Gnathostoma adult worms were found in the stomachs of domestic pigs in the Republic of Palau, with a prevalence of 0.7% (2/277) in the meat inspections conducted between 2020 and 2022. Based on morphological characteristics and nucleotide sequence analysis, the worms were identified as the adult stage of Gnathostoma doloresi Tubangui, 1925 (Rhabditida: Gnathostomatidae). These findings suggest the presence of this zoonotic nematode in Palau, which warrants further surveillance to determine its route of transmission in this island country.
{"title":"Gnathostoma doloresi in domestic pigs in the Republic of Palau, 2020–2022","authors":"Ryo Suzuki , Toshihiro Tokiwa , Takuma Kasahara , Kashgar Rengulbai","doi":"10.1016/j.parint.2024.103001","DOIUrl":"10.1016/j.parint.2024.103001","url":null,"abstract":"<div><div><em>Gnathostoma</em> adult worms were found in the stomachs of domestic pigs in the Republic of Palau, with a prevalence of 0.7% (2/277) in the meat inspections conducted between 2020 and 2022. Based on morphological characteristics and nucleotide sequence analysis, the worms were identified as the adult stage of <em>Gnathostoma doloresi</em> Tubangui, 1925 (Rhabditida: Gnathostomatidae)<em>.</em> These findings suggest the presence of this zoonotic nematode in Palau, which warrants further surveillance to determine its route of transmission in this island country.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"105 ","pages":"Article 103001"},"PeriodicalIF":1.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142740080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.parint.2024.103002
Constantin Constantinoiu, Wei Wang, Cadhla Firth, Richard Duffy, Jaqueline Picard, Bruce Gummow
A new species of sucking louse, Hoplopleura kuhnludwigi (Phthiraptera: Hoplopleuridae), from the Cape York rat Rattus leucopus cooktownensis Tate, 1951 (Rodentia: Muridae) is described and illustrated with photos and drawings. The host rat(s) were trapped in Northeast Queensland, Australia and identified using morphological characters and DNA sequencing. Hoplopleura kuhnludwigi is the first louse species to be described on R. leucopus. The morphology of the new louse species is contrasted with the morphology of Hoplopleura spp. previously described in Australian murids and shown to be different from other louse species that infest Australian native murids. Both conventional lice processing and staining methodology and a novel method, based on autofluorescence of chitin, have been used to describe and illustrate the diagnostic characters of H. kuhnludwigi. Processing of H. kuhnludwigi for epifluorescence microscopy (EM) is fast and easy, and the examination of the lice processed by this method can improve the accuracy of the description and identification of the lice species from genus Hoplopleura and potentially other louse species.
{"title":"Description of a new species of sucking louse Hoplopleura kuhnludwigi (Phthiraptera: Anoplura: Hoplopleuridae) from the Cape York rat Rattus leucopus cooktownensis (Rodentia: Muridae) in Australia using conventional methodology and novel epiflourescence microscopy.","authors":"Constantin Constantinoiu, Wei Wang, Cadhla Firth, Richard Duffy, Jaqueline Picard, Bruce Gummow","doi":"10.1016/j.parint.2024.103002","DOIUrl":"10.1016/j.parint.2024.103002","url":null,"abstract":"<p><p>A new species of sucking louse, Hoplopleura kuhnludwigi (Phthiraptera: Hoplopleuridae), from the Cape York rat Rattus leucopus cooktownensis Tate, 1951 (Rodentia: Muridae) is described and illustrated with photos and drawings. The host rat(s) were trapped in Northeast Queensland, Australia and identified using morphological characters and DNA sequencing. Hoplopleura kuhnludwigi is the first louse species to be described on R. leucopus. The morphology of the new louse species is contrasted with the morphology of Hoplopleura spp. previously described in Australian murids and shown to be different from other louse species that infest Australian native murids. Both conventional lice processing and staining methodology and a novel method, based on autofluorescence of chitin, have been used to describe and illustrate the diagnostic characters of H. kuhnludwigi. Processing of H. kuhnludwigi for epifluorescence microscopy (EM) is fast and easy, and the examination of the lice processed by this method can improve the accuracy of the description and identification of the lice species from genus Hoplopleura and potentially other louse species.</p>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":" ","pages":"103002"},"PeriodicalIF":1.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142751455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.parint.2024.102999
