Parasites & Vectors最新文献

{"title":"PD-1-dependent therapeutic effect of Trichinella spiralis cystatin on myocardial infarction in a mice model.","authors":"Weixiao Zhang, Wenhui Yin, Hongtao Wang, Lingqin Wu, Chang Li, Xinyu Peng, Xiang Li, Kaibo Jiang, Huiqi Yang, Chenyue Dang, Erhe Gao, Qiwang Jin, Xiaodi Yang","doi":"10.1186/s13071-025-06854-4","DOIUrl":"10.1186/s13071-025-06854-4","url":null,"abstract":"<p><strong>Background: </strong>Ischemia-induced inflammation is the primary pathological mechanism underlying cardiac tissue injury caused by myocardial infarction (MI). Trichinella spiralis cystatin (Ts-Cys) has been shown to regulate macrophage polarization and alleviate various inflammatory and immune-related diseases. Programmed cell death-1 (PD-1) is a crucial checkpoint receptor molecule and highly involved in maintaining immune tolerance. In this study, our aims were to investigate whether recombinant Ts-Cys protein (rTs-Cys) could be used to treat MI with recruited macrophage-dominant myocardial inflammation and whether PD-1 is involved in the immunomodulation of Ts-Cys in inflammatory diseases.</p><p><strong>Methods: </strong>MI models were established in wild-type (WT) and PD-1 knockout (PD-1^-/-) mice, followed by the intraperitoneal injection of rTs-Cys. The survival rates of mice were observed for 28 days post-surgery and treatment. Cardiac function was assessed by echocardiography. Histopathological evaluation of heart tissue affected by infarction was conducted to examine local inflammatory cell infiltration and cardiac tissue damage. Real-time quantitative PCR was used to detect messenger RNA expression levels of vascular endothelial growth factor (VEGF) and the macrophage surface markers inducible nitric oxide synthase and arginase-1 in the MI area. Serological levels of cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10) and transforming growth factor-beta (TGF-β), were measured using an enzyme-linked immunosorbent assay. Bone marrow-derived macrophages from WT and PD-1^-/- mice were used to assess the effects of rTs-Cys on macrophage polarization in vitro.</p><p><strong>Results: </strong>In WT mice, rTs-Cys treatment significantly improved the 28-day survival rate and cardiac function, reduced local inflammatory cell infiltration and cardiac pathological damage and increased VEGF expression levels of MI mice. The therapeutic effect of rTs-Cys was associated with macrophage polarization from the pro-inflammatory M1 phenotype to the regulatory M2 phenotype with reduced levels of inflammatory cytokines (TNF-α and IL-6) and increased levels of regulatory cytokines (IL-10 and TGF-β), as determined by both in vivo and in vitro tests. However, this therapeutic effect of rTs-Cys on MI was significantly reduced in PD-1^-/- mice, as reflected by the higher level of M1 macrophages, elevated levels of inflammatory cytokines and decreased levels of regulatory cytokines.</p><p><strong>Conclusions: </strong>rTs-Cys promotes M2-type polarization of macrophages through the PD-1 pathway to alleviate MI in mice and is, therefore, a potential drug for the treatment of MI and other inflammation-related diseases with involvement of the PD-1 checkpoint molecule.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"209"},"PeriodicalIF":3.0,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12142987/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144234724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular characterization of tick-borne bacterial and protozoan pathogens in parasitic ticks from Xinjiang, China.","authors":"Bingjie Wang, Zhiqiang Liu, Shiying Zhu, Jinchao Zhang, Wenwen Qi, Jianyu Wang, Dongfang Li, Lan He, Junlong Zhao","doi":"10.1186/s13071-025-06857-1","DOIUrl":"10.1186/s13071-025-06857-1","url":null,"abstract":"<p><strong>Background: </strong>Ticks are a type of hematophagous parasite, serving as critical vectors of pathogens that cause numerous human and animal diseases. Climate change has driven the geographical expansion of tick populations and increased the global transmission risk of tick-borne diseases. However, there has been a lack of comprehensive data on tick species distribution and their associated pathogen profiles in Xinjiang, China.