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Al-Abodi1 HR. Assessment of the variability of the hematological and biochemical parameters in giardiasis patients. BIONATURA 2023. [DOI: 10.21931/rb/2023.08.01.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
Abstract
Giardiasis is one of the essential parasitic intestinal diseases, widespread in many countries. Therefore, it has occupied a necessary place among public health priorities. Children are the most vulnerable and affected by this disease. The current study evaluated the physiological and biochemical hematological changes of affected children under 12 in Al-Diwaniyah Governorate, middle of Iraq. Hemoglobin levels and the volume of compacted blood cells decreased in patients (10.4g/dL and 33.7%, respectively). In contrast, the number of white blood cells increased to (7700 cells/mm3), indicating substantial differences between the hematological parameters and the control group's results.
Regarding the number of cells, the investigation revealed a reduction of (64.1%) in the total number of cells. In contrast to the control data, the results showed a rise in the number of lymphocytes, eosinophils, and basophils, with respective percentages of (%28.4), (%0.6), and (%0.4). Monocytes were unaffected. The findings of the biochemical parameters demonstrated that the concentrations of liver enzymes varied significantly, with the attention of GPT and GOT increasing to(18.7) and (19.9)international units/liter. Additionally, lipid level variations, including lower cholesterol and triglycerides, were discovered. Compared to the control groups, it reached (163.8) and (122.5) mg/DL.
Keywords: Giardiasis, blood parameters, GOT, Giardia lamblia.
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Peirasmaki D, Ma'ayeh SY, Xu F, Ferella M, Campos S, Liu J, Svärd SG. High Cysteine Membrane Proteins (HCMPs) Are Up-Regulated During Giardia-Host Cell Interactions. Front Genet 2020; 11:913. [PMID: 33014015 PMCID: PMC7461913 DOI: 10.3389/fgene.2020.00913] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022] Open
Abstract
Giardia intestinalis colonizes the upper small intestine of humans and animals, causing the diarrheal disease giardiasis. This unicellular eukaryotic parasite is not invasive but it attaches to the surface of small intestinal epithelial cells (IECs), disrupting the epithelial barrier. Here, we used an in vitro model of the parasite’s interaction with host IECs (differentiated Caco-2 cells) and RNA sequencing (RNAseq) to identify differentially expressed genes (DEGs) in Giardia, which might relate to the establishment of infection and disease induction. Giardia trophozoites interacted with differentiated Caco-2 cells for 1.5, 3, and 4.5 h and at each time point, 61, 89, and 148 parasite genes were up-regulated more than twofold, whereas 209, 265, and 313 parasite genes were down-regulated more than twofold. The most abundant DEGs encode hypothetical proteins and members of the High Cysteine Membrane Protein (HCMP) family. Among the up-regulated genes we also observed proteins associated with proteolysis, cellular redox balance, as well as lipid and nucleic acid metabolic pathways. In contrast, genes encoding kinases, regulators of the cell cycle and arginine metabolism and cytoskeletal proteins were down-regulated. Immunofluorescence imaging of selected, up-regulated HCMPs, using C-terminal HA-tagging, showed localization to the plasma membrane and peripheral vesicles (PVs). The expression of the HCMPs was affected by histone acetylation and free iron-levels. In fact, the latter was shown to regulate the expression of many putative giardial virulence factors in subsequent RNAseq experiments. We suggest that the plasma membrane localized and differentially expressed HCMPs play important roles during Giardia-host cell interactions.
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Affiliation(s)
- Dimitra Peirasmaki
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Showgy Y Ma'ayeh
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Feifei Xu
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Marcela Ferella
- Eukaryotic Single Cell Genomics Platform, Karolinska Institute, Science for Life Laboratory (SciLifeLab), Solna, Sweden
| | - Sara Campos
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Jingyi Liu
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Staffan G Svärd
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.,Science for Life Laboratory (SciLifeLab), Uppsala University, Uppsala, Sweden
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3
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Beri D, Yadav P, Devi HRN, Narayana C, Gadara D, Tatu U. Demonstration and Characterization of Cyst-Like Structures in the Life Cycle of Trichomonas vaginalis. Front Cell Infect Microbiol 2020; 9:430. [PMID: 32010634 PMCID: PMC6972724 DOI: 10.3389/fcimb.2019.00430] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 12/02/2019] [Indexed: 12/14/2022] Open
Abstract
Trichomonas vaginalis is the parasitic protozoan residing in human urogenital tract causing trichomoniasis, which is the leading non-viral sexually transmitted disease. It has cosmopolitan distribution throughout the globe and affects both men and women. Lifecycle of the parasite has been traditionally described as consisting of motile and symptom-causing trophozoites. Chemical and temperature perturbations in trophozoites have been shown to aid conversion to pseudocysts, which is poorly investigated. In the current study, we show the formation of viable cyst-like structures (CLS) in stationary phase of T. vaginalis axenic culture. We used a fluorescent stain called calcofluor white, which specifically binds to chitin and cellulose-containing structures, to score for T. vaginalis CLS. Using flow cytometry, we demonstrated and quantitated the processes of encystation as well as excystation; thus, completing the parasite's lifecycle in vitro without any chemical/temperature alterations. Like cysts from other protozoan parasites such as Entamoeba histolytica and Giardia lamblia, T. vaginalis CLS appeared spherical, immotile, and resistant to osmotic lysis and detergent treatments. Ultrastructure of CLS demonstrated by Transmission Electron Microscopy showed a thick electron-dense deposition along its outer membrane. To probe the physiological role of CLS, we exposed parasites to vaginal pH and observed that trophozoites took this as a cue to convert to CLS. Further, upon co- culturing with cells of cervical origin, CLS rapidly excysted to form trophozoites which abrogated the cervical cell monolayer in a dose-dependent manner. To further corroborate the presence of two distinct forms in T. vaginalis, we performed two-dimensional gel electrophoresis and global, untargeted mass spectrometry to highlight differences in the proteome with trophozoites. Interestingly, CLS remained viable in chlorinated swimming pool water implicating the possibility of its role as environmentally resistant structures involved in non-sexual mode of parasite transmission. Finally, we showed that symptomatic human patient vaginal swabs had both T. vaginalis trophozoites and CLS; thus, highlighting its importance in clinical infections. Overall, our study highlights the plasticity of the pathogen and its rapid adaption when subjected to stressful environmental cues and suggests an important role of CLS in the parasite's life cycle, pathogenesis and transmission.
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Affiliation(s)
- Divya Beri
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Priya Yadav
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | | | - Chinmaya Narayana
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Darshak Gadara
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Utpal Tatu
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
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Emery-Corbin SJ, Grüttner J, Svärd S. Transcriptomic and proteomic analyses of Giardia intestinalis: Intestinal epithelial cell interactions. ADVANCES IN PARASITOLOGY 2019; 107:139-171. [PMID: 32122528 DOI: 10.1016/bs.apar.2019.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Giardia intestinalis is a unicellular protozoan parasite that infects the small intestines of humans and animals. Giardiasis, the disease caused by the parasite, occurs globally across socioeconomic boundaries but is mainly endemic in developing countries and particularly within young children, where pronounced effects manifests in a failure to thrive condition. The molecular pathogenesis of Giardia has been studied using in vitro models of human and rat intestinal epithelial cells (IECs) and parasites from the two major human genotypes or assemblages (A and B). High-quality, genome sequencing of representative isolates from assemblages A (WB) and B (GS) has enabled exploration of these host-parasite models using 'omics' technologies, allowing deep and quantitative analyses of global gene expression changes in IECs and parasites during their interactions, cross-talk and competition. These include a major up-regulation of immune-related genes in the IECs early after the start of interactions, as well as competition between host cells and parasites for nutrients like sugars, amino acids and lipids, which is also reflected in their secretome interactions. Unique parasite proteins dominate these interactions, with many major up-regulated genes being either hypothetical proteins or members of Giardia-specific gene families like the high-cysteine-rich membrane proteins (HCMPs), variable surface proteins (VSPs), alpha-giardins and cysteine proteases. Furthermore, these proteins also dominate in the secretomes, suggesting that they are important virulence factors in Giardia and crucial molecular effectors at the host-parasite interface.
