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Sannigrahi A, Chattopadhyay K. Pore formation by pore forming membrane proteins towards infections. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:79-111. [PMID: 35034727 DOI: 10.1016/bs.apcsb.2021.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Over the last 25 years, the biology of membrane proteins, including the PFPs-membranes interactions is seeking attention for the development of successful drug molecules against a number of infectious diseases. Pore forming toxins (PFTs), the largest family of PFPs are considered as a group of virulence factors produced in a large number of pathogenic systems which include streptococcus, pneumonia, Staphylococcus aureus, E. coli, Mycobacterium tuberculosis, group A and B streptococci, Corynebacterium diphtheria and many more. PFTs are generally utilized by the disease causing pathogens to disrupt the host first line of defense i.e. host cell membranes through pore formation strategy. Although, pore formation is the principal mode of action of the PFTs but they can have additional adverse effects on the hosts including immune evasion. Recently, structural investigation of different PFTs have imparted the molecular mechanistic insights into how PFTs get transformed from its inactive state to active toxic state. On the basis of their structural entity, PFTs have been classified in different types and their mode of actions alters in terms of pore formation and corresponding cellular toxicity. Although pathogen genome analysis can identify the probable PFTs depending upon their structural diversity, there are so many PFTs which utilize the local environmental conditions to generate their pore forming ability using a novel strategy which is known as "conformational switch" of a protein. This conformational switch is considered as characteristics of the phase shifting proteins which were often utilized by many pathogenic systems to protect them from the invaders through allosteric communication between distant regions of the protein. In this chapter, we discuss the structure function relationships of PFTs and how activity of PFTs varies with the change in the environmental conditions has been explored. Finally, we demonstrate these structural insights to develop therapeutic potential to treat the infections caused by multidrug resistant pathogens.
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Affiliation(s)
- Achinta Sannigrahi
- Department of Chemical Engineering, Indian Institute of Science, Bengaluru, Karnataka, India.
| | - Krishnananda Chattopadhyay
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India.
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2
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Abou-El-Naga IF, Gomaa MM, ElAchy SN. Effect of HIV aspartyl protease inhibitors on experimental infection with a cystogenic Me49 strain of Toxoplasma gondii. Pathog Glob Health 2021; 116:107-118. [PMID: 34420500 DOI: 10.1080/20477724.2021.1967628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Toxoplasmosis is a zoonotic disease of major significant perspectives in public health and veterinary medicine. So far, the available drugs control only the active infection, once the parasite encysts in the tissues, they lose their efficacy. Cytokines; IFN-γ and IL-10, play a critical role in the modulation of toxoplasmic encephalitis and neuro-inflammation in chronic toxoplasmosis. Antiretroviral protease inhibitors applied in the treatment of acquired immunodeficiency syndrome, revealed activity against multiple parasites. Aluvia (lopinavir/ritonavir) (L/R); an aspartyl protease inhibitor, had efficiently treated T. gondii RH strain infection. We investigated the potential activity of L/R against experimental T. gondii infection with a cystogenic Me49 strain in mice, considering the role of IFN-γ and IL-10 in the neuropathology versus pyrimethamine-sulfadiazine combination therapy. Three aluvia regimens were applied; starting on the day of infection (acute phase), 2-week PI (early chronic phase) and eight weeks PI (late chronic phase). L/R reduced the brain-tissue cyst burden significantly in all treatment regimens. It impaired the parasite infectivity markedly in the late chronic phase. Ultrastructural changes were detected in Toxoplasma cyst membrane and wall, bradyzoite membrane and nuclear envelope. The signs of bradyzoite paraptosis and cytoplasmic lipid droplets were observed. L/R had significantly reduced the brain-homogenate levels of IFN-γ and IL-10 in its three regimens however, they could not reach the normal level in chronic phases. Cerebral hypercellularity, perivascular inflammatory response, lymphoplasmacytic infiltrates and glial cellular reaction were ameliorated by L/R treatment. Herein, L/R was proved to possess promising preventive and therapeutic perspectives in chronic cerebral toxoplasmosis.
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Affiliation(s)
- Iman Fathy Abou-El-Naga
- Department Of Medical Parasitology, Faculty Of Medicine, Alexandria University, Alexandria, Egypt
| | - Maha Mohamed Gomaa
- Department Of Medical Parasitology, Faculty Of Medicine, Alexandria University, Alexandria, Egypt
| | - Samar Nabil ElAchy
- Department Of Pathology, Faculty Of Medicine, Alexandria University, Alexandria, Egypt
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3
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Li S, Liu J, Zhang H, Sun Z, Ying Z, Wu Y, Xu J, Liu Q. Toxoplasma gondii glutathione S-transferase 2 plays an important role in partial secretory protein transport. FASEB J 2021; 35:e21352. [PMID: 33543805 DOI: 10.1096/fj.202001987rr] [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: 08/23/2020] [Revised: 12/17/2020] [Accepted: 12/22/2020] [Indexed: 11/11/2022]
Abstract
Toxoplasma gondii is an apicomplexan parasite, which has three unique secretory organelles: micronemes, rhoptries, and dense granules. Almost all the secreted proteins are transported through the endoplasmic reticulum (ER) and Golgi system to function in their respective destination by accurate targeting and packaging. Glutathione S-transferase (GST) is a supergene family enzyme that has multiple functions, which include regulation of cell proliferation and death signaling pathways, and participation in transportation and metabolism in mammal cells. However, the role of GST in Toxoplasma gondii has not been explained. In this study, we identified three GST proteins in T gondii, of which GST2 acts as a membrane protein that localizes to the Golgi-endosomal system and colocalizes with proteins involved in vesicle transport as well, including synaptobrevin, putative sortilin (VPS10), Rab5 and Rab6, which function as vesicle transport factors. Moreover, the loss of TgGST2 leads to Rab5 and Rab6 distribution of discrete puncta, and incorrect localization and decreased expression of several secretory proteins, and to significantly reduced invasion capacity and virulence to mice. Consistent with its relation to vesicle transport proteins, the distribution of TgGST2 relies on post-Golgi trafficking. Overall, our findings demonstrated that TgGST2 contributes to vesicle trafficking and plays a critical role in parasite lytic cycle.
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Affiliation(s)
- Shuang Li
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jing Liu
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Heng Zhang
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Zhepeng Sun
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Zhu Ying
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yihan Wu
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jianhai Xu
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Qun Liu
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
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4
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Paoletta MS, Laughery JM, Arias LSL, Ortiz JMJ, Montenegro VN, Petrigh R, Ueti MW, Suarez CE, Farber MD, Wilkowsky SE. The key to egress? Babesia bovis perforin-like protein 1 (PLP1) with hemolytic capacity is required for blood stage replication and is involved in the exit of the parasite from the host cell. Int J Parasitol 2021; 51:643-658. [PMID: 33753093 DOI: 10.1016/j.ijpara.2020.12.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/27/2020] [Accepted: 12/03/2020] [Indexed: 12/18/2022]
Abstract
Bovine babesiosis is a tick-borne disease caused by apicomplexan parasites of the Babesia genus that represents a major constraint to livestock production worldwide. Currently available vaccines are based on live parasites which have archetypal limitations. Our goal is to identify candidate antigens so that new and effective vaccines against Babesia may be developed. The perforin-like protein (PLP) family has been identified as a key player in cell traversal and egress in related apicomplexans and it was also identified in Babesia, but its function in this parasite remains unknown. The aim of this work was to define the PLP family in Babesia and functionally characterize PLP1, a representative member of the family in Babesia bovis. Bioinformatic analyses demonstrate a variable number of plp genes (four to eight) in the genomes of six different Babesia spp. and conservation of the family members at the secondary and tertiary structure levels. We demonstrate here that Babesia PLPs contain the critical domains present in other apicomplexan PLPs to display the lytic capacity. We then focused on the functional characterization of PLP1 of B. bovis, both in vitro and in vivo. PLP1 is expressed and exposed to the host immune system during infection and has high hemolytic capacity under a wide range of conditions in vitro. A B. bovis plp1 knockout line displayed a decreased growth rate in vitro compared with the wild type strain and a peculiar phenotype consisting of multiple parasites within a single red blood cell, although at low frequency. This phenotype suggests that the lack of PLP1 has a negative impact on the mechanism of egression of the parasite and, therefore, on its capacity to proliferate. It is possible that PLP1 is associated with other proteins in the processes of invasion and egress, which were found to have redundant mechanisms in related apicomplexans. Future work will be focused on unravelling the network of proteins involved in these essential parasite functions.
