Pub Date : 2023-11-21DOI: 10.3389/fpara.2023.1241154
M. Pinazo, Colin J. Forsyth, Constanza Lopez-Albizu, M. Bisio, Adriana González-Martínez, Laura Bohorquez, Jimy Pinto, Israel Molina, A. Marchiol, Rafael Herazo, I. Galván, Tayná Marques, Fabiana Barreira, Juan Carlos Villar, Yanina Sguassero, Maria Soledad Santini, J. Altcheh, B. Alarcón de Noya, S. Sosa-Estani
Trypanosoma cruzi infection is diagnosed by parasitological, molecular, and serological tests. Molecular methods based on DNA amplification provide a more sensitive alternative to classical parasitological techniques for detecting evidence of T. cruzi parasitemia, and are the preferred tests for congenital and oral transmission cases and parasite reactivation in chronically infected immunosuppressed individuals. In newborns at risk of vertical transmission, simplified diagnostic algorithms that provide timely results can reduce the high follow-up losses observed with current algorithms. Molecular methods have also proved useful for monitoring T. cruzi infection in solid organ transplantation recipients, regardless of host immune status, allowing parasite detection even before symptom manifestation. Furthermore, in the absence of other biomarkers and a practical test of cure, and given the limitations of serological methods, recent clinical guidelines have included polymerase chain reaction (PCR) to detect therapeutic failure after antiparasitic treatment in chronically infected adults. Increasing evidence supports the use of molecular tests in a clinical context, given the improved sensitivity and specificity of current assays – characteristics which largely depend on epidemiological factors and genetic and antigenic variability among T. cruzi strains. Further development and registration of commercial PCR kits will improve the use of molecular tests. We discuss the attributes of PCR and other molecular tests for clinical management in people with T. cruzi infection.
克鲁兹锥虫感染可通过寄生虫学、分子和血清学检测进行诊断。以 DNA 扩增为基础的分子方法比传统的寄生虫学技术更灵敏，可用于检测克鲁兹锥虫寄生虫血症的证据，是先天性和经口传播病例以及慢性感染的免疫抑制患者寄生虫再活化的首选检测方法。对于有垂直传播风险的新生儿，能及时提供结果的简化诊断算法可减少目前算法中观察到的高随访损失。事实证明，分子方法对于监测实体器官移植受者的 T. cruzi 感染也很有用，无论宿主的免疫状态如何，甚至在症状出现之前就能检测到寄生虫。此外，由于缺乏其他生物标志物和实用的治愈检测方法，并考虑到血清学方法的局限性，近期的临床指南已将聚合酶链反应（PCR）纳入其中，用于检测慢性感染成人抗寄生虫治疗后的治疗失败情况。鉴于目前检测方法的灵敏度和特异性有所提高，越来越多的证据支持在临床中使用分子检测方法，而这些特点在很大程度上取决于流行病学因素以及 T. cruzi 菌株之间的遗传和抗原变异性。商业 PCR 试剂盒的进一步开发和注册将提高分子检测的使用率。我们讨论了 PCR 和其他分子检验在临床管理中对 T. cruzi 感染者的作用。
{"title":"Clinical use of molecular methods for Trypanosoma cruzi infection in endemic and non-endemic countries: Benefits, limitations and challenges","authors":"M. Pinazo, Colin J. Forsyth, Constanza Lopez-Albizu, M. Bisio, Adriana González-Martínez, Laura Bohorquez, Jimy Pinto, Israel Molina, A. Marchiol, Rafael Herazo, I. Galván, Tayná Marques, Fabiana Barreira, Juan Carlos Villar, Yanina Sguassero, Maria Soledad Santini, J. Altcheh, B. Alarcón de Noya, S. Sosa-Estani","doi":"10.3389/fpara.2023.1241154","DOIUrl":"https://doi.org/10.3389/fpara.2023.1241154","url":null,"abstract":"Trypanosoma cruzi infection is diagnosed by parasitological, molecular, and serological tests. Molecular methods based on DNA amplification provide a more sensitive alternative to classical parasitological techniques for detecting evidence of T. cruzi parasitemia, and are the preferred tests for congenital and oral transmission cases and parasite reactivation in chronically infected immunosuppressed individuals. In newborns at risk of vertical transmission, simplified diagnostic algorithms that provide timely results can reduce the high follow-up losses observed with current algorithms. Molecular methods have also proved useful for monitoring T. cruzi infection in solid organ transplantation recipients, regardless of host immune status, allowing parasite detection even before symptom manifestation. Furthermore, in the absence of other biomarkers and a practical test of cure, and given the limitations of serological methods, recent clinical guidelines have included polymerase chain reaction (PCR) to detect therapeutic failure after antiparasitic treatment in chronically infected adults. Increasing evidence supports the use of molecular tests in a clinical context, given the improved sensitivity and specificity of current assays – characteristics which largely depend on epidemiological factors and genetic and antigenic variability among T. cruzi strains. Further development and registration of commercial PCR kits will improve the use of molecular tests. We discuss the attributes of PCR and other molecular tests for clinical management in people with T. cruzi infection.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"6 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139252371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-17DOI: 10.3389/fpara.2023.1292837
Linda Djune-Yemeli, Marla I Hertz, H. Nana-Djeunga, Amy Rush, Petra Erdmann-Gilmore, Robert Sprung, J. Bopda, Reid Townsend, P. Netongo, Joseph Kamgno, Philip J. Budge
Circulating Loa loa antigens are often detected in individuals with heavy L. loa infections by diagnostic tests for lymphatic filariasis (LF) caused by Wuchereria bancrofti. This is a major challenge to LF mapping and elimination efforts in loiasis co-endemic areas. However, it also provides an opportunity to identify antigen biomarkers for loiasis. To determine which L. loa antigens might be promising biomarkers for distinguishing true LF from loiasis, we screened for L. loa antigens in a group of individuals with heavy L. loa infections living in the Okola Health District of Cameroon. In this longitudinal study, participants were tested for cross-reactive antigenemia by filariasis test strip (FTS), ELISA, and western blot, and were monitored for FTS status at 6, 9, 12, and 15 months post-enrollment. We then identified specific circulating L. loa antigens by liquid chromatography-tandem mass spectrometry (LC-MS/MS) from baseline and 15-month plasma samples.Among 73 FTS-positive (FTS+) and 13 FTS-negative (FTS-) participants with high L. loa microfilarial loads, 83% maintained their FTS status over the course of the study, while 17% experienced at least one FTS conversion event (from FTS+ to FTS- or vice versa). Cross-reactive antigens were detected in both FTS+ and FTS- sera by western blot, and there was poor agreement in antigen detection by FTS, western blot, and ELISA methods. One protein family, a group of Nas-14 metalloproteases, was detected by LC MS/MS in >80% of tested samples, including FTS- samples. These data identify Nas-14 as a promising loiasis biomarker potentially capable of distinguishing loiasis from lymphatic filariasis.