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Affiliation(s)
- Samantha J Emery-Corbin
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia
| | - Jana Grüttner
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Staffan Svärd
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
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Tjondro HC, Loke I, Chatterjee S, Thaysen-Andersen M. Human protein paucimannosylation: cues from the eukaryotic kingdoms. Biol Rev Camb Philos Soc 2019; 94:2068-2100. [PMID: 31410980 DOI: 10.1111/brv.12548] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 07/10/2019] [Accepted: 07/17/2019] [Indexed: 12/11/2022]
Abstract
Paucimannosidic proteins (PMPs) are bioactive glycoproteins carrying truncated α- or β-mannosyl-terminating asparagine (N)-linked glycans widely reported across the eukaryotic domain. Our understanding of human PMPs remains limited, despite findings documenting their existence and association with human disease glycobiology. This review comprehensively surveys the structures, biosynthetic routes and functions of PMPs across the eukaryotic kingdoms with the aim of synthesising an improved understanding on the role of protein paucimannosylation in human health and diseases. Convincing biochemical, glycoanalytical and biological data detail a vast structural heterogeneity and fascinating tissue- and subcellular-specific expression of PMPs within invertebrates and plants, often comprising multi-α1,3/6-fucosylation and β1,2-xylosylation amongst other glycan modifications and non-glycan substitutions e.g. O-methylation. Vertebrates and protists express less-heterogeneous PMPs typically only comprising variable core fucosylation of bi- and trimannosylchitobiose core glycans. In particular, the Manα1,6Manβ1,4GlcNAc(α1,6Fuc)β1,4GlcNAcβAsn glycan (M2F) decorates various human neutrophil proteins reportedly displaying bioactivity and structural integrity demonstrating that they are not degradation products. Less-truncated paucimannosidic glycans (e.g. M3F) are characteristic glycosylation features of proteins expressed by human cancer and stem cells. Concertedly, these observations suggest the involvement of human PMPs in processes related to innate immunity, tumorigenesis and cellular differentiation. The absence of human PMPs in diverse bodily fluids studied under many (patho)physiological conditions suggests extravascular residence and points to localised functions of PMPs in peripheral tissues. Absence of PMPs in Fungi indicates that paucimannosylation is common, but not universally conserved, in eukaryotes. Relative to human PMPs, the expression of PMPs in plants, invertebrates and protists is more tissue-wide and constitutive yet, similar to their human counterparts, PMP expression remains regulated by the physiology of the producing organism and PMPs evidently serve essential functions in development, cell-cell communication and host-pathogen/symbiont interactions. In most PMP-producing organisms, including humans, the N-acetyl-β-hexosaminidase isoenzymes and linkage-specific α-mannosidases are glycoside hydrolases critical for generating PMPs via N-acetylglucosaminyltransferase I (GnT-I)-dependent and GnT-I-independent truncation pathways. However, the identity and structure of many species-specific PMPs in eukaryotes, their biosynthetic routes, strong tissue- and development-specific expression, and diverse functions are still elusive. Deep exploration of these PMP features involving, for example, the characterisation of endogenous PMP-recognising lectins across a variety of healthy and N-acetyl-β-hexosaminidase-deficient human tissue types and identification of microbial adhesins reactive to human PMPs, are amongst the many tasks required for enhanced insight into the glycobiology of human PMPs. In conclusion, the literature supports the notion that PMPs are significant, yet still heavily under-studied biomolecules in human glycobiology that serve essential functions and create structural heterogeneity not dissimilar to other human N-glycoprotein types. Human PMPs should therefore be recognised as bioactive glycoproteins that are distinctly different from the canonical N-glycoprotein classes and which warrant a more dedicated focus in glycobiological research.
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Affiliation(s)
- Harry C Tjondro
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - Ian Loke
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Sayantani Chatterjee
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - Morten Thaysen-Andersen
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
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Singer SM, Fink MY, Angelova VV. Recent insights into innate and adaptive immune responses to Giardia. ADVANCES IN PARASITOLOGY 2019; 106:171-208. [PMID: 31630758 DOI: 10.1016/bs.apar.2019.07.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Infection with Giardia produces a wide range of clinical outcomes. Acutely infected patients may have no overt symptoms or suffer from severe cramps, diarrhea, nausea and even urticaria. Recently, post-infectious irritable bowel syndrome and chronic fatigue syndrome have been identified as long-term sequelae of giardiasis. Frequently, recurrent and chronic Giardia infection is considered a major contributor to stunting in children from low and middle income countries. Perhaps the most unusual outcome of infection with Giardia is the apparent reduced risk of developing moderate-to-severe diarrhea due to other enteric infections which has been noted in several recent studies. The goal of understanding immune responses against Giardia is therefore to identify protective mechanisms which could become targets for vaccine development, but also to identify mechanisms whereby infections lead to these other diverse outcomes. Giardia induces a robust adaptive immune response in both humans and animals. It has been known for many years that there is production of large amounts of parasite-specific IgA following infection and that CD4+ T cell responses contribute to this IgA production and control of the infection. In the past decade, there have been advances in our understanding of the non-antibody effector mechanisms used by the host to fight Giardia infections, in particular the importance of the cytokine interleukin (IL)-17 in orchestrating these responses. There have also been major advances in understanding how the innate response to Giardia infection is initiated and how it contributes to the development of adaptive immunity. Finally, there here have been significant increases in our knowledge of how the resident microbial community influences the immune response and how these responses contribute to the development of some of the symptoms of giardiasis. In this article, we will focus on data generated in the last 10 years and how it has advanced our knowledge about this important parasitic disease.
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Affiliation(s)
- Steven M Singer
- Department of Biology, Georgetown University, Washington, DC, United States.
| | - Marc Y Fink
- Department of Biology, Georgetown University, Washington, DC, United States
| | - Vanessa V Angelova
- Department of Biology, Georgetown University, Washington, DC, United States
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7
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Obregón A, Flores MS, Rangel R, Arévalo K, Maldonado G, Quintero I, Galán L. Characterization of N-glycosylations in Entamoeba histolytica ubiquitin. Exp Parasitol 2019; 196:38-47. [DOI: 10.1016/j.exppara.2018.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 11/10/2018] [Accepted: 11/13/2018] [Indexed: 12/30/2022]
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Lactoferrin and lactoferricin endocytosis halt Giardia cell growth and prevent infective cyst production. Sci Rep 2018; 8:18020. [PMID: 30575774 PMCID: PMC6303297 DOI: 10.1038/s41598-018-36563-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 11/23/2018] [Indexed: 12/13/2022] Open
Abstract
Lactoferrin (LF) is an 80 KDa iron-binding glycoprotein that plays a significant role in the innate immune system and is considered to be an important microbicide molecule. It has been suggested to be effective in the treatment of giardiasis, an intestinal disease caused by the protozoan parasite G. lamblia. However, the molecular mechanisms by which LF exerts its effect on this parasite are unknown. Most of the microbicidal activity of human or bovine LF (hLF or bLF) has been associated with the N-terminal region of the mature LF - lactoferricin (LFcin). LFcin is produced by pepsin cleavage of the native protein in vitro and likely in vivo. In this work, we analyse the participation of the endocytic machinery of G. lamblia in the internalization of bLF and bLFcin and their effects on cell homeostasis. Our results show that, when bLF or bLFcin are internalized by receptor-mediated endocytosis, cell growth stops, and morphological changes are produced in the trophozoites, which ultimately will produce immature cysts. Our findings contribute to disclose the fine mechanism by which bLF and bLFcin may function as an antigiardial molecule and why they have therapeutic potential to eradicate giardiasis.
