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Lopes EA, Santos MMM, Mori M. Antimalarial drugs: what's new in the patents? Expert Opin Ther Pat 2023; 33:151-168. [PMID: 37060305 DOI: 10.1080/13543776.2023.2203814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
INTRODUCTION The efficacy of current therapeutic warheads in preventing malaria transmission or treating the disease is often hampered by the emergence of drug-resistance. No effective vaccines are available to date, and novel drugs able to counteract drug-resistant forms of malaria and/or to target multiple stages of the parasite's lifecycle are urgently needed. AREAS COVERED This review covers patents that protect antimalarial small molecules bearing the artemisinin or other chemical scaffolds, as well as vaccines, that have been published in the period 2015-2022. Literature was searched in public databases of articles and patents. Patents protecting small molecules that prevent malaria transmission are not discussed herein. EXPERT OPINION Significant progress has been made in the design of antimalarial agents. Most of these candidates have been tested in standardized strains, with the use of Plasmodium clinical isolates for testing still underdeveloped. Several compounds have been profiled in in vivo mouse models of malaria, including humanised mice. Despite having different efficacy, these new molecules might further progress the field and hopefully will advance to clinical development soon.
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Affiliation(s)
- Elizabeth A Lopes
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Maria M M Santos
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Mattia Mori
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Siena, Italy
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2
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Chen G, Liu SC, Fan XY, Jin YL, Li X, Du YT. Plasmodium manipulates the expression of host long non-coding RNA during red blood cell intracellular infection. Parasit Vectors 2022; 15:182. [PMID: 35643541 PMCID: PMC9148527 DOI: 10.1186/s13071-022-05298-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/26/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Parasites interact with their host through "direct" and/or "indirect" mechanisms. Plasmodium, for example, either mediates direct physical interactions with host factors or triggers the immune system of the host indirectly, leading to changes in infectious outcomes. Long non-coding RNAs (lncRNAs) participate in regulating biological processes, especially host-pathogen interactions. However, research on the role of host lncRNAs during Plasmodium infection is limited. METHODS A RNA sequencing method (RNA-seq) was used to confirm the differential expression profiles of lncRNAs in Plasmodium yeolii 17XL (P.y17XL)-infected BALB/c mice. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to elucidate the potential functions of Plasmodium-induced genes. Subsequently, the effect of specific lncRNAs on the modulation of immune-related signaling pathways in malaria was determined by fluorescence-activated cell sorting, western blot and enzyme-linked immunosorbent assay. RESULTS The data showed that in P.y17XL-infected BALB/c mice, Plasmodium upregulated the expression of 132 lncRNAs and downregulated the expression of 159 lncRNAs. Differentially expressed lncRNAs clearly associated with malaria infection were annotated, including four novel dominant lncRNAs: ENMSUSG00000111521.1, XLOC_038009, XLOC_058629 and XLOC_065676. GO and KEGG pathway analyses demonstrated that these four differentially expressed lncRNAs were associated with co-localized/co-expressed protein-coding genes that were totally enriched in malaria and with the transforming growth factor beta (TGF-β) signaling pathway. Using the models of P.y17XL-infected BALB/c mice, data certified that the level of TGF-β production and activation of TGF-β/Smad2/3 signaling pathway were obviously changed in malaria infection. CONCLUSIONS These differentially expressed immune-related genes were deemed to have a role in the process of Plasmodium infection in the host via dendritic/T regulatory cells and the TGF-β/Smad2/3 signaling pathway. The results of the present study confirmed that Plasmodium infection-induced lncRNA expression is a novel mechanism used by Plasmodium parasites to modify host immune signaling. These results further enhance current understanding of the interaction between Plasmodium and host cells.