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Affiliation(s)
- Martina Soledad Paoletta
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO) INTA - CONICET, De Los Reseros y Dr. Nicolás Repetto s/n, P.O. Box 25 (B1712WAA), Castelar, Buenos Aires, Argentina
| | - Jacob Michael Laughery
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA
| | - Ludmila Sol López Arias
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO) INTA - CONICET, De Los Reseros y Dr. Nicolás Repetto s/n, P.O. Box 25 (B1712WAA), Castelar, Buenos Aires, Argentina
| | - José Manuel Jaramillo Ortiz
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO) INTA - CONICET, De Los Reseros y Dr. Nicolás Repetto s/n, P.O. Box 25 (B1712WAA), Castelar, Buenos Aires, Argentina
| | - Valeria Noely Montenegro
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO) INTA - CONICET, De Los Reseros y Dr. Nicolás Repetto s/n, P.O. Box 25 (B1712WAA), Castelar, Buenos Aires, Argentina
| | - Romina Petrigh
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO) INTA - CONICET, De Los Reseros y Dr. Nicolás Repetto s/n, P.O. Box 25 (B1712WAA), Castelar, Buenos Aires, Argentina
| | - Massaro W Ueti
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; Animal Disease Research Unit, USDA-ARS, Washington State University, 3003 ADBF, P.O. Box 646630, Pullman, WA 99164, USA
| | - Carlos Esteban Suarez
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; Animal Disease Research Unit, USDA-ARS, Washington State University, 3003 ADBF, P.O. Box 646630, Pullman, WA 99164, USA
| | - Marisa Diana Farber
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO) INTA - CONICET, De Los Reseros y Dr. Nicolás Repetto s/n, P.O. Box 25 (B1712WAA), Castelar, Buenos Aires, Argentina
| | - Silvina Elizabeth Wilkowsky
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO) INTA - CONICET, De Los Reseros y Dr. Nicolás Repetto s/n, P.O. Box 25 (B1712WAA), Castelar, Buenos Aires, Argentina.
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Yan X, Han W, Liu X, Suo X. Exogenous nitric oxide stimulates early egress of Eimeria tenella sporozoites from primary chicken kidney cells in vitro. Parasite 2021; 28:11. [PMID: 33576739 PMCID: PMC7880050 DOI: 10.1051/parasite/2021007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/24/2021] [Indexed: 11/21/2022] Open
Abstract
Egress plays a vital role in the life cycle of apicomplexan parasites including Eimeria tenella, which has been attracting attention from various research groups. Many recent studies have focused on early egress induced by immune molecules to develop a new method of apicomplexan parasite elimination. In this study, we investigated whether nitric oxide (NO), an immune molecule produced by different types of cells in response to cytokine stimulation, could induce early egress of eimerian sporozoites in vitro. Eimeria tenella sporozoites were extracted and cultured in primary chicken kidney cells. The number of sporozoites egressed from infected cells was analyzed by flow cytometry after treatment with NO released by sodium nitroferricyanide (II) dihydrate. The results showed that exogenous NO stimulated the rapid egress of E. tenella sporozoites from primary chicken kidney cells before replication of the parasite. We also found that egress was dependent on intra-parasitic calcium ion (Ca2+) levels and no damage occurred to host cells after egress. The virulence of egressed sporozoites was significantly lower than that of fresh sporozoites. The results of this study contribute to a novel field examining the interactions between apicomplexan parasites and their host cells, as well as that of the clearance of intracellular pathogens by the host immune system.
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Affiliation(s)
- Xinlei Yan
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Food Science and Engineering College of Inner Mongolia Agricultural University Hohhot 010018 China
| | - Wenying Han
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Food Science and Engineering College of Inner Mongolia Agricultural University Hohhot 010018 China
| | - Xianyong Liu
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State Key Laboratory of Agrobiotechnology, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University Beijing 100193 China
| | - Xun Suo
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State Key Laboratory of Agrobiotechnology, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University Beijing 100193 China
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Bisio H, Soldati-Favre D. Signaling Cascades Governing Entry into and Exit from Host Cells by Toxoplasma gondii. Annu Rev Microbiol 2020; 73:579-599. [PMID: 31500539 DOI: 10.1146/annurev-micro-020518-120235] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Apicomplexa phylum includes a large group of obligate intracellular protozoan parasites responsible for important diseases in humans and animals. Toxoplasma gondii is a widespread parasite with considerable versatility, and it is capable of infecting virtually any warm-blooded animal, including humans. This outstanding success can be attributed at least in part to an efficient and continuous sensing of the environment, with a ready-to-adapt strategy. This review updates the current understanding of the signals governing the lytic cycle of T. gondii, with particular focus on egress from infected cells, a key step for balancing survival, multiplication, and spreading in the host. We cover the recent advances in the conceptual framework of regulation of microneme exocytosis that ensures egress, motility, and invasion. Particular emphasis is given to the trigger molecules and signaling cascades regulating exit from host cells.
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Affiliation(s)
- Hugo Bisio
- Département de Microbiologie et Médecine Moléculaire, Centre Médical Universitaire, Université de Genève, 1211 Geneva 4, Switzerland;
| | - Dominique Soldati-Favre
- Département de Microbiologie et Médecine Moléculaire, Centre Médical Universitaire, Université de Genève, 1211 Geneva 4, Switzerland;
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7
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Xue Q. Pathogen proteases and host protease inhibitors in molluscan infectious diseases. J Invertebr Pathol 2019; 166:107214. [PMID: 31348922 DOI: 10.1016/j.jip.2019.107214] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 04/11/2019] [Accepted: 06/28/2019] [Indexed: 12/17/2022]
Abstract
The development of infectious diseases represents an outcome of dynamic interactions between the disease-producing agent's pathogenicity and the host's self-defense mechanism. Proteases secreted by pathogenic microorganisms and protease inhibitors produced by host species play an important role in the process. This review aimed at summarizing major findings in research on pathogen proteases and host protease inhibitors that had been proposed to be related to the development of mollusk diseases. Metalloproteases and serine proteases respectively belonging to Family M4 and Family S8 of the MEROPS system are among the most studied proteases that may function as virulence factors in mollusk pathogens. On the other hand, a mollusk-specific family (Family I84) of novel serine protease inhibitors and homologues of the tissue inhibitor of metalloprotease have been studied for their potential in the molluscan host defense. In addition, research at the genomic and transcriptomic levels showed that more proteases of pathogens and protease inhibitor of hosts are likely involved in mollusk disease processes. Therefore, the pathological significance of interactions between pathogen proteases and host protease inhibitors in the development of molluscan infectious diseases deserves more research efforts.
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Affiliation(s)
- Qinggang Xue
- Zhejiang Key Lab of Aquatic Germplasm Resources, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
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Cryptosporidium parvum Subtilisin-Like Serine Protease (SUB1) Is Crucial for Parasite Egress from Host Cells. Infect Immun 2019; 87:IAI.00784-18. [PMID: 30782859 DOI: 10.1128/iai.00784-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/28/2019] [Indexed: 01/28/2023] Open
Abstract
Despite the severity and global burden of Cryptosporidium infection, treatments are less than optimal, and there is no effective vaccine. Egress from host cells is a key process for the completion of the life cycle of apicomplexan parasites. For Plasmodium species, subtilisin-like serine protease (SUB1) is a key mediator of egress. For Toxoplasma species, calcium-dependent protein kinases (CDPKs) are critical. In this study, we characterized Cryptosporidium SUB1 expression and evaluated its effect using an infection model. We found increased expression between 12 and 20 h after in vitro infection, prior to egress. We induced silencing of SUB1 (ΔSUB1) mRNA using SUB1 single-stranded antisense RNA coupled with human Argonaute 2. Silencing of SUB1 mRNA expression did not affect parasite viability, excystation, or invasion of target cells. However, knockdown led to a 95% decrease in the proportion of released merozoites in vitro (P < 0.0001). In contrast, silencing of CDPK5 had no effect on egress. Overall, our results indicate that SUB1 is a key mediator of Cryptosporidium egress and suggest that interruption of the life cycle at this stage may effectively inhibit the propagation of infection.