Hirotomo Kato
Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the genus Leishmania. About 20 species of Leishmania are pathogenic to humans, with the specific infecting species playing a crucial role in determining clinical outcomes. There are three main forms of disease: cutaneous, mucocutaneous and visceral leishmaniasis. In addition to the infecting species, it has recently been suggested that parasite strains and genetic factors affect disease manifestation and response to treatment. This suggests that infecting parasites are a crucial risk factor for the pathology of leishmaniasis. These parasites are transmitted by sand flies, of which more than 1000 species have been recorded. However, only approximately 10 % of these species are responsible for transmitting Leishmania, with each sand fly species typically transmitting specific species of Leishmania. Most Leishmania species are zoonotically transmitted by sand flies, with reservoir animals playing a crucial role in disease transmission and endemicity. This aspect of the disease ecology highlights the importance of considering both vectors and reservoir animals in endemic areas as risk factors for leishmaniasis. Our epidemiological studies on leishmaniasis focus mainly on South American countries. This review describes the epidemiological aspects of leishmaniasis in Ecuador and Peru, with a focus on pathological and infectious risks.
{"title":"Epidemiology of Leishmaniasis: Risk factors for its pathology and infection","authors":"Hirotomo Kato","doi":"10.1016/j.parint.2024.102999","DOIUrl":"10.1016/j.parint.2024.102999","url":null,"abstract":"<div><div>Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the genus <em>Leishmania</em>. About 20 species of <em>Leishmania</em> are pathogenic to humans, with the specific infecting species playing a crucial role in determining clinical outcomes. There are three main forms of disease: cutaneous, mucocutaneous and visceral leishmaniasis. In addition to the infecting species, it has recently been suggested that parasite strains and genetic factors affect disease manifestation and response to treatment. This suggests that infecting parasites are a crucial risk factor for the pathology of leishmaniasis. These parasites are transmitted by sand flies, of which more than 1000 species have been recorded. However, only approximately 10 % of these species are responsible for transmitting <em>Leishmania</em>, with each sand fly species typically transmitting specific species of <em>Leishmania</em>. Most <em>Leishmania</em> species are zoonotically transmitted by sand flies, with reservoir animals playing a crucial role in disease transmission and endemicity. This aspect of the disease ecology highlights the importance of considering both vectors and reservoir animals in endemic areas as risk factors for leishmaniasis. Our epidemiological studies on leishmaniasis focus mainly on South American countries. This review describes the epidemiological aspects of leishmaniasis in Ecuador and Peru, with a focus on pathological and infectious risks.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"105 ","pages":"Article 102999"},"PeriodicalIF":1.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.parint.2024.103000
Yoshio Osada , Shoichi Shimizu, Kentaro Morita
Parasites generally survive in their hosts by employing various immunomodulation and immune evasion mechanisms. “helminth therapy” is one strategy that harnesses these parasite-specific beneficial properties for the therapeutic treatment of autoimmune and allergic diseases. Although numerous experimental reports have documented the anti-autoimmune activities of parasitic infections and parasite-derived products, the underlying mechanisms remain insufficiently elucidated due to the significant diversity among parasite species and autoimmune conditions. Rheumatoid arthritis (RA) is one of the most prevalent autoimmune disorders, presenting a substantial opportunity for the therapeutic use of parasites as novel disease-modifying antirheumatic drugs (DMARDs). In this paper, we summarize the immunomodulatory properties of parasites, focusing on their anti-arthritic mechanisms, and discuss the potential of parasite-derived products for the treatment of RA.