{"title":"Longitudinal study of cross-reactive antigenemia in individuals with high Loa loa microfilarial density reveals promising biomarkers for distinguishing lymphatic filariasis from loiasis","authors":"Linda Djune-Yemeli, Marla I Hertz, H. Nana-Djeunga, Amy Rush, Petra Erdmann-Gilmore, Robert Sprung, J. Bopda, Reid Townsend, P. Netongo, Joseph Kamgno, Philip J. Budge","doi":"10.3389/fpara.2023.1292837","DOIUrl":"https://doi.org/10.3389/fpara.2023.1292837","url":null,"abstract":"Circulating Loa loa antigens are often detected in individuals with heavy L. loa infections by diagnostic tests for lymphatic filariasis (LF) caused by Wuchereria bancrofti. This is a major challenge to LF mapping and elimination efforts in loiasis co-endemic areas. However, it also provides an opportunity to identify antigen biomarkers for loiasis. To determine which L. loa antigens might be promising biomarkers for distinguishing true LF from loiasis, we screened for L. loa antigens in a group of individuals with heavy L. loa infections living in the Okola Health District of Cameroon. In this longitudinal study, participants were tested for cross-reactive antigenemia by filariasis test strip (FTS), ELISA, and western blot, and were monitored for FTS status at 6, 9, 12, and 15 months post-enrollment. We then identified specific circulating L. loa antigens by liquid chromatography-tandem mass spectrometry (LC-MS/MS) from baseline and 15-month plasma samples.Among 73 FTS-positive (FTS+) and 13 FTS-negative (FTS-) participants with high L. loa microfilarial loads, 83% maintained their FTS status over the course of the study, while 17% experienced at least one FTS conversion event (from FTS+ to FTS- or vice versa). Cross-reactive antigens were detected in both FTS+ and FTS- sera by western blot, and there was poor agreement in antigen detection by FTS, western blot, and ELISA methods. One protein family, a group of Nas-14 metalloproteases, was detected by LC MS/MS in >80% of tested samples, including FTS- samples. These data identify Nas-14 as a promising loiasis biomarker potentially capable of distinguishing loiasis from lymphatic filariasis.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139265868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-14DOI: 10.3389/fpara.2023.1272378
Marilyn Parsons, Ben Parsons, Marissa Dean, Amy E. DeRocher, Zeba Islam, Dustin J. Maly, Bryan C. Jensen
Introduction The protein serine/threonine kinase AEK1 is essential in the pathogenic stage of Trypanosoma brucei, the causative agent of African trypanosomiasis. AEK1 is a member of the AGC protein kinase family, although it is not closely related to a specific human AGC kinase. Our previous chemical genetic studies showed that targeted inhibition of AEK1 in parasites expressing analog-sensitive AEK1 blocked parasite growth and enhanced survival of infected mice. Methods To further validate AEK1 as a drug target, we used the chemical genetic system to determine the effect of a 24 hour loss of AEK1 activity on cell viability at the clonal level. A panel of 429 protein kinase inhibitors were screened against the wild-type protein for binding, using time-resolved fluorescence energy transfer (TR-FRET). The role of phosphorylation sites and motifs was probed by determining whether expression of proteins harboring mutations in these sequences could rescue AEK1 conditional knockout parasites. To determine the effect that mutations in the phosphosites have on the kinase activity of cellular AEK1 we compared the in vitro kinase activity of mutant and wild-type proteins immunoprecipitated from parasite lysates using the exogenous substrate MBP. Finally, the tagged AEK1 protein was localized by deconvolution microscopy. Results After a 24 hour exposure to an AEK1 inhibitory analog in the chemical genetic system, less than five percent of the remaining live cells can clonally expand, further validating AEK1 as a drug target. In the AEK1 inhibitor screening assay, we identified 17 hit compounds. Complementation studies showed that of the two known phosphorylation sites in the activation loop; mutation of one abolished function while mutation of the other had no discernable effect. Mutation of the other two AEK1 phosphosites gave intermediate phenotypes. Mutations in either the hydrophobic motif at the C-terminus of the protein or in the region of AEK1 predicted to bind the hydrophobic motif were also required for function. All parasites with defective AEK1 showed reduced proliferation and defects in cytokinesis, although the tested mutations differed in terms of the extent of cell death. Kinase activity of immunoprecipitated AEK1 phosphosite mutants largely paralleled the effects seen in complementation studies, although the mutation of the phosphosite adjacent to the hydrophobic motif had a greater impact on activity than predicted by the complementation studies. AEK1 was localized to cytoplasmic puncta distinct from glycosomes and acidocalcisomes. Discussion The rapid loss of viability of cells inhibited for AEK1 supports the idea that a short course of treatment that target AEK1 may be sufficient for treatment of people or animals infected with T. brucei. Key regulatory elements between AEK1 and its closest mammalian homolog appear to be largely conserved despite the vast evolutionary distance between mammals and T. brucei. The presence of AEK1 in cytopla