</p><p><strong>Methods: </strong>Ticks were collected from 19 sampling sites across nine regions in Xinjiang. The species were identified using both morphological and molecular biological methods. The presence of tick-borne bacterial and protozoan pathogens was detected through polymerase chain reaction (PCR). Finally, sequencing and phylogenetic analyses were performed to further characterize the identified ticks and pathogens.</p><p><strong>Results: </strong>A total of 1093 ticks were collected and identified, representing four genera and nine species, with Hyalomma asiaticum being the dominant species. Haplotype diversity and genetic differentiation analysis based on the 16S rRNA gene of the dominant species demonstrated that the Hy. asiaticum population in Xinjiang exhibits high haplotype diversity (Hd = 0.734), low nucleotide diversity (π = 0.00403), and significant genetic differentiation (Fst = 0.19716). Pathogen detection using PCR revealed an infection rate of 9.3% for Anaplasma, 18.1% for Rickettsia, and 9.0% for piroplasms. Phylogenetic analysis based on 16S rRNA sequences indicated that the Anaplasma genus identified in ticks comprised Anaplasma ovis, Anaplasma sp., and Anaplasma phagocytophilum. Phylogenetic analysis based on the opmA gene showed that the Rickettsia genus identified in ticks included Rickettsia aeschlimannii, Rickettsia conorii, Rickettsia slovaca, Rickettsia conorii subsp. raoultii, Rickettsia sp., Candidatus Rickettsia barbariae, and Candidatus Rickettsia jingxinensis. Similarly, phylogenetic analysis based on the 18S rRNA gene demonstrated that the piroplasms identified in ticks included Theileria annulata, Theileria ovis, Babesia bigemina, Babesia occultans, and Babesia sp. All gene sequences of the detected pathogens showed 99.8-100% identity with corresponding sequences deposited in GenBank.</p><p><strong>Conclusions: </strong>This study demonstrates that Xinjiang harbors a rich diversity of tick species with a wide geographical distribution. Furthermore, the tick-borne pathogens in this region are complex and diverse. These results underscore the necessity of sustained and enhanced surveillance efforts targeting ticks and tick-borne diseases in this region.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"207"},"PeriodicalIF":3.0,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12139197/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144226157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental evidence rules out mosquitoes as vectors of Lyme disease.","authors":"Miriama Pekľanská, Kateřina Kuníková, Romana Vlčková, Hana Slabová, David Hartmann, Karolina Volfová, Ivo Rudolf, Silvie Šikutová, Ryan O M Rego, Fernando Gabriel Noriega, Ondřej Hajdušek, Jan Perner, Jan Votýpka, Marcela Nouzová, Radek Šíma","doi":"10.1186/s13071-025-06823-x","DOIUrl":"10.1186/s13071-025-06823-x","url":null,"abstract":"<p><strong>Background: </strong>Lyme disease, caused by Borrelia burgdorferi sensu lato (s.l.), is the most common vector-borne disease in the Northern Hemisphere, with Ixodes ticks as its primary vectors. However, many patients do not recall tick bites, fueling speculation about alternative transmission routes, particularly via mosquito bites. This belief is reinforced by studies reporting Borrelia presence in mosquitoes. This study evaluates whether three mosquito species can acquire, maintain, and transmit Borrelia spirochetes.</p><p><strong>Methods: </strong>Mosquitoes (Aedes aegypti, Culex quinquefasciatus, and Culex pipiens biotype molestus) were fed on Borrelia-infected mice to assess pathogen acquisition. Additional experiments involved ex vivo feeding on Borrelia-enriched blood to examine spirochete persistence in the mosquito gut. The potential for mechanical transmission was tested by simulating interrupted feeding between infected and naive hosts. The role of trypsin in Borrelia survival and infectivity was also investigated.</p><p><strong>Results: </strong>Mosquitoes exhibited low efficiency in acquiring Borrelia from infected hosts. Spirochetes artificially introduced through ex vivo blood meals were rapidly eliminated during digestion, primarily due to trypsin activity. Inhibition of trypsin prolonged spirochete persistence and infectivity in the mosquito gut. Mechanical transmission experiments revealed no evidence of Borrelia transmission from infected to naive hosts.