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Juban P, Bart JM, Ségard A, Jamonneau V, Ravel S. Trypanosoma brucei gambiense group 2 experimental in vivo life cycle: from procyclic to bloodstream form. Parasite 2024; 31:15. [PMID: 38520091 PMCID: PMC10960050 DOI: 10.1051/parasite/2024009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 02/06/2024] [Indexed: 03/25/2024] Open
Abstract
Trypanosoma brucei gambiense (Tbg) group 2 is a subgroup of trypanosomes able to infect humans and is found in West and Central Africa. Unlike other agents causing sleeping sickness, such as Tbg group 1 and Trypanosoma brucei rhodesiense, Tbg2 lacks the typical molecular markers associated with resistance to human serum. Only 36 strains of Tbg2 have been documented, and therefore, very limited research has been conducted despite their zoonotic nature. Some of these strains are only available in their procyclic form, which hinders human serum resistance assays and mechanistic studies. Furthermore, the understanding of Tbg2's potential to infect tsetse flies and mammalian hosts is limited. In this study, 165 Glossina palpalis gambiensis flies were experimentally infected with procyclic Tbg2 parasites. It was found that 35 days post-infection, 43 flies out of the 80 still alive were found to be Tbg2 PCR-positive in the saliva. These flies were able to infect 3 out of the 4 mice used for blood-feeding. Dissection revealed that only six flies in fact carried mature infections in their midguts and salivary glands. Importantly, a single fly with a mature infection was sufficient to infect a mammalian host. This Tbg2 transmission success confirms that Tbg2 strains can establish in tsetse flies and infect mammalian hosts. This study describes an effective in vivo protocol for transforming Tbg2 from procyclic to bloodstream form, reproducing the complete Tbg2 cycle from G. p. gambiensis to mice. These findings provide valuable insights into Tbg2's host infectivity, and will facilitate further research on mechanisms of human serum resistance.
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Affiliation(s)
- Paola Juban
- INTERTRYP, Université de Montpellier, Cirad, IRD Montpellier France
| | | | - Adeline Ségard
- INTERTRYP, Université de Montpellier, Cirad, IRD Montpellier France
| | | | - Sophie Ravel
- INTERTRYP, Université de Montpellier, Cirad, IRD Montpellier France
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2
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Stijlemans B, De Baetselier P, Van Molle I, Lecordier L, Hendrickx E, Romão E, Vincke C, Baetens W, Schoonooghe S, Hassanzadeh-Ghassabeh G, Korf H, Wallays M, Pinto Torres JE, Perez-Morga D, Brys L, Campetella O, Leguizamón MS, Claes M, Hendrickx S, Mabille D, Caljon G, Remaut H, Roelants K, Magez S, Van Ginderachter JA, De Trez C. Q586B2 is a crucial virulence factor during the early stages of Trypanosoma brucei infection that is conserved amongst trypanosomatids. Nat Commun 2024; 15:1779. [PMID: 38413606 PMCID: PMC10899635 DOI: 10.1038/s41467-024-46067-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 02/09/2024] [Indexed: 02/29/2024] Open
Abstract
Human African trypanosomiasis or sleeping sickness, caused by the protozoan parasite Trypanosoma brucei, is characterized by the manipulation of the host's immune response to ensure parasite invasion and persistence. Uncovering key molecules that support parasite establishment is a prerequisite to interfere with this process. We identified Q586B2 as a T. brucei protein that induces IL-10 in myeloid cells, which promotes parasite infection invasiveness. Q586B2 is expressed during all T. brucei life stages and is conserved in all Trypanosomatidae. Deleting the Q586B2-encoding Tb927.6.4140 gene in T. brucei results in a decreased peak parasitemia and prolonged survival, without affecting parasite fitness in vitro, yet promoting short stumpy differentiation in vivo. Accordingly, neutralization of Q586B2 with newly generated nanobodies could hamper myeloid-derived IL-10 production and reduce parasitemia. In addition, immunization with Q586B2 delays mortality upon a challenge with various trypanosomes, including Trypanosoma cruzi. Collectively, we uncovered a conserved protein playing an important regulatory role in Trypanosomatid infection establishment.
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Affiliation(s)
- Benoit Stijlemans
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium.
- Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium.
| | - Patrick De Baetselier
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium
- Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | - Inge Van Molle
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- VIB-VUB Center for Structural Biology, Brussels, Belgium
| | - Laurence Lecordier
- Biology of Membrane Transport Laboratory, Université Libre de Bruxelles, Gosselies, Belgium
| | - Erika Hendrickx
- Laboratory of Molecular Parasitology, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Ema Romão
- VIB Nanobody Core, Vrije Universiteit Brussel, Brussels, Belgium
| | - Cécile Vincke
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium
- Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | - Wendy Baetens
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium
- Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | | | | | - Hannelie Korf
- Laboratory of Hepatology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium
| | - Marie Wallays
- Laboratory of Hepatology, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium
| | - Joar E Pinto Torres
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - David Perez-Morga
- Laboratory of Molecular Parasitology, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, Gosselies, Belgium
| | - Lea Brys
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium
- Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | - Oscar Campetella
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín-CONICET, Buenos Aires, Argentina
| | - María S Leguizamón
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín-CONICET, Buenos Aires, Argentina
| | - Mathieu Claes
- Laboratory of Microbiology, Parasitology, and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Sarah Hendrickx
- Laboratory of Microbiology, Parasitology, and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Dorien Mabille
- Laboratory of Microbiology, Parasitology, and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology, and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Han Remaut
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- VIB-VUB Center for Structural Biology, Brussels, Belgium
| | - Kim Roelants
- Amphibian Evolution Lab, Biology Department, Vrije Universiteit Brussel, Brussels, Belgium
| | - Stefan Magez
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium
- Laboratory of Biomedical Research, Ghent University Global Campus, Incheon, South Korea
| | - Jo A Van Ginderachter
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium
- Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | - Carl De Trez
- Brussels Center for Immunology, Vrije Universiteit Brussel, Brussels, Belgium
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3
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Morrison LJ, Steketee PC, Tettey MD, Matthews KR. Pathogenicity and virulence of African trypanosomes: From laboratory models to clinically relevant hosts. Virulence 2023; 14:2150445. [PMID: 36419235 DOI: 10.1080/21505594.2022.2150445] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
African trypanosomes are vector-borne protozoa, which cause significant human and animal disease across sub-Saharan Africa, and animal disease across Asia and South America. In humans, infection is caused by variants of Trypanosoma brucei, and is characterized by varying rate of progression to neurological disease, caused by parasites exiting the vasculature and entering the brain. Animal disease is caused by multiple species of trypanosome, primarily T. congolense, T. vivax, and T. brucei. These trypanosomes also infect multiple species of mammalian host, and this complexity of trypanosome and host diversity is reflected in the spectrum of severity of disease in animal trypanosomiasis, ranging from hyperacute infections associated with mortality to long-term chronic infections, and is also a main reason why designing interventions for animal trypanosomiasis is so challenging. In this review, we will provide an overview of the current understanding of trypanosome determinants of infection progression and severity, covering laboratory models of disease, as well as human and livestock disease. We will also highlight gaps in knowledge and capabilities, which represent opportunities to both further our fundamental understanding of how trypanosomes cause disease, as well as facilitating the development of the novel interventions that are so badly needed to reduce the burden of disease caused by these important pathogens.
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Affiliation(s)
- Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Pieter C Steketee
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Mabel D Tettey
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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Lorentzen J, Olesen HG, Hansen AG, Thiel S, Birkelund S, Andersen CBF, Andersen GR. Trypanosoma brucei Invariant Surface gp65 Inhibits the Alternative Pathway of Complement by Accelerating C3b Degradation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:862-873. [PMID: 37466368 DOI: 10.4049/jimmunol.2300128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/30/2023] [Indexed: 07/20/2023]
Abstract
Trypanosomes are known to activate the complement system on their surface, but they control the cascade in a manner such that the cascade does not progress into the terminal pathway. It was recently reported that the invariant surface glycoprotein ISG65 from Trypanosoma brucei interacts reversibly with complement C3 and its degradation products, but the molecular mechanism by which ISG65 interferes with complement activation remains unknown. In this study, we show that ISG65 does not interfere directly with the assembly or activity of the two C3 convertases. However, ISG65 acts as a potent inhibitor of C3 deposition through the alternative pathway in human and murine serum. Degradation assays demonstrate that ISG65 stimulates the C3b to iC3b converting activity of complement factor I in the presence of the cofactors factor H or complement receptor 1. A structure-based model suggests that ISG65 promotes a C3b conformation susceptible to degradation or directly bridges factor I and C3b without contact with the cofactor. In addition, ISG65 is observed to form a stable ternary complex with the ligand binding domain of complement receptor 3 and iC3b. Our data suggest that ISG65 supports trypanosome complement evasion by accelerating the conversion of C3b to iC3b through a unique mechanism.
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Affiliation(s)
- Josefine Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Heidi G Olesen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | | | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Svend Birkelund
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | | | - Gregers R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
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Sülzen H, Began J, Dhillon A, Kereïche S, Pompach P, Votrubova J, Zahedifard F, Šubrtova A, Šafner M, Hubalek M, Thompson M, Zoltner M, Zoll S. Cryo-EM structures of Trypanosoma brucei gambiense ISG65 with human complement C3 and C3b and their roles in alternative pathway restriction. Nat Commun 2023; 14:2403. [PMID: 37105991 PMCID: PMC10140031 DOI: 10.1038/s41467-023-37988-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
African Trypanosomes have developed elaborate mechanisms to escape the adaptive immune response, but little is known about complement evasion particularly at the early stage of infection. Here we show that ISG65 of the human-infective parasite Trypanosoma brucei gambiense is a receptor for human complement factor C3 and its activation fragments and that it takes over a role in selective inhibition of the alternative pathway C5 convertase and thus abrogation of the terminal pathway. No deposition of C4b, as part of the classical and lectin pathway convertases, was detected on trypanosomes. We present the cryo-electron microscopy (EM) structures of native C3 and C3b in complex with ISG65 which reveal a set of modes of complement interaction. Based on these findings, we propose a model for receptor-ligand interactions as they occur at the plasma membrane of blood-stage trypanosomes and may facilitate innate immune escape of the parasite.
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Affiliation(s)
- Hagen Sülzen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
- Faculty of Science, Charles University, Albertov 6, 12800, Prague 2, Czech Republic
| | - Jakub Began
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
- Department of Immunobiology, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Arun Dhillon
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Sami Kereïche
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
- First Faculty of Medicine, Charles University, Albertov 4, 12800, Prague, Czech Republic
| | - Petr Pompach
- Institute of Biotechnology of the Czech Academy of Sciences, 25250, Vestec, Czech Republic
| | - Jitka Votrubova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Farnaz Zahedifard
- Department of Parasitology, Faculty of Science, Charles University Prague, Biocev, 25250, Vestec, Czech Republic
| | - Adriana Šubrtova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Marie Šafner
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Martin Hubalek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Maaike Thompson
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
- University of Antwerp, Antwerp, Belgium
- Agidens, Industrial Machinery Manufacturing, Zwijndrecht, Antwerp, Belgium
| | - Martin Zoltner
- Department of Parasitology, Faculty of Science, Charles University Prague, Biocev, 25250, Vestec, Czech Republic
| | - Sebastian Zoll
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic.