{"title":"An essential Trypanosoma brucei protein kinase: a functional analysis of regulation and the identification of inhibitors","authors":"Marilyn Parsons, Ben Parsons, Marissa Dean, Amy E. DeRocher, Zeba Islam, Dustin J. Maly, Bryan C. Jensen","doi":"10.3389/fpara.2023.1272378","DOIUrl":"https://doi.org/10.3389/fpara.2023.1272378","url":null,"abstract":"Introduction The protein serine/threonine kinase AEK1 is essential in the pathogenic stage of Trypanosoma brucei, the causative agent of African trypanosomiasis. AEK1 is a member of the AGC protein kinase family, although it is not closely related to a specific human AGC kinase. Our previous chemical genetic studies showed that targeted inhibition of AEK1 in parasites expressing analog-sensitive AEK1 blocked parasite growth and enhanced survival of infected mice. Methods To further validate AEK1 as a drug target, we used the chemical genetic system to determine the effect of a 24 hour loss of AEK1 activity on cell viability at the clonal level. A panel of 429 protein kinase inhibitors were screened against the wild-type protein for binding, using time-resolved fluorescence energy transfer (TR-FRET). The role of phosphorylation sites and motifs was probed by determining whether expression of proteins harboring mutations in these sequences could rescue AEK1 conditional knockout parasites. To determine the effect that mutations in the phosphosites have on the kinase activity of cellular AEK1 we compared the in vitro kinase activity of mutant and wild-type proteins immunoprecipitated from parasite lysates using the exogenous substrate MBP. Finally, the tagged AEK1 protein was localized by deconvolution microscopy. Results After a 24 hour exposure to an AEK1 inhibitory analog in the chemical genetic system, less than five percent of the remaining live cells can clonally expand, further validating AEK1 as a drug target. In the AEK1 inhibitor screening assay, we identified 17 hit compounds. Complementation studies showed that of the two known phosphorylation sites in the activation loop; mutation of one abolished function while mutation of the other had no discernable effect. Mutation of the other two AEK1 phosphosites gave intermediate phenotypes. Mutations in either the hydrophobic motif at the C-terminus of the protein or in the region of AEK1 predicted to bind the hydrophobic motif were also required for function. All parasites with defective AEK1 showed reduced proliferation and defects in cytokinesis, although the tested mutations differed in terms of the extent of cell death. Kinase activity of immunoprecipitated AEK1 phosphosite mutants largely paralleled the effects seen in complementation studies, although the mutation of the phosphosite adjacent to the hydrophobic motif had a greater impact on activity than predicted by the complementation studies. AEK1 was localized to cytoplasmic puncta distinct from glycosomes and acidocalcisomes. Discussion The rapid loss of viability of cells inhibited for AEK1 supports the idea that a short course of treatment that target AEK1 may be sufficient for treatment of people or animals infected with T. brucei. Key regulatory elements between AEK1 and its closest mammalian homolog appear to be largely conserved despite the vast evolutionary distance between mammals and T. brucei. The presence of AEK1 in cytopla","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134993001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-27DOI: 10.3389/fpara.2023.1277372
Linda J. Wammes, Suzanne A. V. van Asten, Lisette van Lieshout, Els Wessels, Jaco J. Verweij
Word count: 211 Introduction The laboratory diagnosis of Strongyloides stercoralis is notoriously difficult. Microscopic diagnosis, even using concentration techniques and repeated sampling, is known to lack sensitivity. Serology depending on the type of test used have shown adequate sensitivity but specificity is generally low. In the present study the performance of S. stercoralis real-time PCR as a routine diagnostic test is evaluated in two different non-endemic settings. Methods Strongyloides stercoralis real-time PCR, serology, and microscopy results with available clinical and anamnestic data were extracted from the laboratory information management systems between August 2005 and December 2022. Results A total of 19179 Strongyloides stercoralis PCR results were retrieved in which in 149 specimens from 103 patients S. stercoralisspecific DNA was detected. Microscopy revealed S. stercoralis larvae in 19 of 36 (53%) PCR positive patients. Whereas serology tested positive in 70 of 74 (94.6%) of all available serum samples of S. stercoralis PCR positive patients and in 61 of 63 (96.8%) when limited to serology results within 6 weeks around the primary PCR-positive specimen. In 79% (38 of 48 patients) the first follow-up feces sample tested PCR negative. Discussion Strongyloides stercoralis real-time PCR showed a valuable diagnostic tool for the detecting and monitoring of S. stercoralis infections and detected additional cases compared to microscopy and serology.
