitivity. By contrast, blood showed limited and stage-dependent diagnostic value, while urine and hair demonstrated very low sensitivity. Quantitative PCR showed slightly higher sensitivity than nPCR in most tissues, except for lymph node and blood samples. A CT cut-off of 39.00 was applied to minimise non-specific amplification, which was particularly pronounced in urine qPCR, achieving 100% specificity across all other tissues. The qPCR showed a reaction efficiency of 85.4% (R2 = 0.997), with a limit of detection of 0.5 parasite equivalents/reaction. Parasite load increased significantly from stage I to stage II dogs, but did not differ between stages II and III. After treatment, clinical scores and parasite loads decreased significantly in lymph node, oral and conjunctival swab samples. PCR performance in canine leishmaniosis is strongly influenced by tissue, technique and clinical stage. nPCR should be the test of choice for diagnostic confirmation, with lymph node as the gold standard sample, while oral swabs represent the most reliable non-invasive alternative, particularly in dogs with clinically relevant disease. For clinical follow-up, qPCR is preferable due to its ability to monitor parasite load changes in appropriate tissues, particularly lymph node and oral swab samples. The limited reliability of PCR from non-invasive samples in early stages of infection reinforces the need for a multimodal diagnostic approach in the clinical management of canine leishmaniosis.

Neospora caninum is a major cause of abortion in cattle worldwide, leading to substantial economic losses in the livestock industry. As no effective drug or vaccine is currently available, a deeper understanding of the host immune response against N. caninum is essential for developing effective control strategies. The absent in melanoma 2 (AIM2) inflammasome is involved in host defense and regulation of disease pathology, while its role in N. caninum infection remains unclear. This study shows that N. caninum activates the AIM2 inflammasome in wild-type (WT) murine peritoneal macrophage (PMϕs), characterized by increased expression of AIM2, pro-IL-1β, caspase-1 p20, and IL-1β p17, along with elevated IL-1β secretion and cell death rates. Guanylate-binding proteins (GBPs) are involved in regulating AIM2 inflammasome activation. Here, we observed that both GBP2 and GBP5 were upregulated by N. caninum, but only GBP5 overexpression played a functional role, as its overexpression enhanced, whereas its knockdown significantly attenuated AIM2 inflammasome in WT PMϕs, suggesting N. caninum activates the AIM2 inflammasome in a GBP5-dependent manner. To further investigate the role of AIM2 in parasite infection, AIM2-/- mice were used. In AIM2-/- PMϕs, inflammasome activation was reduced, accompanied by increased parasite proliferation. In vivo, N. caninum-infected AIM2-/- mice exhibited higher parasite loads but showed increased survival rates, reduced macrophage recruitment, decreased levels of IFN-γ, and IL-18, and alleviated pathological damage. In summary, our findings demonstrate that the AIM2 inflammasome is activated by N. caninum in a GBP5-dependent manner and plays a dual role by restricting parasite proliferation while exacerbating disease pathology.

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite capable of infecting more than 350 species, including humans, livestock, and wildlife. However, available clinical drugs for toxoplasmosis not only cause severe adverse effects but also demonstrate reduced therapeutic efficacy due to the emergence of drug-resistant strains, highlighting the urgent need for novel therapeutic interventions. This study aimed to evaluate the activity of dimethyl itaconate (DI) against T. gondii both in vitro and in vivo and to elucidate its underlying mechanism of action. The in vitro antiparasitic effects of DI were comprehensively investigated using transmission electron microscopy (TEM), plaque assays, quantitative PCR (qPCR), mitochondrial functional assays, ELISA, and transcriptomic profiling. In vivo evaluations were conducted in T. gondii-infected mouse models to assess survival rates, parasite loads, histopathological changes, and oxidative stress modulation. The results revealed that DI-treated tachyzoites exhibited marked organelle disruption, loss of membrane integrity, and activation of autophagy. Plaque assays combined with qPCR analysis consistently demonstrated a dose-dependent suppression of T. gondii proliferation. Notably, DI induced mitochondrial dysfunction, characterized by reduced mitochondrial membrane potential, ATP depletion, and a concomitant increase in reactive oxygen species (ROS) levels, consistent with the transcriptomic profiling data. This mechanistic evidence suggests that DI exerts its inhibitory effects on T. gondii tachyzoites primarily by disrupting the parasite's energy metabolism pathways. In vivo, DI administration increased survival rates, partially alleviated histopathological damage, significantly reduced parasite loads in target organs, and mitigated oxidative stress and inflammatory responses. Overall, DI exhibits promising anti-T. gondii activity both in vitro and in vivo, suggesting its potential as a candidate compound for the treatment of toxoplasmosis.