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Phosphatidic acid governs natural egress in Toxoplasma gondii via a guanylate cyclase receptor platform. Nat Microbiol 2019; 4:420-428. [DOI: 10.1038/s41564-018-0339-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 12/05/2018] [Indexed: 12/12/2022]
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10
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Hammoudi PM, Maco B, Dogga SK, Frénal K, Soldati-Favre D. Toxoplasma gondiiTFP1 is an essential transporter family protein critical for microneme maturation and exocytosis. Mol Microbiol 2018; 109:225-244. [DOI: 10.1111/mmi.13981] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 05/04/2018] [Accepted: 05/04/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Pierre-Mehdi Hammoudi
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine; University of Geneva, 1 Rue Michel-Servet; Geneva 1206 Switzerland
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine; University of Geneva, 1 Rue Michel-Servet; Geneva 1206 Switzerland
| | - Sunil Kumar Dogga
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine; University of Geneva, 1 Rue Michel-Servet; Geneva 1206 Switzerland
| | - Karine Frénal
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine; University of Geneva, 1 Rue Michel-Servet; Geneva 1206 Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine; University of Geneva, 1 Rue Michel-Servet; Geneva 1206 Switzerland
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Targeted Phenotypic Screening in Plasmodium falciparum and Toxoplasma gondii Reveals Novel Modes of Action of Medicines for Malaria Venture Malaria Box Molecules. mSphere 2018; 3:mSphere00534-17. [PMID: 29359192 PMCID: PMC5770543 DOI: 10.1128/msphere.00534-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 12/20/2017] [Indexed: 01/23/2023] Open
Abstract
The Malaria Box collection includes 400 chemically diverse small molecules with documented potency against malaria parasite growth, but the underlying modes of action are largely unknown. Using complementary phenotypic screens against Plasmodium falciparum and Toxoplasma gondii, we report phenotype-specific hits based on inhibition of overall parasite growth, apicoplast segregation, and egress or host invasion, providing hitherto unavailable insights into the possible mechanisms affected. First, the Malaria Box library was screened against tachyzoite stage T. gondii and the half-maximal effective concentrations (EC50s) of molecules showing ≥80% growth inhibition at 10 µM were determined. Comparison of the EC50s for T. gondii and P. falciparum identified a subset of 24 molecules with nanomolar potency against both parasites. Thirty molecules that failed to induce acute growth inhibition in T. gondii tachyzoites in a 2-day assay caused delayed parasite death upon extended exposure, with at least three molecules interfering with apicoplast segregation during daughter cell formation. Using flow cytometry and microscopy-based examinations, we prioritized 26 molecules with the potential to inhibit host cell egress/invasion during asexual developmental stages of P. falciparum. None of the inhibitors affected digestive vacuole integrity, ruling out a mechanism mediated by broadly specific protease inhibitor activity. Interestingly, five of the plasmodial egress inhibitors inhibited ionophore-induced egress of T. gondii tachyzoites. These findings highlight the advantage of comparative and targeted phenotypic screens in related species as a means to identify lead molecules with a conserved mode of action. Further work on target identification and mechanism analysis will facilitate the development of antiparasitic compounds with cross-species efficacy. IMPORTANCE The phylum Apicomplexa includes many human and animal pathogens, such as Plasmodium falciparum (human malaria) and Toxoplasma gondii (human and animal toxoplasmosis). Widespread resistance to current antimalarials and the lack of a commercial vaccine necessitate novel pharmacological interventions with distinct modes of action against malaria. For toxoplasmosis, new drugs to effectively eliminate tissue-dwelling latent cysts of the parasite are needed. The Malaria Box antimalarial collection, managed and distributed by the Medicines for Malaria Venture, includes molecules of novel chemical classes with proven antimalarial efficacy. Using targeted phenotypic assays of P. falciparum and T. gondii, we have identified a subset of the Malaria Box molecules as potent inhibitors of plastid segregation and parasite invasion and egress, thereby providing early insights into their probable mode of action. Five molecules that inhibit the egress of both parasites have been identified for further mechanistic studies. Thus, the approach we have used to identify novel molecules with defined modes of action in multiple parasites can expedite the development of pan-active antiparasitic agents.
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Chakraborty S, Roy S, Mistry HU, Murthy S, George N, Bhandari V, Sharma P. Potential Sabotage of Host Cell Physiology by Apicomplexan Parasites for Their Survival Benefits. Front Immunol 2017; 8:1261. [PMID: 29081773 PMCID: PMC5645534 DOI: 10.3389/fimmu.2017.01261] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 09/21/2017] [Indexed: 12/26/2022] Open
Abstract
Plasmodium, Toxoplasma, Cryptosporidium, Babesia, and Theileria are the major apicomplexan parasites affecting humans or animals worldwide. These pathogens represent an excellent example of host manipulators who can overturn host signaling pathways for their survival. They infect different types of host cells and take charge of the host machinery to gain nutrients and prevent itself from host attack. The mechanisms by which these pathogens modulate the host signaling pathways are well studied for Plasmodium, Toxoplasma, Cryptosporidium, and Theileria, except for limited studies on Babesia. Theileria is a unique pathogen taking into account the way it modulates host cell transformation, resulting in its clonal expansion. These parasites majorly modulate similar host signaling pathways, however, the disease outcome and effect is different among them. In this review, we discuss the approaches of these apicomplexan to manipulate the host–parasite clearance pathways during infection, invasion, survival, and egress.
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Affiliation(s)
| | - Sonti Roy
- National Institute of Animal Biotechnology (NIAB-DBT), Hyderabad, India
| | - Hiral Uday Mistry
- National Institute of Animal Biotechnology (NIAB-DBT), Hyderabad, India
| | - Shweta Murthy
- National Institute of Animal Biotechnology (NIAB-DBT), Hyderabad, India
| | - Neena George
- National Institute of Animal Biotechnology (NIAB-DBT), Hyderabad, India
| | | | - Paresh Sharma
- National Institute of Animal Biotechnology (NIAB-DBT), Hyderabad, India
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Singh S, Chitnis CE. Molecular Signaling Involved in Entry and Exit of Malaria Parasites from Host Erythrocytes. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a026815. [PMID: 28507195 DOI: 10.1101/cshperspect.a026815] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
During the blood stage, Plasmodium spp. merozoites invade host red blood cells (RBCs), multiply, exit, and reinvade uninfected RBCs in a continuing cycle that is responsible for all the clinical symptoms associated with malaria. Entry into (invasion) and exit from (egress) RBCs are highly regulated processes that are mediated by an array of parasite proteins with specific functional roles. Many of these parasite proteins are stored in specialized apical secretory vesicles, and their timely release is critical for successful invasion and egress. For example, the discharge of parasite protein ligands to the apical surface of merozoites is required for interaction with host receptors to mediate invasion, and the timely discharge of proteases and pore-forming proteins helps in permeabilization and dismantling of limiting membranes during egress. This review focuses on our understanding of the signaling mechanisms that regulate apical organelle secretion during host cell invasion and egress by malaria parasites. The review also explores how understanding key signaling mechanisms in the parasite can open opportunities to develop novel strategies to target Plasmodium parasites and eliminate malaria.
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Affiliation(s)
- Shailja Singh
- Department of Parasites and Insect Vectors, Institut Pasteur, 75015 Paris, France.,Shiv Nadar University, Gautam Buddha Nagar, Uttar Pradesh 201314, India
| | - Chetan E Chitnis
- Department of Parasites and Insect Vectors, Institut Pasteur, 75015 Paris, France.,Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi 110067, India
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Dogga SK, Mukherjee B, Jacot D, Kockmann T, Molino L, Hammoudi PM, Hartkoorn RC, Hehl AB, Soldati-Favre D. A druggable secretory protein maturase of Toxoplasma essential for invasion and egress. eLife 2017; 6. [PMID: 28898199 PMCID: PMC5595437 DOI: 10.7554/elife.27480] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 08/08/2017] [Indexed: 12/19/2022] Open
Abstract
Micronemes and rhoptries are specialized secretory organelles that deploy their contents at the apical tip of apicomplexan parasites in a regulated manner. The secretory proteins participate in motility, invasion, and egress and are subjected to proteolytic maturation prior to organellar storage and discharge. Here we establish that Toxoplasma gondii aspartyl protease 3 (ASP3) resides in the endosomal-like compartment and is crucially associated to rhoptry discharge during invasion and to host cell plasma membrane lysis during egress. A comparison of the N-terminome, by terminal amine isotopic labelling of substrates between wild type and ASP3 depleted parasites identified microneme and rhoptry proteins as repertoire of ASP3 substrates. The role of ASP3 as a maturase for previously described and newly identified secretory proteins is confirmed in vivo and in vitro. An antimalarial compound based on a hydroxyethylamine scaffold interrupts the lytic cycle of T. gondii at submicromolar concentration by targeting ASP3.