{"title":"Real-time PCR for diagnosing and monitoring treatment effect of Strongyloides stercoralis infection in a non-endemic setting","authors":"Linda J. Wammes, Suzanne A. V. van Asten, Lisette van Lieshout, Els Wessels, Jaco J. Verweij","doi":"10.3389/fpara.2023.1277372","DOIUrl":"https://doi.org/10.3389/fpara.2023.1277372","url":null,"abstract":"Word count: 211 Introduction The laboratory diagnosis of Strongyloides stercoralis is notoriously difficult. Microscopic diagnosis, even using concentration techniques and repeated sampling, is known to lack sensitivity. Serology depending on the type of test used have shown adequate sensitivity but specificity is generally low. In the present study the performance of S. stercoralis real-time PCR as a routine diagnostic test is evaluated in two different non-endemic settings. Methods Strongyloides stercoralis real-time PCR, serology, and microscopy results with available clinical and anamnestic data were extracted from the laboratory information management systems between August 2005 and December 2022. Results A total of 19179 Strongyloides stercoralis PCR results were retrieved in which in 149 specimens from 103 patients S. stercoralisspecific DNA was detected. Microscopy revealed S. stercoralis larvae in 19 of 36 (53%) PCR positive patients. Whereas serology tested positive in 70 of 74 (94.6%) of all available serum samples of S. stercoralis PCR positive patients and in 61 of 63 (96.8%) when limited to serology results within 6 weeks around the primary PCR-positive specimen. In 79% (38 of 48 patients) the first follow-up feces sample tested PCR negative. Discussion Strongyloides stercoralis real-time PCR showed a valuable diagnostic tool for the detecting and monitoring of S. stercoralis infections and detected additional cases compared to microscopy and serology.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136312233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-23DOI: 10.3389/fpara.2023.1281092
Devyn Yates, Lucia S. Di Maggio, Bruce A. Rosa, Robert W. Sprung, Petra Erdmann-Gilmore, R. Reid Townsend, Philip J. Budge, Joseph Kamgno, Makedonka Mitreva, Gary J. Weil, Peter U. Fischer
Background Improved diagnostic tools are needed for detecting active filarial infections in humans. Tests are available that detect adult W. bancrofti circulating filarial antigen, but there are no sensitive and specific biomarker tests for brugian filariasis or loiasis. Here we explored whether extracellular vesicles released by filarial parasites contain diagnostic biomarker candidates. Methods Vesicles were isolated using VN96-affinity purification from supernatants of short-term in vitro cultured B. malayi microfilariae (Mf) and analyzed by mass spectrometry (Bruker timsTOF). Parasite-specific proteins were identified by bioinformatic analysis and a protein was called present if supported by ≥ 2 spectra. After validation with cultures parasites, this approach was then used to analyze vesicles isolated from plasma of animals infected with B. malayi and from humans with heavy Loa loa infections. Results Vesicles from Mf cultures contained more than 300 B. malayi proteins with high consistency across biological replicates. These included the known Mf excretory antigen BmR1 (AF225296). Over 150 B. malayi proteins were detected in vesicles isolated from plasma samples from two infected animals. Vesicles isolated from plasma from 10 persons with high L. loa Mf densities contained consistently 21 proteins, 9 of them were supported by at least 5 unique peptides and 7 with spectral counts above 10. The protein EN70_10600 (an orthologue of the B. malayi antigen BmR1, GenBank AF225296) was detected in all 10 samples with a total count of 91 spectra and a paralogue (EN70_10598) was detected in 6 samples with a total of 44 spectra. Discussion Extracellular vesicles released by filarial parasites in vitro and in vivo contain parasite proteins which can be reliably detected by mass spectrometry. This research provides the foundation to develop antigen detection assays to improve diagnosis of active filarial infections in humans.
背景需要改进诊断工具来检测人类活动性丝虫病感染。现有检测成年班氏分枝杆菌循环丝虫病抗原的检测方法，但对于布鲁氏丝虫病或路易病尚无敏感和特异性的生物标志物检测方法。在这里，我们探讨了丝虫寄生虫释放的细胞外囊泡是否含有诊断生物标志物候选物。方法采用vn96亲和纯化法从短期体外培养的马来芽孢杆菌微丝蚴(Mf)上清液中分离出囊泡，并用质谱法(Bruker timsTOF)进行分析。通过生物信息学分析鉴定出寄生虫特异性蛋白，如果有≥2个光谱支持，则称为存在蛋白。在用培养寄生虫进行验证后，该方法随后用于分析从感染马来芽孢杆菌的动物和重度罗阿罗阿感染的人的血浆中分离的囊泡。结果Mf培养的囊泡中含有300多种马来芽孢杆菌蛋白，在不同的生物重复中具有较高的一致性。其中包括已知的Mf排泄抗原BmR1 (AF225296)。在从两只受感染动物的血浆样本中分离的囊泡中检测到150多种马来芽胞杆菌蛋白。从10个高L. loa Mf密度的人的血浆中分离到的小泡一致含有21个蛋白，其中9个蛋白被至少5个独特的肽支持，7个蛋白的光谱计数在10以上。在所有10份样品中检测到EN70_10600蛋白(与马来芽孢杆菌抗原BmR1同源，GenBank AF225296)，共91个光谱;在6份样品中检测到EN70_10598蛋白，共44个光谱。讨论丝虫在体外和体内释放的细胞外囊泡中含有寄生虫蛋白，质谱法可以可靠地检测到这些蛋白。本研究为发展抗原检测方法以提高人类活动性丝虫病的诊断提供了基础。
{"title":"Identification of biomarker candidates for filarial parasite infections by analysis of extracellular vesicles","authors":"Devyn Yates, Lucia S. Di Maggio, Bruce A. Rosa, Robert W. Sprung, Petra Erdmann-Gilmore, R. Reid Townsend, Philip J. Budge, Joseph Kamgno, Makedonka Mitreva, Gary J. Weil, Peter U. Fischer","doi":"10.3389/fpara.2023.1281092","DOIUrl":"https://doi.org/10.3389/fpara.2023.1281092","url":null,"abstract":"Background Improved diagnostic tools are needed for detecting active filarial infections in humans. Tests are available that detect adult W. bancrofti circulating filarial antigen, but there are no sensitive and specific biomarker tests for brugian filariasis or loiasis. Here we explored whether extracellular vesicles released by filarial parasites contain diagnostic biomarker candidates. Methods Vesicles were isolated using VN96-affinity purification from supernatants of short-term in vitro cultured B. malayi microfilariae (Mf) and analyzed by mass spectrometry (Bruker timsTOF). Parasite-specific proteins were identified by bioinformatic analysis and a protein was called present if supported