{"title":"Parasitic helminths and protozoa: Treasure boxes of disease modifying anti-rheumatic drugs","authors":"Yoshio Osada , Shoichi Shimizu, Kentaro Morita","doi":"10.1016/j.parint.2024.103000","DOIUrl":"10.1016/j.parint.2024.103000","url":null,"abstract":"<div><div>Parasites generally survive in their hosts by employing various immunomodulation and immune evasion mechanisms. “helminth therapy” is one strategy that harnesses these parasite-specific beneficial properties for the therapeutic treatment of autoimmune and allergic diseases. Although numerous experimental reports have documented the anti-autoimmune activities of parasitic infections and parasite-derived products, the underlying mechanisms remain insufficiently elucidated due to the significant diversity among parasite species and autoimmune conditions. Rheumatoid arthritis (RA) is one of the most prevalent autoimmune disorders, presenting a substantial opportunity for the therapeutic use of parasites as novel disease-modifying antirheumatic drugs (DMARDs). In this paper, we summarize the immunomodulatory properties of parasites, focusing on their anti-arthritic mechanisms, and discuss the potential of parasite-derived products for the treatment of RA.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"105 ","pages":"Article 103000"},"PeriodicalIF":1.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142731812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-23DOI: 10.1016/j.parint.2024.102996
Dewi Masyithah Darlan , Hemma Yulfi , Sunna Vyatra Hutagalung , Merina Pangabean , Yunilda Andriyani , Irma Sepala Sari Siregar , Inke Nadia Diniyanti Lubis , Toni Wandra , Ivan Elisabeth Purba , Hiroshi Yamasaki , Yasuhito Sako
In the Samosir Island of North Sumatra, Indonesia, the prevalence of taeniasis caused by Taenia asiatica was reported as 2.2 %–20.7 % during 1972–2005. In 2014, another T. asiatica-endemic area was confirmed in the Silau Kahean sub-district of Simalungun District, which is geographically distant from Samosir Island. This study was conducted in the Raya Kahean sub-district of Simalungun District adjacent to the Silau Kahean sub-district in September 2023. The aim was to identify a new T. asiatica-endemic area based on molecular confirmation in addition to determining the prevalence of taeniasis. Men aged ≥18 years and palm plantation male farmers showed a higher prevalence of taeniasis, with an overall prevalence of 21.7 % (93/428). A total of 14 proglottids obtained from 14 tapeworm carriers were identified as T. asiatica by COX1-multiplex PCR analysis, and a new T. asiatica-endemic area was detected in the Raya Kahean sub-district. Genetic analyses of COX1 and pold revealed that T. asiatica from North Sumatra has a poor genetic diversity and is a descendant of the hybrids of T. asiatica and T. saginata. Infections were associated with a habitual consumption of raw pig and wild boar livers. Basic sanitary education, improvement of traditional food habits, and implementation of sentinel surveillance and treatment for tapeworm carriers in endemic areas are required to prevent and control this parasitic disease.