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6
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Abstract
African trypanosomes are bloodstream protozoan parasites that infect mammals including humans, where they cause sleeping sickness. Long-lasting infection is required to favor parasite transmission between hosts. Therefore, trypanosomes have developed strategies to continuously escape innate and adaptive responses of the immune system, while also preventing premature death of the host. The pathology linked to infection mainly results from inflammation and includes anemia and brain dysfunction in addition to loss of specificity and memory of the antibody response. The serum of humans contains an efficient trypanolytic factor, the membrane pore-forming protein apolipoprotein L1 (APOL1). In the two human-infective trypanosomes, specific parasite resistance factors inhibit APOL1 activity. In turn, many African individuals express APOL1 variants that counteract these resistance factors, enabling them to avoid sleeping sickness. However, these variants are associated with chronic kidney disease, particularly in the context of virus-induced inflammation such as coronavirus disease 2019. Vaccination perspectives are discussed.
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Affiliation(s)
- Etienne Pays
- Laboratory of Molecular Parasitology, Université Libre de Bruxelles, Gosselies, Belgium;
| | - Magdalena Radwanska
- Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium;
| | - Stefan Magez
- Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea.,Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium; .,Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
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7
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Heme-deficient metabolism and impaired cellular differentiation as an evolutionary trade-off for human infectivity in Trypanosoma brucei gambiense. Nat Commun 2022; 13:7075. [PMID: 36400774 PMCID: PMC9674590 DOI: 10.1038/s41467-022-34501-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/27/2022] [Indexed: 11/19/2022] Open
Abstract
Resistance to African trypanosomes in humans relies in part on the high affinity targeting of a trypanosome lytic factor 1 (TLF1) to a trypanosome haptoglobin-hemoglobin receptor (HpHbR). While TLF1 avoidance by the inactivation of HpHbR contributes to Trypanosoma brucei gambiense human infectivity, the evolutionary trade-off of this adaptation is unknown, as the physiological function of the receptor remains to be elucidated. Here we show that uptake of hemoglobin via HpHbR constitutes the sole heme import pathway in the trypanosome bloodstream stage. T. b. gambiense strains carrying the inactivating mutation in HpHbR, as well as genetically engineered T. b. brucei HpHbR knock-out lines show only trace levels of intracellular heme and lack hemoprotein-based enzymatic activities, thereby providing an uncommon example of aerobic parasitic proliferation in the absence of heme. We further show that HpHbR facilitates the developmental progression from proliferating long slender forms to cell cycle-arrested stumpy forms in T. b. brucei. Accordingly, T. b. gambiense was found to be poorly competent for slender-to-stumpy differentiation unless a functional HpHbR receptor derived from T. b. brucei was genetically restored. Altogether, we identify heme-deficient metabolism and disrupted cellular differentiation as two distinct HpHbR-dependent evolutionary trade-offs for T. b. gambiense human infectivity.
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ADAR regulates APOL1 via A-to-I RNA editing by inhibition of MDA5 activation in a paradoxical biological circuit. Proc Natl Acad Sci U S A 2022; 119:e2210150119. [PMID: 36282916 PMCID: PMC9636950 DOI: 10.1073/pnas.2210150119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
APOL1 risk variants are associated with increased risk of kidney disease in patients of African ancestry, but not all individuals with the APOL1 high-risk genotype develop kidney disease. As APOL1 gene expression correlates closely with the degree of kidney cell injury in both cell and animal models, the mechanisms regulating APOL1 expression may be critical determinants of risk allele penetrance. The APOL1 messenger RNA includes Alu elements at the 3' untranslated region that can form a double-stranded RNA structure (Alu-dsRNA) susceptible to posttranscriptional adenosine deaminase acting on RNA (ADAR)-mediated adenosine-to-inosine (A-to-I) editing, potentially impacting gene expression. We studied the effects of ADAR expression and A-to-I editing on APOL1 levels in podocytes, human kidney tissue, and a transgenic APOL1 mouse model. In interferon-γ (IFN-γ)-stimulated human podocytes, ADAR down-regulates APOL1 by preventing melanoma differentiation-associated protein 5 (MDA5) recognition of dsRNA and the subsequent type I interferon (IFN-I) response. Knockdown experiments showed that recognition of APOL1 messenger RNA itself is an important contributor to the MDA5-driven IFN-I response. Mathematical modeling suggests that the IFN-ADAR-APOL1 network functions as an incoherent feed-forward loop, a biological circuit capable of generating fast, transient responses to stimuli. Glomeruli from human kidney biopsies exhibited widespread editing of APOL1 Alu-dsRNA, while the transgenic mouse model closely replicated the edited sites in humans. APOL1 expression in mice was inversely correlated with Adar1 expression under IFN-γ stimuli, supporting the idea that ADAR regulates APOL1 levels in vivo. ADAR-mediated A-to-I editing is an important regulator of APOL1 expression that could impact both penetrance and severity of APOL1-associated kidney disease.
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Kumar R, Gupta S, Bhutia WD, Vaid RK, Kumar S. Atypical human trypanosomosis: Potentially emerging disease with lack of understanding. Zoonoses Public Health 2022; 69:259-276. [PMID: 35355422 DOI: 10.1111/zph.12945] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/21/2022] [Accepted: 03/21/2022] [Indexed: 02/03/2023]
Abstract
Trypanosomes are the hemoflagellate kinetoplastid protozoan parasites affecting a wide range of vertebrate hosts having insufficient host specificity. Climatic change, deforestation, globalization, trade agreements, close association and genetic selection in links with environmental, vector, reservoir and potential susceptible hosts' parameters have led to emergence of atypical human trypanosomosis (a-HT). Poor recording of such neglected tropical disease, low awareness in health professions and farming community has approached a serious intimidation for mankind. Reports of animal Trypanosoma species are now gradually increasing in humans, and lack of any compiled literature has diluted the issue. In the present review, global reports of livestock and rodent trypanosomes reported from human beings are assembled and discrepancies with the available literature are discussed along with morphological features of Trypanosoma species. We have described 21 human cases from the published information. Majority of cases 10 (47%) are due to T. lewisi, followed by 5 (24%) cases of T. evansi, 4 (19%) cases of T. brucei and 1 (5%) case each of T. vivax and T. congolense. Indian subcontinent witnessed 13 cases of a-HT, of which 9 cases are reported from India, which includes 7 cases of T. lewisi and 2 cases of T. evansi. Apart from, a-HT case reports, epidemiological investigation and treatment aspects are also discussed. An attempt has been made to provide an overview of the current situation of atypical human trypanosomosis caused by salivarian animal Trypanosoma globally. The probable role of Trypanosoma lytic factors (TLF) present in normal human serum (NHS) in providing innate immunity against salivarian animal Trypanosoma species and the existing paradox in medical science after the finding on intact functional apolipoprotein L1 (ApoL1) in Vietnam T. evansi Type A case is also discussed to provide an update on all aspects of a-HT. Insufficient data and poor reporting in Asian and African countries are the major hurdle resulting in under-reporting of a-HT, which is a potential emerging threat. Therefore, concerted efforts must be directed to address attentiveness, preparedness and regular surveillance in suspected areas with training of field technicians, medical health professionals and veterinarians. Enhancing a one health approach is specifically important in case of trypanosomosis.
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Affiliation(s)
- Rajender Kumar
- Parasitology Lab, ICAR-National Research Centre on Equines, Hisar, India
| | - Snehil Gupta
- Department of Veterinary Parasitology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, India
| | | | | | - Sanjay Kumar
- Parasitology Lab, ICAR-National Research Centre on Equines, Hisar, India
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Kasozi KI, MacLeod ET, Ntulume I, Welburn SC. An Update on African Trypanocide Pharmaceutics and Resistance. Front Vet Sci 2022; 9:828111. [PMID: 35356785 PMCID: PMC8959112 DOI: 10.3389/fvets.2022.828111] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/12/2022] [Indexed: 12/22/2022] Open
Abstract
African trypanosomiasis is associated with Trypanosoma evansi, T. vivax, T. congolense, and T. brucei pathogens in African animal trypanosomiasis (AAT) while T. b gambiense and T. b rhodesiense are responsible for chronic and acute human African trypanosomiasis (HAT), respectively. Suramin sodium suppresses ATP generation during the glycolytic pathway and is ineffective against T. vivax and T. congolense infections. Resistance to suramin is associated with pathogen altered transport proteins. Melarsoprol binds irreversibly with pyruvate kinase protein sulfhydryl groups and neutralizes enzymes which interrupts the trypanosome ATP generation. Melarsoprol resistance is associated with the adenine-adenosine transporter, P2, due to point mutations within this transporter. Eflornithine is used in combination with nifurtimox. Resistance to eflornithine is caused by the deletion or mutation of TbAAT6 gene which encodes the transmembrane amino acid transporter that delivers eflornithine into the cell, thus loss of transporter protein results in eflornithine resistance. Nifurtimox alone is regarded as a poor trypanocide, however, it is effective in melarsoprol-resistant gHAT patients. Resistance is associated with loss of a single copy of the genes encoding for nitroreductase enzymes. Fexinidazole is recommended for first-stage and non-severe second-stage illnesses in gHAT and resistance is associated with trypanosome bacterial nitroreductases which reduce fexinidazole. In AAT, quinapyramine sulfate interferes with DNA synthesis and suppression of cytoplasmic ribosomal activity in the mitochondria. Quinapyramine sulfate resistance is due to variations in the potential of the parasite's mitochondrial membrane. Pentamidines create cross-links between two adenines at 4–5 pairs apart in adenine-thymine-rich portions of Trypanosoma DNA. It also suppresses type II topoisomerase in the mitochondria of Trypanosoma parasites. Pentamidine resistance is due to loss of mitochondria transport proteins P2 and HAPT1. Diamidines are most effective against Trypanosome brucei group and act via the P2/TbAT1 transporters. Diminazene aceturate resistance is due to mutations that alter the activity of P2, TeDR40 (T. b. evansi). Isometamidium chloride is primarily employed in the early stages of trypanosomiasis and resistance is associated with diminazene resistance. Phenanthridine (homidium bromide, also known as ethidium bromide) acts by a breakdown of the kinetoplast network and homidium resistance is comparable to isometamidium. In humans, the development of resistance and adverse side effects against monotherapies has led to the adoption of nifurtimox-eflornithine combination therapy. Current efforts to develop new prodrug combinations of nifurtimox and eflornithine and nitroimidazole fexinidazole as well as benzoxaborole SCYX-7158 (AN5568) for HAT are in progress while little comparable progress has been done for the development of novel therapies to address trypanocide resistance in AAT.
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Affiliation(s)
- Keneth Iceland Kasozi
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- School of Medicine, Kabale University, Kabale, Uganda
- *Correspondence: Keneth Iceland Kasozi ;
| | - Ewan Thomas MacLeod
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ibrahim Ntulume
- School of Biosecurity Biotechnical and Laboratory Sciences, College of Medicine and Veterinary Medicine, Makerere University, Kampala, Uganda
| | - Susan Christina Welburn
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- Zhejiang University-University of Edinburgh Joint Institute, Zhejiang University, Hangzhou, China
- Susan Christina Welburn
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11
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Kim HC, Jolly ER. LncRNAs Are Differentially Expressed between Wildtype and Cell Line Strains of African Trypanosomes. Noncoding RNA 2022; 8:ncrna8010007. [PMID: 35076577 PMCID: PMC8788480 DOI: 10.3390/ncrna8010007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/02/2022] [Accepted: 01/08/2022] [Indexed: 12/15/2022] Open
Abstract
Trypanosoma brucei is a parasitic protist that causes African sleeping sickness. The establishment of T. brucei cell lines has provided a significant advantage for the majority of T. brucei research. However, these cell lines were isolated and maintained in culture for decades, occasionally accumulating changes in gene expression. Since trypanosome strains have been maintained in culture for decades, it is possible that difference may have accumulated in fast-evolving non-coding RNAs between trypanosomes from the wild and those maintained extensively in cultures. To address this, we compared the lncRNA expression profile of trypanosomes maintained as cultured cell lines (CL) to those extracted from human patients, wildtype (WT). We identified lncRNAs from CL and WT from available transcriptomic data and demonstrate that CL and WT have unique sets of lncRNAs expressed. We further demonstrate that the unique and shared lncRNAs are differentially expressed between CL and WT parasites, and that these lncRNAs are more evenly up-regulated and down-regulated than protein-coding genes. We validated the expression of these lncRNAs using qPCR. Taken together, this study demonstrates that lncRNAs are differentially expressed between cell lines and wildtype T. brucei and provides evidence for potential evolution of lncRNAs, specifically in T. brucei maintained in culture.