</p><p><strong>Conclusions: </strong>Our findings demonstrate that mosquitoes lack the biological capacity to efficiently acquire and maintain B. burgdorferi s.l. spirochetes and are unable to transmit them through natural or mechanical means. This study provides compelling evidence against mosquito-borne transmission of Lyme disease and reinforces Ixodes ticks as the sole competent vectors, which is crucial for targeted public health interventions and accurate risk communication.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"206"},"PeriodicalIF":3.0,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12135369/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144226156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MiR-383-5p promotes schistosomiasis-induced liver fibrosis by targeting peroxiredoxin-3.","authors":"Yi-Xin Li, Xin-Yue Zhang, Ju-Lu Lu, Ying-Ying Yang, Cong-Jin Mei, Pan-Pan Dong, Chuan-Xin Yu, Jian-Feng Zhang, Chun-Rong Xiong, Li-Jun Song, Kun Yang","doi":"10.1186/s13071-025-06824-w","DOIUrl":"10.1186/s13071-025-06824-w","url":null,"abstract":"<p><strong>Background: </strong>Schistosomiasis-induced liver fibrosis, a major complication of infection, arises primarily from the host immune response to schistosome eggs. The mechanisms underlying the development of liver fibrosis remain unclear, but microRNAs (miRNAs) are thought to play a crucial role in this process. Our previous study revealed significantly reduced miR-383-5p expression in patients with advanced schistosomiasis, particularly in those with newly developed disease, suggesting a possible association between miR-383-5p and fibrotic progression. This study explores the role and mechanism of miR-383-5p in schistosomiasis-induced liver fibrosis.</p><p><strong>Methods: </strong>The target gene of miR-383-5p was predicted through bioinformatics analysis. The expression levels of miR-383-5p and its target gene in the livers of Schistosoma japonicum (S. japonicum)-infected mice were investigated. Dual-luciferase reporter assays and miR-383-5p mimics and inhibitors were transfected of into LX-2 cells to determine the regulation of miR-383-5p on its target gene. AAV-8-overexpressing miR-383-5p vector injected into mice infected with S. japonicum, the target gene expression level, fibrosis-related factors, and pathological changes of liver were evaluated. The target gene knockout mice were infected with S. japonicum, and the degree of liver fibrosis was detected.</p><p><strong>Results: </strong>Target gene prediction identified peroxiredoxin 3 (PRDX3), a mitochondrial peroxidase that scavenges reactive oxygen species (ROS), as a target of miR-383-5p. During the progression of schistosome infection in mice, the expression level of miR-383-5p in the liver gradually decreased, reaching its lowest level 6 weeks after infection, at the peak of inflammation in egg granulomas, then gradually increasing, while the expression kinetics of PRDX3 were opposite to those of miR-383-5p. Using dual-luciferase reporter assays and transfection of miR-383-5p mimics and inhibitors into LX-2 cells, we confirmed that miR-383-5p directly targeted the 3' untranslated region (UTR) of PRDX3, leading to decreased mRNA levels of PRDX3. AAV8-mediated miR-383-5p overexpression and PRDX3 knockout in the mice infected with S. japonicum led to increased hepatic ROS and promoted the schistosomiasis-induced liver fibrosis.</p><p><strong>Conclusions: </strong>Our findings suggest that downregulating miR-383-5p after schistosome infection may alleviate liver inflammation by de-repressing PRDX3, thereby increasing ROS scavenging and reducing oxidative stress. This study elucidates the role of the miR-383-5p/PRDX3 axis in schistosomiasis-induced liver fibrosis, suggesting that PRDX3 is a potential therapeutic target for this disease.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"205"},"PeriodicalIF":3.0,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12131343/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144216524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Olfactory responses of the variegated fruit fly, Phortica variegata, an emerging vector of the zoonotic eyeworm Thelazia callipaeda, to ecologically relevant volatiles.","authors":"Anna Laura Erdei, Magdolna Olívia Szelényi, Ferenc Deutsch, Balázs Kiss, Béla Péter Molnár","doi":"10.1186/s13071-025-06850-8","DOIUrl":"10.1186/s13071-025-06850-8","url":null,"abstract":"<p><strong>Background: </strong>The variegated fruit fly, Phortica variegata (Drosophilidae: Steganinae), is native to Europe and has emerged as a major vector of ocular nematosis caused by Thelazia callipaeda (Rhabditida: Thelaziidae), following the its introduction into Europe from Asia. Male P. variegata transmit these nematodes by feeding on tears of mammals, including wild and domestic carnivores (foxes, beech martens, wild cats, and dogs), lagomorphs, and humans. Understanding the olfactory responses of P. variegata to volatile cues is essential for developing attractant-based surveillance and control strategies, yet its olfactory ecology remains largely unexplored.