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Affiliation(s)
- Sunil Kumar Dogga
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Budhaditya Mukherjee
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Damien Jacot
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Tobias Kockmann
- Functional Genomics Center Zurich, ETH Zurich/University of Zurich, Zurich, Switzerland
| | - Luca Molino
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Pierre-Mehdi Hammoudi
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Ruben C Hartkoorn
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland.,Chemical Biology of Antibiotics, Center for Infection and Immunity, Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Lille, France
| | - Adrian B Hehl
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
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Abou-El-Naga IF, El Kerdany ED, Mady RF, Shalaby TI, Zaytoun EM. The effect of lopinavir/ritonavir and lopinavir/ritonavir loaded PLGA nanoparticles on experimental toxoplasmosis. Parasitol Int 2017; 66:735-747. [PMID: 28838776 DOI: 10.1016/j.parint.2017.08.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 08/15/2017] [Accepted: 08/18/2017] [Indexed: 12/19/2022]
Abstract
A marked reduction has been achieved in the incidence and clinical course of toxoplasmic encephalitis after the introduction of protease inhibitors within the treatment regimen of HIV (HIV-PIs). This work was undertaken to study for the first time, the efficacy of HIV-PIs, lopinavir/ritonavir (L/R), as a therapeutic agent in acute experimental toxoplasmosis. Lopinavir/ritonavir (L/R) were used in the same ratio present in aluvia, a known HIV-PIs drug used in the developing countries in the treatment regimens of AID's patient. Poly lactic-co-glycolic acid (PLGA) nanoparticles were used as a delivery system to L/R therapy. L/R alone or after its encapsulation on PLGA were given to Swiss strain albino mice that were infected with RH virulent toxoplasma strain. Both forms caused parasitological improvement in both mortality rate and parasite count. The higher efficacy was achieved by using L/R PLGA together with minimizing the effective dose. There was significant reduction in the parasite count in the peritoneal fluid and the liver. Parasite viability and infectivity were also significantly reduced. The anti-toxoplasma effect of the drug was attributed to the morphological distortion of the tachyzoites as evident by the ultrastructure examination and suppressed the egress of tachyzoites. L/R also induced changes that suggest apoptosis and autophagy of tachyzoites. The parasitophorous vacuole membrane was disrupted and vesiculated. The nanotubular networks inside the parasitophorous vacuole were disrupted. Therefore, the present work opens a new possible way for the approved HIV-PIs as an alternative treatment against acute toxoplasmosis. Furthermore, it increases the list of the opportunistic parasites that can be treated by this drug. The successful in vivo effect of HIV-PIs against Toxoplasma gondii suggests that this parasite may be a target in HIV treated patients, thus decrease the possibility of toxoplasmic encephalitis development.
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Affiliation(s)
| | | | - Rasha Fadly Mady
- Medical Parasitology Department, Alexandria Faculty of Medicine, Egypt.
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Klug D, Frischknecht F. Motility precedes egress of malaria parasites from oocysts. eLife 2017; 6. [PMID: 28115054 PMCID: PMC5262382 DOI: 10.7554/elife.19157] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 12/16/2016] [Indexed: 12/19/2022] Open
Abstract
Malaria is transmitted when an infected Anopheles mosquito deposits Plasmodium sporozoites in the skin during a bite. Sporozoites are formed within oocysts at the mosquito midgut wall and are released into the hemolymph, from where they invade the salivary glands and are subsequently transmitted to the vertebrate host. We found that a thrombospondin-repeat containing sporozoite-specific protein named thrombospondin-releated protein 1 (TRP1) is important for oocyst egress and salivary gland invasion, and hence for the transmission of malaria. We imaged the release of sporozoites from oocysts in situ, which was preceded by active motility. Parasites lacking TRP1 failed to migrate within oocysts and did not egress, suggesting that TRP1 is a vital component of the events that precede intra-oocyst motility and subsequently sporozoite egress and salivary gland invasion. DOI:http://dx.doi.org/10.7554/eLife.19157.001 Malaria is caused by a parasite transmitted by certain types of mosquito. The parasite lives in different organs within its vertebrate animal and insect hosts and to cope with these different environments it has a complex life cycle with several highly specialized life stages. To move from an infected mosquito into vertebrates the parasite produces spore-like cells called sporozoites that are able to enter different tissues and move very fast. These cells develop inside parasite-made structures called oocysts, which form at the stomach wall of the mosquito. After emerging from the oocyst, sporozoites float through the mosquito’s circulatory system and eventually enter the salivary glands where they can be transmitted to vertebrates when the mosquito bites. Efforts to develop malaria treatments and vaccines have focused on understanding the parasite’s life cycle and identifying ways to control or eradicate key stages. Most researchers focus on the stage where the parasite is living in the vertebrate and actively causing disease, while the events in the mosquito are less intensely investigated. While several parasite proteins have been shown to be important for the release of sporozoites from oocysts, the molecular events leading to this release have not yet been fully resolved. Klug and Frischknecht used time-lapse microscopy to film the release of the sporozoites of a malaria parasite known as Plasmodium berghei. The experiments show that the sporozoites can leave oocysts in several different ways. Furthermore, Klug and Frischknecht identified a new parasite protein named TRP1 that is essential for the sporozoites to leave oocysts and invade the salivary glands. Sporozoites lacking TRP1 were not able to move and they were unable to leave the oocyst or invade the salivary glands. Klug and Frischknecht propose a new working model of the molecular events that govern sporozoite release in which TRP1 is required for sporozoites to move prior to their exit from oocysts. In the future, using the same techniques to analyze genetically modified parasites will help to reveal more details about sporozoite release. DOI:http://dx.doi.org/10.7554/eLife.19157.002
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Affiliation(s)
- Dennis Klug
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
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17
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Wang JL, Li TT, Elsheikha HM, Chen K, Zhu WN, Yue DM, Zhu XQ, Huang SY. Functional Characterization of Rhoptry Kinome in the Virulent Toxoplasma gondii RH Strain. Front Microbiol 2017; 8:84. [PMID: 28174572 PMCID: PMC5258691 DOI: 10.3389/fmicb.2017.00084] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 01/12/2017] [Indexed: 11/13/2022] Open
Abstract
Toxoplasma gondii is an obligatory intracellular apicomplexan protozoan which can infect any warm-blooded animal and causes severe diseases in immunocompromised individuals or infants infected in utero. The survival and success of this parasite require that it colonizes the host cell, avoids host immune defenses, replicates within an appropriate niche, and exits the infected host cell to spread to neighboring non-infected cells. All of these processes depend on the parasite ability to synthesis and export secreted proteins. Amongst the secreted proteins, rhoptry organelle proteins (ROPs) are essential for the parasite invasion and host cell manipulation. Even though the functions of most ROPs have been elucidated in the less virulent T. gondii (type II), the roles of ROPs in the highly virulent type I strain remain largely un-characterized. Herein, we investigated the contributions of 15 ROPs (ROP10, ROP11, ROP15, ROP20, ROP23, ROP31, ROP32, ROP33, ROP34, ROP35, ROP36, ROP40, ROP41, ROP46, and ROP47) to the infectivity of the high virulent type I T. gondii (RH strain). Using CRISPR-Cas9, these 15 ROPs genes were successfully disrupted and the effects of gene knockout on the parasite's ability to infect cells in vitro and BALB/c mice in vivo were investigated. These results showed that deletions of these ROPs did not interfere with the parasite ability to grow in cultured human foreskin fibroblast cells and did not significantly alter parasite pathogenicity for BALB/c mice. Although these ROPs did not seem to be essential for the acute infectious stage of type I T. gondii in the mouse model, they might have different functions in other intermediate hosts or play different roles in other life cycle forms of this parasite due to the different expression patterns; this warrants further investigations.
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Affiliation(s)
- Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| | - Ting-Ting Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus Loughborough, UK
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| | - Wei-Ning Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural SciencesLanzhou, China; College of Animal Science and Veterinary Medicine, Shandong Agricultural UniversityTai'an, China
| | - Dong-Mei Yue
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural SciencesLanzhou, China; College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural UniversityDaqing, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| | - Si-Yang Huang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
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18
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Review of Experimental Compounds Demonstrating Anti-Toxoplasma Activity. Antimicrob Agents Chemother 2016; 60:7017-7034. [PMID: 27600037 DOI: 10.1128/aac.01176-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous apicomplexan parasite capable of infecting humans and other animals. Current treatment options for T. gondii infection are limited and most have drawbacks, including high toxicity and low tolerability. Additionally, no FDA-approved treatments are available for pregnant women, a high-risk population due to transplacental infection. Therefore, the development of novel treatment options is needed. To aid this effort, this review highlights experimental compounds that, at a minimum, demonstrate inhibition of in vitro growth of T. gondii When available, host cell toxicity and in vivo data are also discussed. The purpose of this review is to facilitate additional development of anti-Toxoplasma compounds and potentially to extend our knowledge of the parasite.