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Affiliation(s)
- Hyung Chul Kim
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA;
| | - Emmitt R. Jolly
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA;
- Center for Global Health and Disease, Case Western Reserve University, Cleveland, OH 44106, USA
- Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, OH 44106, USA
- Correspondence:
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12
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Kun Á. Is there still evolution in the human population? Biol Futur 2022; 73:359-374. [PMID: 36592324 PMCID: PMC9806833 DOI: 10.1007/s42977-022-00146-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 12/08/2022] [Indexed: 01/03/2023]
Abstract
It is often claimed that humanity has stopped evolving because modern medicine erased all selection on survival. Even if that would be true, and it is not, there would be other mechanisms of evolution which could still led to changes in allelic frequencies. Here I show, by applying basic evolutionary genetics knowledge, that we expect humanity to evolve. The results from genome sequencing projects have repeatedly affirmed that there are still recent signs of selection in our genomes. I give some examples of such adaptation. Then I briefly discuss what our evolutionary future has in store for us.
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Affiliation(s)
- Ádám Kun
- grid.5591.80000 0001 2294 6276Department of Plant Systematics, Ecology and Theoretical Biology, Eötvös University, Budapest, Hungary ,Parmenides Center for the Conceptual Foundations of Science, Pöcking, Germany ,grid.481817.3Institute of Evolution, Centre for Ecological Research, Budapest, Hungary ,grid.5018.c0000 0001 2149 4407MTA-ELTE Theoretical Biology and Evolutionary Ecology Research Group, Budapest, Hungary ,grid.5018.c0000 0001 2149 4407MTA-ELTE-MTM Ecology Research Group, Budapest, Hungary
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13
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Horn D. Genome-scale RNAi screens in African trypanosomes. Trends Parasitol 2021; 38:160-173. [PMID: 34580035 DOI: 10.1016/j.pt.2021.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 12/11/2022]
Abstract
Genome-scale genetic screens allow researchers to rapidly identify the genes and proteins that impact a particular phenotype of interest. In African trypanosomes, RNA interference (RNAi) knockdown screens have revealed mechanisms underpinning drug resistance, drug transport, prodrug metabolism, quorum sensing, genome replication, and gene expression control. RNAi screening has also been remarkably effective at highlighting promising potential antitrypanosomal drug targets. The first ever RNAi library screen was implemented in African trypanosomes, and genome-scale RNAi screens and other related approaches continue to have a major impact on trypanosomatid research. Here, I review those impacts in terms of both discovery and translation.
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Affiliation(s)
- David Horn
- The Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
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14
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Silva Pereira S, Jackson AP, Figueiredo LM. Evolution of the variant surface glycoprotein family in African trypanosomes. Trends Parasitol 2021; 38:23-36. [PMID: 34376326 DOI: 10.1016/j.pt.2021.07.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 01/22/2023]
Abstract
An intriguing and remarkable feature of African trypanosomes is their antigenic variation system, mediated by the variant surface glycoprotein (VSG) family and fundamental to both immune evasion and disease epidemiology within host populations. Recent studies have revealed that the VSG repertoire has a complex evolutionary history. Sequence diversity, genomic organization, and expression patterns are species-specific, which may explain other variations in parasite virulence and disease pathology. Evidence also shows that we may be underestimating the extent to what VSGs are repurposed beyond their roles as variant antigens, establishing a need to examine VSG functionality more deeply. Here, we review sequence variation within the VSG gene family, and highlight the many opportunities to explore their likely diverse contributions to parasite survival.
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Affiliation(s)
- Sara Silva Pereira
- Instituto de Medicina Molecular - João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Andrew P Jackson
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Luísa M Figueiredo
- Instituto de Medicina Molecular - João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
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15
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Abstract
African trypanosomes are responsible for important diseases of humans and animals in sub-Saharan Africa. The best-studied species is Trypanosoma brucei, which is characterized by development in the mammalian host between morphologically slender and stumpy forms. The latter are adapted for transmission by the parasite's vector, the tsetse fly. The development of stumpy forms is driven by density-dependent quorum-sensing (QS), the molecular basis for which is now coming to light. In this review, I discuss the historical context and biological features of trypanosome QS and how it contributes to the parasite's infection dynamics within its mammalian host. Also, I discuss how QS can be lost in different trypanosome species, such as T. brucei evansi and T. brucei equiperdum, or modulated when parasites find themselves competing with others of different genotypes or of different trypanosome species in the same host. Finally, I consider the potential to exploit trypanosome QS therapeutically. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Keith R Matthews
- Institute for Immunology and Infection Research, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom;
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16
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Schaub C, Lee P, Racho-Jansen A, Giovinazzo J, Terra N, Raper J, Thomson R. Coiled-coil binding of the leucine zipper domains of APOL1 is necessary for the open cation channel conformation. J Biol Chem 2021; 297:101009. [PMID: 34331942 PMCID: PMC8446801 DOI: 10.1016/j.jbc.2021.101009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 07/12/2021] [Accepted: 07/23/2021] [Indexed: 11/17/2022] Open
Abstract
Apolipoprotein L-I (APOL1) is a channel-forming effector of innate immunity. The common human APOL1 variant G0 provides protection against infection with certain Trypanosoma and Leishmania parasite species, but it cannot protect against the trypanosomes responsible for human African trypanosomiasis. Human APOL1 variants G1 and G2 protect against human-infective trypanosomes but also confer a higher risk of developing chronic kidney disease. Trypanosome-killing activity is dependent on the ability of APOL1 to insert into membranes at acidic pH and form pH-gated cation channels. We previously mapped the channel’s pore-lining region to the C-terminal domain (residues 332–398) and identified a membrane-insertion domain (MID, residues 177–228) that facilitates acidic pH-dependent membrane insertion. In this article, we further investigate structural determinants of cation channel formation by APOL1. Using a combination of site-directed mutagenesis and targeted chemical modification, our data indicate that the C-terminal heptad-repeat sequence (residues 368–395) is a bona fide leucine zipper domain (ZIP) that is required for cation channel formation as well as lysis of trypanosomes and mammalian cells. Using protein-wide cysteine-scanning mutagenesis, coupled with the substituted cysteine accessibility method, we determined that, in the open channel state, both the N-terminal domain and the C-terminal ZIP domain are exposed on the intralumenal/extracellular side of the membrane and provide evidence that each APOL1 monomer contributes four transmembrane domains to the open cation channel conformation. Based on these data, we propose an oligomeric topology model in which the open APOL1 cation channel is assembled from the coiled-coil association of C-terminal ZIP domains.
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Affiliation(s)
- Charles Schaub
- Department of Biological sciences, Hunter College, City University of New York, USA; The Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York; Vanderbilt University, Nashville, Tennessee, USA
| | - Penny Lee
- Department of Biological sciences, Hunter College, City University of New York, USA; John Jay College, City University of New York, USA
| | - Alisha Racho-Jansen
- Department of Biological sciences, Hunter College, City University of New York, USA
| | - Joe Giovinazzo
- Department of Biological sciences, Hunter College, City University of New York, USA; University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Nada Terra
- Department of Biological sciences, Hunter College, City University of New York, USA; Icahn School of Medicine at Mount Sinai, New York, USA
| | - Jayne Raper
- Department of Biological sciences, Hunter College, City University of New York, USA; The Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York.
| | - Russell Thomson
- Department of Biological sciences, Hunter College, City University of New York, USA.
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17
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Dean S. Basic Biology of Trypanosoma brucei with Reference to the Development of Chemotherapies. Curr Pharm Des 2021; 27:1650-1670. [PMID: 33463458 DOI: 10.2174/1381612827666210119105008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/01/2020] [Accepted: 12/08/2020] [Indexed: 11/22/2022]
Abstract
Trypanosoma brucei are protozoan parasites that cause the lethal human disease African sleeping sickness and the economically devastating disease of cattle, Nagana. African sleeping sickness, also known as Human African Trypanosomiasis (HAT), threatens 65 million people and animal trypanosomiasis makes large areas of farmland unusable. There is no vaccine and licensed therapies against the most severe, late-stage disease are toxic, impractical and ineffective. Trypanosomes are transmitted by tsetse flies, and HAT is therefore predominantly confined to the tsetse fly belt in sub-Saharan Africa. They are exclusively extracellular and they differentiate between at least seven developmental forms that are highly adapted to host and vector niches. In the mammalian (human) host they inhabit the blood, cerebrospinal fluid (late-stage disease), skin, and adipose fat. In the tsetse fly vector they travel from the tsetse midgut to the salivary glands via the ectoperitrophic space and proventriculus. Trypanosomes are evolutionarily divergent compared with most branches of eukaryotic life. Perhaps most famous for their extraordinary mechanisms of monoallelic gene expression and antigenic variation, they have also been investigated because much of their biology is either highly unconventional or extreme. Moreover, in addition to their importance as pathogens, many researchers have been attracted to the field because trypanosomes have some of the most advanced molecular genetic tools and database resources of any model system. The following will cover just some aspects of trypanosome biology and how its divergent biochemistry has been leveraged to develop drugs to treat African sleeping sickness. This is by no means intended to be a comprehensive survey of trypanosome features. Rather, I hope to present trypanosomes as one of the most fascinating and tractable systems to do discovery biology.
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Affiliation(s)
- Samuel Dean
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, United Kingdom
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18
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Salivarian Trypanosomes Have Adopted Intricate Host-Pathogen Interaction Mechanisms That Ensure Survival in Plain Sight of the Adaptive Immune System. Pathogens 2021; 10:pathogens10060679. [PMID: 34072674 PMCID: PMC8229994 DOI: 10.3390/pathogens10060679] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/24/2021] [Accepted: 05/28/2021] [Indexed: 12/21/2022] Open
Abstract
Salivarian trypanosomes are extracellular parasites affecting humans, livestock and game animals. Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense are human infective sub-species of T. brucei causing human African trypanosomiasis (HAT—sleeping sickness). The related T. b. brucei parasite lacks the resistance to survive in human serum, and only inflicts animal infections. Animal trypanosomiasis (AT) is not restricted to Africa, but is present on all continents. T. congolense and T. vivax are the most widespread pathogenic trypanosomes in sub-Saharan Africa. Through mechanical transmission, T. vivax has also been introduced into South America. T. evansi is a unique animal trypanosome that is found in vast territories around the world and can cause atypical human trypanosomiasis (aHT). All salivarian trypanosomes are well adapted to survival inside the host’s immune system. This is not a hostile environment for these parasites, but the place where they thrive. Here we provide an overview of the latest insights into the host-parasite interaction and the unique survival strategies that allow trypanosomes to outsmart the immune system. In addition, we review new developments in treatment and diagnosis as well as the issues that have hampered the development of field-applicable anti-trypanosome vaccines for the implementation of sustainable disease control.