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Affiliation(s)
- Guang Chen
- Department of Basic Medical Sciences, Taizhou University, No. 1139 Shifu Road, Jiaojiang District, Taizhou, 318000, China
| | - Shuang-Chun Liu
- Municipal Hospital Affiliated to Medical School of Taizhou University, No. 381, Zhongshan East Road, Jiaojiang District, Taizhou, 318000, China
| | - Xiao-Yan Fan
- Department of Basic Medical Sciences, Taizhou University, No. 1139 Shifu Road, Jiaojiang District, Taizhou, 318000, China
| | - Yue-Lei Jin
- Department of Basic Medical Sciences, Taizhou University, No. 1139 Shifu Road, Jiaojiang District, Taizhou, 318000, China
| | - Xin Li
- Department of Basic Medical Sciences, Taizhou University, No. 1139 Shifu Road, Jiaojiang District, Taizhou, 318000, China
| | - Yun-Ting Du
- Department of Laboratory Medicine, Cancer Hospital of China Medical University-Liaoning Cancer Hospital & Institute, No. 44 Xiaoheyan Road, Dadong District, Shenyang, 110042, China.
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Hentzschel F, Obrova K, Marti M. No evidence for Ago2 translocation from the host erythrocyte into the Plasmodium parasite. Wellcome Open Res 2020; 5:92. [PMID: 33501380 PMCID: PMC7808052 DOI: 10.12688/wellcomeopenres.15852.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2020] [Indexed: 12/13/2022] Open
Abstract
Background: Plasmodium parasites rely on various host factors to grow and replicate within red blood cells (RBC). While many host proteins are known that mediate parasite adhesion and invasion, few examples of host enzymes co-opted by the parasite during intracellular development have been described. Recent studies suggested that the host protein Argonaute 2 (Ago2), which is involved in RNA interference, can translocate into the parasite and affect its development. Here, we investigated this hypothesis. Methods: We used several different monoclonal antibodies to test for Ago2 localisation in the human malaria parasite, P. falciparum and rodent P. berghei parasites. In addition, we biochemically fractionated infected red blood cells to localize Ago2. We also quantified parasite growth and sexual commitment in the presence of the Ago2 inhibitor BCI-137. Results: Ago2 localization by fluorescence microscopy produced inconclusive results across the three different antibodies, suggesting cross-reactivity with parasite targets. Biochemical separation of parasite and RBC cytoplasm detected Ago2 only in the RBC cytoplasm and not in the parasite. Inhibition of Ago2 using BCl-137 did not result in altered parasite development. Conclusion: Ago2 localization in infected RBCs by microscopy is confounded by non-specific binding of antibodies. Complementary results using biochemical fractionation and Ago2 detection by western blot did not detect the protein in the parasite cytosol, and growth assays using a specific inhibitor demonstrated that its catalytical activity is not required for parasite development. We therefore conclude that previous data localising Ago2 to parasite ring stages are due to antibody cross reactivity, and that Ago2 is not required for intracellular Plasmodium development.
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Affiliation(s)
- Franziska Hentzschel
- Wellcome Center for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
- Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg, 69120, Germany
| | - Klara Obrova
- Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg, 69120, Germany
| | - Matthias Marti
- Wellcome Center for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
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4
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Hentzschel F, Obrova K, Marti M. No evidence for Ago2 translocation from the host erythrocyte into the Plasmodium parasite. Wellcome Open Res 2020; 5:92. [PMID: 33501380 PMCID: PMC7808052 DOI: 10.12688/wellcomeopenres.15852.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2020] [Indexed: 02/15/2024] Open
Abstract
Background: Plasmodium parasites rely on various host factors to grow and replicate within red blood cells (RBC). While many host proteins are known that mediate parasite adhesion and invasion, few examples of host enzymes co-opted by the parasite during intracellular development have been described. Recent studies suggested that the host protein Argonaute 2 (Ago2), which is involved in RNA interference, can translocate into the parasite and affect its development. Here, we investigated this hypothesis. Methods: We used several different monoclonal antibodies to test for Ago2 localisation in the human malaria parasite, P. falciparum and rodent P. berghei parasites. In addition, we biochemically fractionated infected red blood cells to localize Ago2. We also quantified parasite growth and sexual commitment in the presence of the Ago2 inhibitor BCI-137. Results: Ago2 localization by fluorescence microscopy produced inconclusive results across the three different antibodies, suggesting cross-reactivity with parasite targets. Biochemical separation of parasite and RBC cytoplasm detected Ago2 only in the RBC cytoplasm and not in the parasite. Inhibition of Ago2 using BCl-137 did not result in altered parasite development. Conclusion: Ago2 localization in infected RBCs by microscopy is confounded by non-specific binding of antibodies. Complementary results using biochemical fractionation and Ago2 detection by western blot did not detect the protein in the parasite cytosol, and growth assays using a specific inhibitor demonstrated that its catalytical activity is not required for parasite development. We therefore conclude that previous data localising Ago2 to parasite ring stages are due to antibody cross reactivity, and that Ago2 is not required for intracellular Plasmodium development.