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9
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Ma’ayeh SY, Liu J, Peirasmaki D, Hörnaeus K, Bergström Lind S, Grabherr M, Bergquist J, Svärd SG. Characterization of the Giardia intestinalis secretome during interaction with human intestinal epithelial cells: The impact on host cells. PLoS Negl Trop Dis 2017; 11:e0006120. [PMID: 29228011 PMCID: PMC5739509 DOI: 10.1371/journal.pntd.0006120] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 12/21/2017] [Accepted: 11/17/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Giardia intestinalis is a non-invasive protozoan parasite that causes giardiasis in humans, the most common form of parasite-induced diarrhea. Disease mechanisms are not completely defined and very few virulence factors are known. METHODOLOGY To identify putative virulence factors and elucidate mechanistic pathways leading to disease, we have used proteomics to identify the major excretory-secretory products (ESPs) when Giardia trophozoites of WB and GS isolates (assemblages A and B, respectively) interact with intestinal epithelial cells (IECs) in vitro. FINDINGS The main parts of the IEC and parasite secretomes are constitutively released proteins, the majority of which are associated with metabolism but several proteins are released in response to their interaction (87 and 41 WB and GS proteins, respectively, 76 and 45 human proteins in response to the respective isolates). In parasitized IECs, the secretome profile indicated effects on the cell actin cytoskeleton and the induction of immune responses whereas that of Giardia showed anti-oxidation, proteolysis (protease-associated) and induction of encystation responses. The Giardia secretome also contained immunodominant and glycosylated proteins as well as new candidate virulence factors and assemblage-specific differences were identified. A minor part of Giardia ESPs had signal peptides (29% for both isolates) and extracellular vesicles were detected in the ESPs fractions, suggesting alternative secretory pathways. Microscopic analyses showed ESPs binding to IECs and partial internalization. Parasite ESPs reduced ERK1/2 and P38 phosphorylation and NF-κB nuclear translocation. Giardia ESPs altered gene expression in IECs, with a transcriptional profile indicating recruitment of immune cells via chemokines, disturbances in glucose homeostasis, cholesterol and lipid metabolism, cell cycle and induction of apoptosis. CONCLUSIONS This is the first study identifying Giardia ESPs and evaluating their effects on IECs. It highlights the importance of host and parasite ESPs during interactions and reveals the intricate cellular responses that can explain disease mechanisms and attenuated inflammatory responses during giardiasis.
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Affiliation(s)
- Showgy Y. Ma’ayeh
- Department of Cell and Molecular Biology, Uppsala University, BMC, Uppsala, Sweden
| | - Jingyi Liu
- Department of Cell and Molecular Biology, Uppsala University, BMC, Uppsala, Sweden
| | - Dimitra Peirasmaki
- Department of Cell and Molecular Biology, Uppsala University, BMC, Uppsala, Sweden
| | - Katarina Hörnaeus
- Department of Chemistry-BMC, Analytical Chemistry, Uppsala University, Uppsala, Sweden
| | - Sara Bergström Lind
- Department of Chemistry-BMC, Analytical Chemistry, Uppsala University, Uppsala, Sweden
| | - Manfred Grabherr
- Department of Medical Biochemsitry and Microbiology, BMC, Uppsala, Sweden
| | - Jonas Bergquist
- Department of Chemistry-BMC, Analytical Chemistry, Uppsala University, Uppsala, Sweden
| | - Staffan G. Svärd
- Department of Cell and Molecular Biology, Uppsala University, BMC, Uppsala, Sweden
- * E-mail:
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10
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Fink MY, Singer SM. The Intersection of Immune Responses, Microbiota, and Pathogenesis in Giardiasis. Trends Parasitol 2017; 33:901-913. [PMID: 28830665 DOI: 10.1016/j.pt.2017.08.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/18/2017] [Accepted: 08/01/2017] [Indexed: 02/07/2023]
Abstract
Giardia lamblia is one of the most common infectious protozoans in the world. Giardia rarely causes severe life-threatening diarrhea, and may even have a slight protective effect in this regard, but it is a major contributor to malnutrition and growth faltering in children in the developing world. Giardia infection also appears to be a significant risk factor for postinfectious irritable bowel and chronic fatigue syndromes. In this review we highlight recent work focused on the impact of giardiasis and the mechanisms that contribute to the various outcomes of this infection, including changes in the composition of the microbiota, activation of immune responses, and immunopathology.
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Affiliation(s)
- Marc Y Fink
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Steven M Singer
- Department of Biology, Georgetown University, Washington, DC, USA.
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11
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Robles-Martinez L, Mendez TL, Apodaca J, Das S. Glucosylceramide transferase in Giardia preferentially catalyzes the synthesis of galactosylceramide during encystation. Mol Biochem Parasitol 2016; 211:75-83. [PMID: 27840079 DOI: 10.1016/j.molbiopara.2016.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 11/06/2016] [Accepted: 11/09/2016] [Indexed: 11/27/2022]
Abstract
The stage differentiation from trophozoite to cyst (i.e., encystation) is an essential step for Giardia to survive outside its human host and spread the infection via the fecal-oral route. We have previously shown that Giardia expresses glucosylceramide transferase 1 (GlcT1) enzyme, the activity of which is elevated during encystation. We have also reported that blocking the activity of gGlcT1 interferes with the biogenesis of encystation-specific vesicles (ESVs) and cyst viability in Giardia. To further understand the role of this enzyme and how it regulates encystation, we overexpressed, knocked down, and rescued the giardial GlcT1 (gGlcT1) gene and measured its enzymatic activity in live parasites as well as in isolated membrane fractions using NBD-ceramide and UDP-glucose or UDP-galactose. We observed that gGlcT1 is able to catalyze the synthesis of both glucosylceramide (GlcCer) and galactosylceramide (GalCer), however the synthesis of GalCer is 2-3 fold higher than of GlcCer. Although both activities follow Michaelis-Menten kinetics, the bindings of UDP-glucose and UDP-galactose with the enzyme appear to be non-competitive and independent of each other. The modulation of gGlcT1 synthesis concomitantly influenced the expression cyst-wall protein (CWP) and overall encystation. We propose that gGlcT1 is a unique enzyme and that Giardia uses this enzyme to synthesize both GlcCer and GalCer to facilitate the process of encystation/cyst production.