by ≥ 2 spectra. After validation with cultures parasites, this approach was then used to analyze vesicles isolated from plasma of animals infected with B. malayi and from humans with heavy Loa loa infections. Results Vesicles from Mf cultures contained more than 300 B. malayi proteins with high consistency across biological replicates. These included the known Mf excretory antigen BmR1 (AF225296). Over 150 B. malayi proteins were detected in vesicles isolated from plasma samples from two infected animals. Vesicles isolated from plasma from 10 persons with high L. loa Mf densities contained consistently 21 proteins, 9 of them were supported by at least 5 unique peptides and 7 with spectral counts above 10. The protein EN70_10600 (an orthologue of the B. malayi antigen BmR1, GenBank AF225296) was detected in all 10 samples with a total count of 91 spectra and a paralogue (EN70_10598) was detected in 6 samples with a total of 44 spectra. Discussion Extracellular vesicles released by filarial parasites in vitro and in vivo contain parasite proteins which can be reliably detected by mass spectrometry. This research provides the foundation to develop antigen detection assays to improve diagnosis of active filarial infections in humans.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"21 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135366507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-13DOI: 10.3389/fpara.2023.1242866
Stefanie N. Sveiven, Sang Yong Kim, Valeria Barrientos, Jiang Li, Jennell Jennett, Samuel Asiedu, Kyle Anesko, Tara M. Nordgren, Meera G. Nair
Soil-transmitted helminth (STH) infections impact billions of individuals globally; however, there is a need to clarify the long-term impacts of these infections on pulmonary health owing to their transient migration and subsequent damage to the lungs. In mouse models of these infections using Nippostrongylus brasiliensis , lung pathology persists at later time points post single infection. These studies also indicate the persistent transcriptional expression of resistin-like molecule α (RELMα), an immunomodulatory protein induced in type 2 immunity and alternatively activated macrophages. Using constitutive and tamoxifen-inducible cell-specific RELMα knockout mouse strains, we identified that epithelial- and myeloid-derived RELMα protein remained elevated at 30 days post infection and altered the immune cell signature and gene expression in lung compartments. Histopathological assessment of alveolar damage revealed a role for RELMα in tissue repair, suggesting the importance of sustained RELMα expression for lung recovery from helminth infection. Acellular three-dimensional (3D) lung scaffolds were prepared from the lungs of wild-type (WT), RELMα KO-naive, or 30 days post N. brasiliensis -infected mice to assess their ability to support epithelial cell growth. N. brasiliensis infection significantly altered the scaffold and impaired epithelial cell growth and metabolic activity, especially in the RELMα KO scaffolds. These findings underscore a need to identify the long-term impacts of helminth infection on human pulmonary disease, particularly as alveolar destruction can develop into chronic obstructive pulmonary disease (COPD), which remains among the top global causes of death. Translation of these findings to human protein resistin, with sequence homology to RELMα therapeutic opportunities in lung repair.
{"title":"Myeloid- and epithelial-derived RELMα contribute to tissue repair following lung helminth infection","authors":"Stefanie N. Sveiven, Sang Yong Kim, Valeria Barrientos, Jiang Li, Jennell Jennett, Samuel Asiedu, Kyle Anesko, Tara M. Nordgren, Meera G. Nair","doi":"10.3389/fpara.2023.1242866","DOIUrl":"https://doi.org/10.3389/fpara.2023.1242866","url":null,"abstract":"Soil-transmitted helminth (STH) infections impact billions of individuals globally; however, there is a need to clarify the long-term impacts of these infections on pulmonary health owing to their transient migration and subsequent damage to the lungs. In mouse models of these infections using Nippostrongylus brasiliensis , lung pathology persists at later time points post single infection. These studies also indicate the persistent transcriptional expression of resistin-like molecule α (RELMα), an immunomodulatory protein induced in type 2 immunity and alternatively activated macrophages. Using constitutive and tamoxifen-inducible cell-specific RELMα knockout mouse strains, we identified that epithelial- and myeloid-derived RELMα protein remained elevated at 30 days post infection and altered the immune cell signature and gene expression in lung compartments. Histopathological assessment of alveolar damage revealed a role for RELMα in tissue repair, suggesting the importance of sustained RELMα expression for lung recovery from helminth infection. Acellular three-dimensional (3D) lung scaffolds were prepared from the lungs of wild-type (WT), RELMα KO-naive, or 30 days post N. brasiliensis -infected mice to assess their ability to support epithelial cell growth. N. brasiliensis infection significantly altered the scaffold and impaired epithelial cell growth and metabolic activity, especially in the RELMα KO scaffolds. These findings underscore a need to identify the long-term impacts of helminth infection on human pulmonary disease, particularly as alveolar destruction can develop into chronic obstructive pulmonary disease (COPD), which remains among the top global causes of death. Translation of these findings to human protein resistin, with sequence homology to RELMα therapeutic opportunities in lung repair.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135918091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-12DOI: 10.3389/fpara.2023.1244604