Feline leishmaniosis (FeL) caused by Leishmania infantum is increasingly recognized in endemic areas, but factors influencing susceptibility in cats remain incompletely understood. Because blood group antigens may modulate host-pathogen interactions, this study evaluated whether feline AB blood system phenotypes are associated with L. infantum seropositivity and/or molecular positivity in cats from Italy. Exploratory analyses further assessed whether blood phenotype was associated with the magnitude of indirect fluorescent antibody test (IFAT) antibody titres or with real-time PCR (qPCR) parasite load. In this retrospective cross-sectional study, cats were classified as L. infantum-positive when they had an IFAT titre ≥1:80 and/or a positive qPCR on blood or lymph node aspirates. Feline AB blood typing was performed by tube agglutination, with type B and AB samples confirmed by immunochromatographic testing and back typing. A total of 706 cats were included. Overall, 67/706 cats (9.5%) were classified as L. infantum-positive. Blood phenotype distribution was 83.1% type A, 10.1% type B, and 6.8% type AB. L. infantum positivity was detected in all three phenotypes, and no evidence of association was found between blood phenotype and L. infantum positivity, IFAT seropositivity, qPCR positivity, IFAT titre, or qPCR parasite load. After adjustment for region, blood phenotype remained not significantly associated with L. infantum positivity. These findings suggest that feline AB blood system phenotypes were not associated with L. infantum infection in this feline cohort. Future studies should investigate whether blood phenotype may influence other aspects of FeL, such as clinical expression or disease outcome.

The Manila clam (Ruditapes philippinarum) is one of the most valuable bivalves in global aquaculture, but its production is increasingly threatened by Perkinsus olseni, a protozoan parasite responsible for severe mortality events on shellfish beds. Understanding the genetic basis of resistance to this pathogen is essential for developing sustainable breeding strategies and reducing economic losses. We conducted a genome-wide association study (GWAS) on 606 Manila clam offspring from 32 full-sib families to investigate the heritability and genomic architecture of resistance to P. olseni. Following quality control and exclusion of the 42 smallest individuals potentially affected by size-related exposure bias, 564 offspring were retained for the final GWAS analyses. Genomic screening was performed with a newly developed multispecies SNP array comprising 49,392 SNPs for R. philippinarum. Experimental challenges were carried out in two tanks (challenged and control), each containing 1,500 offspring, and parasite load was quantified by qPCR using control Ct values as a non-infected reference. A substantial proportion of phenotypic variation in parasite load was explained by additive genetic effects, with heritability estimated at h² = 0.45 ± 0.09 using the full dataset and increasing to h² = 0.53 ± 0.08 after filtering. Several genome-wide significant quantitative trait loci (QTL) were identified across seven chromosomes, supporting a polygenic basis for resistance. Notably, one QTL on chromosome 18 also showed a highly significant association within one of the largest families. Patterns of linkage disequilibrium (LD) revealed rapid decay across most chromosomes, typical of marine bivalves, except for three chromosomes showing extended LD patterns compatible with putative structural polymorphisms, including possible inversions. These results demonstrate a substantial additive genetic component underlying resistance to P. olseni in Manila clam and highlight chromosome 18 as an important genomic region associated with parasite burden. Overall, our findings support the future integration of genomic tools into selective breeding programmes aimed at improving disease resilience and promoting the long-term sustainability of Manila clam aquaculture under increasing environmental and pathogen pressures.