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Affiliation(s)
- Franziska Hentzschel
- Wellcome Center for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
- Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg, 69120, Germany
| | - Klara Obrova
- Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg, 69120, Germany
| | - Matthias Marti
- Wellcome Center for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
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5
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Gbedande K, Carpio VH, Stephens R. Using two phases of the CD4 T cell response to blood-stage murine malaria to understand regulation of systemic immunity and placental pathology in Plasmodium falciparum infection. Immunol Rev 2020; 293:88-114. [PMID: 31903675 PMCID: PMC7540220 DOI: 10.1111/imr.12835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/08/2019] [Accepted: 12/09/2019] [Indexed: 02/06/2023]
Abstract
Plasmodium falciparum infection and malaria remain a risk for millions of children and pregnant women. Here, we seek to integrate knowledge of mouse and human T helper cell (Th) responses to blood-stage Plasmodium infection to understand their contribution to protection and pathology. Although there is no complete Th subset differentiation, the adaptive response occurs in two phases in non-lethal rodent Plasmodium infection, coordinated by Th cells. In short, cellular immune responses limit the peak of parasitemia during the first phase; in the second phase, humoral immunity from T cell-dependent germinal centers is critical for complete clearance of rapidly changing parasite. A strong IFN-γ response kills parasite, but an excess of TNF compared with regulatory cytokines (IL-10, TGF-β) can cause immunopathology. This common pathway for pathology is associated with anemia, cerebral malaria, and placental malaria. These two phases can be used to both understand how the host responds to rapidly growing parasite and how it attempts to control immunopathology and variation. This dual nature of T cell immunity to Plasmodium is discussed, with particular reference to the protective nature of the continuous generation of effector T cells, and the unique contribution of effector memory T cells.
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Affiliation(s)
- Komi Gbedande
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas
| | - Victor H Carpio
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Robin Stephens
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
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6
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Vera IM, Grilo Ruivo MT, Lemos Rocha LF, Marques S, Bhatia SN, Mota MM, Mancio-Silva L. Targeting liver stage malaria with metformin. JCI Insight 2019; 4:127441. [PMID: 31852843 DOI: 10.1172/jci.insight.127441] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 11/13/2019] [Indexed: 12/29/2022] Open
Abstract
Despite an unprecedented 2 decades of success, the combat against malaria - the mosquito-transmitted disease caused by Plasmodium parasites - is no longer progressing. Efforts toward eradication are threatened by the lack of an effective vaccine and a rise in antiparasite drug resistance. Alternative approaches are urgently needed. Repurposing of available, approved drugs with distinct modes of action are being considered as viable and immediate adjuncts to standard antimicrobial treatment. Such strategies may be well suited to the obligatory and clinically silent first phase of Plasmodium infection, where massive parasite replication occurs within hepatocytes in the liver. Here, we report that the widely used antidiabetic drug, metformin, impairs parasite liver stage development of both rodent-infecting Plasmodium berghei and human-infecting P. falciparum parasites. Prophylactic treatment with metformin curtails parasite intracellular growth in vitro. An additional effect was observed in mice with a decrease in the numbers of infected hepatocytes. Moreover, metformin provided in combination with conventional liver- or blood-acting antimalarial drugs further reduced the total burden of P. berghei infection and substantially lessened disease severity in mice. Together, our findings indicate that repurposing of metformin in a prophylactic regimen could be considered for malaria chemoprevention.