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19
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Yan X, Tao G, Liu X, Ji Y, Suo X. Calcium-dependent microneme protein discharge and in vitro egress of Eimeria tenella sporozoites. Exp Parasitol 2016; 170:193-197. [PMID: 27680997 DOI: 10.1016/j.exppara.2016.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/02/2016] [Accepted: 09/15/2016] [Indexed: 11/17/2022]
Abstract
Egress is a vital step in the endogenous development of apicomplexan parasites, as it assures the parasites exit from consumed host cells and entry into fresh ones. However, little information has previously been reported on this step of Eimeria spp. In this study, we investigated in vitro egress of Eimeria tenella sporozoites triggered by acetaldehyde. We found that addition of exogenous acetaldehyde induces egress of sporozoites from primary chicken kidney cells (PCKs) and stimulate secretion of E. tenella microneme 2 protein (EtMic 2). Moreover, by using cellular calcium inhibitors, we further proved that these processes were dependent on the intracellular calcium of the parasites. Our findings provide clues to the study of interaction between eimerian parasites and their hosts.
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Affiliation(s)
- Xinlei Yan
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Geru Tao
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Xianyong Liu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China; Key Laboratory of Zoonosis of Ministry of Agriculture & College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Yongsheng Ji
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Xun Suo
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China; National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China; Key Laboratory of Zoonosis of Ministry of Agriculture & College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
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20
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Cabrera-Muñoz A, Rojas L, Gil DF, González-González Y, Mansur M, Camejo A, Pires JR, Alonso-Del-Rivero Antigua M. Heterologous expression of Cenchritis muricatus protease inhibitor II (CmPI-II) in Pichia pastoris system: Purification, isotopic labeling and preliminary characterization. Protein Expr Purif 2016; 126:127-136. [PMID: 27353494 DOI: 10.1016/j.pep.2016.06.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 10/21/2022]
Abstract
Cenchritis muricatus protease inhibitor II (CmPI-II) is a tight-binding serine protease inhibitor of the Kazal family with an atypical broad specificity, being active against several proteases such as bovine pancreatic trypsin, human neutrophil elastase and subtilisin A. CmPI-II 3D structures are necessary for understanding the molecular basis of its activity. In the present work, we describe an efficient and straightforward recombinant expression strategy, as well as a cost-effective procedure for isotope labeling for NMR structure determination purposes. The vector pCM101 containing the CmPI-II gene, under the control of Pichia pastoris AOX1 promoter was constructed. Methylotrophic Pichia pastoris strain KM71H was then transformed with the plasmid and the recombinant protein (rCmPI-II) was expressed in benchtop fermenter in unlabeled or (15)N-labeled forms using ammonium chloride ((15)N, 99%) as the sole nitrogen source. Protein purification was accomplished by sequential cation exchange chromatography in STREAMLINE DirectHST, anion exchange chromatography on Hitrap Q-Sepharose FF and gel filtration on Superdex 75 10/30, yielding high quantities of pure rCmPI-II and (15)N rCmPI-II. Recombinant proteins displayed similar functional features as compared to the natural inhibitor and NMR spectra indicated folded and homogeneously labeled samples, suitable for further studies of structure and protease-inhibitor interactions.
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Affiliation(s)
- Aymara Cabrera-Muñoz
- Centro de Estudios de Proteínas, Facultad de Biología, Universidad de La Habana, Ciudad de La Habana-Cuba, Calle 25 No 455, Vedado, La Habana, Cuba.
| | - Laritza Rojas
- Centro de Estudios de Proteínas, Facultad de Biología, Universidad de La Habana, Ciudad de La Habana-Cuba, Calle 25 No 455, Vedado, La Habana, Cuba.
| | - Dayrom F Gil
- Centro de Estudios de Proteínas, Facultad de Biología, Universidad de La Habana, Ciudad de La Habana-Cuba, Calle 25 No 455, Vedado, La Habana, Cuba.
| | - Yamile González-González
- Centro de Estudios de Proteínas, Facultad de Biología, Universidad de La Habana, Ciudad de La Habana-Cuba, Calle 25 No 455, Vedado, La Habana, Cuba.
| | - Manuel Mansur
- Institut de Biotecnología i de Biomedicina, Universitat Autònoma de Barcelona, Campus Universitari, 08193, Bellaterra, Cerdanyola del Vallès, Barcelona, Spain.
| | - Ayamey Camejo
- Centro de Estudios de Proteínas, Facultad de Biología, Universidad de La Habana, Ciudad de La Habana-Cuba, Calle 25 No 455, Vedado, La Habana, Cuba.
| | - José R Pires
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373 - Bloco E, Sala 10, 21941-902, Rio de Janeiro, RJ, Brazil.
| | - Maday Alonso-Del-Rivero Antigua
- Centro de Estudios de Proteínas, Facultad de Biología, Universidad de La Habana, Ciudad de La Habana-Cuba, Calle 25 No 455, Vedado, La Habana, Cuba.
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21
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Toxoplasma gondii Arginine Methyltransferase 1 (PRMT1) Is Necessary for Centrosome Dynamics during Tachyzoite Cell Division. mBio 2016; 7:e02094-15. [PMID: 26838719 PMCID: PMC4742710 DOI: 10.1128/mbio.02094-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The arginine methyltransferase family (PRMT) has been implicated in a variety of cellular processes, including signal transduction, epigenetic regulation, and DNA repair pathways. PRMT1 is thought to be responsible for the majority of PRMT activity in Toxoplasma gondii, but its exact function is unknown. To further define the biological function of the PRMT family, we generated T. gondii mutants lacking PRMT1 (Δprmt1) by deletion of the PRMT1 gene. Δprmt1 parasites exhibit morphological defects during cell division and grow slowly, and this phenotype reverses in the Δprmt::PRMT1mRFP complemented strain. Tagged PRMT1 localizes primarily in the cytoplasm with enrichment at the pericentriolar material, and the strain lacking PRMT1 is unable to segregate progeny accurately. Unlike wild-type and complemented parasites, Δprmt1 parasites have abnormal daughter buds, perturbed centrosome stoichiometry, and loss of synchronous replication. Whole-genome expression profiling demonstrated differences in expression of cell-cycle-regulated genes in the Δprmt1 strain relative to the complemented Δprmt1::PRMT1mRFP and parental wild-type strains, but these changes do not correlate with a specific block in cell cycle. Although PRMT1’s primary biological function was previously proposed to be methylation of histones, our studies suggest that PRMT1 plays an important role within the centrosome to ensure the proper replication of the parasite. Apicomplexan parasites include several important pathogens, including Toxoplasma gondii, a major cause of opportunistic infections and congenital birth defects. These parasites divide using a unique form of cell division called endodyogeny that is different from those of most eukaryotes. PRMT1 is a conserved arginine methyltransferase that was thought to regulate gene expression of T. gondii by modifying histone methylation. Using genetic techniques, we show that disruption of PRMT1 affects the parasite’s ability to perform accurate cell division. Our studies reveal an unexpected role for arginine methylation in centrosome biology and regulation of parasite replication.