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19
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de Castro Neto AL, da Silveira JF, Mortara RA. Comparative Analysis of Virulence Mechanisms of Trypanosomatids Pathogenic to Humans. Front Cell Infect Microbiol 2021; 11:669079. [PMID: 33937106 PMCID: PMC8085324 DOI: 10.3389/fcimb.2021.669079] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/30/2021] [Indexed: 11/23/2022] Open
Abstract
Trypanosoma brucei, Leishmania spp., and T. cruzi are flagellate protozoans of the family Trypanosomatidae and the causative agents of human African trypanosomiasis, leishmaniasis, and Chagas disease, respectively. These diseases affect humans worldwide and exert a significant impact on public health. Over the course of evolution, the parasites associated with these pathologies have developed mechanisms to circumvent the immune response system throughout the infection cycle. In cases of human infection, this function is undertaken by a group of proteins and processes that allow the parasites to propagate and survive during host invasion. In T. brucei, antigenic variation is promoted by variant surface glycoproteins and other proteins involved in evasion from the humoral immune response, which helps the parasite sustain itself in the extracellular milieu during infection. Conversely, Leishmania spp. and T. cruzi possess a more complex infection cycle, with specific intracellular stages. In addition to mechanisms for evading humoral immunity, the pathogens have also developed mechanisms for facilitating their adhesion and incorporation into host cells. In this review, the different immune evasion strategies at cellular and molecular levels developed by these human-pathogenic trypanosomatids have been discussed, with a focus on the key molecules responsible for mediating the invasion and evasion mechanisms and the effects of these molecules on virulence.
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Affiliation(s)
- Artur Leonel de Castro Neto
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - José Franco da Silveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Renato Arruda Mortara
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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20
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Zhang K, Jiang N, Chen H, Zhang N, Sang X, Feng Y, Chen R, Chen Q. TatD DNases of African trypanosomes confer resistance to host neutrophil extracellular traps. SCIENCE CHINA. LIFE SCIENCES 2021; 64:621-632. [PMID: 33420923 DOI: 10.1007/s11427-020-1854-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 11/19/2020] [Indexed: 01/07/2023]
Abstract
African trypanosomatid parasites escape host acquired immune responses through periodic antigenic variation of their surface coat. In this study, we describe a mechanism by which the parasites counteract innate immune responses. Two TatD DNases were identified in each of Trypanosoma evansi and Trypanosoma brucei. These DNases are bivalent metal-dependent endonucleases localized in the cytoplasm and flagella of the parasites that can also be secreted by the parasites. These enzymes possess conserved functional domains and have efficient DNA hydrolysis activity. Host neutrophil extracellular traps (NETs) induced by the parasites could be hydrolyzed by native and recombinant TatD DNases. NET disruption was prevented, and the survival rate of parasites was decreased, in the presence of the DNase inhibitor aurintricarboxylic acid. These data suggest that trypanosomes can counteract host innate immune responses by active secretion of TatD DNases to degrade NETs.
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Affiliation(s)
- Kai Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Ning Jiang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Hongyu Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Naiwen Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Xiaoyu Sang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Ying Feng
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Ran Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Qijun Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China.
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China.
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21
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Pays E, Nolan DP. Genetic and immunological basis of human African trypanosomiasis. Curr Opin Immunol 2021; 72:13-20. [PMID: 33721725 PMCID: PMC8589022 DOI: 10.1016/j.coi.2021.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/11/2021] [Accepted: 02/19/2021] [Indexed: 12/11/2022]
Abstract
Human African trypanosomiasis, or sleeping sickness, results from infection by two subspecies of the protozoan flagellate parasite Trypanosoma brucei, termed Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense, prevalent in western and eastern Africa respectively. These subspecies escape the trypanolytic potential of human serum, which efficiently acts against the prototype species Trypanosoma brucei brucei, responsible for the Nagana disease in cattle. We review the various strategies and components used by trypanosomes to counteract the immune defences of their host, highlighting the adaptive genomic evolution that occurred in both parasite and host to take the lead in this battle. The main parasite surface antigen, named Variant Surface Glycoprotein or VSG, appears to play a key role in different processes involved in the dialogue with the host.
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Affiliation(s)
- Etienne Pays
- Laboratory of Molecular Parasitology, IBMM, Université Libre de Bruxelles, 6041 Gosselies, Belgium.
| | - Derek P Nolan
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin 2, Ireland
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22
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De Simone G, Pasquadibisceglie A, Polticelli F, di Masi A, Ascenzi P. Haptoglobin and the related haptoglobin protein: the N-terminus makes the difference. J Biomol Struct Dyn 2020; 40:2244-2253. [DOI: 10.1080/07391102.2020.1837675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | | | - Fabio Polticelli
- Dipartimento di Scienze, Università Roma Tre, Roma, Italy
- Istituto Nazionale di Fisica Nucleare, Roma Tre Section, Roma, Italy
| | | | - Paolo Ascenzi
- Laboratorio Interdipartimentale di Microscopia Elettronica, Università Roma Tre, Roma, Italy
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23
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Rijo-Ferreira F, Takahashi JS. Sleeping Sickness: A Tale of Two Clocks. Front Cell Infect Microbiol 2020; 10:525097. [PMID: 33134186 PMCID: PMC7562814 DOI: 10.3389/fcimb.2020.525097] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 08/31/2020] [Indexed: 12/17/2022] Open
Abstract
Sleeping sickness is caused by a eukaryotic unicellular parasite known to infect wild animals, cattle, and humans. It causes a fatal disease that disrupts many rhythmic physiological processes, including daily rhythms of hormonal secretion, temperature regulation, and sleep, all of which are under circadian (24-h) control. In this review, we summarize research on sleeping sickness parasite biology and the impact it has on host health. We also consider the possible evolutionary advantages of sleep and circadian deregulation for the parasite.
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Affiliation(s)
- Filipa Rijo-Ferreira
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Joseph S Takahashi
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States
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24
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Dufourc EJ. Bicelles and nanodiscs for biophysical chemistry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183478. [PMID: 32971065 DOI: 10.1016/j.bbamem.2020.183478] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 01/14/2023]
Abstract
Membrane nanoobjects are very important tools to study biomembrane properties. Two types are described herein: Bicelles and Nanodiscs. Bicelles are obtained by thorough water mixing of long chain and short chain lipids and may take the form of membranous discs of 10-50 nm. Temperature-composition-hydration diagrams have been established for Phosphatidylcholines and show limited domains of existence. Bicelles can be doped with charged lipids, surfactants or with cholesterol and offer a wide variety of membranous platforms for structural biology. Internal dynamics as measured by solid-state NMR is very similar to that of liposomes in their fluid phase. Because of the magnetic susceptibility anisotropy of the lipid chains, discs may be aligned along or perpendicular to the magnetic field. They may serve as weak orienting media to provide distance information in determining the 3D structure of soluble proteins. In different conditions they show strong orienting properties which may be used to study the 3D structure, topology and dynamics of membrane proteins. Lipid Bicelles with biphenyl chains or doped with lanthanides show long lasting remnant orientation after removing the magnetic field due to smectic-like properties. An alternative to pure lipid Bicelles is provided by nanodiscs where the half torus composed by short chain lipids is replaced by proteins. This renders the nano-objects less fragile as they can be used to stabilize membrane protein assemblies to be studied by electron microscopy. Internal dynamics is again similar to liposomes except that the phase transition is abolished, possibly due to lateral constrain imposed by the toroidal proteins limiting the disc size. Advantages and drawbacks of both nanoplatforms are discussed.
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Affiliation(s)
- Erick J Dufourc
- Institute of Chemistry and Biology of membranes and Nanoobjects, UMR5248, CNRS, University of Bordeaux, Bordeaux Polytechnic Institute, Allée Geoffroy Saint Hilaire, 33600 Pessac, France.
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25
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Blood of African Hedgehog Atelerix albiventris Contains 115-kDa Trypanolytic Protein that Kills Trypanosoma congolense. Acta Parasitol 2020; 65:733-742. [PMID: 32385812 DOI: 10.2478/s11686-020-00211-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 04/01/2020] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Protozoan parasites of the Order Trypanosomatida infect a wide range of multicellular plants and animals, causing devastating and potentially fatal diseases. Trypanosomes are the most relevant members of the order in sub-Saharan Africa because of mortalities and morbidities caused to humans and livestock. PURPOSE There are growing concerns that trypanosomes are expanding their reservoirs among wild animals, which habours the parasites, withstand the infection, and from which tsetse flies transmit the parasites back to humans and livestock. This study was designed to investigate the potentials of the African hedgehog serving as reservoir for African animal trypanosomes. METHODS Five adult hedgehogs alongside five laboratory mice were intraperitoneally inoculated with 106 and 104 of Trypanosoma congolense cells, respectively, and monitored for parasitemia and survival. Serum from twenty hedgehogs was subjected to trypanocidal activity-guided fractionation by successive ion-exchange and gel-filtration chromatographies, followed by characterization with Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE). RESULTS Hedgehogs were resistant to the infection as no parasite was detected and none died even after 60 days, while all the mice died within 12 days. Both the serum and plasma prepared from hedgehogs demonstrated trypanocidal activity- rapidly killed trypanosomes even when diluted 1000 times. The trypanolytic factor was identified to be proteinaceous with an estimated molecular weight of 115-kDa. CONCLUSION For the first time, it is here demonstrated that hedgehog blood has significant trypanolytic activity against T. congolense. The potential application of the hedgehog protein for the breeding of trypanosomosis-resistant livestock in tsetse fly belt is discussed.
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26
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di Masi A, De Simone G, Ciaccio C, D'Orso S, Coletta M, Ascenzi P. Haptoglobin: From hemoglobin scavenging to human health. Mol Aspects Med 2020; 73:100851. [PMID: 32660714 DOI: 10.1016/j.mam.2020.100851] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/23/2020] [Accepted: 03/25/2020] [Indexed: 02/07/2023]
Abstract
Haptoglobin (Hp) belongs to the family of acute-phase plasma proteins and represents the most important plasma detoxifier of hemoglobin (Hb). The basic Hp molecule is a tetrameric protein built by two α/β dimers. Each Hp α/β dimer is encoded by a single gene and is synthesized as a single polypeptide. Following post-translational protease-dependent cleavage of the Hp polypeptide, the α and β chains are linked by disulfide bridge(s) to generate the mature Hp protein. As human Hp gene is characterized by two common Hp1 and Hp2 alleles, three major genotypes can result (i.e., Hp1-1, Hp2-1, and Hp2-2). Hp regulates Hb clearance from circulation by the macrophage-specific receptor CD163, thus preventing Hb-mediated severe consequences for health. Indeed, the antioxidant and Hb binding properties of Hp as well as its ability to stimulate cells of the monocyte/macrophage lineage and to modulate the helper T-cell type 1 and type 2 balance significantly associate with a variety of pathogenic disorders (e.g., infectious diseases, diabetes, cardiovascular diseases, and cancer). Alternative functions of the variants Hp1 and Hp2 have been reported, particularly in the susceptibility and protection against infectious (e.g., pulmonary tuberculosis, HIV, and malaria) and non-infectious (e.g., diabetes, cardiovascular diseases and obesity) diseases. Both high and low levels of Hp are indicative of clinical conditions: Hp plasma levels increase during infections, inflammation, and various malignant diseases, and decrease during malnutrition, hemolysis, hepatic disease, allergic reactions, and seizure disorders. Of note, the Hp:Hb complexes display heme-based reactivity; in fact, they bind several ferrous and ferric ligands, including O2, CO, and NO, and display (pseudo-)enzymatic properties (e.g., NO and peroxynitrite detoxification). Here, genetic, biochemical, biomedical, and biotechnological aspects of Hp are reviewed.