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Affiliation(s)
- Leobarda Robles-Martinez
- Infectious Disease and Immunology Cluster, Border Biomedical Research Center (BBRC), University of Texas at El Paso, El Paso, TX 79968-0519, USA; Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519/USA, Tel: (915) 747-6896∥.,Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968-0519, USA; Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519/USA, Tel: (915) 747-6896∥
| | - Tavis L Mendez
- Infectious Disease and Immunology Cluster, Border Biomedical Research Center (BBRC), University of Texas at El Paso, El Paso, TX 79968-0519, USA; Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519/USA, Tel: (915) 747-6896∥.,Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968-0519, USA; Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519/USA, Tel: (915) 747-6896∥
| | - Jennifer Apodaca
- Infectious Disease and Immunology Cluster, Border Biomedical Research Center (BBRC), University of Texas at El Paso, El Paso, TX 79968-0519, USA; Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519/USA, Tel: (915) 747-6896∥.,Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968-0519, USA; Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519/USA, Tel: (915) 747-6896∥
| | - Siddhartha Das
- Infectious Disease and Immunology Cluster, Border Biomedical Research Center (BBRC), University of Texas at El Paso, El Paso, TX 79968-0519, USA; Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519/USA, Tel: (915) 747-6896∥.,Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968-0519, USA; Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519/USA, Tel: (915) 747-6896∥
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12
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Emery SJ, Lacey E, Haynes PA. Quantitative proteomics in Giardia duodenalis —Achievements and challenges. Mol Biochem Parasitol 2016; 208:96-112. [DOI: 10.1016/j.molbiopara.2016.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/13/2016] [Accepted: 07/16/2016] [Indexed: 12/31/2022]
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13
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Li E, Tako EA, Singer SM. Complement Activation by Giardia duodenalis Parasites through the Lectin Pathway Contributes to Mast Cell Responses and Parasite Control. Infect Immun 2016; 84:1092-1099. [PMID: 26831470 PMCID: PMC4807472 DOI: 10.1128/iai.00074-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 01/26/2016] [Indexed: 11/20/2022] Open
Abstract
Infection with Giardia duodenalis is one of the most common causes of diarrheal disease in the world. While numerous studies have identified important contributions of adaptive immune responses to parasite control, much less work has examined innate immunity and its connections to the adaptive response during this infection. We explored the role of complement in immunity to Giardia using mice deficient in mannose-binding lectin (Mbl2) or complement factor 3a receptor (C3aR). Both strains exhibited delayed clearance of parasites and a reduced ability to recruit mast cells in the intestinal submucosa. C3aR-deficient mice had normal production of antiparasite IgA, butex vivo T cell recall responses were impaired. These data suggest that complement is a key factor in the innate recognition of Giardia and that recruitment of mast cells and activation of T cell immunity through C3a are important for parasite control.
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Affiliation(s)
- Erqiu Li
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Ernest A Tako
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Steven M Singer
- Department of Biology, Georgetown University, Washington, DC, USA
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Ethanol and isopropanol in concentrations present in hand sanitizers sharply reduce excystation of Giardia and Entamoeba and eliminate oral infectivity of Giardia cysts in gerbils. Antimicrob Agents Chemother 2015; 59:6749-54. [PMID: 26282413 DOI: 10.1128/aac.01290-15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 08/07/2015] [Indexed: 12/17/2022] Open
Abstract
Enteric protozoan parasites, which are spread by the fecal-oral route, are important causes of diarrhea (Giardia duodenalis) and amebic dysentery (Entamoeba histolytica). Cyst walls of Giardia and Entamoeba have a single layer composed of fibrils of β-1,3-linked GalNAc and β-1,4-linked GlcNAc (chitin), respectively. The goal here was to determine whether hand sanitizers that contain ethanol or isopropanol as the active microbicide might reduce transmission of these parasites. We found that treatment with these alcohols with or without drying in a rotary evaporator (to model rapid evaporation of sanitizers on hands) kills 85 to 100% of cysts of G. duodenalis and 90 to 100% of cysts of Entamoeba invadens (a nonpathogenic model for E. histolytica), as shown by nuclear labeling with propidium iodide and failure to excyst in vitro. Alcohols with or without drying collapsed the cyst walls of Giardia but did not collapse the cyst walls of Entamoeba. To validate the in vitro results, we showed that treatment with alcohols eliminated oral infection of gerbils by 1,000 G. duodenalis cysts, while a commercial hand sanitizer (Purell) killed E. invadens cysts that were directly applied to the hands. These results suggest that expanded use of alcohol-based hand sanitizers might reduce the transmission of Giardia and Entamoeba.
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Sphingolipids, Lipid Rafts, and Giardial Encystation: The Show Must Go On. CURRENT TROPICAL MEDICINE REPORTS 2015; 2:136-143. [PMID: 26587369 DOI: 10.1007/s40475-015-0052-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Sphingolipids are sphingosine-based phospholipids, which are present in the plasma and endomembranes of many eukaryotic cells. These lipids are involved in various cellular functions, including cell growth, differentiation, and apoptosis. In addition, sphingolipid and cholesterol-enriched membrane microdomains (also called "lipid rafts") contain a set of proteins and lipids, which take part in the signaling process in response to intra- or extracellular stimuli. Recent findings suggest that sphingolipids, especially glucosylceramide, play a critical role in inducing encystation and maintaining the cyst viability in Giardia. Similarly, the assembly/disassembly of lipid rafts modulates the encystation and cyst production of this ubiquitous enteric parasite. In this review article, we discuss the overall progress in the field and examine whether sphingolipids and lipid rafts can be used as novel targets for designing therapies to control infection by Giardia, which is rampant in developing countries, where children are especially vulnerable.
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Mohanty S, Jagannathan L, Ganguli G, Padhi A, Roy D, Alaridah N, Saha P, Nongthomba U, Godaly G, Gopal RK, Banerjee S, Sonawane A. A mycobacterial phosphoribosyltransferase promotes bacillary survival by inhibiting oxidative stress and autophagy pathways in macrophages and zebrafish. J Biol Chem 2015; 290:13321-43. [PMID: 25825498 DOI: 10.1074/jbc.m114.598482] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis employs various strategies to modulate host immune responses to facilitate its persistence in macrophages. The M. tuberculosis cell wall contains numerous glycoproteins with unknown roles in pathogenesis. Here, by using Concanavalin A and LC-MS analysis, we identified a novel mannosylated glycoprotein phosphoribosyltransferase, encoded by Rv3242c from M. tuberculosis cell walls. Homology modeling, bioinformatic analyses, and an assay of phosphoribosyltransferase activity in Mycobacterium smegmatis expressing recombinant Rv3242c (MsmRv3242c) confirmed the mass spectrometry data. Using Mycobacterium marinum-zebrafish and the surrogate MsmRv3242c infection models, we proved that phosphoribosyltransferase is involved in mycobacterial virulence. Histological and infection assays showed that the M. marinum mimG mutant, an Rv3242c orthologue in a pathogenic M. marinum strain, was strongly attenuated in adult zebrafish and also survived less in macrophages. In contrast, infection with wild type and the complemented ΔmimG:Rv3242c M. marinum strains showed prominent pathological features, such as severe emaciation, skin lesions, hemorrhaging, and more zebrafish death. Similarly, recombinant MsmRv3242c bacteria showed increased invasion in non-phagocytic epithelial cells and longer intracellular survival in macrophages as compared with wild type and vector control M. smegmatis strains. Further mechanistic studies revealed that the Rv3242c- and mimG-mediated enhancement of intramacrophagic survival was due to inhibition of autophagy, reactive oxygen species, and reduced activities of superoxide dismutase and catalase enzymes. Infection with MsmRv3242c also activated the MAPK pathway, NF-κB, and inflammatory cytokines. In summary, we show that a novel mycobacterial mannosylated phosphoribosyltransferase acts as a virulence and immunomodulatory factor, suggesting that it may constitute a novel target for antimycobacterial drugs.