Kathryn M. Jones, Bin Zhan, Keenan J. Ernste, Maria Jose Villar, Nalini Bisht, Duc Nguyen, Li-Yen Chang, Cristina Poveda, Gonteria J. Robinson, Akshar J. Trivedi, Colby J. Hofferek, William K. Decker, Vanaja Konduri
Introduction Hookworms are parasitic helminths that secrete a variety of proteins that induce anti-inflammatory immune responses, stimulating increased CD4+Foxp3+ regulatory T cells and IL-10 production. Hookworm-derived recombinant proteins AIP-1 and AIP-2 have been shown to reduce inflammation in mouse models of inflammatory bowel disease and inflammatory airway disease by inducing CD4+Foxp3+ cells and IL-10 production. In contrast, chronic infection with the protozoal parasite Trypanosoma cruzi , the causative agent of Chagas disease, leads to chronic inflammation in tissues. Persistence of the parasites in tissues drives chronic low-grade inflammation, with increased infiltration of inflammatory cells into the heart, accompanied by increased production of inflammatory cytokines. There are no current antiparasitic drugs that effectively reduce or prevent chronic myocarditis caused by the onset of Chagas disease, thus new therapies are urgently needed. Therefore, the impact of AIP-1 and AIP-2 on myocarditis was investigated in a mouse model of chronic T. cruzi infection. Methods Female BALB/c mice infected with bioluminescent T. cruzi H1 strain trypomastigotes for 70 days were treated once daily for 7 days with 1mg/kg AIP-1 or AIP-2 protein by intraperitoneal injection. Control mice were left untreated or treated once daily for 14 days with 25mg/kg aspirin in drinking water. At 84 days of infection, splenocytes, cardiac tissue and serum were collected for evaluation. Results Treatment with both AIP-1 and AIP-2 proteins significantly reduced cardiac cellular infiltration, and reduced cardiac levels of IFNγ, IL-6 and IL-2. AIP-2 treatment reduced cardiac expression of COX-2. Further, while incubation with AIP-1 and AIP-2 proteins did not induce a significant upregulation of an immunoregulatory phenotype in dendritic cells (DC), there was a modest upregulation of CD11c+CD11b+MHCII+SIRPα+ expression, suggesting a regulatory phenotype. Ex-vivo stimulation of splenocytes from the treatment groups with AIP-1 loaded DC induced reduced levels of cytotoxic and pro-inflammatory T cells, stimulation with AIP-2 loaded DC specifically induced enhanced levels of CD4+CD25+Foxp3+ regulatory T cells among treatment groups. Discussion All in vivo and in vitro results demonstrate that hookworm-derived AIP-1 and AIP-2 proteins reduce T. cruzi induced cardiac inflammation, possibly through multiple anti-inflammatory mechanisms.
{"title":"Immunomodulatory proteins from hookworms reduce cardiac inflammation and modulate regulatory responses in a mouse model of chronic Trypanosoma cruzi infection","authors":"Kathryn M. Jones, Bin Zhan, Keenan J. Ernste, Maria Jose Villar, Nalini Bisht, Duc Nguyen, Li-Yen Chang, Cristina Poveda, Gonteria J. Robinson, Akshar J. Trivedi, Colby J. Hofferek, William K. Decker, Vanaja Konduri","doi":"10.3389/fpara.2023.1244604","DOIUrl":"https://doi.org/10.3389/fpara.2023.1244604","url":null,"abstract":"Introduction Hookworms are parasitic helminths that secrete a variety of proteins that induce anti-inflammatory immune responses, stimulating increased CD4+Foxp3+ regulatory T cells and IL-10 production. Hookworm-derived recombinant proteins AIP-1 and AIP-2 have been shown to reduce inflammation in mouse models of inflammatory bowel disease and inflammatory airway disease by inducing CD4+Foxp3+ cells and IL-10 production. In contrast, chronic infection with the protozoal parasite Trypanosoma cruzi , the causative agent of Chagas disease, leads to chronic inflammation in tissues. Persistence of the parasites in tissues drives chronic low-grade inflammation, with increased infiltration of inflammatory cells into the heart, accompanied by increased production of inflammatory cytokines. There are no current antiparasitic drugs that effectively reduce or prevent chronic myocarditis caused by the onset of Chagas disease, thus new therapies are urgently needed. Therefore, the impact of AIP-1 and AIP-2 on myocarditis was investigated in a mouse model of chronic T. cruzi infection. Methods Female BALB/c mice infected with bioluminescent T. cruzi H1 strain trypomastigotes for 70 days were treated once daily for 7 days with 1mg/kg AIP-1 or AIP-2 protein by intraperitoneal injection. Control mice were left untreated or treated once daily for 14 days with 25mg/kg aspirin in drinking water. At 84 days of infection, splenocytes, cardiac tissue and serum were collected for evaluation. Results Treatment with both AIP-1 and AIP-2 proteins significantly reduced cardiac cellular infiltration, and reduced cardiac levels of IFNγ, IL-6 and IL-2. AIP-2 treatment reduced cardiac expression of COX-2. Further, while incubation with AIP-1 and AIP-2 proteins did not induce a significant upregulation of an immunoregulatory phenotype in dendritic cells (DC), there was a modest upregulation of CD11c+CD11b+MHCII+SIRPα+ expression, suggesting a regulatory phenotype. Ex-vivo stimulation of splenocytes from the treatment groups with AIP-1 loaded DC induced reduced levels of cytotoxic and pro-inflammatory T cells, stimulation with AIP-2 loaded DC specifically induced enhanced levels of CD4+CD25+Foxp3+ regulatory T cells among treatment groups. Discussion All in vivo and in vitro results demonstrate that hookworm-derived AIP-1 and AIP-2 proteins reduce T. cruzi induced cardiac inflammation, possibly through multiple anti-inflammatory mechanisms.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135968674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-11DOI: 10.3389/fpara.2023.1258429
Melanie Koinari, Nakei Bubun, David Wilson, Evodia Anetul, Lincoln Timinao, Petrina Johnson, Norelle L. Daly, Moses Laman, Tim Freeman, Stephan Karl