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Affiliation(s)
- Alessandra di Masi
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Giovanna De Simone
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Chiara Ciaccio
- Department of Clinical Sciences and Translational Medicine, University of Roma "Tor Vergata", Via Montpellier 1, I-00133, Roma, Italy; Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, Via Celso Ulpiani 27, I-70126, Bari, Italy
| | - Silvia D'Orso
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Massimo Coletta
- Department of Clinical Sciences and Translational Medicine, University of Roma "Tor Vergata", Via Montpellier 1, I-00133, Roma, Italy; Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, Via Celso Ulpiani 27, I-70126, Bari, Italy
| | - Paolo Ascenzi
- Interdepartmental Laboratory for Electron Microscopy, Roma Tre University, Via della Vasca Navale 79, I-00146, Roma, Italy.
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Zhang N, Jiang N, Zhang K, Zheng L, Zhang D, Sang X, Feng Y, Chen R, Yang N, Wang X, Cheng Z, Suo X, Lun Z, Chen Q. Landscapes of Protein Posttranslational Modifications of African Trypanosoma Parasites. iScience 2020; 23:101074. [PMID: 32403088 PMCID: PMC7218301 DOI: 10.1016/j.isci.2020.101074] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/22/2020] [Accepted: 04/14/2020] [Indexed: 12/13/2022] Open
Abstract
Proteins of all living cells undergo a myriad of post-translational modifications (PTMs) that are critical to multifarious life processes. In this study, we describe the first comprehensive multiple PTM-omics atlas in parallel with quantitative proteome analyses of two representative species of African trypanosomes, Trypanosoma brucei and Trypanosoma evansi. Ten PTM types with approximately 40,000 modified sites and 150 histone marks with a fine map on each protein of the two African trypanosomes were accomplished. The two biologically different trypanosomal species displayed distinct PTM-omic features, regulation pathways, and networks. Modifications in the proteins involved in the redox system were mainly upregulated in T. brucei, whereas proteins associated with motility were predominantly modified in T. evansi. The establishment of a database of multiple PTMs in the two parasites provides us with a deep insight into the biological mechanisms that underpin life processes in trypanosomes with different life cycles.
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Affiliation(s)
- Naiwen Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Ning Jiang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Kai Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Lili Zheng
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Di Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China
| | - Xiaoyu Sang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Ying Feng
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Ran Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Na Yang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China
| | - Xinyi Wang
- College of Basic Sciences, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China
| | - Zhongyi Cheng
- Jingjie PTM Biolab (Hangzhou) Co. Ltd, Hangzhou 310018, China
| | - Xun Suo
- National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhaorong Lun
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Qijun Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China.
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28
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Giovinazzo JA, Thomson RP, Khalizova N, Zager PJ, Malani N, Rodriguez-Boulan E, Raper J, Schreiner R. Apolipoprotein L-1 renal risk variants form active channels at the plasma membrane driving cytotoxicity. eLife 2020; 9:51185. [PMID: 32427098 PMCID: PMC7292663 DOI: 10.7554/elife.51185] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 05/14/2020] [Indexed: 12/25/2022] Open
Abstract
Recently evolved alleles of Apolipoprotein L-1 (APOL1) provide increased protection against African trypanosome parasites while also significantly increasing the risk of developing kidney disease in humans. APOL1 protects against trypanosome infections by forming ion channels within the parasite, causing lysis. While the correlation to kidney disease is robust, there is little consensus concerning the underlying disease mechanism. We show in human cells that the APOL1 renal risk variants have a population of active channels at the plasma membrane, which results in an influx of both Na+ and Ca2+. We propose a model wherein APOL1 channel activity is the upstream event causing cell death, and that the activate-state, plasma membrane-localized channel represents the ideal drug target to combat APOL1-mediated kidney disease.
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Affiliation(s)
- Joseph A Giovinazzo
- Department of Biological Sciences, Hunter College at City University of New York, New York, United States
| | - Russell P Thomson
- Department of Biological Sciences, Hunter College at City University of New York, New York, United States
| | - Nailya Khalizova
- Department of Biological Sciences, Hunter College at City University of New York, New York, United States
| | - Patrick J Zager
- Department of Ophthalmology, Margaret Dyson Vision Research Institute, Weill Cornell Medicine, New York, United States
| | | | - Enrique Rodriguez-Boulan
- Department of Ophthalmology, Margaret Dyson Vision Research Institute, Weill Cornell Medicine, New York, United States
| | - Jayne Raper
- Department of Biological Sciences, Hunter College at City University of New York, New York, United States
| | - Ryan Schreiner
- Department of Ophthalmology, Margaret Dyson Vision Research Institute, Weill Cornell Medicine, New York, United States
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29
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Inducible Germline IgMs Bridge Trypanosome Lytic Factor Assembly and Parasite Recognition. Cell Host Microbe 2020; 28:79-88.e4. [PMID: 32416060 DOI: 10.1016/j.chom.2020.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 02/20/2020] [Accepted: 04/14/2020] [Indexed: 11/23/2022]
Abstract
Trypanosomiasis is a devastating neglected tropical disease affecting livestock and humans. Humans are susceptible to two Trypanosoma brucei subspecies but protected from other trypanosomes by circulating high-density lipoprotein (HDL) complexes called trypanosome lytic factors (TLFs) 1 and 2. TLFs contain apolipoprotein L-1 contributing to lysis and haptoglobin-related protein (HPR), which can function as a ligand for a parasite receptor. TLF2 also uniquely contains non-covalently associated immunoglobin M (IgM) antibodies, the role and origin of which remain unclear. Here, we show that these TLF2-associated IgMs interact with both HPR and alternate trypanosome surface proteins, including variant surface glycoprotein, likely facilitating complex biogenesis and TLF uptake into parasites. TLF2-IgMs are germline antibodies that, while present at basal concentrations in healthy individuals, are elicited by trypanosome infection in both murine models and human sleeping sickness patients. These data suggest that poly- and self-reactive germline antibodies such as TLF2-associated IgMs play a role in antimicrobial immunity.
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Abstract
Apolipoprotein L1 (APOL1) is a protein encoded by the APOL1 gene, found only in humans and several primates. Two variants encoding two different isoforms exist for APOL1, namely G1 and G2. These variants confer increased protection against trypanosome infection, and subsequent African sleeping sickness, and also increase the likelihood of renal disease in individuals of African ancestry. APOL1 mutations are associated with increased risk of chronic kidney disease, inflammation, and exacerbation of systemic lupus erythematosus-associated renal dysfunction. This review serves to outline the structure and function of APOL1, as well as its role in several disease outcomes.
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Affiliation(s)
- Shanel Raghubeer
- Biomedical Sciences, Cape Peninsula University of Technology-Bellville Campus, Cape Town, Western Cape, South Africa
| | - Tahir S Pillay
- Department of Chemical Pathology, University of Pretoria Faculty of Health Sciences, Pretoria, Gauteng, South Africa.,Division of Chemical Pathology, University of Cape Town, Rondebosch, Western Cape, South Africa
| | - Tandi Edith Matsha
- Biomedical Sciences, Cape Peninsula University of Technology-Bellville Campus, Cape Town, Western Cape, South Africa
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31
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Xu ZS, Li FJ, Hide G, Lun ZR, Lai DH. Vacuolar ATPase depletion contributes to dysregulation of endocytosis in bloodstream forms of Trypanosoma brucei. Parasit Vectors 2020; 13:214. [PMID: 32334612 PMCID: PMC7183646 DOI: 10.1186/s13071-020-04068-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/09/2020] [Indexed: 12/04/2022] Open
Abstract
Background Vacuolar H+-ATPase (V-ATPase) is a highly conserved protein complex which hydrolyzes ATP and pumps protons to acidify vacuolar vesicles. Beyond its role in pH maintenance, the involvement of V-ATPase in endocytosis is well documented in mammals and plants but is less clear in Trypanosoma brucei. Methods In this study, the subcellular localization of V-ATPase subunit B (TbVAB) of T. brucei was assessed via in situ N-terminal YFP-tagging and immunofluorescence assays. Transgenic bloodstream forms (BSF) of T. brucei were generated which comprised either a V-ATPase subunit B (TbVAB) conditional knockout or a V-ATPase subunit A (TbVAA) knockdown. Acridine orange and BCECF-AM were employed to assess the roles of V-ATPase in the pH regulation of BSF T. brucei. The endocytic activities of three markers were also characterized by flow cytometry analyses. Furthermore, trypanosomes were counted from trypanolysis treatment groups (either containing 1% or 5% NHS) and endocytosed trypanosome lytic factor (TLF) was also analyzed by an immunoblotting assay. Results TbVAB was found to localize to acidocalcisomes, lysosomes and probably also to endosomes of BSF of T. brucei and was demonstrated to be essential for cell growth. TbVAB depletion neutralized acidic organelles at 24 hours post-tetracycline depletion (hpd), meanwhile the steady state intracellular pH increased from 7.016 ± 0.013 to 7.422 ± 0.058. Trypanosomes with TbVAB depletion at 24 hpd were found to take up more transferrin (2.068 ± 0.277 fold) but less tomato lectin (49.31 ± 22.57%) by endocytosis, while no significant change was detected in dextran uptake. Similar endocytic dysregulated phenotypes were also observed in TbVAA knockdown cells. In addition, TbVAB depleted trypanosomes showed a low uptake of TLF and exhibited less sensitive to lysis in both 1% and 5% NHS treatments. Conclusions TbVAB is a key component of V-ATPase and was found to play a key function in endocytosis as well as exhibiting different effects in a receptor/cargo dependent manner in BSF of T. brucei. Besides vacuolar alkalinization, the dysregulation of endocytosis in TbVAB depleted T. brucei is considered to contribute to the reduced sensitivity to lysis by normal human serum.![]()
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Affiliation(s)
- Zhi-Shen Xu
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, and Key Laboratory of Tropical Disease Control (Sun Yat-Sen University), Ministry of Education, Sun Yat-Sen University, Guangzhou, 510275, The People's Republic of China
| | - Feng-Jun Li
- Department of Biological Sciences, National University of Singapore, Singapore, 11754, Singapore
| | - Geoff Hide
- Biomedical Research Centre and Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Salford, M5 4WT, UK
| | - Zhao-Rong Lun
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, and Key Laboratory of Tropical Disease Control (Sun Yat-Sen University), Ministry of Education, Sun Yat-Sen University, Guangzhou, 510275, The People's Republic of China. .,Biomedical Research Centre and Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Salford, M5 4WT, UK.
| | - De-Hua Lai
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, and Key Laboratory of Tropical Disease Control (Sun Yat-Sen University), Ministry of Education, Sun Yat-Sen University, Guangzhou, 510275, The People's Republic of China.
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32
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Dazzoni R, Grélard A, Morvan E, Bouter A, Applebee CJ, Loquet A, Larijani B, Dufourc EJ. The unprecedented membrane deformation of the human nuclear envelope, in a magnetic field, indicates formation of nuclear membrane invaginations. Sci Rep 2020; 10:5147. [PMID: 32198481 PMCID: PMC7083927 DOI: 10.1038/s41598-020-61746-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/14/2020] [Indexed: 12/04/2022] Open
Abstract
Human nuclear membrane (hNM) invaginations are thought to be crucial in fusion, fission and remodeling of cells and present in many human diseases. There is however little knowledge, if any, about their lipid composition and dynamics. We therefore isolated nuclear envelope lipids from human kidney cells, analyzed their composition and determined the membrane dynamics after resuspension in buffer. The hNM lipid extract was composed of a complex mixture of phospholipids, with high amounts of phosphatidylcholines, phosphatidylinositols (PI) and cholesterol. hNM dynamics was determined by solid-state NMR and revealed that the lamellar gel-to-fluid phase transition occurs below 0 °C, reflecting the presence of elevated amounts of unsaturated fatty acid chains. Fluidity was higher than the plasma membrane, illustrating the dual action of Cholesterol (ordering) and PI lipids (disordering). The most striking result was the large magnetic field-induced membrane deformation allowing to determine the membrane bending elasticity, a property related to hydrodynamics of cells and organelles. Human Nuclear Lipid Membranes were at least two orders of magnitude more elastic than the classical plasma membrane suggesting a physical explanation for the formation of nuclear membrane invaginations.