据报道，1972-2005年间，印度尼西亚北苏门答腊的萨莫西尔岛由亚洲奚蚊引起的奚蚊病发病率为2.2%-20.7%。2014 年，在与萨莫西尔岛地理位置相距较远的西马伦贡区 Silau Kahean 分区确认了另一个亚洲弓形虫流行区。这项研究于 2023 年 9 月在毗邻 Silau Kahean 分区的西马伦贡区 Raya Kahean 分区进行。目的是根据分子确认确定一个新的亚洲锥虫病流行区，同时确定锥虫病的流行率。年龄大于 18 岁的男性和棕榈种植园男农民的尾丝虫病发病率较高，总体发病率为 21.7%（93/428）。通过 COX1-多重 PCR 分析，从 14 名绦虫携带者身上获得的 14 个原虫被鉴定为 T. asiatica，并在 Raya Kahean 分区发现了一个新的 T. asiatica 流行区。COX1 和 pold 的遗传分析表明，北苏门答腊的 T. asiatica 遗传多样性较差，是 T. asiatica 和 T. saginata 杂交种的后代。感染与习惯性食用生猪和野猪肝脏有关。要预防和控制这种寄生虫病，就必须开展基本的卫生教育，改善传统的饮食习惯，并在绦虫流行地区对绦虫携带者实施定点监测和治疗。
{"title":"A new focus of Taenia asiatica taeniasis in North Sumatra, Indonesia: Molecular confirmation and prevalence","authors":"Dewi Masyithah Darlan , Hemma Yulfi , Sunna Vyatra Hutagalung , Merina Pangabean , Yunilda Andriyani , Irma Sepala Sari Siregar , Inke Nadia Diniyanti Lubis , Toni Wandra , Ivan Elisabeth Purba , Hiroshi Yamasaki , Yasuhito Sako","doi":"10.1016/j.parint.2024.102996","DOIUrl":"10.1016/j.parint.2024.102996","url":null,"abstract":"<div><div>In the Samosir Island of North Sumatra, Indonesia, the prevalence of taeniasis caused by <em>Taenia asiatica</em> was reported as 2.2 %–20.7 % during 1972–2005. In 2014, another <em>T. asiatica</em>-endemic area was confirmed in the Silau Kahean sub-district of Simalungun District, which is geographically distant from Samosir Island. This study was conducted in the Raya Kahean sub-district of Simalungun District adjacent to the Silau Kahean sub-district in September 2023. The aim was to identify a new <em>T. asiatica</em>-endemic area based on molecular confirmation in addition to determining the prevalence of taeniasis. Men aged ≥18 years and palm plantation male farmers showed a higher prevalence of taeniasis, with an overall prevalence of 21.7 % (93/428). A total of 14 proglottids obtained from 14 tapeworm carriers were identified as <em>T. asiatica</em> by COX1-multiplex PCR analysis, and a new <em>T. asiatica</em>-endemic area was detected in the Raya Kahean sub-district. Genetic analyses of COX1 and <em>pold</em> revealed that <em>T. asiatica</em> from North Sumatra has a poor genetic diversity and is a descendant of the hybrids of <em>T. asiatica</em> and <em>T. saginata</em>. Infections were associated with a habitual consumption of raw pig and wild boar livers. Basic sanitary education, improvement of traditional food habits, and implementation of sentinel surveillance and treatment for tapeworm carriers in endemic areas are required to prevent and control this parasitic disease.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"105 ","pages":"Article 102996"},"PeriodicalIF":1.5,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142710867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-23DOI: 10.1016/j.parint.2024.102998
Hirotomo Kato
Phlebotomine sand flies are very small hematophagous insects, and some species transmit human pathogens, such as Leishmania protozoa. Similar to other hematophagous insects, sand flies possess unique bioactive substances in their saliva to facilitate blood feeding. Active transcriptome and proteome analyses revealed that sand flies have unique molecules in their saliva that are structurally different from those of other arthropods. These components exert anticoagulant, antiplatelet, vasodilator, and anti-inflammatory effects on the host, and the unique bioactivities of each molecule are currently being characterized. Several bioactivities of salivary components have been associated with the exacerbation of Leishmania infection, and investigations on the molecular mechanisms responsible are underway. On the other hand, host immunity to some salivary components has been shown to confer protection against Leishmania infection, suggesting the potential of salivary components as vaccine candidates. Although some negative effects of protection by sand fly saliva have been reported, the identification of suitable immunogens and elucidation of appropriate protective immunity are expected for the development of a sand fly saliva vaccine against Leishmania infection.