Toxoplasma gondii is a globally distributed intracellular parasitic protozoan. It infects nearly all warm-blooded animals and causes a zoonotic disease of worldwide significance. Currently, the only commercially available vaccine, Toxovax®, is solely used for the prevention of Toxoplasma-induced abortion in sheep, but it has limitations such as a short shelf life and the potential of reversion to virulence. This study evaluated the safety and immune-protective efficacy of two live-attenuated strains RHΔtkl1 and PruΔpp2a-c in sheep. Sheep were immunized via intramuscular injection in the neck with 1 × 107 tachyzoites of RHΔtkl1 or PruΔpp2a-c. Sheep were challenged orally with 5 × 105 type II Pru oocysts at 28days post-vaccination (dpv), followed by a second challenge on day 70 with 1 × 107 type II Pru tachyzoites injected intramuscularly at 70 dpv. Safety and immuno-protection were evaluated by monitoring clinical symptoms and body temperatures, T. gondii-specific IgG antibody levels, histopathological changes, immunohistochemistry, brain cysts, parasite load, and mouse bioassay results. The results demonstrated that both knockout strains induced only transient fever. Following immunization and subsequent challenge with Pru oocysts, the T. gondii-specific IgG antibody levels in sheep increased rapidly and remained elevated for an extended period. Histopathological analysis indicated mild organ lesions in heart, liver and lung tissues among immunized infected sheep, whereas non-immunized infected sheep exhibited severe widespread inflammation. Immunohistochemical analysis of brain tissue revealed significantly lower values for four parameters (positive cell ratio, density, histochemistry score, immunoreactive score) in immunized groups (P < 0.01). A significant reduction in brain cysts was observed in immunized and challenged sheep (P < 0.01) compared with unimmunized and challenged sheep. The parasite burden of T. gondii in heart tissue was significantly reduced (P < 0.01). Compared with mice inoculated with sheep brain tissue from unimmunized groups challenged with T. gondii Pru oocysts and tachyzoites, mouse bioassay results showed that the mice inoculated with sheep brain tissue from groups immunized with RHΔtkl1 or PruΔpp2a-c tachyzoites and subsequently challenged with T. gondii Pru oocysts and tachyzoites exhibited a significantly lower proportion of positive genomic T. gondii DNA in the brain (P < 0.001), as well as significantly reduced levels of T. gondii-specific antibody IgG in the serum (P < 0.0001). Similarly, mice inoculated with sheep visceral tissue from the same immunized and challenged groups also showed a significantly reduced proportion of positive genomic T. gondii DNA in the brain (P < 0.0001) and significantly reduced levels of T. gondii-specific antibody IgG in the serum (P < 0.0001). The gene knockout strains RHΔtkl1 and PruΔpp2a-c showed a certain degree of safety in sheep, and they induced strong humoral and cellular immune responses in sheep, significantly mitigating acute infection symptoms and tissue damage. Notably, PruΔpp2a-c showed greater potential in suppressing cyst formation. Both strains are potential attenuated candidates against sheep toxoplasmosis.

Lauramide-coated silver selenide nanoparticles exhibit potent multimodal activity against cystic echinococcosis through host-directed and protoscolicidal effects.

The interplay between host and parasite determines parasite burden and disease outcome. Parasite exploits host signaling pathways like p38-MAPK for its survival and pathogenesis. Here we have used NR-7h, a proteolysis-targeting chimera (PROTAC) targeting human p38-MAPK to assess p38-MAPK's role in Leishmania donovani and Plasmodium falciparum infection in their respective host cells. NR-7h degrades host p38-MAPK in a time- and dose-dependent manner. Degradation of host p38-MAPK by NR-7h reduces parasite load in host cells dose-dependently, implicating the role of p38-MAPK in parasite survival. During Leishmania infection, the modulation of cytokine profiling and oxidative burst upon NR-7h mediated degradation of host p38-MAPK is further correlated with parasite death. The effect of host p38-MAPK degradation by NR-7h with Amphotericin B enhances the efficacy of parasite-directed therapy. For Plasmodium infection, growth inhibition and invasion assays reveal impaired growth and merozoite invasion, suggesting that host p38-MAPK signaling contributes to both parasite invasion and intraerythrocytic development. This study underscores the importance of host p38-MAPK for L. donovani and P. falciparum progression and highlights NR-7h's potential in antiparasitic therapy by targeting this pathway.