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Affiliation(s)
- Soumitra Mohanty
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India
| | - Lakshmanan Jagannathan
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India, the AU-KBC Research Center, MIT Campus, Anna University, Chromepet, Chennai, Tamil Nadu 600025, India
| | - Geetanjali Ganguli
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India
| | - Avinash Padhi
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India
| | - Debasish Roy
- the Department of Molecular Reproduction, Development, and Genetics, Indian Institute of Science, Bangalore 560012, India
| | - Nader Alaridah
- the Department of Microbiology, Immunology, and Glycobiology, Institute of Laboratory Medicine, Lund University, 221 00 Lund, Sweden
| | - Pratip Saha
- the Bioinformatics Center, Indian Institute of Science, Bangalore, Karnataka 560012, India, and
| | - Upendra Nongthomba
- the Department of Molecular Reproduction, Development, and Genetics, Indian Institute of Science, Bangalore 560012, India
| | - Gabriela Godaly
- the Department of Microbiology, Immunology, and Glycobiology, Institute of Laboratory Medicine, Lund University, 221 00 Lund, Sweden
| | - Ramesh Kumar Gopal
- the AU-KBC Research Center, MIT Campus, Anna University, Chromepet, Chennai, Tamil Nadu 600025, India
| | - Sulagna Banerjee
- the AU-KBC Research Center, MIT Campus, Anna University, Chromepet, Chennai, Tamil Nadu 600025, India, the Department of Surgery, University of Minnesota, Minneapolis, Minnesota 55455
| | - Avinash Sonawane
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India,
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Samuelson J, Robbins PW. Effects of N-glycan precursor length diversity on quality control of protein folding and on protein glycosylation. Semin Cell Dev Biol 2014; 41:121-8. [PMID: 25475176 DOI: 10.1016/j.semcdb.2014.11.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 11/24/2014] [Accepted: 11/26/2014] [Indexed: 01/24/2023]
Abstract
Asparagine-linked glycans (N-glycans) of medically important protists have much to tell us about the evolution of N-glycosylation and of N-glycan-dependent quality control (N-glycan QC) of protein folding in the endoplasmic reticulum. While host N-glycans are built upon a dolichol-pyrophosphate-linked precursor with 14 sugars (Glc3Man9GlcNAc2), protist N-glycan precursors vary from Glc3Man9GlcNAc2 (Acanthamoeba) to Man9GlcNAc2 (Trypanosoma) to Glc3Man5GlcNAc2 (Toxoplasma) to Man5GlcNAc2 (Entamoeba, Trichomonas, and Eimeria) to GlcNAc2 (Plasmodium and Giardia) to zero (Theileria). As related organisms have differing N-glycan lengths (e.g. Toxoplasma, Eimeria, Plasmodium, and Theileria), the present N-glycan variation is based upon secondary loss of Alg genes, which encode enzymes that add sugars to the N-glycan precursor. An N-glycan precursor with Man5GlcNAc2 is necessary but not sufficient for N-glycan QC, which is predicted by the presence of the UDP-glucose:glucosyltransferase (UGGT) plus calreticulin and/or calnexin. As many parasites lack glucose in their N-glycan precursor, UGGT product may be identified by inhibition of glucosidase II. The presence of an armless calnexin in Toxoplasma suggests secondary loss of N-glycan QC from coccidia. Positive selection for N-glycan sites occurs in secreted proteins of organisms with N-glycan QC and is based upon an increased likelihood of threonine but not serine in the +2 position versus asparagine. In contrast, there appears to be selection against N-glycan length in Plasmodium and N-glycan site density in Toxoplasma. Finally, there is suggestive evidence for N-glycan-dependent ERAD in Trichomonas, which glycosylates and degrades the exogenous reporter mutant carboxypeptidase Y (CPY*).
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Affiliation(s)
- John Samuelson
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, 72 East Concord St, Evans 425, Boston, MA 02118, USA.
| | - Phillips W Robbins
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, 72 East Concord St, Evans 425, Boston, MA 02118, USA.
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Strategies to discover the structural components of cyst and oocyst walls. EUKARYOTIC CELL 2013; 12:1578-87. [PMID: 24096907 DOI: 10.1128/ec.00213-13] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cysts of Giardia lamblia and Entamoeba histolytica and oocysts of Toxoplasma gondii and Cryptosporidium parvum are the infectious and sometimes diagnostic forms of these parasites. To discover the structural components of cyst and oocyst walls, we have developed strategies based upon a few simple assumptions. Briefly, the most abundant wall proteins are identified by monoclonal antibodies or mass spectrometry. Structural components include a sugar polysaccharide (chitin for Entamoeba, β-1,3-linked glucose for Toxoplasma, and β-1,3-linked GalNAc for Giardia) and/or acid-fast lipids (Toxoplasma and Cryptosporidium). Because Entamoeba cysts and Toxoplasma oocysts are difficult to obtain, studies of walls of nonhuman pathogens (E. invadens and Eimeria, respectively) accelerate discovery. Biochemical methods to dissect fungal walls work well for cyst and oocyst walls, although the results are often unexpected. For example, echinocandins, which inhibit glucan synthases and kill fungi, arrest the development of oocyst walls and block their release into the intestinal lumen. Candida walls are coated with mannans, while Entamoeba cysts are coated in a dextran-like glucose polymer. Models for cyst and oocyst walls derive from their structural components and organization within the wall. Cyst walls are composed of chitin fibrils and lectins that bind chitin (Entamoeba) or fibrils of the β-1,3-GalNAc polymer and lectins that bind the polymer (Giardia). Oocyst walls of Toxoplasma have two distinct layers that resemble those of fungi (β-1,3-glucan in the inner layer) or mycobacteria (acid-fast lipids in the outer layer). Oocyst walls of Cryptosporidium have a rigid bilayer of acid-fast lipids and inner layer of oocyst wall proteins.
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Schiller B, Hykollari A, Yan S, Paschinger K, Wilson IBH. Complicated N-linked glycans in simple organisms. Biol Chem 2013; 393:661-73. [PMID: 22944671 DOI: 10.1515/hsz-2012-0150] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 04/07/2012] [Indexed: 11/15/2022]
Abstract
Although countless genomes have now been sequenced, the glycomes of the vast majority of eukaryotes still present a series of unmapped frontiers. However, strides are being made in a few groups of invertebrate and unicellular organisms as regards their N-glycans and N-glycosylation pathways. Thereby, the traditional classification of glycan structures inevitably approaches its boundaries. Indeed, the glycomes of these organisms are rich in surprises, including a multitude of modifications of the core regions of N-glycans and unusual antennae. From the actually rather limited glycomic information we have, it is nevertheless obvious that the biotechnological, developmental and immunological relevance of these modifications, especially in insect cell lines, model organisms and parasites means that deciphering unusual glycomes is of more than just academic interest.
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Affiliation(s)
- Birgit Schiller
- Department für Chemie, Universität für Bodenkultur, A-1190 Wien, Austria
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20
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A new set of carbohydrate-positive vesicles in encysting Giardia lamblia. Protist 2012; 164:261-71. [PMID: 23266141 DOI: 10.1016/j.protis.2012.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 11/04/2012] [Accepted: 11/05/2012] [Indexed: 11/24/2022]
Abstract
Giardia lamblia is a protozoan parasite that presents both trophozoite and cyst forms. In this study, the distribution of the different sugar residues and the origin of the carbohydrate components of the cyst wall were studied using transmission electron microscopy, ultrastructural cytochemistry for carbohydrate detection and immunocytochemistry. Immunofluorescence microscopy using anti-cyst wall protein 1 (CWP1) and gold- and fluorescent-conjugated lectins, such as WGA and DBA, were also used. Interestingly, a population of carbohydrate-containing vesicles, distinct from the encystation-specific vesicles (ESVs) was found in the encysting cells and was named encystation carbohydrate-positive vesicles (ECVs). The differences between the ECVs and the ESVs were: (1) they are electron-translucent, whereas ESVs are electron dense; (2) they do not react with antibodies against cyst wall proteins; (3) the contents are positive for carbohydrates, whereas ESVs display a negative reaction; and (4) they exhibit a positive labeling for DBA indicating the presence of N-acetyl-galactosamine, whereas ESVs are negative. To evaluate if ECVs could be vesicles involved in the endocytic pathway, endocytic markers were used. No co-localization of these markers with ECVs was observed. We suggest that the ECVs may represent a new structure involved in cyst wall formation.