</p><p><strong>Methods: </strong>We used gas chromatography coupled electroantennography to measure antennal responses to synthetic and natural volatile blends. A comparative analysis was performed on the antennal responses of both sexes of P. variegata and its well-studied relative, Drosophila melanogaster. Components of the synthetic blends were selected based on the odorant receptor repertoire of D. melanogaster and established mosquito attractants, with the rationale that conserved olfactory receptors among dipterans may allow P. variegata to detect similar compounds. Volatile extracts collected using active carbon adsorbent traps were also tested on the antennae and analyzed using gas chromatography coupled mass spectrometry.</p><p><strong>Results: </strong>Male P. variegata showed higher antennal responses to phenol, 3-octanone, and sulcatone than females, indicating olfactory sexual dimorphism. Compared to D. melanogaster, the antennae of P. variegata did not respond to several common plant alcohols and terpenoids. Instead, they showed stronger responses to compounds such as anisole, ethyl propanoate, butyl propanoate, propyl acetate, 3-octanone, nonanal, and decanal, suggesting that peripheral olfaction in P. variegata may be more tuned to microbial volatiles.</p><p><strong>Conclusions: </strong>Phortica variegata exhibits sexual dimorphism in olfactory responsivity, with males showing greater responsiveness to volatiles associated with host-seeking in other zoophilic dipterans, potentially guiding them to mammalian hosts for tear-feeding. Compared to D. melanogaster, P. variegata is more responsive to microbial and yeast-related volatiles and less responsive to plant-derived terpenoids, suggesting a foraging ecology linked to microbial substrates. The antennally detected volatiles identified in this study can be used as candidates for further behavioral studies to develop lures for vector management.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"204"},"PeriodicalIF":3.0,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12131565/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144209077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association between landscape transformation and the Chagas disease vector dynamics in a rural area with continuous surveillance and control.","authors":"Leonardo Sandon, Diego Weinberg, Manuel O Espinosa, Marcelo C Abril, Roberto Chuit, Ximena Porcasi, Maria V Periago","doi":"10.1186/s13071-025-06849-1","DOIUrl":"10.1186/s13071-025-06849-1","url":null,"abstract":"<p><strong>Background: </strong>The Gran Chaco Region of Argentina, a hotspot for neglected tropical diseases (NTDs) including Chagas disease (CD), has undergone significant landscape transformations due to deforestation and agricultural expansion. These changes have altered the dynamics of Triatoma infestans, the primary vector of Trypanosoma cruzi, the causative agent of CD. This study investigates the association between environmental changes and vector infestation patterns in a rural area of Añatuya, Santiago del Estero, Argentina, under continuous surveillance and control since 2005.</p><p><strong>Methods: </strong>Entomological data from 502 households across 13 rural settlements were collected over a decade (2009-2019). Spatial patterns of triatomine infestation were analyzed using kernel density estimation (KDE), and relationships between infestation, land use changes, household density, and proximity to deforested areas were assessed. Random Forest models were employed to identify key predictors of infestation, incorporating variables such as deforestation percentage, distance to agricultural plots, and domestic animal density.