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Affiliation(s)
- Iset Medina Vera
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Margarida T Grilo Ruivo
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Leonardo F Lemos Rocha
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Sofia Marques
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Sangeeta N Bhatia
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Koch Institute for Integrative Cancer Research, Cambridge, Massachusetts, USA.,Howard Hughes Medical Institute, Cambridge, Masschusetts, USA
| | - Maria M Mota
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Liliana Mancio-Silva
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Koch Institute for Integrative Cancer Research, Cambridge, Massachusetts, USA
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7
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Chen G, Du YT, Liu JH, Li Y, Zheng L, Qin XS, Cao YM. Modulation of anti-malaria immunity by vitamin A in C57BL/6J mice infected with heterogenic plasmodium. Int Immunopharmacol 2019; 76:105882. [PMID: 31520991 DOI: 10.1016/j.intimp.2019.105882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/02/2019] [Accepted: 09/04/2019] [Indexed: 12/12/2022]
Abstract
Vitamin A (VA) is an anti-inflammatory agent that is important in modulating and balancing the immune system. The present study aimed to investigate the immunoregulatory effects of vitamin A supplement (VAS) in C57BL/6J mice infected with Plasmodium yoelii 17XL (P.y17XL) or Plasmodium berghei ANKA (P.bANKA). Following VA treatment, parasitaemia decreased, but survival rate did not significantly change during P.y17XL infection. However, in P.bANKA infected C57BL/6J mice, VA pretreatment decreased parasitaemia, and a lag in cerebral malaria (CM) was observed during the early stages of infection. Furthermore, VA pretreatment was also demonstrated to upregulate MHCII expression in dendritic cells (DCs), downregulate Th1 and Tregs, and downregulate TNF-α and IFN-γ production. The results of the current study indicated that VAS downregulated the inflammation response in CM, but did not exhibit an immunoregulatory effect against P.y17XL infection. VAS protected the onset of CM by reducing inflammation, and was also correlated with the downregulation of Th1 by modifying the function of DCs and Tregs. However, no significant effect was observed during P.y17XL infection.
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Affiliation(s)
- Guang Chen
- Department of Basic Medical Sciences, Taizhou University Hospital, Taizhou University, No 1139 Shifu Road, Jiaojiang District, Taizhou 318000, China; Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang 110013, China
| | - Yun-Ting Du
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang 110013, China; Department of Clinical Lab, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Number 44 Xiaoheyan Road, Dadong District, Shenyang 110042, China
| | - Jian-Hua Liu
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Ying Li
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Li Zheng
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang 110013, China
| | - Xiao-Song Qin
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Ya-Ming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang 110013, China.