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Affiliation(s)
- Régine Dazzoni
- Institute of Chemistry & Biology of Membranes & Nanoobjects, UMR5248, CNRS, Université Bordeaux, INP-Bordeaux, F-33600, Pessac, France.,Cell Biophysics Laboratory, Ikerbasque Basque Foundation for Science, Instituto Biofísika (CSIC, UPV/EHU) and Research Centre for Experimental Marine Biology and Biotechnology (PiE), University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Axelle Grélard
- Institute of Chemistry & Biology of Membranes & Nanoobjects, UMR5248, CNRS, Université Bordeaux, INP-Bordeaux, F-33600, Pessac, France
| | - Estelle Morvan
- Institut Européen de Chimie et Biologie, UMS3033, CNRS, Université Bordeaux, INSERM (US001), 2 rue Escarpit, Pessac, 33600, France
| | - Anthony Bouter
- Institute of Chemistry & Biology of Membranes & Nanoobjects, UMR5248, CNRS, Université Bordeaux, INP-Bordeaux, F-33600, Pessac, France
| | - Christopher J Applebee
- Cell Biophysics Laboratory, Ikerbasque Basque Foundation for Science, Instituto Biofísika (CSIC, UPV/EHU) and Research Centre for Experimental Marine Biology and Biotechnology (PiE), University of the Basque Country (UPV/EHU), Leioa, Spain.,Cell Biophysics Laboratory, Centre for Therapeutic Innovation & Department of Pharmacy and Pharmacology, & Department of Physics, University of Bath, Bath, United Kingdom
| | - Antoine Loquet
- Institute of Chemistry & Biology of Membranes & Nanoobjects, UMR5248, CNRS, Université Bordeaux, INP-Bordeaux, F-33600, Pessac, France
| | - Banafshé Larijani
- Cell Biophysics Laboratory, Ikerbasque Basque Foundation for Science, Instituto Biofísika (CSIC, UPV/EHU) and Research Centre for Experimental Marine Biology and Biotechnology (PiE), University of the Basque Country (UPV/EHU), Leioa, Spain. .,Cell Biophysics Laboratory, Centre for Therapeutic Innovation & Department of Pharmacy and Pharmacology, & Department of Physics, University of Bath, Bath, United Kingdom.
| | - Erick J Dufourc
- Institute of Chemistry & Biology of Membranes & Nanoobjects, UMR5248, CNRS, Université Bordeaux, INP-Bordeaux, F-33600, Pessac, France.
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33
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Silva Pereira S, Heap J, Jones AR, Jackson AP. VAPPER: High-throughput variant antigen profiling in African trypanosomes of livestock. Gigascience 2020; 8:5556439. [PMID: 31494667 PMCID: PMC6735694 DOI: 10.1093/gigascience/giz091] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 06/17/2019] [Accepted: 07/09/2019] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Analysing variant antigen gene families on a population scale is a difficult challenge for conventional methods of read mapping and variant calling due to the great variability in sequence, copy number, and genomic loci. In African trypanosomes, hemoparasites of humans and animals, this is complicated by variant antigen repertoires containing hundreds of genes subject to various degrees of sequence recombination. FINDINGS We introduce Variant Antigen Profiler (VAPPER), a tool that allows automated analysis of the variant surface glycoprotein repertoires of the most prevalent livestock African trypanosomes. VAPPER produces variant antigen profiles for any isolate of the veterinary pathogens Trypanosoma congolense and Trypanosoma vivax from genomic and transcriptomic sequencing data and delivers publication-ready figures that show how the queried isolate compares with a database of existing strains. VAPPER is implemented in Python. It can be installed to a local Galaxy instance from the ToolShed (https://toolshed.g2.bx.psu.edu/) or locally on a Linux platform via the command line (https://github.com/PGB-LIV/VAPPER). The documentation, requirements, examples, and test data are provided in the Github repository. CONCLUSION By establishing two different, yet comparable methodologies, our approach is the first to allow large-scale analysis of African trypanosome variant antigens, large multi-copy gene families that are otherwise refractory to high-throughput analysis.
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Affiliation(s)
- Sara Silva Pereira
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool Science Park Ic2, 146 Brownlow Hill, Liverpool L3 5RF, UK
- Correspondence addres. Sara Silva Pereira, E-mail:
| | - John Heap
- Computational Biology Facility, University of Liverpool, Liverpool L69 7ZB, UK
| | - Andrew R Jones
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Andrew P Jackson
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool Science Park Ic2, 146 Brownlow Hill, Liverpool L3 5RF, UK
- Correspondence addres. Andrew P. Jackson, E-mail:
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34
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Trypanosoma brucei gambiense Group 2: The Unusual Suspect. Trends Parasitol 2019; 35:983-995. [DOI: 10.1016/j.pt.2019.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/31/2019] [Accepted: 09/08/2019] [Indexed: 11/23/2022]
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35
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Onyilagha C, Uzonna JE. Host Immune Responses and Immune Evasion Strategies in African Trypanosomiasis. Front Immunol 2019; 10:2738. [PMID: 31824512 PMCID: PMC6883386 DOI: 10.3389/fimmu.2019.02738] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/08/2019] [Indexed: 01/11/2023] Open
Abstract
Parasites, including African trypanosomes, utilize several immune evasion strategies to ensure their survival and completion of their life cycles within their hosts. The defense factors activated by the host to resolve inflammation and restore homeostasis during active infection could be exploited and/or manipulated by the parasites in an attempt to ensure their survival and propagation. This often results in the parasites evading the host immune responses as well as the host sustaining some self-inflicted collateral tissue damage. During infection with African trypanosomes, both effector and suppressor cells are activated and the balance between these opposing arms of immunity determines susceptibility or resistance of infected host to the parasites. Immune evasion by the parasites could be directly related to parasite factors, (e.g., antigenic variation), or indirectly through the induction of suppressor cells following infection. Several cell types, including suppressive macrophages, myeloid-derived suppressor cells (MDSCs), and regulatory T cells have been shown to contribute to immunosuppression in African trypanosomiasis. In this review, we discuss the key factors that contribute to immunity and immunosuppression during T. congolense infection, and how these factors could aid immune evasion by African trypanosomes. Understanding the regulatory mechanisms that influence resistance and/or susceptibility during African trypanosomiasis could be beneficial in designing effective vaccination and therapeutic strategies against the disease.
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Affiliation(s)
- Chukwunonso Onyilagha
- Department of Immunology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - Jude Ezeh Uzonna
- Department of Immunology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada.,Department of Medical Microbiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
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36
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Abstract
Genetic variants in the APOL1 gene, found only in individuals of recent African ancestry, greatly increase risk of multiple types of kidney disease. These APOL1 kidney risk alleles are a rare example of genetic variants that are common but also have a powerful effect on disease susceptibility. These alleles rose to high frequency in sub-Saharan Africa because they conferred protection against pathogenic trypanosomes that cause African sleeping sickness. We consider the genetic evidence supporting the association between APOL1 and kidney disease across the range of clinical phenotypes in the APOL1 nephropathy spectrum. We then explore the origins of the APOL1 risk variants and evolutionary struggle between humans and trypanosomes at both the molecular and population genetic level. Finally, we survey the rapidly growing literature investigating APOL1 biology as elucidated from experiments in cell-based systems, cell-free systems, mouse and lower organism models of disease, and through illuminating natural experiments in humans.
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Affiliation(s)
- David J Friedman
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA; ,
| | - Martin R Pollak
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA; ,
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37
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Shah SS, Lannon H, Dias L, Zhang JY, Alper SL, Pollak MR, Friedman DJ. APOL1 Kidney Risk Variants Induce Cell Death via Mitochondrial Translocation and Opening of the Mitochondrial Permeability Transition Pore. J Am Soc Nephrol 2019; 30:2355-2368. [PMID: 31558683 DOI: 10.1681/asn.2019020114] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 08/15/2019] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Genetic Variants in Apolipoprotein L1 (APOL1) are associated with large increases in CKD rates among African Americans. Experiments in cell and mouse models suggest that these risk-related polymorphisms are toxic gain-of-function variants that cause kidney dysfunction, following a recessive mode of inheritance. Recent data in trypanosomes and in human cells indicate that such variants may cause toxicity through their effects on mitochondria. METHODS To examine the molecular mechanisms underlying APOL1 risk variant-induced mitochondrial dysfunction, we generated tetracycline-inducible HEK293 T-REx cells stably expressing the APOL1 nonrisk G0 variant or APOL1 risk variants. Using these cells, we mapped the molecular pathway from mitochondrial import of APOL1 protein to APOL1-induced cell death with small interfering RNA knockdowns, pharmacologic inhibitors, blue native PAGE, mass spectrometry, and assessment of mitochondrial permeability transition pore function. RESULTS We found that the APOL1 G0 and risk variant proteins shared the same import pathway into the mitochondrial matrix. Once inside, G0 remained monomeric, whereas risk variant proteins were prone to forming higher-order oligomers. Both nonrisk G0 and risk variant proteins bound components of the mitochondrial permeability transition pore, but only risk variant proteins activated pore opening. Blocking mitochondrial import of APOL1 risk variants largely eliminated oligomer formation and also rescued toxicity. CONCLUSIONS Our study illuminates important differences in the molecular behavior of APOL1 nonrisk and risk variants, and our observations suggest a mechanism that may explain the very different functional effects of these variants, despite the lack of consistently observed differences in trafficking patterns, intracellular localization, or binding partners. Variant-dependent differences in oligomerization pattern may underlie APOL1's recessive, gain-of-function biology.
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Affiliation(s)
- Shrijal S Shah
- Renal Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Herbert Lannon
- Renal Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Leny Dias
- Renal Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Jia-Yue Zhang
- Renal Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Seth L Alper
- Renal Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Martin R Pollak
- Renal Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - David J Friedman
- Renal Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
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Akazue PI, Ebiloma GU, Ajibola O, Isaac C, Onyekwelu K, Ezeh CO, Eze AA. Sustainable Elimination (Zero Cases) of Sleeping Sickness: How Far Are We from Achieving This Goal? Pathogens 2019; 8:E135. [PMID: 31470522 PMCID: PMC6789789 DOI: 10.3390/pathogens8030135] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 08/26/2019] [Accepted: 08/26/2019] [Indexed: 01/02/2023] Open
Abstract
The recent massive reduction in the numbers of fresh Human African Trypanosomiasis (HAT) infection has presented an opportunity for the global elimination of this disease. To prevent a possible resurgence, as was the case after the reduced transmission of the 1960s, surveillance needs to be sustained and the necessary tools for detection and treatment of cases need to be made available at the points of care. In this review, we examine the available resources and make recommendations for improvement to ensure the sustenance of the already achieved gains to keep the trend moving towards elimination.