Background Long-lasting insecticidal nets (LLINs) are a key vector control tool used for the prevention of malaria. Active ingredient (AI) measurements in LLINs are essential for evaluating their quality and efficacy. The main aim of the present study was to determine the utility of X-ray fluorescence (XRF) spectroscopy as a suitable field-deployable tool for total AI quantification in LLINs. Methods New and unused LLIN samples containing deltamethrin (PermaNet® 2.0, n = 35) and alpha-cypermethrin (SafeNet®, n = 43) were obtained from batches delivered to Papua New Guinea (PNG) for mass distribution. Insecticides were extracted from the LLINs using a simple extraction technique and quantified using liquid chromatography mass spectrometry (LC-MS). The LC-MS results were correlated with XRF spectroscopy measurements on the same nets. Operators were blinded regarding the type of net. Bioefficacy of the LLIN samples was tested using WHO cone bioassays and test results were correlated with total AI content. Results The results indicate correlation between quantitative XRF and LC-MS. Interestingly, the total AI content was negatively correlated with bioefficacy in PermaNet® 2.0 (especially in recently manufactured nets). In contrast, AI content was positively correlated with bioefficacy in SafeNet®. These results indicate that the chemical content analysis in predelivery inspections does not always predict bioefficacy. Conclusion XRF is a promising field-deployable tool for quantification of both deltamethrin- and alpha-cypermethrin-coated LLINs. Because total AI content is not always a predictor of the efficacy of LLINs to kill mosquitoes, bioefficacy measurements should be included in predelivery inspections.
{"title":"Analysis of insecticides in long-lasting insecticidal nets using X-ray fluorescence spectroscopy and correlation with bioefficacy","authors":"Melanie Koinari, Nakei Bubun, David Wilson, Evodia Anetul, Lincoln Timinao, Petrina Johnson, Norelle L. Daly, Moses Laman, Tim Freeman, Stephan Karl","doi":"10.3389/fpara.2023.1258429","DOIUrl":"https://doi.org/10.3389/fpara.2023.1258429","url":null,"abstract":"Background Long-lasting insecticidal nets (LLINs) are a key vector control tool used for the prevention of malaria. Active ingredient (AI) measurements in LLINs are essential for evaluating their quality and efficacy. The main aim of the present study was to determine the utility of X-ray fluorescence (XRF) spectroscopy as a suitable field-deployable tool for total AI quantification in LLINs. Methods New and unused LLIN samples containing deltamethrin (PermaNet® 2.0, n = 35) and alpha-cypermethrin (SafeNet®, n = 43) were obtained from batches delivered to Papua New Guinea (PNG) for mass distribution. Insecticides were extracted from the LLINs using a simple extraction technique and quantified using liquid chromatography mass spectrometry (LC-MS). The LC-MS results were correlated with XRF spectroscopy measurements on the same nets. Operators were blinded regarding the type of net. Bioefficacy of the LLIN samples was tested using WHO cone bioassays and test results were correlated with total AI content. Results The results indicate correlation between quantitative XRF and LC-MS. Interestingly, the total AI content was negatively correlated with bioefficacy in PermaNet® 2.0 (especially in recently manufactured nets). In contrast, AI content was positively correlated with bioefficacy in SafeNet®. These results indicate that the chemical content analysis in predelivery inspections does not always predict bioefficacy. Conclusion XRF is a promising field-deployable tool for quantification of both deltamethrin- and alpha-cypermethrin-coated LLINs. Because total AI content is not always a predictor of the efficacy of LLINs to kill mosquitoes, bioefficacy measurements should be included in predelivery inspections.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136062855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.3389/fpara.2023.1195457
Yide Wong, Mark S. Pearson, Olga Fedorova, Vladimir Ivanov, Ekaterina Khmelevskaya, Bemnet Tedla, Buddhika Jayakody Arachchige, Sarah Reed, Matt Field, Thewarach Laha, Alex Loukas, Javier Sotillo
Introduction Opisthorchis felineus , Opisthorchis viverrini , and Clonorchis sinensis are the most medically important species of fish-borne zoonotic trematodes. O. felineus is endemic to the river plains of Western Siberia and Eastern Europe, and it is estimated that more than 1.6 million people could be infected with this parasite. Chronic opisthorchiasis may lead to significant gastrointestinal and hepatobiliary pathology. This study aimed to identify and characterize proteins from the secreted and tegumental proteomes of O. felineus . Methods Adult flukes were collected from experimentally infected hamsters and cultured in vitro in serum-free media. We extracted proteins from different compartments of the O. felineus secretome, including (i) soluble excretory/secretory (ES) products; (ii) secreted 15K-extracellular vesicles (EVs); and (iii) tegument. Results We also generated a transcriptome using long-read sequencing, and when this was combined with high-resolution mass spectrometry, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) separation, and protein digestion, we identified 686, 894, 389, 324, and 165 proteins from the ES, 15K-EV, and the three sequentially extracted tegument (TEG) protein fractions, respectively. We conducted in-depth gene ontology and protein family analyses on the identified proteins and discussed comparisons against similar proteome data sets acquired for the Southeast Asian liver fluke O. viverrini and the Chinese liver fluke C. sinensis . Discussion The information from this study will form a biologically relevant data set of O. felineus proteins that could be used to develop diagnostic and therapeutic tools to manage the human cost of O. felineus infection and its associated comorbidities.