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Ma’ayeh SY, Brook-Carter PT. Representational difference analysis identifies specific genes in the interaction of Giardia duodenalis with the murine intestinal epithelial cell line, IEC-6. Int J Parasitol 2012; 42:501-9. [DOI: 10.1016/j.ijpara.2012.04.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 03/30/2012] [Accepted: 04/02/2012] [Indexed: 10/28/2022]
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Abstract
Giardia lamblia, a parasite of humans, is a major source of waterborne diarrhoeal disease. Giardia is also an excellent system to study basic biochemical processes because it is a single-celled eukaryote with a small genome and its entire life cycle can be replicated in vitro. Giardia trophozoites undergo fundamental changes to survive outside the intestine of their host by differentiating into infective cysts. Encystation entails the synthesis, processing, transport, secretion and extracellular assembly of cyst wall components. To survive within the intestine, Giardia undergoes antigenic variation, a process by which the parasite continuously switches its major surface molecules, allowing the parasite to evade the host's immune response and produce chronic and recurrent infections. The objective of the present chapter is to provide a better understanding of the molecular mechanisms involved in adaptation and differentiation in Giardia, with a particular focus on the process of encystation and antigenic variation of this interesting micro-organism.
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23
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Impaired parasite attachment as fitness cost of metronidazole resistance in Giardia lamblia. Antimicrob Agents Chemother 2011; 55:4643-51. [PMID: 21825286 DOI: 10.1128/aac.00384-11] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Infections with the diarrheagenic protozoan pathogen Giardia lamblia are most commonly treated with metronidazole (Mz). Treatment failures with Mz occur in 10 to 20% of cases and Mz resistance develops in the laboratory, yet clinically, Mz-resistant (Mz(r)) G. lamblia has rarely been isolated from patients. To understand why clinical Mz(r) isolates are rare, we questioned whether Mz resistance entails fitness costs to the parasite. Our studies employed several newly generated and established isogenic Mz(r) cell lines with stable, high-level resistance to Mz and significant cross-resistance to tinidazole, nitazoxanide, and furazolidone. Oral infection of suckling mice revealed that three of five Mz(r) cell lines could not establish infection, while two Mz(r) cell lines infected pups, albeit with reduced efficiencies. Failure to colonize resulted from a diminished capacity of the parasite to attach to the intestinal mucosa in vivo and to epithelial cells and plastic surfaces in vitro. The attachment defect was related to impaired glucose metabolism, since the noninfectious Mz(r) lines consumed less glucose, and glucose promoted ATP-independent parasite attachment in the parental lines. Thus, resistance of Giardia to Mz is accompanied by a glucose metabolism-related attachment defect that can interfere with colonization of the host. Because glucose-metabolizing pathways are important for activation of the prodrug Mz, it follows that a fitness trade-off exists between diminished Mz activation and reduced infectivity, which may explain the observed paucity of clinical Mz(r) isolates of Giardia. However, the data also caution that some forms of Mz resistance do not markedly interfere with in vivo infectivity.
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Transcriptional changes in Giardia during host–parasite interactions. Int J Parasitol 2011; 41:277-85. [DOI: 10.1016/j.ijpara.2010.09.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 09/15/2010] [Accepted: 09/16/2010] [Indexed: 11/20/2022]
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Faso C, Hehl AB. Membrane trafficking and organelle biogenesis in Giardia lamblia: use it or lose it. Int J Parasitol 2011; 41:471-80. [PMID: 21296082 DOI: 10.1016/j.ijpara.2010.12.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 12/23/2010] [Accepted: 12/24/2010] [Indexed: 01/06/2023]
Abstract
The secretory transport capacity of Giardia trophozoites is perfectly adapted to the changing environment in the small intestine of the host and is able to deploy essential protective surface coats as well as molecules which act on epithelia. These lumen-dwelling parasites take up nutrients by bulk endocytosis through peripheral vesicles or by receptor-mediated transport. The environmentally-resistant cyst form is quiescent but poised for activation following stomach passage. Its versatility and fidelity notwithstanding, the giardial trafficking systems appear to be the product of a general secondary reduction process geared towards minimization of all components and machineries identified to date. Since membrane transport is directly linked to organelle biogenesis and maintenance, less complexity also means loss of organelle structures and functions. A case in point is the Golgi apparatus which is missing as a steady-state organelle system. Only a few basic Golgi functions have been experimentally demonstrated in trophozoites undergoing encystation. Similarly, mitochondrial remnants have reached a terminally minimized state and appear to be functionally restricted to essential iron-sulfur protein maturation processes. Giardia's minimized organization combined with its genetic tractability provides unique opportunities to study basic principles of secretory transport in an uncluttered cellular environment. Not surprisingly, Giardia is gaining increasing attention as a model for the investigation of gene regulation, organelle biogenesis, and export of simple but highly protective cell wall biopolymers, a hallmark of all perorally transmitted protozoan and metazoan parasites.
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Affiliation(s)
- Carmen Faso
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland
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26
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Samuelson J, Robbins P. A simple fibril and lectin model for cyst walls of Entamoeba and perhaps Giardia. Trends Parasitol 2011; 27:17-22. [PMID: 20934911 DOI: 10.1016/j.pt.2010.09.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 09/03/2010] [Accepted: 09/07/2010] [Indexed: 01/24/2023]
Abstract
Cyst walls of Entamoeba and Giardia protect them from environmental insults, stomach acids, and intestinal proteases. Each cyst wall contains a sugar homopolymer: chitin in Entamoeba and a unique N-acetylgalactosamine (GalNAc) homopolymer in Giardia. Entamoeba cyst wall proteins include Jacob lectins (carbohydrate-binding proteins) that crosslink chitin, chitinases that degrade chitin, and Jessie lectins that make walls impermeable. Giardia cyst wall proteins are also lectins that bind fibrils of the GalNAc homopolymer. Although many of the details remain to be determined for the cyst wall of Giardia, current data suggest a relatively simple fibril and lectin model for the Entamoeba cyst wall.
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Affiliation(s)
- John Samuelson
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, MA, USA.
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27
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Davids BJ, Gilbert MA, Liu Q, Reiner DS, Smith AJ, Lauwaet T, Lee C, McArthur AG, Gillin FD. An atypical proprotein convertase in Giardia lamblia differentiation. Mol Biochem Parasitol 2010; 175:169-80. [PMID: 21075147 DOI: 10.1016/j.molbiopara.2010.11.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 10/29/2010] [Accepted: 11/05/2010] [Indexed: 01/24/2023]
Abstract
Proteolytic activity is important in the lifecycles of parasites and their interactions with hosts. Cysteine proteases have been best studied in Giardia, but other protease classes have been implicated in growth and/or differentiation. In this study, we employed bioinformatics to reveal the complete set of putative proteases in the Giardia genome. We identified 73 peptidase homologs distributed over 5 catalytic classes in the genome. Serial analysis of gene expression of the G. lamblia lifecycle found thirteen protease genes with significant transcriptional variation over the lifecycle, with only one serine protease transcript upregulated late in encystation. The translated gene sequence of this encystation-specific transcript was most similar to eukaryotic subtilisin-like proprotein convertases (SPC), although the typical catalytic triad was not identified. Epitope-tagged gSPC protein expressed in Giardia under its own promoter was upregulated during encystation with highest expression in cysts and it localized to encystation-specific secretory vesicles (ESV). Total gSPC from encysting cells produced proteolysis in gelatin gels that co-migrated with the epitope-tagged protease in immunoblots. Immuno-purified gSPC also had gelatinase activity. To test whether endogenous gSPC activity is involved in differentiation, trophozoites and cysts were exposed to the specific serine proteinase inhibitor 4-(2-aminoethyl)-benzenesulfonyl fluoride hydrochloride (AEBSF). After 21 h encystation, a significant decrease in ESV was observed with 1mM AEBSF and by 42 h the number of cysts was significantly reduced, but trophozoite growth was not inhibited. Concurrently, levels of cyst wall proteins 1 and 2, and AU1-tagged gSPC protein itself were decreased. Excystation of G. muris cysts was also significantly reduced in the presence of AEBSF. These results support the idea that serine protease activity is essential for Giardia encystation and excystation.