{"title":"Dr. Jekyll and Mr. Hyde in sand fly saliva","authors":"Hirotomo Kato","doi":"10.1016/j.parint.2024.102998","DOIUrl":"10.1016/j.parint.2024.102998","url":null,"abstract":"<div><div>Phlebotomine sand flies are very small hematophagous insects, and some species transmit human pathogens, such as <em>Leishmania</em> protozoa. Similar to other hematophagous insects, sand flies possess unique bioactive substances in their saliva to facilitate blood feeding. Active transcriptome and proteome analyses revealed that sand flies have unique molecules in their saliva that are structurally different from those of other arthropods. These components exert anticoagulant, antiplatelet, vasodilator, and anti-inflammatory effects on the host, and the unique bioactivities of each molecule are currently being characterized. Several bioactivities of salivary components have been associated with the exacerbation of <em>Leishmania</em> infection, and investigations on the molecular mechanisms responsible are underway. On the other hand, host immunity to some salivary components has been shown to confer protection against <em>Leishmania</em> infection, suggesting the potential of salivary components as vaccine candidates. Although some negative effects of protection by sand fly saliva have been reported, the identification of suitable immunogens and elucidation of appropriate protective immunity are expected for the development of a sand fly saliva vaccine against <em>Leishmania</em> infection.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"105 ","pages":"Article 102998"},"PeriodicalIF":1.5,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142710868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-23DOI: 10.1016/j.parint.2024.102997
Yuta Tachibana , Masahiro Yamamoto
The apicomplexan parasite, Toxoplasma gondii, develops unique secretory organelles, such as micronemes, rhoptries, and dense granules, which do not exist in other well-studied eukaryotic organisms. These secretory organelles are key features of apicomplexan parasites and discharge various proteins that are essential for invasion, replication, egress, host-parasite interactions, and virulence. Many studies have therefore focused on identifying and characterizing the proteins secreted by T. gondii that play essential roles in pathology and that can be targeted for therapeutics and vaccine development. The recent development of functional genetic screens based on CRISPR/Cas9 technology has revolutionized this field and has enabled the identification of genes that contribute to parasite fitness in vitro and in vivo. Consequently, characterization of genes identified by unbiased CRISPR screens has revealed novel aspects of apicomplexan biology. In this review, we describe the development of CRIPSR-based screening technology for T. gondii, and recent advances in our understanding of secretory proteins identified and characterized by CRISPR-based screening.
{"title":"Recent advances in identifying and characterizing secretory proteins of Toxoplasma gondii by CRISPR-based screening","authors":"Yuta Tachibana , Masahiro Yamamoto","doi":"10.1016/j.parint.2024.102997","DOIUrl":"10.1016/j.parint.2024.102997","url":null,"abstract":"<div><div>The apicomplexan parasite, <em>Toxoplasma gondii</em>, develops unique secretory organelles, such as micronemes, rhoptries, and dense granules, which do not exist in other well-studied eukaryotic organisms. These secretory organelles are key features of apicomplexan parasites and discharge various proteins that are essential for invasion, replication, egress, host-parasite interactions, and virulence. Many studies have therefore focused on identifying and characterizing the proteins secreted by <em>T. gondii</em> that play essential roles in pathology and that can be targeted for therapeutics and vaccine development. The recent development of functional genetic screens based on CRISPR/Cas9 technology has revolutionized this field and has enabled the identification of genes that contribute to parasite fitness <em>in vitro</em> and <em>in vivo</em>. Consequently, characterization of genes identified by unbiased CRISPR screens has revealed novel aspects of apicomplexan biology. In this review, we describe the development of CRIPSR-based screening technology for <em>T. gondii</em>, and recent advances in our understanding of secretory proteins identified and characterized by CRISPR-based screening.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"105 ","pages":"Article 102997"},"PeriodicalIF":1.5,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142716815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the dense granule proteins named GRA15 in Toxoplasma gondii (T. gondii), is known to support an innate immune response in host through activation of NF-κB. However, little is known about advantages of GRA15 for parasites. By examining the role of GRA15 in the host-parasite interactions, it was clarified that GRA15 in T. gondii suppressed acquired immune responses in host. Wild-type parasite infection to C57BL/6 mice resulted in lower titers of T. gondii antibody and lower plasma cell counts compared to Δgra15 T. gondii. To identify host cells in which GRA15 acts to suppress antibody production, we generated conditional knock-in mice that express GRA15 in specific cell lineages. Anti-T. gondii antibodies were not reduced in macrophages of conditional knock-in mice after infection with Δgra15 T. gondii, while the production of T. gondii antibody was suppressed in dendritic cells of the conditional knock-in mice (CD11c-Cre/GRA15cKI). In the CD11c-Cre/GRA15cKI immunized with ovalbumin (OVA), the titers of anti-OVA antibody were reduced compared to control mice. Furthermore, the number of OVA antigen-specific T cells was also decreased in CD11c-Cre/GRA15cKI. These data showed that GRA15 in dendritic cells suppressed T cell-mediated humoral immunity. These findings might implicate the pathological significance of GRA15 and facilitate Toxoplasma vaccines production.