</p><p><strong>Results: </strong>Infestation patterns were highly heterogeneous, with significant hotspots identified in settlements such as Lote 27, Lote 47, and La Salamanca. Household density and distance to main roads emerged as the most important predictors of infestation, with higher infestation rates observed in areas with lower deforestation and greater distance from agricultural plots. Deforestation reduced sylvatic reservoirs of T. cruzi but influenced domestic triatomine populations, particularly in areas with intermediate household density. Continuous surveillance and control efforts, including insecticide application and house improvements, led to a significant reduction in infestation rates over time.</p><p><strong>Conclusions: </strong>Landscape transformation plays a critical role in shaping T. cruzi transmission dynamics. While deforestation reduces sylvatic reservoirs, it also influences domestic triatomine populations, highlighting the complex interplay between environmental changes and vector ecology. Tailored control strategies that address both domestic and sylvatic cycles are essential for sustainable vector elimination. These findings underscore the importance of integrating environmental and spatial factors into CD control programs to achieve certification of transmission-free areas and reduce the burden of CD in endemic regions.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"203"},"PeriodicalIF":3.0,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12131463/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144209076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigations on the occurrence of West Nile virus, Usutu virus and Sindbis virus RNA in avian louse flies (Diptera: Hippoboscidae) collected in Germany (2016-2022).","authors":"Markus Freick, Isabelle Vogt, Stephanie Schröter, Robert Kohl, Denise Heidl, Ruben Schreiter, Hein Sprong, Matthias Jentzsch","doi":"10.1186/s13071-025-06841-9","DOIUrl":"10.1186/s13071-025-06841-9","url":null,"abstract":"<p><strong>Background: </strong>As living vectors, arthropods play a crucial role in the transmission of viruses, bacteria and parasites. Previous research on virus transmission has focussed mainly on the roles of mosquitoes and ticks, while the potential importance of other blood-sucking arthropods such as louse flies (Hippoboscidae) has been somewhat neglected. The aim of this study was to detect viruses in avian louse flies from Germany to assess whether they could be used as sentinel organisms for monitoring arboviruses with zoonotic potential.</p><p><strong>Methods: </strong>We collected 1000 louse flies of the species Crataerina hirundinis, C. pallida, Ornithomya avicularia, O. biloba, O. fringillina, O. chloropus, Ornithophila metallica and Pseudolynchia canariensis in Germany and screened the samples via RT-PCR for West Nile virus (WNV), Usutu virus (USUV) and Sindbis virus (SINV), which are arboviruses with avian hosts as reservoirs.</p><p><strong>Results: </strong>While WNV was not detected, we found one louse fly positive for USUV and one for SINV RNA, both of which belonged to the species O. avicularia (n = 279). Therefore, the detection rates for both USUV and SINV were 0.1% (95% CI 0.0-0.3%) in the total sample and 0.36% (95% CI 0.00-1.09%) in O. avicularia. For the sample that tested positive for SINV, the PCR results were confirmed by sequencing a 288-bp segment that encoded part of the virus's structural polyprotein.</p><p><strong>Conclusions: </strong>This is the first time that USUV RNA and SINV RNA have been detected in louse flies. In addition, it is the first detection of human pathogenic viruses in the louse fly species O. avicularia. The results of this study indicate that louse flies should not be neglected as possible sentinels of viral pathogens with zoonotic potential in the sense of the One Health concept.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"200"},"PeriodicalIF":3.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12128526/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144199806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"miRNA let-7-5p present in the extracellular vesicles of Trichinella spiralis newborn larvae inhibits the function of M1-type RAW264.7 macrophages by targeting C/EBPδ.","authors":"Yi Liu, Yu Chun Cai, Jia Xu Chen, Shao Hong Chen, Ying Fang Yu","doi":"10.1186/s13071-025-06802-2","DOIUrl":"10.1186/s13071-025-06802-2","url":null,"abstract":"<p><strong>Background: </strong>Trichinella spiralis, in its newborn larva (NBL) stage, invades the host bloodstream and disseminates throughout the body. Concurrently, M1 macrophages undergo transformation into M2 macrophages. In our previous studies, we demonstrated that extracellular vesicles secreted by NBL (NBL-EVs) significantly express the microRNA (miRNA) cel-let-7-5p. In this study, we investigated the immunomodulatory effects and mechanisms of action of EVs derived from T. spiralis NBL and the influence of their key miRNA, cel-let-7-5p, on M1 macrophages.