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Affiliation(s)
- B J Davids
- Department of Pathology, University of California, San Diego, CA 92103-8416, USA.
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28
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Abstract
Giardia lamblia, a protozoan parasite, infects a wide variety of vertebrates, including humans. Studies indicate that this anaerobic protist possesses a limited ability to synthesize lipid molecules de novo and depends on supplies from its environment for growth and differentiation. It has been suggested that most lipids and fatty acids are taken up by endocytic and non-endocytic pathways and are used by Giardia for energy production and membrane/organelle biosynthesis. The purpose of this article is to provide an update on recent progress in the field of lipid research of this parasite and the validation of lipid metabolic pathways through recent genomic information. Based on current cellular, biochemical and genomic data, a comprehensive pathway has been proposed to facilitate our understanding of lipid and fatty acid metabolism/syntheses in this waterborne pathogen. We envision that the current review will be helpful in identifying targets from the pathways that could be used to design novel therapies to control giardiasis and related diseases.
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The antiretroviral lectin cyanovirin-N targets well-known and novel targets on the surface of Entamoeba histolytica trophozoites. EUKARYOTIC CELL 2010; 9:1661-8. [PMID: 20852023 DOI: 10.1128/ec.00166-10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Entamoeba histolytica, the protist that causes amebic dysentery and liver abscess, has a truncated Asn-linked glycan (N-glycan) precursor composed of seven sugars (Man(5)GlcNAc(2)). Here, we show that glycoproteins with unmodified N-glycans are aggregated and capped on the surface of E. histolytica trophozoites by the antiretroviral lectin cyanovirin-N and then replenished from large intracellular pools. Cyanovirin-N cocaps the Gal/GalNAc adherence lectin, as well as glycoproteins containing O-phosphodiester-linked glycans recognized by an anti-proteophosphoglycan monoclonal antibody. Cyanovirin-N inhibits phagocytosis by E. histolytica trophozoites of mucin-coated beads, a surrogate assay for amebic virulence. For technical reasons, we used the plant lectin concanavalin A rather than cyanovirin-N to enrich secreted and membrane proteins for mass spectrometric identification. E. histolytica glycoproteins with occupied N-glycan sites include Gal/GalNAc lectins, proteases, and 17 previously hypothetical proteins. The latter glycoproteins, as well as 50 previously hypothetical proteins enriched by concanavalin A, may be vaccine targets as they are abundant and unique. In summary, the antiretroviral lectin cyanovirin-N binds to well-known and novel targets on the surface of E. histolytica that are rapidly replenished from large intracellular pools.
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Chatterjee A, Carpentieri A, Ratner DM, Bullitt E, Costello CE, Robbins PW, Samuelson J. Giardia cyst wall protein 1 is a lectin that binds to curled fibrils of the GalNAc homopolymer. PLoS Pathog 2010; 6:e1001059. [PMID: 20808847 PMCID: PMC2924369 DOI: 10.1371/journal.ppat.1001059] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 07/22/2010] [Indexed: 11/18/2022] Open
Abstract
The infectious and diagnostic stage of Giardia lamblia (also known as G. intestinalis or G. duodenalis) is the cyst. The Giardia cyst wall contains fibrils of a unique beta-1,3-linked N-acetylgalactosamine (GalNAc) homopolymer and at least three cyst wall proteins (CWPs) composed of Leu-rich repeats (CWP(LRR)) and a C-terminal conserved Cys-rich region (CWP(CRR)). Our goals were to dissect the structure of the cyst wall and determine how it is disrupted during excystation. The intact Giardia cyst wall is thin (approximately 400 nm), easily fractured by sonication, and impermeable to small molecules. Curled fibrils of the GalNAc homopolymer are restricted to a narrow plane and are coated with linear arrays of oval-shaped protein complex. In contrast, cyst walls of Giardia treated with hot alkali to deproteinate fibrils of the GalNAc homopolymer are thick (approximately 1.2 microm), resistant to sonication, and permeable. The deproteinated GalNAc homopolymer, which forms a loose lattice of curled fibrils, is bound by native CWP1 and CWP2, as well as by maltose-binding protein (MBP)-fusions containing the full-length CWP1 or CWP1(LRR). In contrast, neither MBP alone nor MBP fused to CWP1(CRR) bind to the GalNAc homopolymer. Recombinant CWP1 binds to the GalNAc homopolymer within secretory vesicles of Giardia encysting in vitro. Fibrils of the GalNAc homopolymer are exposed during excystation or by treatment of heat-killed cysts with chymotrypsin, while deproteinated fibrils of the GalNAc homopolymer are degraded by extracts of Giardia cysts but not trophozoites. These results show the Leu-rich repeat domain of CWP1 is a lectin that binds to curled fibrils of the GalNAc homopolymer. During excystation, host and Giardia proteases appear to degrade bound CWPs, exposing fibrils of the GalNAc homopolymer that are digested by a stage-specific glycohydrolase.
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Affiliation(s)
- Aparajita Chatterjee
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Andrea Carpentieri
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Daniel M. Ratner
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Esther Bullitt
- Department of Biophysics and Physiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Catherine E. Costello
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Phillips W. Robbins
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
| | - John Samuelson
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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Mitra S, Cui J, Robbins PW, Samuelson J. A deeply divergent phosphoglucomutase (PGM) of Giardia lamblia has both PGM and phosphomannomutase activities. Glycobiology 2010; 20:1233-40. [PMID: 20507884 DOI: 10.1093/glycob/cwq081] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Giardia lamblia, which is an important parasitic cause of diarrhea, uses activated forms of glucose to make glycogen and activated forms of mannose to make glycophosphosphoinositol anchors. A necessary step for glucose activation is isomerization of glucose-6-phosphate to glucose-1-phosphate by a phosphoglucomutase (PGM). Similarly, a phosphomannomutase (PMM) converts mannose-6-phosphate to mannose-1-phosphate. While whole genome sequences of Giardia predict two PGM candidates, no PMM candidate is present. The hypothesis tested here is that at least one of the two Giardia PGM candidates has both PGM and PMM activity, as has been described for bacterial PGM orthologs. Nondenaturing gels showed that Giardia has two proteins with PGM activity, one of which also has PMM activity. Phylogenetic analyses showed that one of the two Giardia PGM candidates (Gl-PGM1) shares recent common ancestry with other eukaryotic PGMs, while the other Giardia PGM candidate (Gl-PGM2) is deeply divergent. Both Gl-PGM1 and Gl-PGM2 rescue a Saccharomyces cerevisiae pgm1Delta/pgm2Delta double deletion strain, while only Gl-PGM2 rescues a temperature-sensitive PMM mutant of S. cerevisiae (sec53-ts). Recombinant Gl-PGM1 has PGM activity only, whereas Gl-PGM2 has both PGM and PMM activities. We conclude that Gl-PGM1 behaves as a conventional eukaryotic PGM, while Gl-PGM2 is a novel eukaryotic PGM that also has PMM activity.