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8
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Need for sustainable approaches in antileishmanial drug discovery. Parasitol Res 2019; 118:2743-2752. [DOI: 10.1007/s00436-019-06443-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 08/23/2019] [Indexed: 12/16/2022]
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9
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Posfai D, Sylvester K, Reddy A, Ganley JG, Wirth J, Cullen QE, Dave T, Kato N, Dave SS, Derbyshire ER. Plasmodium parasite exploits host aquaporin-3 during liver stage malaria infection. PLoS Pathog 2018; 14:e1007057. [PMID: 29775485 PMCID: PMC5979039 DOI: 10.1371/journal.ppat.1007057] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 05/31/2018] [Accepted: 04/25/2018] [Indexed: 12/22/2022] Open
Abstract
Within the liver a single Plasmodium parasite transforms into thousands of blood-infective forms to cause malaria. Here, we use RNA-sequencing to identify host genes that are upregulated upon Plasmodium berghei infection of hepatocytes with the hypothesis that host pathways are hijacked to benefit parasite development. We found that expression of aquaporin-3 (AQP3), a water and glycerol channel, is significantly induced in Plasmodium-infected hepatocytes compared to uninfected cells. This aquaglyceroporin localizes to the parasitophorous vacuole membrane, the compartmental interface between the host and pathogen, with a temporal pattern that correlates with the parasite’s expansion in the liver. Depletion or elimination of host AQP3 expression significantly reduces P. berghei parasite burden during the liver stage and chemical disruption by a known AQP3 inhibitor, auphen, reduces P. falciparum asexual blood stage and P. berghei liver stage parasite load. Further use of this inhibitor as a chemical probe suggests that AQP3-mediated nutrient transport is an important function for parasite development. This study reveals a previously unknown potential route for host-dependent nutrient acquisition by Plasmodium which was discovered by mapping the transcriptional changes that occur in hepatocytes throughout P. berghei infection. The dataset reported may be leveraged to identify additional host factors that are essential for Plasmodium liver stage infection and highlights Plasmodium’s dependence on host factors within hepatocytes. Plasmodium parasites undergo an obligatory morphogenesis and replication within the liver before they invade red blood cells and cause malaria. The liver stage is clinically silent but essential for the Plasmodium parasite to complete its life cycle. During this time, the parasite relies on the host cell to support a massive replication event, yet host factors that are critical to this expansion are largely unknown. We identify human aquaporin-3 (AQP3), a water and glycerol channel, as essential for the proper development of the parasite within the liver cell. AQP3 localizes to the parasitophorous vacuole membrane, the interface between the host cytoplasm and the parasite, possibly aiding in the nutritional uptake for the parasite. Genetic disruption or treatment with the AQP3 inhibitor auphen, reduces parasite load in liver and blood cells.
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Affiliation(s)
- Dora Posfai
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, North Carolina, United States of America
| | - Kayla Sylvester
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, North Carolina, United States of America
| | - Anupama Reddy
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Jack G. Ganley
- Department of Chemistry, Duke University, Durham, North Carolina, United States of America
| | - Johannes Wirth
- Department of Chemistry, Duke University, Durham, North Carolina, United States of America
| | - Quinlan E. Cullen
- Department of Chemistry, Duke University, Durham, North Carolina, United States of America
| | - Tushar Dave
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Nobutaka Kato
- The Broad Institute, 7 Cambridge Center, Cambridge, Massachusetts, United States of America
| | - Sandeep S. Dave
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Emily R. Derbyshire
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, North Carolina, United States of America
- Department of Chemistry, Duke University, Durham, North Carolina, United States of America
- * E-mail:
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10
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Lu H, Qin X, Zhang J, Zhang S, Zhu Y, Wu WH. Molecular target analysis of stearoyl-CoA desaturase genes of protozoan parasites. Acta Parasitol 2018; 63:48-54. [PMID: 29351064 DOI: 10.1515/ap-2018-0006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 10/09/2017] [Indexed: 11/15/2022]
Abstract
Protozoan parasites can synthesize polyunsaturated fatty acids. They possess stearoyl-CoA desaturase to convert stearate into oleate and linoleate. Stearoyl-CoA desaturase are the key enzymes required for the synthesis of unsaturated fatty acids. It seems attractive to evaluate the possibility of using unsaturated fatty acid biosynthesis pathways as drug targets. In this study, the authors investigate codon usage bias, base composition variations and protein sequence in ten available complete stearoyl-CoA desaturase gene sequences from Toxoplasma gondii, Neospora caninum etc. The results show that fatty acid desaturase genes GC content high of parasitic protozoa genes, GC content up to 63.37%, while fatty acid desaturase genes of parasitic protozoa prefers to use codon ending with G/C. In addition, the expected curve was also drawn to reveal the relationship of ENC and GC3s when the codon usage was only subjected to the nucleotide composition constraint. The genes lied on the expected curve in ENC-plot, indicating nucleotide composition constraint played a role in the condon usage pattern. Protein analysis, we find that all proteins are stearoyl-CoA desaturase, have sites of iron-binding active centers and contain three conserved His-rich motifs. If stearoyl-CoA desaturase is unusual to these parasites, it provides basis as a promising target for the development of selective chemical intervention. Therefore, the Bioinformatics analysis of protein and codon can help improve the work of genetic engineering and drug screening.