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Affiliation(s)
- Pearl Ihuoma Akazue
- Department of Biochemistry, Faculty of Life Sciences, University of Benin, Benin City 300283, Nigeria
| | - Godwin U Ebiloma
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Olumide Ajibola
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul PO Box 273, The Gambia
| | - Clement Isaac
- Department of Zoology, Faculty of Life Sciences, Ambrose Alli University, Ekpoma 310101, Nigeria
| | - Kenechukwu Onyekwelu
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, University of Nigeria, Enugu Campus, Enugu 410001, Nigeria
| | - Charles O Ezeh
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, University of Nigeria, Enugu Campus, Enugu 410001, Nigeria
| | - Anthonius Anayochukwu Eze
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, University of Nigeria, Enugu Campus, Enugu 410001, Nigeria.
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Identification of Trypanosoma brucei gambiense in naturally infected dogs in Nigeria. Parasit Vectors 2019; 12:420. [PMID: 31455430 PMCID: PMC6712790 DOI: 10.1186/s13071-019-3680-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/21/2019] [Indexed: 11/11/2022] Open
Abstract
Background Animal trypanosomosis is endemic in Nigeria, while the human disease caused by Trypanosoma brucei gambiense is rarely reported nowadays after efforts to bring it under control in the 20th century. The University of Nigeria Veterinary Teaching Hospital (UNVTH) is a reference centre located within the Nsukka area and serves Enugu and neighboring states, Benue, Kogi, Anambra and Delta. Among dogs presented to the UNVTH with canine trypanosomosis, T. brucei is frequently reported as the causative agent. However, this is by morphological identification under the microscope, which does not allow distinction of human-infective (T. b. gambiense) and non-human-infective (T. b. brucei) subspecies. Here, we used subspecies-specific PCR tests to distinguish T. b. gambiense and T. b. brucei. Methods Blood samples were collected on FTA cards from 19 dogs presenting with clinical signs of trypanosomosis at the UNVTH from January 2017 to December 2018. All dogs had a patent parasitaemia. DNA was extracted from the FTA cards using Chelex 100 resin and used as template for PCR. Results All infections were initially identified as belonging to subgenus Trypanozoon using a generic PCR test based on the internal transcribed spacer 1 (ITS1) of the ribosomal RNA locus and a PCR test specific for the 177 bp satellite DNA of subgenus Trypanozoon. None of the samples were positive using a specific PCR test for T. evansi Type A kinetoplast DNA minicircles. Further PCR tests specific for T. b. gambiense based on the TgsGP and AnTat 11.17 genes revealed that two of the dogs harboured T. b. gambiense. In addition to trypanosomes of subgenus Trypanozoon, T. congolense savannah was identified in one dog using a species-specific PCR test for this taxon. Conclusions Nineteen dogs presenting with canine African trypanosomosis at UNVTH were infected with trypanosomes of the T. brucei group and in two cases the trypanosomes were further identified to subspecies T. b. gambiense using specific PCR tests. Thus T. b. gambiense is one of the parasites responsible for canine African trypanosomosis in the Nsukka area of Nigeria and represents a serious danger to human health.
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Zhang SY, Jouanguy E, Zhang Q, Abel L, Puel A, Casanova JL. Human inborn errors of immunity to infection affecting cells other than leukocytes: from the immune system to the whole organism. Curr Opin Immunol 2019; 59:88-100. [PMID: 31121434 PMCID: PMC6774828 DOI: 10.1016/j.coi.2019.03.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 03/29/2019] [Indexed: 01/19/2023]
Abstract
Studies of vertebrate immunity have traditionally focused on professional cells, including circulating and tissue-resident leukocytes. Evidence that non-professional cells are also intrinsically essential (i.e. not via their effect on leukocytes) for protective immunity in natural conditions of infection has emerged from three lines of research in human genetics. First, studies of Mendelian resistance to infection have revealed an essential role of DARC-expressing erythrocytes in protection against Plasmodium vivax infection, and an essential role of FUT2-expressing intestinal epithelial cells for protection against norovirus and rotavirus infections. Second, studies of inborn errors of non-hematopoietic cell-extrinsic immunity have shown that APOL1 and complement cascade components secreted by hepatocytes are essential for protective immunity to trypanosome and pyogenic bacteria, respectively. Third, studies of inborn errors of non-hematopoietic cell-intrinsic immunity have suggested that keratinocytes, pulmonary epithelial cells, and cortical neurons are essential for tissue-specific protective immunity to human papillomaviruses, influenza virus, and herpes simplex virus, respectively. Various other types of genetic resistance or predisposition to infection in human populations are not readily explained by inborn variants of genes operating in leukocytes and may, therefore, involve defects in other cells. The probing of this unchartered territory by human genetics is reshaping immunology, by scaling immunity to infection up from the immune system to the whole organism.
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Affiliation(s)
- Shen-Ying Zhang
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR 1163, Necker Hospital for Sick Children, 75015 Paris, France; Paris Descartes University, Imagine Institute, 75015 Paris, France
| | - Emmanuelle Jouanguy
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR 1163, Necker Hospital for Sick Children, 75015 Paris, France; Paris Descartes University, Imagine Institute, 75015 Paris, France
| | - Qian Zhang
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA
| | - Laurent Abel
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR 1163, Necker Hospital for Sick Children, 75015 Paris, France; Paris Descartes University, Imagine Institute, 75015 Paris, France
| | - Anne Puel
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR 1163, Necker Hospital for Sick Children, 75015 Paris, France; Paris Descartes University, Imagine Institute, 75015 Paris, France
| | - Jean-Laurent Casanova
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR 1163, Necker Hospital for Sick Children, 75015 Paris, France; Paris Descartes University, Imagine Institute, 75015 Paris, France; Pediatric Hematology-Immunology Unit, Necker Hospital for Sick Children, 75015 Paris, France; Howard Hughes Medical Institute, New York, NY 10065, USA.
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MacGregor P, Gonzalez-Munoz AL, Jobe F, Taylor MC, Rust S, Sandercock AM, Macleod OJS, Van Bocxlaer K, Francisco AF, D’Hooge F, Tiberghien A, Barry CS, Howard P, Higgins MK, Vaughan TJ, Minter R, Carrington M. A single dose of antibody-drug conjugate cures a stage 1 model of African trypanosomiasis. PLoS Negl Trop Dis 2019; 13:e0007373. [PMID: 31120889 PMCID: PMC6532856 DOI: 10.1371/journal.pntd.0007373] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/09/2019] [Indexed: 02/02/2023] Open
Abstract
Infections of humans and livestock with African trypanosomes are treated with drugs introduced decades ago that are not always fully effective and often have severe side effects. Here, the trypanosome haptoglobin-haemoglobin receptor (HpHbR) has been exploited as a route of uptake for an antibody-drug conjugate (ADC) that is completely effective against Trypanosoma brucei in the standard mouse model of infection. Recombinant human anti-HpHbR monoclonal antibodies were isolated and shown to be internalised in a receptor-dependent manner. Antibodies were conjugated to a pyrrolobenzodiazepine (PBD) toxin and killed T. brucei in vitro at picomolar concentrations. A single therapeutic dose (0.25 mg/kg) of a HpHbR antibody-PBD conjugate completely cured a T. brucei mouse infection within 2 days with no re-emergence of infection over a subsequent time course of 77 days. These experiments provide a demonstration of how ADCs can be exploited to treat protozoal diseases that desperately require new therapeutics.
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Affiliation(s)
- Paula MacGregor
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Fatoumatta Jobe
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | - Martin C. Taylor
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Steven Rust
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | - Alan M. Sandercock
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | | | | | | | | | | | | | | | - Matthew K. Higgins
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Tristan J. Vaughan
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | - Ralph Minter
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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Cayla M, Rojas F, Silvester E, Venter F, Matthews KR. African trypanosomes. Parasit Vectors 2019; 12:190. [PMID: 31036044 PMCID: PMC6489224 DOI: 10.1186/s13071-019-3355-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/26/2019] [Indexed: 12/15/2022] Open
Abstract
African trypanosomes cause human African trypanosomiasis and animal African trypanosomiasis. They are transmitted by tsetse flies in sub-Saharan Africa. Although most famous for their mechanisms of immune evasion by antigenic variation, there have been recent important studies that illuminate important aspects of the biology of these parasites both in their mammalian host and during passage through their tsetse fly vector. This Primer overviews current research themes focused on these parasites and discusses how these biological insights and the development of new technologies to interrogate gene function are being used in the search for new approaches to control the parasite. The new insights into the biology of trypanosomes in their host and vector highlight that we are in a ‘golden age’ of discovery for these fascinating parasites.
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Affiliation(s)
- Mathieu Cayla
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Federico Rojas
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Eleanor Silvester
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Frank Venter
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
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43
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Balancing the genetic risk of APOL1 kidney disease variants. Nephrol Ther 2019; 15 Suppl 1:S79-S84. [PMID: 30981400 DOI: 10.1016/j.nephro.2019.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/04/2019] [Indexed: 01/03/2023]
Abstract
African-Americans exhibit an excess risk for chronic and end-stage kidney disease compared to the non-African populations. Two APOL1 genetic variants were shown to account for the majority of this racial disparity in glomerulopathies and other non-diabetic kidney disease. The high-risk genotype has only been reported in populations with recent African ancestry (14 % in African-Americans and up to more than 30 % in West Africa). In less than 10 years, the community has accumulated extensive knowledge on APOL1 and its genetic variants, from their positive selection for resistance against African trypanosomes to potential molecular mechanisms of podocyte injury. Finally, APOL1 associations with kidney transplantation outcomes and with postdonation end-stage kidney disease in living donors have paved the way for a personalized medicine implementation of APOL1 genotyping.
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Leeder WM, Giehler F, Joswig J, Göringer HU. Bioinspired Design of Lysolytic Triterpenoid-Peptide Conjugates that Kill African Trypanosomes. Chembiochem 2019; 20:1251-1255. [PMID: 30609206 DOI: 10.1002/cbic.201800674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/19/2018] [Indexed: 11/07/2022]
Abstract
Humans have evolved a natural immunity against Trypanosoma brucei infections, which is executed by two serum (lipo)protein complexes known as trypanolytic factors (TLF). The active TLF ingredient is the primate-specific apolipoprotein L1 (APOL1). The protein has a pore-forming activity that kills parasites by lysosomal and mitochondrial membrane fenestration. Of the many trypanosome subspecies, only two are able to counteract the activity of APOL1; this illustrates its evolutionarily optimized design and trypanocidal potency. Herein, we ask whether a synthetic (syn) TLF can be synthesized by using the design principles of the natural TLF complexes but with different chemical building blocks. We demonstrate the stepwise development of triterpenoid-peptide conjugates, in which the triterpenoids act as a cell-binding, uptake and lysosomal-transport modules and the synthetic peptide GALA acts as a pH-sensitive, pore-forming lysolytic toxin. As designed, the conjugate kills infective-stage African trypanosomes through lysosomal lysis thus demonstrating a proof-of-principle for the bioinspired, forward-design of a synTLF.