{"title":"Toxoplasma GRA15 expression on dendritic cells inhibits B cell differentiation and antibody production","authors":"Yuki Nakayama , Fumiaki Ihara , Daisuke Okuzaki , Yoshifumi Nishikawa , Miwa Sasai , Masahiro Yamamoto","doi":"10.1016/j.parint.2024.102995","DOIUrl":"10.1016/j.parint.2024.102995","url":null,"abstract":"<div><div>One of the dense granule proteins named GRA15 in <em>Toxoplasma gondii</em> (<em>T. gondii</em>), is known to support an innate immune response in host through activation of NF-κB. However, little is known about advantages of GRA15 for parasites. By examining the role of GRA15 in the host-parasite interactions, it was clarified that GRA15 in <em>T. gondii</em> suppressed acquired immune responses in host. Wild-type parasite infection to C57BL/6 mice resulted in lower titers of <em>T. gondii</em> antibody and lower plasma cell counts compared to Δgra15 <em>T. gondii</em>. To identify host cells in which GRA15 acts to suppress antibody production, we generated conditional knock-in mice that express GRA15 in specific cell lineages. Anti-<em>T. gondii</em> antibodies were not reduced in macrophages of conditional knock-in mice after infection with Δgra15 <em>T. gondii</em>, while the production of <em>T. gondii</em> antibody was suppressed in dendritic cells of the conditional knock-in mice (CD11c-Cre/GRA15cKI). In the CD11c-Cre/GRA15cKI immunized with ovalbumin (OVA), the titers of anti-OVA antibody were reduced compared to control mice. Furthermore, the number of OVA antigen-specific T cells was also decreased in CD11c-Cre/GRA15cKI. These data showed that GRA15 in dendritic cells suppressed T cell-mediated humoral immunity. These findings might implicate the pathological significance of GRA15 and facilitate <em>Toxoplasma</em> vaccines production.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"105 ","pages":"Article 102995"},"PeriodicalIF":1.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142668592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-17DOI: 10.1016/j.parint.2024.102993
Shoichi Shimizu , Junko Shin , Takuma Ota , Hirofumi Kondo , Susumu Nakae , Katsuko Sudo , Eman M. Gaballah , Kentaro Morita , Yoshio Osada
We previously reported that Plasmodium yoelii 17XNL (Py), a non-lethal rodent malarial parasite, could suppress collagen-induced arthritis (CIA) and increase the production of T cell-derived interleukin (IL)-10. However, it remained unclear whether IL-10 is essential for the Py-induced suppression of CIA. Male IL-10 knockout (KO) DBA/1 J mice were immunized with bovine type II collagen (CII) and subsequently infected with Py at one week post-immunization. The development of arthritis was evaluated by an arthritis score up to 6 weeks post-immunization. At 3 weeks post-immunization, cytokine production from splenocytes and serum anti-CII IgG/IgG1/IgG2a levels were compared between non-infected control mice and Py-infected mice. Py infection inhibited the development of CIA in IL-10KO mice until 4 weeks post-immunization, after which the arthritis score reached levels comparable with the control mice. Both pro-arthritic (IL-17 and TNF-α) and anti-arthritic (IFN-γ and IL-4) cytokines were down-regulated during the periods of parasitemia, while no significant differences were observed in levels of anti-CII IgG antibodies. Our findings indicate that Py alleviates CIA via IL-10-independent mechanisms.