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Affiliation(s)
- He Lu
- Department of Microbiology, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Xin Qin
- Department of Microbiology, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Jing Zhang
- Department of Microbiology, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Shuang Zhang
- Department of Microbiology, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Yu Zhu
- Department of Immunology, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Wei Hua Wu
- Department of Microbiology, Chongqing Medical University, Chongqing 400016, People's Republic of China
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11
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Microorganisms in the Treatment of Cancer: Advantages and Limitations. J Immunol Res 2018; 2018:2397808. [PMID: 29682586 PMCID: PMC5848056 DOI: 10.1155/2018/2397808] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 01/09/2018] [Indexed: 12/22/2022] Open
Abstract
Cancer remains one of the major challenges of the 21st century. The increasing numbers of cases are not accompanied by adequate progress in therapy. The standard methods of treatment often do not lead to the expected effects. Therefore, it is extremely important to find new, more effective treatments. One of the most promising research directions is immunotherapy, including the use of specific types of microorganisms. This type of treatment is expected to stimulate the immune system for the selective elimination of cancer cells. The research results seem to be promising and show the intensive activation of the immune response as a result of bacterial stimulation. In addition, it is possible to use microorganisms in many different ways, based on their specific properties, that is, toxin production, anaerobic lifestyle, or binding substances that can be delivered to a specific location (vectors). This paper provides an overview of selected microorganisms which are already in use or that are in the experimental phase. Just like any other therapy, the use of microbes for cancer treatment also has some disadvantages. Nevertheless, this kind of treatment can supplement conventional anticancer therapy, giving cancer patients a chance and hope of recovery.
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12
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Abstract
Systemic inflammation mediated by Plasmodium parasites is central to malaria disease and its complications. Plasmodium parasites reside in erythrocytes and can theoretically reach all host tissues via the circulation. However, actual interactions between parasitized erythrocytes and host tissues, along with the consequent damage and pathological changes, are limited locally to specific tissue sites. Such tissue specificity of the parasite can alter the outcome of malaria disease, determining whether acute or chronic complications occur. Here, we give an overview of the recent progress that has been made in understanding tissue-specific immunopathology during Plasmodium infection. As knowledge on tissue-specific host-parasite interactions accumulates, better treatment modalities and targets may emerge for intervention in malaria disease.
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13
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Hematologic Aspects of Parasitic Diseases. Hematology 2018. [DOI: 10.1016/b978-0-323-35762-3.00158-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
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14
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Abstract
Safe and efficacious vaccines are arguably the most successful medical interventions of all time. Yet the ongoing discovery of new pathogens, along with emergence of antibiotic-resistant pathogens and a burgeoning population at risk of such infections, imposes unprecedented public health challenges. To meet these challenges, innovative strategies to discover and develop new or improved anti-infective vaccines are necessary. These approaches must intersect the most meaningful insights into protective immunity and advanced technologies with capabilities to deliver immunogens for optimal immune protection. This goal is considered through several recent advances in host-pathogen relationships, conceptual strides in vaccinology, and emerging technologies. Given a clear and growing risk of pandemic disease should the threat of infection go unmet, developing vaccines that optimize protective immunity against high-priority and antibiotic-resistant pathogens represents an urgent and unifying imperative.