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Affiliation(s)
- W-Matthias Leeder
- Molecular Genetics, Darmstadt University of Technology, Schnittspahnstrasse 10, 64287, Darmstadt, Germany
| | - Fabian Giehler
- Molecular Genetics, Darmstadt University of Technology, Schnittspahnstrasse 10, 64287, Darmstadt, Germany.,Present address: Helmholtz Zentrum München für Gesundheit und Umwelt (GmbH), Research Unit Gene Vectors Munich (Germany) and, German Center for Infection Research (DZIF), Partner Site Munich, Marchionistrasse 25, 81377, Munich, Germany
| | - Juliane Joswig
- Molecular Genetics, Darmstadt University of Technology, Schnittspahnstrasse 10, 64287, Darmstadt, Germany
| | - H Ulrich Göringer
- Molecular Genetics, Darmstadt University of Technology, Schnittspahnstrasse 10, 64287, Darmstadt, Germany
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Abstract
PURPOSE OF REVIEW Consistent associations between variants of the apolipoprotein L1 (APOL1) gene and nondiabetic nephropathy have been reported in individuals of African descent. Donor APOL1 genotype has also been linked to shorter renal allograft survival. This review summarizes recent advances in understanding the biology of APOL1 and their implications to kidney donors and recipients. RECENT FINDINGS Approximately 12-13% of African Americans have two renal risk APOL1 variants but most do not develop kidney disease. Although the exact mechanisms linking APOL1 genotype to renal injury are not known, evidence from new experimental models suggests APOL1 mutations may accelerate age-related podocyte loss. Recent epidemiological studies indicate potential kidney donors with high-risk APOL1 variants have increased risk of chronic kidney disease (CKD) and donors with high-risk APOL1 variants have lower estimated glomerular filtration rate (eGFR) than those with low-risk variants. The absolute risk of CKD in otherwise healthy individuals carrying high-risk APOL1 mutations is likely low. SUMMARY Recent studies suggest high-risk APOL1 mutations in kidney donors are linked to shorter graft survival and lower postdonation eGFR. APOL1 genotyping may be used as one of many factors that contribute to assessment of the risk of postdonation CKD and informed decision making.
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46
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Lechuga GC, Pereira MCS, Bourguignon SC. Heme metabolism as a therapeutic target against protozoan parasites. J Drug Target 2018; 27:767-779. [DOI: 10.1080/1061186x.2018.1536982] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Guilherme Curty Lechuga
- Laboratório de Interação celular e molecular, Departamento de Biologia Celular e Molecular, Universidade Federal Fluminense, Rua Outeiro São João Batista, Rio de Janeiro, Brazil
- Fundação Oswaldo Cruz, Laboratório de Ultraestrutura Celular, Rio de Janeiro, Brazil
- Instituto de Biologia, Programa de Pós-graduação em Ciências e Biotecnologia (PPBI), Universidade Federal Fluminense, Rio de Janeiro, Brazil
| | - Mirian C. S. Pereira
- Fundação Oswaldo Cruz, Laboratório de Ultraestrutura Celular, Rio de Janeiro, Brazil
| | - Saulo C. Bourguignon
- Laboratório de Interação celular e molecular, Departamento de Biologia Celular e Molecular, Universidade Federal Fluminense, Rua Outeiro São João Batista, Rio de Janeiro, Brazil
- Instituto de Biologia, Programa de Pós-graduação em Ciências e Biotecnologia (PPBI), Universidade Federal Fluminense, Rio de Janeiro, Brazil
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Mozzi A, Forni D, Clerici M, Cagliani R, Sironi M. The Diversity of Mammalian Hemoproteins and Microbial Heme Scavengers Is Shaped by an Arms Race for Iron Piracy. Front Immunol 2018; 9:2086. [PMID: 30271410 PMCID: PMC6142043 DOI: 10.3389/fimmu.2018.02086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/23/2018] [Indexed: 11/13/2022] Open
Abstract
Iron is an essential micronutrient for most living species. In mammals, hemoglobin (Hb) stores more than two thirds of the body's iron content. In the bloodstream, haptoglobin (Hp) and hemopexin (Hpx) sequester free Hb or heme. Pathogenic microorganisms usually acquire iron from their hosts and have evolved complex systems of iron piracy to circumvent nutritional immunity. Herein, we performed an evolutionary analysis of genes coding for mammalian heme-binding proteins and heme-scavengers in pathogen species. The underlying hypothesis is that these molecules are engaged in a molecular arms race. We show that positive selection drove the evolution of mammalian Hb and Hpx. Positively selected sites in Hb are located at the interaction surface with Neisseria meningitidis heme scavenger HpuA and with Staphylococcus aureus iron-regulated surface determinant B (IsdB). In turn, positively selected sites in HpuA and IsdB are located in the flexible protein regions that contact Hb. A residue in Hb (S45H) was also selected on the Caprinae branch. This site stabilizes the interaction with Trypanosoma brucei hemoglobin-haptoglobin (HbHp) receptor (TbHpHbR), a molecule that also mediates trypanosome lytic factor (TLF) entry. In TbHpHbR, positive selection drove the evolution of a variant (L210S) which allows evasion from TLF but reduces affinity for HbHp. Finally, selected sites in Hpx are located at the interaction surface with the Haemophilus influenzae hemophore HxuA, which in turn displays fast evolving sites at the Hpx-binding interface. These results shed light into host-pathogens conflicts and establish the importance of nutritional immunity as an evolutionary force.
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Affiliation(s)
- Alessandra Mozzi
- Scientific Institute, IRCCS E. Medea, Bioinformatics, Lecco, Italy
| | - Diego Forni
- Scientific Institute, IRCCS E. Medea, Bioinformatics, Lecco, Italy
| | - Mario Clerici
- Department of Physiopathology and Transplantation, University of Milan, Milan, Italy.,Don C. Gnocchi Foundation ONLUS, IRCCS, Milan, Italy
| | - Rachele Cagliani
- Scientific Institute, IRCCS E. Medea, Bioinformatics, Lecco, Italy
| | - Manuela Sironi
- Scientific Institute, IRCCS E. Medea, Bioinformatics, Lecco, Italy
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Radwanska M, Vereecke N, Deleeuw V, Pinto J, Magez S. Salivarian Trypanosomosis: A Review of Parasites Involved, Their Global Distribution and Their Interaction With the Innate and Adaptive Mammalian Host Immune System. Front Immunol 2018; 9:2253. [PMID: 30333827 PMCID: PMC6175991 DOI: 10.3389/fimmu.2018.02253] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/11/2018] [Indexed: 01/27/2023] Open
Abstract
Salivarian trypanosomes are single cell extracellular parasites that cause infections in a wide range of hosts. Most pathogenic infections worldwide are caused by one of four major species of trypanosomes including (i) Trypanosoma brucei and the human infective subspecies T. b. gambiense and T. b. rhodesiense, (ii) Trypanosoma evansi and T. equiperdum, (iii) Trypanosoma congolense and (iv) Trypanosoma vivax. Infections with these parasites are marked by excessive immune dysfunction and immunopathology, both related to prolonged inflammatory host immune responses. Here we review the classification and global distribution of these parasites, highlight the adaptation of human infective trypanosomes that allow them to survive innate defense molecules unique to man, gorilla, and baboon serum and refer to the discovery of sexual reproduction of trypanosomes in the tsetse vector. With respect to the immunology of mammalian host-parasite interactions, the review highlights recent findings with respect to the B cell destruction capacity of trypanosomes and the role of T cells in the governance of infection control. Understanding infection-associated dysfunction and regulation of both these immune compartments is crucial to explain the continued failures of anti-trypanosome vaccine developments as well as the lack of any field-applicable vaccine based anti-trypanosomosis intervention strategy. Finally, the link between infection-associated inflammation and trypanosomosis induced anemia is covered in the context of both livestock and human infections.
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Affiliation(s)
- Magdalena Radwanska
- Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea
| | - Nick Vereecke
- Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea.,Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Violette Deleeuw
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Joar Pinto
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Stefan Magez
- Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea.,Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
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49
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Siqueira-Neto JL, Debnath A, McCall LI, Bernatchez JA, Ndao M, Reed SL, Rosenthal PJ. Cysteine proteases in protozoan parasites. PLoS Negl Trop Dis 2018; 12:e0006512. [PMID: 30138453 PMCID: PMC6107107 DOI: 10.1371/journal.pntd.0006512] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cysteine proteases (CPs) play key roles in the pathogenesis of protozoan parasites, including cell/tissue penetration, hydrolysis of host or parasite proteins, autophagy, and evasion or modulation of the host immune response, making them attractive chemotherapeutic and vaccine targets. This review highlights current knowledge on clan CA cysteine proteases, the best-characterized group of cysteine proteases, from 7 protozoan organisms causing human diseases with significant impact: Entamoeba histolytica, Leishmania species (sp.), Trypanosoma brucei, T. cruzi, Cryptosporidium sp., Plasmodium sp., and Toxoplasma gondii. Clan CA proteases from three organisms (T. brucei, T. cruzi, and Plasmodium sp.) are well characterized as druggable targets based on in vitro and in vivo models. A number of candidate inhibitors are under development. CPs from these organisms and from other protozoan parasites should be further characterized to improve our understanding of their biological functions and identify novel targets for chemotherapy.
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Affiliation(s)
- Jair L. Siqueira-Neto
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
| | - Anjan Debnath
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Laura-Isobel McCall
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Jean A. Bernatchez
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Momar Ndao
- National Reference Centre for Parasitology, The Research Institute of the McGill University Health Center, Montreal, Canada
- Program in Infectious Diseases and Immunity in Global Health, The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Sharon L. Reed
- Departments of Pathology and Medicine, University of California San Diego School of Medicine, La Jolla, California, United States of America
| | - Philip J. Rosenthal
- Department of Medicine, University of California, San Francisco, San Francisco, California, United States of America
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Silva Pereira S, Casas-Sánchez A, Haines LR, Ogugo M, Absolomon K, Sanders M, Kemp S, Acosta-Serrano Á, Noyes H, Berriman M, Jackson AP. Variant antigen repertoires in Trypanosoma congolense populations and experimental infections can be profiled from deep sequence data using universal protein motifs. Genome Res 2018; 28:1383-1394. [PMID: 30006414 PMCID: PMC6120623 DOI: 10.1101/gr.234146.118] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 07/12/2018] [Indexed: 11/25/2022]
Abstract
African trypanosomes are vector-borne hemoparasites of humans and animals. In the mammal, parasites evade the immune response through antigenic variation. Periodic switching of the variant surface glycoprotein (VSG) coat covering their cell surface allows sequential expansion of serologically distinct parasite clones. Trypanosome genomes contain many hundreds of VSG genes, subject to rapid changes in nucleotide sequence, copy number, and chromosomal position. Thus, analyzing, or even quantifying, VSG diversity over space and time presents an enormous challenge to conventional techniques. Indeed, previous population genomic studies have overlooked this vital aspect of pathogen biology for lack of analytical tools. Here we present a method for analyzing population-scale VSG diversity in Trypanosoma congolense from deep sequencing data. Previously, we suggested that T. congolense VSGs segregate into defined “phylotypes” that do not recombine. In our data set comprising 41 T. congolense genome sequences from across Africa, these phylotypes are universal and exhaustive. Screening sequence contigs with diagnostic protein motifs accurately quantifies relative phylotype frequencies, providing a metric of VSG diversity, called the “variant antigen profile.” We applied our metric to VSG expression in the tsetse fly, showing that certain, rare VSG phylotypes may be preferentially expressed in infective, metacyclic-stage parasites. Hence, variant antigen profiling accurately and rapidly determines the T. congolense VSG gene and transcript repertoire from sequence data, without need for manual curation or highly contiguous sequences. It offers a tractable approach to measuring VSG diversity across strains and during infections, which is imperative to understanding the host–parasite interaction at population and individual scales.
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Affiliation(s)
- Sara Silva Pereira
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
| | - Aitor Casas-Sánchez
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Lee R Haines
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Moses Ogugo
- International Livestock Research Institute, Nairobi 00100, Kenya
| | - Kihara Absolomon
- International Livestock Research Institute, Nairobi 00100, Kenya
| | - Mandy Sanders
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, United Kingdom
| | - Steve Kemp
- International Livestock Research Institute, Nairobi 00100, Kenya
| | - Álvaro Acosta-Serrano
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom.,Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Harry Noyes
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Matthew Berriman
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, United Kingdom
| | - Andrew P Jackson
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
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