BackgroundMalaria is one of the most devastating infectious diseases in humans, and antimalarial drugs have been used to combat it with minimal success. Worldwide, malaria treatment is threatened by the emergence and spread of artemisinin resistance, which is associated with mutations in the PfK13 propeller domain. In Sub‐saharan Africa, data relating to the prevalence of Plasmodium falciparum malaria infection in association with the Kelch 13 mutations are mainly from research settings outside disease‐endemic areas. This study is aimed at establishing the prevalence of P. falciparum malaria infection in association with Kelch 13 mutations among patients presenting with fever at Gulu Regional Referral Hospital (GRRH) in northern Uganda.MethodsThis cross‐sectional study enrolled all participants presenting with fever at GRRH between April 2022 and January 2024. Data on adults and children aged ≥ 6 months with fever and confirmed diagnosis of malaria using mRDT, microscopy, and PCR were collected. Parasite DNA was extracted using the Chelex method and sequenced for multidrug resistance genes, and Sanger customized CRF forms were used to capture variables on social demographics, clinical presentation, and treatment. Data were analyzed using IBM SPSS Version 25, and the sequenced data were analyzed using molecular evolutionary genetic analysis (MEGA) Version 11.1.10. All sequences from a single population were aligned using the National Center for Biotechnology Information (NCBI) database.ResultsIn total, 353 participants were recruited, and the overall prevalence of P. falciparum malaria was 60.6% (n = 214), with the highest number of cases registered in Gulu City (24.9%). Women were the most affected participants (37.1%). The most common clinical presentations among the participants were fever (91.8%; n = 324), chills (90.7%; n = 320), and headaches (72.0%; n = 254). Genotyping results of the mutant genes showed that of all 214 P. falciparum isolates examined, the pfmdr1 SNP at Codon 1034 1042 (29.6%, n = 94) had the highest prevalence, followed by the pfmdr SNP at Codon 86 184 (28%, n = 89), and the SNP fragment at codon 1246 (25.8%, n = 82) recorded the lowest prevalence. Kelch 13 propeller gene, known to be associated with artemisinin resistance, was also isolated in 16.7% (n = 53) of the samples. There was a 90.1% (n = 318) prevalence of the SNPs 86 184, 1034 1042 of the pfmdr1 gene, and K13 propeller gene, with no significant difference between the sexes (p = 0.756). The SNP at Codon 1246 of pfmdr1 showed a significant difference between the location and mutation (p = 0.017). The median parasite load in patients with mutations in 86 184, 1034 1042, and K13 propeller genes varied significantly among patients who received treatment p ≤ 0.0001, p = 0.0061, and p = 0.012, respectively.ConclusionThe presence of pfmdr1 mutant genes suggests resistance of P. falciparum to most antimalarial drugs used in treatment. Therefore, it is important to monitor the prevalence of Kelch 13 mutations and P. falciparum to contribute to global efforts to control and eliminate malaria.

Immunomodulatory effects of snake venom C-type lectins in vaccine formulations against ascariasis in mice.