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Affiliation(s)
- Michael R Yeaman
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California 90024.,Division of Molecular Medicine, Department of Medicine, Harbor-UCLA Medical Center, Torrance, California 90509; .,Division of Infectious Diseases, Department of Medicine, Harbor-UCLA Medical Center, Torrance, California 90509.,Los Angeles Biomedical Research Institute, Torrance, California 90502
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15
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Bioinformatics in translational drug discovery. Biosci Rep 2017; 37:BSR20160180. [PMID: 28487472 PMCID: PMC6448364 DOI: 10.1042/bsr20160180] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 05/04/2017] [Accepted: 05/08/2017] [Indexed: 12/31/2022] Open
Abstract
Bioinformatics approaches are becoming ever more essential in translational drug discovery both in academia and within the pharmaceutical industry. Computational exploitation of the increasing volumes of data generated during all phases of drug discovery is enabling key challenges of the process to be addressed. Here, we highlight some of the areas in which bioinformatics resources and methods are being developed to support the drug discovery pipeline. These include the creation of large data warehouses, bioinformatics algorithms to analyse 'big data' that identify novel drug targets and/or biomarkers, programs to assess the tractability of targets, and prediction of repositioning opportunities that use licensed drugs to treat additional indications.
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Acharya P, Garg M, Kumar P, Munjal A, Raja KD. Host-Parasite Interactions in Human Malaria: Clinical Implications of Basic Research. Front Microbiol 2017; 8:889. [PMID: 28572796 PMCID: PMC5435807 DOI: 10.3389/fmicb.2017.00889] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 05/02/2017] [Indexed: 12/21/2022] Open
Abstract
The malaria parasite, Plasmodium, is one of the oldest parasites documented to infect humans and has proven particularly hard to eradicate. One of the major hurdles in designing an effective subunit vaccine against the malaria parasite is the insufficient understanding of host–parasite interactions within the human host during infections. The success of the parasite lies in its ability to evade the human immune system and recruit host responses as physiological cues to regulate its life cycle, leading to rapid acclimatization of the parasite to its immediate host environment. Hence understanding the environmental niche of the parasite is crucial in developing strategies to combat this deadly infectious disease. It has been increasingly recognized that interactions between parasite proteins and host factors are essential to establishing infection and virulence at every stage of the parasite life cycle. This review reassesses all of these interactions and discusses their clinical importance in designing therapeutic approaches such as design of novel vaccines. The interactions have been followed from the initial stages of introduction of the parasite under the human dermis until asexual and sexual blood stages which are essential for transmission of malaria. We further classify the interactions as “direct” or “indirect” depending upon their demonstrated ability to mediate direct physical interactions of the parasite with host factors or their indirect manipulation of the host immune system since both forms of interactions are known to have a crucial role during infections. We also discuss the many ways in which this understanding has been taken to the field and the success of these strategies in controlling human malaria.
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Affiliation(s)
- Pragyan Acharya
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - Manika Garg
- Department of Biochemistry, Jamia Hamdard UniversityNew Delhi, India
| | - Praveen Kumar
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - Akshay Munjal
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - K D Raja
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
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Frischknecht F, Fackler OT. Experimental systems for studying Plasmodium/HIV coinfection. FEBS Lett 2016; 590:2000-13. [PMID: 27009943 DOI: 10.1002/1873-3468.12151] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 03/22/2016] [Indexed: 12/30/2022]
Abstract
Coinfections with Human Immunodeficiency Virus (HIV) and Plasmodium, the causative agents of AIDS and malaria, respectively, are frequent and their comorbidity especially in sub-Saharan Africa is high. While clinical studies suggest an influence of the two pathogens on the outcome of the respective infections, experimental studies on the molecular and immunological impact of coinfections are rare. This reflects the limited availability of suitable model systems that reproduce key properties of both pathologies. Here, we discuss key aspects of coinfection with a focus on currently established experimental systems, their limitations for coinfection studies and potential strategies for their improvement.
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Affiliation(s)
- Friedrich Frischknecht
- Center for Infectious Diseases, Integrative Parasitology, University Hospital Heidelberg, Germany
| | - Oliver T Fackler
- Center for Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Germany
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