{"title":"Secreted and surface proteome and transcriptome of Opisthorchis felineus","authors":"Yide Wong, Mark S. Pearson, Olga Fedorova, Vladimir Ivanov, Ekaterina Khmelevskaya, Bemnet Tedla, Buddhika Jayakody Arachchige, Sarah Reed, Matt Field, Thewarach Laha, Alex Loukas, Javier Sotillo","doi":"10.3389/fpara.2023.1195457","DOIUrl":"https://doi.org/10.3389/fpara.2023.1195457","url":null,"abstract":"Introduction Opisthorchis felineus , Opisthorchis viverrini , and Clonorchis sinensis are the most medically important species of fish-borne zoonotic trematodes. O. felineus is endemic to the river plains of Western Siberia and Eastern Europe, and it is estimated that more than 1.6 million people could be infected with this parasite. Chronic opisthorchiasis may lead to significant gastrointestinal and hepatobiliary pathology. This study aimed to identify and characterize proteins from the secreted and tegumental proteomes of O. felineus . Methods Adult flukes were collected from experimentally infected hamsters and cultured in vitro in serum-free media. We extracted proteins from different compartments of the O. felineus secretome, including (i) soluble excretory/secretory (ES) products; (ii) secreted 15K-extracellular vesicles (EVs); and (iii) tegument. Results We also generated a transcriptome using long-read sequencing, and when this was combined with high-resolution mass spectrometry, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) separation, and protein digestion, we identified 686, 894, 389, 324, and 165 proteins from the ES, 15K-EV, and the three sequentially extracted tegument (TEG) protein fractions, respectively. We conducted in-depth gene ontology and protein family analyses on the identified proteins and discussed comparisons against similar proteome data sets acquired for the Southeast Asian liver fluke O. viverrini and the Chinese liver fluke C. sinensis . Discussion The information from this study will form a biologically relevant data set of O. felineus proteins that could be used to develop diagnostic and therapeutic tools to manage the human cost of O. felineus infection and its associated comorbidities.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136295448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-09DOI: 10.3389/fpara.2023.1272386
Natasha S. Hochberg, Srinivasa P. S. Rao, Gerhild Angyalosi, Xiaojun Zhao, Leticia Carballo, Caroline Demacq, Sofia Braud-Perez, Daniela Wieser, JP Casas, John Millholland, Debby Ngo
Novel therapies for chronic indeterminate Chagas disease (CICD) are needed, but trials are limited by the absence of tests to detect infection and early treatment efficacy. This perspective highlights the shortfalls and strengths of polymerase chain reaction (PCR) as a study endpoint for anti-parasitic drug development. Serologic reversion, the gold standard test of cure, may take decades to occur in adults and therefore is challenging as an endpoint for drug development. Use of PCR as a marker of infection and treatment response has notable limitations due to low parasitemia in CICD, fluctuations in circulating (versus tissue) parasite burden, strain differences, and assay performance. It is, however, rapidly responsive to therapy, and technological advances have improved detection of different strains and may allow for parasite quantification. Until we have more sensitive tests for parasitological clearance, PCR as a measure of treatment failure may be the best available efficacy endpoint to accelerate early development of much-needed novel therapies. Adequately designed clinical studies are needed to correlate PCR clearance with clinical outcomes and to identify novel biomarkers predictive of clinical outcomes in patients with CICD. Public-private partnerships and health authority engagement are paramount to identify feasible trial endpoints and deliver promising new drug candidates for Chagas disease.
{"title":"An end is in sight: a perspective on PCR as an endpoint for Chagas disease treatment trials","authors":"Natasha S. Hochberg, Srinivasa P. S. Rao, Gerhild Angyalosi, Xiaojun Zhao, Leticia Carballo, Caroline Demacq, Sofia Braud-Perez, Daniela Wieser, JP Casas, John Millholland, Debby Ngo","doi":"10.3389/fpara.2023.1272386","DOIUrl":"https://doi.org/10.3389/fpara.2023.1272386","url":null,"abstract":"Novel therapies for chronic indeterminate Chagas disease (CICD) are needed, but trials are limited by the absence of tests to detect infection and early treatment efficacy. This perspective highlights the shortfalls and strengths of polymerase chain reaction (PCR) as a study endpoint for anti-parasitic drug development. Serologic reversion, the gold standard test of cure, may take decades to occur in adults and therefore is challenging as an endpoint for drug development. Use of PCR as a marker of infection and treatment response has notable limitations due to low parasitemia in CICD, fluctuations in circulating (versus tissue) parasite burden, strain differences, and assay performance. It is, however, rapidly responsive to therapy, and technological advances have improved detection of different strains and may allow for parasite quantification. Until we have more sensitive tests for parasitological clearance, PCR as a measure of treatment failure may be the best available efficacy endpoint to accelerate early development of much-needed novel therapies. Adequately designed clinical studies are needed to correlate PCR clearance with clinical outcomes and to identify novel biomarkers predictive of clinical outcomes in patients with CICD. Public-private partnerships and health authority engagement are paramount to identify feasible trial endpoints and deliver promising new drug candidates for Chagas disease.","PeriodicalId":73098,"journal":{"name":"Frontiers in parasitology","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135094122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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