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22
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Peraro MD, van der Goot FG. Pore-forming toxins: ancient, but never really out of fashion. Nat Rev Microbiol 2015; 14:77-92. [DOI: 10.1038/nrmicro.2015.3] [Citation(s) in RCA: 476] [Impact Index Per Article: 52.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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23
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Woo YH, Ansari H, Otto TD, Klinger CM, Kolisko M, Michálek J, Saxena A, Shanmugam D, Tayyrov A, Veluchamy A, Ali S, Bernal A, del Campo J, Cihlář J, Flegontov P, Gornik SG, Hajdušková E, Horák A, Janouškovec J, Katris NJ, Mast FD, Miranda-Saavedra D, Mourier T, Naeem R, Nair M, Panigrahi AK, Rawlings ND, Padron-Regalado E, Ramaprasad A, Samad N, Tomčala A, Wilkes J, Neafsey DE, Doerig C, Bowler C, Keeling PJ, Roos DS, Dacks JB, Templeton TJ, Waller RF, Lukeš J, Oborník M, Pain A. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites. eLife 2015; 4:e06974. [PMID: 26175406 PMCID: PMC4501334 DOI: 10.7554/elife.06974] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 06/16/2015] [Indexed: 12/18/2022] Open
Abstract
The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga. DOI:http://dx.doi.org/10.7554/eLife.06974.001 Single-celled parasites cause many severe diseases in humans and animals. The apicomplexans form probably the most successful group of these parasites and include the parasites that cause malaria. Apicomplexans infect a broad range of hosts, including humans, reptiles, birds, and insects, and often have complicated life cycles. For example, the malaria-causing parasites spread by moving from humans to female mosquitoes and then back to humans. Despite significant differences amongst apicomplexans, these single-celled parasites also share a number of features that are not seen in other living species. How and when these features arose remains unclear. It is known from previous work that apicomplexans are closely related to single-celled algae. But unlike apicomplexans, which depend on a host animal to survive, these algae live freely in their environment, often in close association with corals. Woo et al. have now sequenced the genomes of two photosynthetic algae that are thought to be close living relatives of the apicomplexans. These genomes were then compared to each other and to the genomes of other algae and apicomplexans. These comparisons reconfirmed that the two algae that were studied were close relatives of the apicomplexans. Further analyses suggested that thousands of genes were lost as an ancient free-living algae evolved into the apicomplexan ancestor, and further losses occurred as these early parasites evolved into modern species. The lost genes were typically those that are important for free-living organisms, but are either a hindrance to, or not needed in, a parasitic lifestyle. Some of the ancestor's genes, especially those that coded for the building blocks of flagella (structures which free-living algae use to move around), were repurposed in ways that helped the apicomplexans to invade their hosts. Understanding this repurposing process in greater detail will help to identify key molecules in these deadly parasites that could be targeted by drug treatments. It will also offer answers to one of the most fascinating questions in evolutionary biology: how parasites have evolved from free-living organisms. DOI:http://dx.doi.org/10.7554/eLife.06974.002
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Affiliation(s)
- Yong H Woo
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Hifzur Ansari
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Thomas D Otto
- Parasite Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge, United Kingdom
| | | | - Martin Kolisko
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada
| | - Jan Michálek
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Alka Saxena
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | | | - Annageldi Tayyrov
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Alaguraj Veluchamy
- Ecology and Evolutionary Biology Section, Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR8197 INSERM U1024, Paris, France
| | - Shahjahan Ali
- Bioscience Core Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Axel Bernal
- Department of Biology, University of Pennsylvania, Philadelphia, United States
| | - Javier del Campo
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada
| | - Jaromír Cihlář
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Pavel Flegontov
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | | | - Eva Hajdušková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Aleš Horák
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Jan Janouškovec
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada
| | | | - Fred D Mast
- Seattle Biomedical Research Institute, Seattle, United States
| | - Diego Miranda-Saavedra
- Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, Madrid, Spain
| | - Tobias Mourier
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Raeece Naeem
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Mridul Nair
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Aswini K Panigrahi
- Bioscience Core Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Neil D Rawlings
- European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Eriko Padron-Regalado
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Abhinay Ramaprasad
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Nadira Samad
- School of Botany, University of Melbourne, Parkville, Australia
| | - Aleš Tomčala
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Jon Wilkes
- Wellcome Trust Centre For Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Daniel E Neafsey
- Broad Genome Sequencing and Analysis Program, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Christian Doerig
- Department of Microbiology, Monash University, Clayton, Australia
| | - Chris Bowler
- Ecology and Evolutionary Biology Section, Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR8197 INSERM U1024, Paris, France
| | - Patrick J Keeling
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada
| | - David S Roos
- Department of Biology, University of Pennsylvania, Philadelphia, United States
| | - Joel B Dacks
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Thomas J Templeton
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, United States
| | - Ross F Waller
- School of Botany, University of Melbourne, Parkville, Australia
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Arnab Pain
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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Identification and co-localization of perforin-like (TgPLP1) protein in Toxoplasma gondii bradyzoites. Exp Parasitol 2015; 153:39-44. [DOI: 10.1016/j.exppara.2015.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 01/20/2023]
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Ectopic expression of a Neospora caninum Kazal type inhibitor triggers developmental defects in Toxoplasma and Plasmodium. PLoS One 2015; 10:e0121379. [PMID: 25803874 PMCID: PMC4372514 DOI: 10.1371/journal.pone.0121379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 01/31/2015] [Indexed: 11/19/2022] Open
Abstract
Regulated proteolysis is known to control a variety of vital processes in apicomplexan parasites including invasion and egress of host cells. Serine proteases have been proposed as targets for drug development based upon inhibitor studies that show parasite attenuation and transmission blockage. Genetic studies suggest that serine proteases, such as subtilisin and rhomboid proteases, are essential but functional studies have proved challenging as active proteases are difficult to express. Proteinaceous Protease Inhibitors (PPIs) provide an alternative way to address the role of serine proteases in apicomplexan biology. To validate such an approach, a Neospora caninum Kazal inhibitor (NcPI-S) was expressed ectopically in two apicomplexan species, Toxoplasma gondii tachyzoites and Plasmodium berghei ookinetes, with the aim to disrupt proteolytic processes taking place within the secretory pathway. NcPI-S negatively affected proliferation of Toxoplasma tachyzoites, while it had no effect on invasion and egress. Expression of the inhibitor in P. berghei zygotes blocked their development into mature and invasive ookinetes. Moreover, ultra-structural studies indicated that expression of NcPI-S interfered with normal formation of micronemes, which was also confirmed by the lack of expression of the micronemal protein SOAP in these parasites. Our results suggest that NcPI-S could be a useful tool to investigate the function of proteases in processes fundamental for parasite survival, contributing to the effort to identify targets for parasite attenuation and transmission blockage.
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Yan X, Liu X, Ji Y, Tao G, Suo X. Ethanol and isopropanol trigger rapid egress of intracellular Eimeria tenella sporozoites. Parasitol Res 2014; 114:625-30. [PMID: 25407127 DOI: 10.1007/s00436-014-4224-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 11/06/2014] [Indexed: 10/24/2022]
Abstract
Egress from host cells is a vital step of the intracellular life cycle of apicomplexan parasites such as Toxoplasma gondii. This phenomenon has attracted attentions from many research groups. Previous studies have shown that ethanol could stimulate the release of microneme proteins by elevating intracellular Ca(2+) concentration of T. gondii, resulting in the parasite egress from host cells. However, little information about egress is known on Eimeria species, the causative agent of coccidiosis in poultry and livestock. In this report, we studied the effect of ethanol and isopropanol on the egress of eimerian parasites. Eimeria tenella sporozoites cultured in primary chicken kidney cells were treated with ethanol and isopropanol, then the egressed parasites were analyzed. Ethanol and isopropanol could induce the rapid egress of E. tenella sporozoites from host cells. No substantial damage was found in parasite-egressed host cells. Compared to the freshly isolated sporozoites, the re-invading ability and reproductivity of the egressed parasites significantly decreased by 43.4 and 44.1 % individually. We also found that fewer sporozoites egressed from host cells when the parasites developed for a longer time before the alcohol treatment. These results demonstrate an in vitro egress mode different from that of T. gondii, facilitating the deciphering of the mechanisms of egress of eimerian parasites.
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Affiliation(s)
- Xinlei Yan
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
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Lehmann C, Heitmann A, Mishra S, Burda PC, Singer M, Prado M, Niklaus L, Lacroix C, Ménard R, Frischknecht F, Stanway R, Sinnis P, Heussler V. A cysteine protease inhibitor of plasmodium berghei is essential for exo-erythrocytic development. PLoS Pathog 2014; 10:e1004336. [PMID: 25166051 PMCID: PMC4148452 DOI: 10.1371/journal.ppat.1004336] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Accepted: 07/08/2014] [Indexed: 11/18/2022] Open
Abstract
Plasmodium parasites express a potent inhibitor of cysteine proteases (ICP) throughout their life cycle. To analyze the role of ICP in different life cycle stages, we generated a stage-specific knockout of the Plasmodium berghei ICP (PbICP). Excision of the pbicb gene occurred in infective sporozoites and resulted in impaired sporozoite invasion of hepatocytes, despite residual PbICP protein being detectable in sporozoites. The vast majority of these parasites invading a cultured hepatocyte cell line did not develop to mature liver stages, but the few that successfully developed hepatic merozoites were able to initiate a blood stage infection in mice. These blood stage parasites, now completely lacking PbICP, exhibited an attenuated phenotype but were able to infect mosquitoes and develop to the oocyst stage. However, PbICP-negative sporozoites liberated from oocysts exhibited defective motility and invaded mosquito salivary glands in low numbers. They were also unable to invade hepatocytes, confirming that control of cysteine protease activity is of critical importance for sporozoites. Importantly, transfection of PbICP-knockout parasites with a pbicp-gfp construct fully reversed these defects. Taken together, in P. berghei this inhibitor of the ICP family is essential for sporozoite motility but also appears to play a role during parasite development in hepatocytes and erythrocytes.