</p><p><strong>Methods: </strong>This study investigates the impact of T. spiralis NBL-EVs and cel-let-7-5p on RAW264.7 macrophages through in vitro co-culture, followed by a dual luciferase assay to confirm C/EBPδ as the target of cel-let-7-5p. M1-polarized RAW264.7 cells were subsequently transfected with various agents, including NBL-EVs, cel-let-7-5p mimic, C/EBPδ small interfering RNA (siRNA), and so forth. The cell functions, surface molecule expression, transcription, and cytokine release were analyzed using flow cytometry, reverse transcription polymerase chain reaction (RT-PCR), western blot, and enzyme-linked immunosorbent assay (ELISA) to elucidate the regulatory mechanisms of NBL-EVs and cel-let-7-5p on macrophage polarization.</p><p><strong>Results: </strong>Results show that cel-let-7-5p transported by T. spiralis NBL-EVs inhibited the functional activity of M1 RAW264.7 macrophages by targeting C/EBPδ. This inhibition was validated by reduced CD86 and increased CD206 expression, along with decreased nitric oxide (NO) synthesis and downregulation of the M1 marker genes interleukin-12 (IL-12) and inducible nitric oxide synthase (iNOS). In contrast, the messenger RNA (mRNA) levels of IL-10 and arginase-1 (Arg1), which are M2 characteristic genes, were significantly enhanced. However, the release of M1 pro-inflammatory cytokines, such as IL-6, tumor necrosis factor-alpha (TNF-α), and IL-1β, was decreased proportionally. Notably, introducing a cel-let-7-5p inhibitor effectively reversed the suppressive effect of NBL-EVs on M1 macrophage function and partially mitigated their transition to the M2 phenotype, notably impacting Arg1 gene expression. However, no significant changes were observed in CD206 protein expression or IL-10 mRNA levels.</p><p><strong>Conclusions: </strong>The findings of this study reveal that cel-let-7-5p in T. spiralis NBL-EVs can inhibit the function of M1-type RAW264.7 macrophages by targeting C/EBPδ.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"199"},"PeriodicalIF":3.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12126876/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144199807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of vector competence for dengue virus type 2 in rural and urban populations of Aedes albopictus: implications for infectious disease control.","authors":"Jehangir Khan, Muhammad Adil, Zhang Junyan, Dongjing Zhang, Yidong Deng, Zhiyue Lv, Tao Chen","doi":"10.1186/s13071-025-06826-8","DOIUrl":"10.1186/s13071-025-06826-8","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Understanding the intrinsic factors that influence mosquito vector competence (VC) to pathogens is crucial for assessing the risk of disease transmission in both rural and urban environments. We assessed the VC of Aedes albopictus mosquitoes from urban (dengue-endemic) and rural (dengue-free) areas in Guangzhou, China, for dengue virus-2 (DENV-2), while also examining intrinsic factors such as Wolbachia and immune-related gene expression influencing VC.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Adult females of rural, urban, and laboratory (control) populations of Ae. albopictus were orally exposed to a freshly prepared suspension of the DENV-2 New Guinea C strain (GenBank: AF038403.1), with a final titer of 1 × 10&lt;sup&gt;7&lt;/sup&gt; plaque-forming units (PFU)/ml, for a period of 60 min. Three different bioassays (B1-B3) were conducted on 60 mosquitoes per population: B1 at 7 days post-exposure (dpe) to assess viral infection in the mosquito midgut, and B2 and B3 at 14 dpe to evaluate viral dissemination in the carcass and transmission via saliva. The mosquito samples were processed for total RNA and DNA extraction. RNA was subsequently analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) to quantify viral load and measure the expression of immune-related genes, while DNA was assessed via quantitative PCR (qPCR) to determine Wolbachia density (wAlbA and wAlbB) and the rps6 gene.