{"title":"IL-10 is not required for the alleviation of collagen-induced arthritis by non-lethal malarial infection in mice","authors":"Shoichi Shimizu , Junko Shin , Takuma Ota , Hirofumi Kondo , Susumu Nakae , Katsuko Sudo , Eman M. Gaballah , Kentaro Morita , Yoshio Osada","doi":"10.1016/j.parint.2024.102993","DOIUrl":"10.1016/j.parint.2024.102993","url":null,"abstract":"<div><div>We previously reported that <em>Plasmodium yoelii</em> 17XNL (Py), a non-lethal rodent malarial parasite, could suppress collagen-induced arthritis (CIA) and increase the production of T cell-derived interleukin (IL)-10. However, it remained unclear whether IL-10 is essential for the Py-induced suppression of CIA. Male IL-10 knockout (KO) DBA/1 J mice were immunized with bovine type II collagen (CII) and subsequently infected with Py at one week post-immunization. The development of arthritis was evaluated by an arthritis score up to 6 weeks post-immunization. At 3 weeks post-immunization, cytokine production from splenocytes and serum anti-CII IgG/IgG1/IgG2a levels were compared between non-infected control mice and Py-infected mice. Py infection inhibited the development of CIA in IL-10KO mice until 4 weeks post-immunization, after which the arthritis score reached levels comparable with the control mice. Both pro-arthritic (IL-17 and TNF-α) and anti-arthritic (IFN-γ and IL-4) cytokines were down-regulated during the periods of parasitemia, while no significant differences were observed in levels of anti-CII IgG antibodies. Our findings indicate that Py alleviates CIA via IL-10-independent mechanisms.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"104 ","pages":"Article 102993"},"PeriodicalIF":1.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142676259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Schistosomiasis is a parasitic disease affecting more than 250 million people worldwide. Schistosomes infect humans by cercariae penetrating the skin in a freshwater environment. Findings obtained more than 100 years prior showed that miracidium develops into cercaria in freshwater snails, though detailed development dynamics have not been elucidated. Although results of histological analyses of development of schistosomes in snails were presented in our previous studies, findings obtained with dynamic imaging have yet to be reported. In the present study, imaging of schistosome infection and dynamics in snails occuring within a short period was performed using fluorescent labeling agents. Labeling of S. mansoni cercariae with carboxyfluorescein succinimidyl ester (CFSE) caused no toxicity, and allowed for monitoring of schistosome dynamics in snails for up to 10 days and release of infective cercariae without fluorescence in 40 days following infection.
{"title":"Labeling of miracidium using fluorescent agents to visualize infection of schistosome in intermediate host snails","authors":"Yukiteru Ouji , Megumi Hamasaki , Masayasu Misu , Masahide Yoshikawa , Shinjiro Hamano","doi":"10.1016/j.parint.2024.102994","DOIUrl":"10.1016/j.parint.2024.102994","url":null,"abstract":"<div><div>Schistosomiasis is a parasitic disease affecting more than 250 million people worldwide. Schistosomes infect humans by cercariae penetrating the skin in a freshwater environment. Findings obtained more than 100 years prior showed that miracidium develops into cercaria in freshwater snails, though detailed development dynamics have not been elucidated. Although results of histological analyses of development of schistosomes in snails were presented in our previous studies, findings obtained with dynamic imaging have yet to be reported. In the present study, imaging of schistosome infection and dynamics in snails occuring within a short period was performed using fluorescent labeling agents. Labeling of <em>S. mansoni</em> cercariae with carboxyfluorescein succinimidyl ester (CFSE) caused no toxicity, and allowed for monitoring of schistosome dynamics in snails for up to 10 days and release of infective cercariae without fluorescence in 40 days following infection.</div></div>","PeriodicalId":19983,"journal":{"name":"Parasitology International","volume":"104 ","pages":"Article 102994"},"PeriodicalIF":1.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142676394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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