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Affiliation(s)
- Sanghamitra Mitra
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, MA 02118, USA
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Chiu PW, Huang YC, Pan YJ, Wang CH, Sun CH. A novel family of cyst proteins with epidermal growth factor repeats in Giardia lamblia. PLoS Negl Trop Dis 2010; 4:e677. [PMID: 20485485 PMCID: PMC2867935 DOI: 10.1371/journal.pntd.0000677] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 03/23/2010] [Indexed: 11/26/2022] Open
Abstract
Background Giardia lamblia parasitizes the human small intestine to cause diarrhea and malabsorption. It undergoes differentiation from a pathogenic trophozoite form into a resistant walled cyst form. Few cyst proteins have been identified to date, including three cyst wall proteins (CWPs) and one High Cysteine Non-variant Cyst protein (HCNCp). They are highly expressed during encystation and are mainly targeted to the cyst wall. Methodology and Principal Findings To identify new cyst wall proteins, we searched the G. lamblia genome data base with the sequence of the Cryptosporidium parvum oocyst wall protein as a query and found an Epidermal Growth Factor (EGF)-like Cyst Protein (EGFCP1). Sequence analysis revealed that the EGF-like repeats of the EGFCP1 are similar to those of the tenascin family of extracellular matrix glycoproteins. EGFCP1 and HCNCp have a higher percentage of cysteine than CWPs, but EGFCP1 has no C-terminal transmembrane region found in HCNCp. Like CWPs and HCNCp, the EGFCP1 protein (but not transcript) was expressed at higher levels during encystation and it was localized to encystation-specific vesicles in encysting trophozoites. Like HCNCp, EGFCP1 was localized to the encystation-specific vesicles, cyst wall and cell body of cysts, suggesting that they may share a common trafficking pathway. Interestingly, overexpression of EGFCP1 induced cyst formation and deletion of the signal peptide from EGFCP1 reduced its protein levels and cyst formation, suggesting that EGFCP1 may help mediate cyst wall synthesis. We also found that five other putative EGFCPs have similar expression profiles and similar locations and that the cyst formation was induced upon their overexpression. Conclusions and Significance Our results suggest that EGFCPs may function like cyst wall proteins, involved in differentiation of G. lamblia trophozoites into cysts. The results lead to greater understanding of parasite cyst walls and provide valuable information that helps develop ways to interrupt the G. lamblia life cycle. The biological goal of Giardia lamblia life cycle is differentiation into a cyst form (encystation) that can survive in the environment and infect a new host. Since cystic stages are key to transmission of parasites, this differentiation may be a target for interruption of the life cycle. Synthesis and assembly of the extracellular cyst wall are the major hallmarks of this important differentiation. During encystation, cyst wall structural proteins are coordinately synthesized and are mainly targeted to the cyst wall. However, only a few such proteins have been identified to date. In this study, we used a combination of bioinformatics and molecular approaches to identify new cyst structural proteins from G. lamblia and found a group of Epidermal Growth Factor (EGF)-like Repeats containing Cyst Proteins (EGFCPs). Interestingly, the levels of EGFCPs proteins increased significantly during encystation, which matches the characteristics of the Giardia cyst wall protein. Further characterization and localization studies suggest that EGFCPs may function like cyst wall proteins, involved in differentiation of G. lamblia trophozoites into cysts. Our results provide valuable information regarding the function of a new group of cyst proteins in parasite differentiation into cysts and help develop ways to interrupt the parasite life cycle.
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Affiliation(s)
- Pei-Wei Chiu
- Department of Parasitology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Yu-Chang Huang
- Department of Parasitology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Yu-Jiao Pan
- Department of Parasitology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Chih-Hung Wang
- Department of Parasitology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Chin-Hung Sun
- Department of Parasitology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China
- * E-mail:
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Suggestive evidence for Darwinian Selection against asparagine-linked glycans of Plasmodium falciparum and Toxoplasma gondii. EUKARYOTIC CELL 2009; 9:228-41. [PMID: 19783771 DOI: 10.1128/ec.00197-09] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We are interested in asparagine-linked glycans (N-glycans) of Plasmodium falciparum and Toxoplasma gondii, because their N-glycan structures have been controversial and because we hypothesize that there might be selection against N-glycans in nucleus-encoded proteins that must pass through the endoplasmic reticulum (ER) prior to threading into the apicoplast. In support of our hypothesis, we observed the following. First, in protists with apicoplasts, there is extensive secondary loss of Alg enzymes that make lipid-linked precursors to N-glycans. Theileria makes no N-glycans, and Plasmodium makes a severely truncated N-glycan precursor composed of one or two GlcNAc residues. Second, secreted proteins of Toxoplasma, which uses its own 10-sugar precursor (Glc(3)Man(5)GlcNAc(2)) and the host 14-sugar precursor (Glc(3)Man(9)GlcNAc(2)) to make N-glycans, have very few sites for N glycosylation, and there is additional selection against N-glycan sites in its apicoplast-targeted proteins. Third, while the GlcNAc-binding Griffonia simplicifolia lectin II labels ER, rhoptries, and surface of plasmodia, there is no apicoplast labeling. Similarly, the antiretroviral lectin cyanovirin-N, which binds to N-glycans of Toxoplasma, labels ER and rhoptries, but there is no apicoplast labeling. We conclude that possible selection against N-glycans in protists with apicoplasts occurs by eliminating N-glycans (Theileria), reducing their length (Plasmodium), or reducing the number of N-glycan sites (Toxoplasma). In addition, occupation of N-glycan sites is markedly reduced in apicoplast proteins versus some secretory proteins in both Plasmodium and Toxoplasma.
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Ortega-Pierres G, Smith HV, Cacciò SM, Thompson RA. New tools provide further insights into Giardia and Cryptosporidium biology. Trends Parasitol 2009; 25:410-6. [DOI: 10.1016/j.pt.2009.06.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 06/02/2009] [Accepted: 06/12/2009] [Indexed: 12/12/2022]
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Darwinian selection for sites of Asn-linked glycosylation in phylogenetically disparate eukaryotes and viruses. Proc Natl Acad Sci U S A 2009; 106:13421-6. [PMID: 19666543 DOI: 10.1073/pnas.0905818106] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Numerous protists and rare fungi have truncated Asn-linked glycan precursors and lack N-glycan-dependent quality control (QC) systems for glycoprotein folding in the endoplasmic reticulum. Here, we show that the abundance of sequons (NXT or NXS), which are sites for N-glycosylation of secreted and membrane proteins, varies by more than a factor of 4 among phylogenetically diverse eukaryotes, based on a few variables. There is positive correlation between the density of sequons and the AT content of coding regions, although no causality can be inferred. In contrast, there appears to be Darwinian selection for sequons containing Thr, but not Ser, in eukaryotes that have N-glycan-dependent QC systems. Selection for sequons with Thr, which nearly doubles the sequon density in human secreted and membrane proteins, occurs by an increased conditional probability that Asn and Thr are present in sequons rather than elsewhere. Increasing sequon densities of the hemagglutinin (HA) of influenza viruses A/H3N2 and A/H1N1 during the past few decades of human infection also result from an increased conditional probability that Asn, Thr, and Ser are present in sequons rather than elsewhere. In contrast, there is no selection on sequons by this mechanism in HA of A/H5N1 or 2009 A/H1N1 (Swine flu). Very strong selection for sequons with both Thr and Ser in glycoprotein of M(r) 120,000 (gp120) of HIV and related retroviruses results from this same mechanism, as well as amino acid composition bias and increases in AT content. We conclude that there is Darwinian selection for sequons in phylogenetically disparate eukaryotes and viruses.
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