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;At 7 dpe, virus proliferation in rural mosquitoes was similar to that in urban mosquitoes (P = 0.10). By 14 dpe, rural mosquitoes showed a significantly lower status of virus dissemination (P &lt; 0.04) and transmission (P &lt; 0.012). Wolbachia (-0.12 &lt; r &lt; -0.92) and immune effectors (-0.025 &lt; r &lt; -0.568) were negatively correlated with DENV in all mosquitoes, with more negative values indicating a stronger inverse relationship. The wAlbA and wAlbB strains exhibited similar densities across all the mosquito populations, with wAlbB revealing a slightly greater abundance in rural mosquitoes, although the difference was not significant. Elevated Relish 2 (Rel2), defensin A (DefA), and the signal transducers and activators of transcription (STAT) levels indicate activation of the Toll and JAK-STAT pathways, contributing to resistance against DENV replication and reduced VC in rural mosquitoes.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;This study indicates that rural Ae. albopictus mosquitoes may possess intrinsic barriers limiting their VC for DENV-2, offering valuable preliminary insights into VC across geographically distinct populations. However, further research across a broader range of urban and rural locations is needed to validate these findings and better understand the local factors influencing VC. Such insights are vital for public health, as they can help prioritize locations for dengue surveillance and effective vector control. Future studies should investigate the roles of intestinal microflora a","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"201"},"PeriodicalIF":3.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12128243/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144199805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sexual epigenetics: genome-wide analysis revealed differential DNA methylation in the vector tick Haemaphysalis longicornis.","authors":"Han Wang, Ziyan Bing, Lu Li, Ziwen Gao, Chuks Fidelis Nwanade, Na Dong, Ke Li, Leyan Du, Zhijun Yu","doi":"10.1186/s13071-025-06810-2","DOIUrl":"10.1186/s13071-025-06810-2","url":null,"abstract":"<p><strong>Background: </strong>Haemaphysalis longicornis is an important vector that transmits a variety of pathogens to humans and animals. This tick species is unique for having two separate reproductive populations: bisexual and parthenogenetic populations. In bisexual populations, morphological differences exist between the males and females, with the females often larger than the males. DNA methylation, as a key epigenetic modification, plays a crucial role in biological processes such as the maintenance of normal cellular function, the regulation of gene expression, and embryonic development. However, the epigenetic mechanism underlying sex differentiation in the bisexual population of H. longicornis has been overlooked.</p><p><strong>Methods: </strong>In the present study, the global DNA methylation profiles of the female and male H. longicornis ticks from the bisexual population were explored using whole-genome bisulfite sequencing. Differentially methylated regions (DMRs) were identified, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of DMR-related genes.</p><p><strong>Results: </strong>The results revealed that DNA methylation levels in H. longicornis varied by sex and sequence context (CG, CHG, and CHH). The 3' untranslated region (UTR) had the highest methylation in the CG context, followed by exons, introns, and CGI_shore regions. Female ticks generally exhibited higher methylation levels than males, particularly in gene body regions. A total of 10,460 DMRs were identified, with 5282 hypermethylated and 5178 hypomethylated. Further, GO and KEGG pathway analyses showed that differentially methylated genes (DMGs) were highly enriched in binding and metabolic pathways.</p><p><strong>Conclusions: </strong>These results broaden our understanding of DNA methylation changes associated with the female and male of H. longicornis and provide an important theoretical basis for subsequent studies of epigenetic mechanisms of sex differences in ticks.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"18 1","pages":"202"},"PeriodicalIF":3.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12128260/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144199808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}