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Affiliation(s)
| | - Anna Heitmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Satish Mishra
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | | | - Mirko Singer
- University of Heidelberg Medical School, Heidelberg, Germany
| | - Monica Prado
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Livia Niklaus
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Céline Lacroix
- Institute Pasteur, Unité de Biologie et Génétique du Paludisme, Paris, France
| | - Robert Ménard
- Institute Pasteur, Unité de Biologie et Génétique du Paludisme, Paris, France
| | | | - Rebecca Stanway
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Photini Sinnis
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Volker Heussler
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- * E-mail:
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28
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Wirth CC, Glushakova S, Scheuermayer M, Repnik U, Garg S, Schaack D, Kachman MM, Weißbach T, Zimmerberg J, Dandekar T, Griffiths G, Chitnis CE, Singh S, Fischer R, Pradel G. Perforin-like protein PPLP2 permeabilizes the red blood cell membrane during egress of Plasmodium falciparum gametocytes. Cell Microbiol 2014; 16:709-33. [PMID: 24602217 PMCID: PMC4312913 DOI: 10.1111/cmi.12288] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/17/2014] [Accepted: 02/21/2014] [Indexed: 12/18/2022]
Abstract
Egress of malaria parasites from the host cell requires the concerted rupture of its enveloping membranes. Hence, we investigated the role of the plasmodial perforin-like protein PPLP2 in the egress of Plasmodium falciparum from erythrocytes. PPLP2 is expressed in blood stage schizonts and mature gametocytes. The protein localizes in vesicular structures, which in activated gametocytes discharge PPLP2 in a calcium-dependent manner. PPLP2 comprises a MACPF domain and recombinant PPLP2 has haemolytic activities towards erythrocytes. PPLP2-deficient [PPLP2(−)] merozoites show normal egress dynamics during the erythrocytic replication cycle, but activated PPLP2(−) gametocytes were unable to leave erythrocytes and stayed trapped within these cells. While the parasitophorous vacuole membrane ruptured normally, the activated PPLP2(−) gametocytes were unable to permeabilize the erythrocyte membrane and to release the erythrocyte cytoplasm. In consequence, transmission of PPLP2(−) parasites to the Anopheles vector was reduced. Pore-forming equinatoxin II rescued both PPLP2(−) gametocyte exflagellation and parasite transmission. The pore sealant Tetronic 90R4, on the other hand, caused trapping of activated wild-type gametocytes within the enveloping erythrocytes, thus mimicking the PPLP2(−) loss-of-function phenotype. We propose that the haemolytic activity of PPLP2 is essential for gametocyte egress due to permeabilization of the erythrocyte membrane and depletion of the erythrocyte cytoplasm.
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Affiliation(s)
- Christine C Wirth
- Institute of Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
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29
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Abstract
SUMMARYCryptosporidiumhost cell interaction remains fairly obscure compared with other apicomplexans such asPlasmodiumorToxoplasma. The reason for this is probably the inability of this parasite to complete its life cyclein vitroand the lack of a system to genetically modifyCryptosporidium. However, there is a substantial set of data about the molecules involved in attachment and invasion and about the host cell pathways involved in actin arrangement that are altered by the parasite. Here we summarize the recent advances in research on host cell infection regarding the excystation process, attachment and invasion, survival in the cell, egress and the available data on omics.
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30
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Abstract
A wide spectrum of pathogenic bacteria and protozoa has adapted to an intracellular life-style, which presents several advantages, including accessibility to host cell metabolites and protection from the host immune system. Intracellular pathogens have developed strategies to enter and exit their host cells while optimizing survival and replication, progression through the life cycle, and transmission. Over the last decades, research has focused primarily on entry, while the exit process has suffered from neglect. However, pathogen exit is of fundamental importance because of its intimate association with dissemination, transmission, and inflammation. Hence, to fully understand virulence mechanisms of intracellular pathogens at cellular and systemic levels, it is essential to consider exit mechanisms to be a key step in infection. Exit from the host cell was initially viewed as a passive process, driven mainly by physical stress as a consequence of the explosive replication of the pathogen. It is now recognized as a complex, strategic process termed "egress," which is just as well orchestrated and temporally defined as entry into the host and relies on a dynamic interplay between host and pathogen factors. This review compares egress strategies of bacteria, pathogenic yeast, and kinetoplastid and apicomplexan parasites. Emphasis is given to recent advances in the biology of egress in mycobacteria and apicomplexans.
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31
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Tawk L, Lacroix C, Gueirard P, Kent R, Gorgette O, Thiberge S, Mercereau-Puijalon O, Ménard R, Barale JC. A key role for Plasmodium subtilisin-like SUB1 protease in egress of malaria parasites from host hepatocytes. J Biol Chem 2013; 288:33336-46. [PMID: 24089525 DOI: 10.1074/jbc.m113.513234] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In their mammalian host, Plasmodium parasites have two obligatory intracellular development phases, first in hepatocytes and subsequently in erythrocytes. Both involve an orchestrated process of invasion into and egress from host cells. The Plasmodium SUB1 protease plays a dual role at the blood stage by enabling egress of the progeny merozoites from the infected erythrocyte and priming merozoites for subsequent erythrocyte invasion. Here, using conditional mutagenesis in P. berghei, we show that SUB1 plays an essential role at the hepatic stage. Stage-specific sub1 invalidation during prehepatocytic development showed that SUB1-deficient parasites failed to rupture the parasitophorous vacuole membrane and to egress from hepatocytes. Furthermore, mechanically released parasites were not adequately primed and failed to establish a blood stage infection in vivo. The critical involvement of SUB1 in both pre-erythrocytic and erythrocytic developmental phases qualifies SUB1 as an attractive multistage target for prophylactic and therapeutic anti-Plasmodium intervention strategies.
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Affiliation(s)
- Lina Tawk
- From the Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, Département de Parasitologie et de Mycologie, F-75015 Paris, France
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32
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Caldas LA, Seabra SH, Attias M, de Souza W. The effect of kinase, actin, myosin and dynamin inhibitors on host cell egress by Toxoplasma gondii. Parasitol Int 2013; 62:475-82. [DOI: 10.1016/j.parint.2013.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 03/26/2013] [Accepted: 04/18/2013] [Indexed: 12/21/2022]
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33
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Deligianni E, Morgan RN, Bertuccini L, Wirth CC, Silmon de Monerri NC, Spanos L, Blackman MJ, Louis C, Pradel G, Siden-Kiamos I. A perforin-like protein mediates disruption of the erythrocyte membrane during egress of Plasmodium berghei male gametocytes. Cell Microbiol 2013; 15:1438-55. [PMID: 23461714 DOI: 10.1111/cmi.12131] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 01/31/2013] [Accepted: 02/25/2013] [Indexed: 12/31/2022]
Abstract
Successful gametogenesis of the malaria parasite depends on egress of the gametocytes from the erythrocytes within which they developed. Egress entails rupture of both the parasitophorous vacuole membrane and the erythrocyte plasma membrane, and precedes the formation of the motile flagellated male gametes in a process called exflagellation. We show here that egress of the male gametocyte depends on the function of a perforin-like protein, PPLP2. A mutant of Plasmodium berghei lacking PPLP2 displayed abnormal exflagellation; instead of each male gametocyte forming eight flagellated gametes, it produced gametocytes with only one, shared thicker flagellum. Using immunofluorescence and transmission electron microscopy analysis, and phenotype rescue with saponin or a pore-forming toxin, we conclude that rupture of the erythrocyte membrane is blocked in the mutant. The parasitophorous vacuole membrane, on the other hand, is ruptured normally. Some mutant parasites are still able to develop in the mosquito, possibly because the vigorous motility of the flagellated gametes eventually leads to escape from the persisting erythrocyte membrane. This is the first example of a perforin-like protein in Plasmodium parasites having a role in egress from the host cell and the first parasite protein shown to be specifically required for erythrocyte membrane disruption during egress.