Interferon-induced transmembrane (IFITM) proteins underpin antiviral responses, yet their role in bacterial infections remains underexplored, particularly for parasites. We probed the role of IFITM1 in Mycobacterium tuberculosis (Mtb), Listeria monocytogenes (Lm), and Leishmania major infection using IFITM1 knockout mice. Notably, IFITM1 was upregulated in murine and human macrophages, as well as in PBMCs during active tuberculosis (TB), subsiding with therapy. IFITM1 also accumulated in the lungs of outbred mice and macaques that progressed to TB. IFITM1-deficient micedisplayed no differences in the acute phase; however, chronic Mtb infection revealed lower bacterial loads, mitigated lung pathology, dampened inflammatory cell recruitment, and decreased cytokines. IFITM1-/- macrophages curbed intracellular H37RV and HN878 growth, skewing proinflammatory cytokine (IL-1α, IL-1β, IL-6, and nitric oxide) production while phagosome maturation and autophagy remained unaffected. Furthermore, HN878-infected IFITM1-/- mice exhibited increased lung cell death by TUNEL staining, driving enhanced mortality. Lm similarly increased IFITM1 expression in macrophages, liver, and spleen. IFITM1-/- mice exhibited reduced early tissue burdens and serum IFN-γ, TNF, and IL-6, yet liver pathology escalated, driving mortality and suggesting dysregulated inflammation. These macrophages also limited intracellular Lm growth, with increased necrosis. By contrast, L. major footpad swelling and parasitic loads remained unaffected in knockout animals. Together, IFITM1 exacerbates TB and listeriosis pathology by calibrating inflammation against bacterial control, but plays no role in cutaneous leishmaniasis. These findings reveal IFITM1-specific contributions to bacterial but not parasitic infections, favoring disease tolerance.

Sessilid ciliates are common epibionts of aquatic crustaceans, where mass colonisation of economically important prawns may lead to adverse effects on host health and ecosystem dynamics. The Oriental river prawn Macrobrachium nipponense, which is native to Asia, has recently expanded into European freshwater and brackish systems. As a host species, it may act as a vector for sessilid ciliates into new habitats, posing risks to native biota and aquaculture. We examined M. nipponense populations in brackish water bodies of southwestern Ukraine to assess the prevalence and localization of sessilid ciliates. Live and preserved specimens were microscopically examined. Morphological analysis focused on the distribution and abundance of Zoothamnium colonies on various body parts. Molecular material was also preserved for future species identification. Over 80% of prawns were found to carry large colonies of Zoothamnium sp., with high infestation intensity particularly on pereiopods and uropods. Ciliate aggregations often appeared near articulation points, which may obstruct mobility or respiration. Infestation patterns were consistent across sexes, though some correlations were noted between parasite load and reproductive condition in females. These results suggest that sessilid ciliates may exhibit parasitic characteristics under favourable conditions, undermining host performance. The expansion of M. nipponense may facilitate the introduction and establishment of such organisms across Europe. This study highlights the ecological implications of overlooked epibionts and stresses the importance of monitoring invasive host-epibiont complexes in aquatic environments.

Comparing performance of copro-diagnostics for monitoring intestinal parasitic infections in the golden jackal (Canis aureus).

Skeletal myositis is a disabling complication of Chagasdiseasefor which the first-choice antiparasitic chemotherapy has limitedefficacy. Therefore, we synthesized and investigated the potentialof the novel nitroimidazole-based drug 1-(2-(2-methoxy-6-nitro-4-propylphenoxy)­ethyl)-2-methyl-5-nitro-1H-imidazole (ME) administered alone or combined with benznidazole(BZ) to control myocytes parasitism and skeletal myositis in Chagasdisease. ME antiparasitic efficacy was investigated in vitro and invivo in C2C12 skeletal myocytes and mice challenged with Trypanosoma cruzi Y strain. Physicochemical modelingindicated that ME presented characteristics compatible with orallybioactive drugs. Similar to BZ, our results indicated that ME showeda marked antiparasitic effect in vitro, attenuating T. cruzi viability, infection rate, and parasiteload in C2C12 myocytes in a dose-dependent manner. In vivo, T. cruzi infection induced intense parasitemia, muscleparasitism, oxidative stress, and inflammation, features associatedwith pathological microstructural remodeling of the skeletal muscle.ME administered alone and mainly in combination with BZ significantlyreduced parasitemia, parasite load, production of reactive oxygenspecies (ROS) and nitrogen species (RNS), oxidation of lipids andcellular proteins, inflammation (e.g., inflammatory infiltrate, NAGand MPO activity, IFN-γ, TNF, IL-6, and IL-10 levels), and microstructuraldamage in skeletal muscle of T. cruzi-infected animals. Our findings provide evidence that ME has directantiparasitic effects in vitro and in vivo, showing potential efficacyfor use as monotherapy and mainly in combination with BZ. This combinationmay be relevant to improve the etiological treatment of Chagas disease,simultaneously attenuating parasitism, oxidative stress, and skeletalmyositis more efficiently than monotherapy with these drugs.

Evaluar biomarcadores hematológicos, bioquímicos y hepáticos y la producción de inmunoglobulina E total en pacientes alcohólicos infectados con S. stercoralis. Materiales y métodos. Se trata de un estudio de casos y controles con 240 pacientes alcohólicos, 60 infectados y 180 no infectados con S. stercoralis. Los biomarcadores sanguíneos se evaluaron mediante métodos automatizados, kits comerciales o nefelometría. Se observó una alta frecuencia de alcohólicos con anemia, sin diferencia entre los grupos infectados y los no infectados, 65,0 % (39/60) y 62,8 % (113/180), respectivamente. La frecuencia de eosinofilia, 58,3 (35/60) y 26,1 % (47/180) y la concentración total de inmunoglobulina E, 2882 y 1400 UI/ml, fueron significativamente mayores (p < 0,05) en los individuos infectados con S. stercoralis en comparación con los no infectados. Los niveles de ALT y AST estuvieron elevados en ambos grupos. Sin embargo, en el grupo infectado se encontraron niveles más bajos de AST, 61,5 ± 38,4 comparado con 84,3 ± 84,6 U/L en no infectados y una menor frecuencia de individuos con niveles elevados de ALT, 26,7 % (16/60) comparado con 40,5 % (73/180) en pacientes infectados. Además, los niveles de AST fueron mayores en individuos con una carga parasitaria superior a 100 larvas/g de heces, en comparación con aquellos con una menor carga parasitaria (90,80 ± 39,9 y 56,42 ± 31,9 U/L (p < 0,05), respectivamente). Este estudio demuestra una menor alteración de las enzimas hepáticas en alcohólicos infectados con S. stercoralis, lo cual podría depender de la carga parasitaria.

Leishmania spp., the causative agents of leishmaniasis, are protozoan parasites displaying two life stages: promastigote in the insect vector and amastigote in host macrophages. After inoculation, the promastigote differentiates into the amastigote which multiplies within a parasitophorous vacuole formed by the fusion of the phagosome with the macrophage endolysosome. This compartment is characterized by a specific enrichment in bis(monoacylglycerol)phosphate (BMP), an atypical phospholipid that regulates endosomal dynamics and cholesterol trafficking. Host cell cholesterol is essential for parasite intracellular development. In this study, we examined the relationships between cholesterol, BMP, and the parasitophorous vacuole during the infection of J774 murine macrophages with L. infantum. Our results showed that cholesterol is redistributed in the vicinity of the parasite within infected cells. BMP is redistributed along with the same pattern and colocalizes with markers of the parasitophorous vacuole. Transcriptomic analyses revealed an upregulation of key genes governing cholesterol uptake and synthesis (HMGCR, SREBP2, LDLR) during infection and conversely a downregulation of ABCA1 involved in cholesterol efflux. Noteworthy, the overexpressions of HMGCR, SREBP2, LDLR were significantly attenuated by macrophage BMP enrichment. As for functional impact, BMP enrichment was associated with a significant increase of the parasite infectivity toward macrophages, assessed by infection rate and parasite load. Together, our results confirm the essentiality of macrophage cholesterol and demonstrate the involvement of BMP during Leishmania infection likely by facilitating parasitophorous vacuole remodeling and cholesterol trafficking.

Circulating microRNA profiles as diagnostic and prognostic biomarkers for acute and carrier Theileria equi infection.