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Affiliation(s)
- Elena Deligianni
- Institute of Molecular Biology and Biotechnology, FORTH, Heraklion, Greece
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34
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Almeida-Campos FR, Castro-Gomes T, Machado-Silva A, de Oliveira JS, Santoro MM, Frézard F, Horta MF. Activation of Leishmania spp. leishporin: evidence that dissociation of an inhibitor not only improves its lipid-binding efficiency but also endows it with the ability to form pores. Parasitol Res 2013; 112:3305-14. [PMID: 23812644 DOI: 10.1007/s00436-013-3510-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 06/14/2013] [Indexed: 11/29/2022]
Abstract
We have previously shown that various species of Leishmania produce a lytic activity, which, in Leishmania amazonensis, is mediated by a pore-forming cytolysin, called leishporin. It is toxic for macrophages in vitro and optimally active at pH 5.0 to 5.5 and at 37 °C, suggesting that it might be active inside phagolysosomes. Leishporin from both L. amazonensis (a-leishporin) and Leishmania guyanensis (g-leishporin) can be activated by proteases, suggesting either a limited proteolysis of an inactive precursor or a proteolytic degradation of a non-covalently linked inhibitor. Here, we show that both a- and g-leishporin are also activated in dissociating conditions, indicating the second hypothesis as the correct one. In fact, we further demonstrated that inactive leishporin is non-covalently associated with an inhibitor, possibly more than one oligopeptide that, when removed, renders leishporin hemolytically active. This activation was shown to be the result of both the improvement of leishporin's ability to bind to phospholipids and the emergence of its pore-forming ability. In vitro results demonstrate that leishporin can be released by the parasites, as they evolve in axenic cultures, in an inactive form that can be activated. These results are compatible with our hypothesis that leishporin can be activated in the protease-rich, low pH, and dissociating environment of parasitophorous vacuoles, leading to disruption of both vacuoles and plasma membranes with the release of amastigotes.
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Affiliation(s)
- Flávia Regina Almeida-Campos
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901, Belo Horizonte, MG, Brazil
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35
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Evolution of apicomplexan secretory organelles. Int J Parasitol 2012; 42:1071-81. [PMID: 23068912 DOI: 10.1016/j.ijpara.2012.09.009] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 09/16/2012] [Accepted: 09/17/2012] [Indexed: 12/26/2022]
Abstract
The alveolate superphylum includes many free-living and parasitic organisms, which are united by the presence of alveolar sacs lying proximal to the plasma membrane, providing cell structure. All species comprising the apicomplexan group of alveolates are parasites and have adapted to the unique requirements of the parasitic lifestyle. Here the evolution of apicomplexan secretory organelles that are involved in the critical process of egress from one cell and invasion of another is explored. The variations within the Apicomplexa and how these relate to species-specific biology will be discussed. In addition, recent studies have identified specific calcium-sensitive molecules that coordinate the various events and regulate the release of these secretory organelles within apicomplexan parasites. Some aspects of this machinery are conserved outside the Apicomplexa, and are beginning to elucidate the conserved nature of the machinery. Briefly, the relationship of this secretion machinery within the Apicomplexa will be discussed, compared with free-living and predatory alveolates, and how these might have evolved from a common ancestor.
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36
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Wirth CC, Pradel G. Molecular mechanisms of host cell egress by malaria parasites. Int J Med Microbiol 2012; 302:172-8. [DOI: 10.1016/j.ijmm.2012.07.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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37
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Cruz LN, Wu Y, Craig AG, Garcia CRS. Signal transduction in Plasmodium-Red Blood Cells interactions and in cytoadherence. AN ACAD BRAS CIENC 2012; 84:555-72. [PMID: 22634746 DOI: 10.1590/s0001-37652012005000036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 03/09/2012] [Indexed: 12/19/2022] Open
Abstract
Malaria is responsible for more than 1.5 million deaths each year, especially among children (Snow et al. 2005). Despite of the severity of malaria situation and great effort to the development of new drug targets (Yuan et al. 2011) there is still a relative low investment toward antimalarial drugs. Briefly there are targets classes of antimalarial drugs currently being tested including: kinases, proteases, ion channel of GPCR, nuclear receptor, among others (Gamo et al. 2010). Here we review malaria signal transduction pathways in Red Blood Cells (RBC) as well as infected RBCs and endothelial cells interactions, namely cytoadherence. The last process is thought to play an important role in the pathogenesis of severe malaria. The molecules displayed on the surface of both infected erythrocytes (IE) and vascular endothelial cells (EC) exert themselves as important mediators in cytoadherence, in that they not only induce structural and metabolic changes on both sides, but also trigger multiple signal transduction processes, leading to alteration of gene expression, with the balance between positive and negative regulation determining endothelial pathology during a malaria infection.
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Affiliation(s)
- Laura N Cruz
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Brasil
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38
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Hopp CS, Bowyer PW, Baker DA. The role of cGMP signalling in regulating life cycle progression of Plasmodium. Microbes Infect 2012; 14:831-7. [PMID: 22613210 PMCID: PMC3484397 DOI: 10.1016/j.micinf.2012.04.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/13/2012] [Accepted: 04/17/2012] [Indexed: 11/25/2022]
Abstract
The 3′-5′-cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) is the main mediator of cGMP signalling in the malaria parasite. This article reviews the role of PKG in Plasmodium falciparum during gametogenesis and blood stage schizont rupture, as well as the role of the Plasmodium berghei orthologue in ookinete differentiation and motility, and liver stage schizont development. The current views on potential effector proteins downstream of PKG and the mechanisms that may regulate cyclic nucleotide levels are presented.
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Affiliation(s)
- Christine S Hopp
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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39
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Control of Plasmodium falciparum erythrocytic cycle: γδ T cells target the red blood cell-invasive merozoites. Blood 2011; 118:6952-62. [PMID: 22045985 DOI: 10.1182/blood-2011-08-376111] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The control of Plasmodium falciparum erythrocytic parasite density is essential for protection against malaria, because it prevents pathogenesis and progression toward severe disease. P falciparum blood-stage parasite cultures are inhibited by human Vγ9Vδ2 γδ T cells, but the underlying mechanism remains poorly understood. Here, we show that both intraerythrocytic parasites and the extracellular red blood cell-invasive merozoites specifically activate Vγ9Vδ2 T cells in a γδ T cell receptor-dependent manner and trigger their degranulation. In contrast, the γδ T cell-mediated antiparasitic activity only targets the extracellular merozoites. Using perforin-deficient and granulysin-silenced T-cell lines, we demonstrate that granulysin is essential for the in vitro antiplasmodial process, whereas perforin is dispensable. Patients infected with P falciparum exhibited elevated granulysin plasma levels associated with high levels of granulysin-expressing Vδ2(+) T cells endowed with parasite-specific degranulation capacity. This indicates in vivo activation of Vγ9Vδ2 T cells along with granulysin triggering and discharge during primary acute falciparum malaria. Altogether, this work identifies Vγ9Vδ2 T cells as unconventional immune effectors targeting the red blood cell-invasive extracellular P falciparum merozoites and opens novel perspectives for immune interventions harnessing the antiparasitic activity of Vγ9Vδ2 T cells to control parasite density in malaria patients.
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40
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Abstract
Intracellular parasitism has arisen only a few times during the long ancestry of protozoan parasites including in diverse groups such as microsporidians, kinetoplastids, and apicomplexans. Strategies used to gain entry differ widely from injection (e.g. microsporidians), active penetration of the host cell (e.g. Toxoplasma), recruitment of lysosomes to a plasma membrane wound (e.g. Trypanosoma cruzi), to host cell-mediated phagocytosis (e.g. Leishmania). The resulting range of intracellular niches is equally diverse ranging from cytosolic (e.g. T. cruzi) to residing within a non-fusigenic vacuole (e.g. Toxoplasma, Encephalitozoon) or a modified phagolysosome (e.g. Leishmania). These lifestyle choices influence access to nutrients, interaction with host cell signaling pathways, and detection by pathogen recognition systems. As such, intracellular life requires a repertoire of adaptations to assure entry-exit from the cell, as well as to thwart innate immune mechanisms and prevent clearance. Elucidating these pathways at the cellular and molecular level may identify key steps that can be targeted to reduce parasite survival or augment immunologic responses and thereby prevent disease.
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Affiliation(s)
- L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63100, USA.
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41
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Enhanced egress of intracellular Eimeria tenella sporozoites by splenic lymphocytes from coccidian-infected chickens. Infect Immun 2011; 79:3465-70. [PMID: 21628515 DOI: 10.1128/iai.01334-10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Egress, which describes the mechanism that some intracellular parasites use to exit from parasitophorous vacuoles and host cells, plays a very important role in the parasite life cycle and is central to Eimeria propagation and pathogenesis. Despite the importance of egress in the intracellular parasite's life cycle, very little information is known on this process compared to other steps, e.g., invasion. The present study was conducted to investigate the interplay between the host adaptive immune system and Eimeria egression. Splenic lymphocytes or soluble immune factors were incubated with parasite-infected host cells for 3 or 5 h, and the percentage of egress was calculated according to an established formula. Viability of egressed parasites and host cells was tested using trypan blue exclusion and annexin V and propidium iodide staining, respectively. We found that premature egression of sporozoites from Eimeria tenella-infected primary chicken kidney cells or from chicken peripheral blood mononuclear cells occurred when the cells were cocultured in vitro with spleen lymphocytes from E. tenella-infected chickens but not when they were cocultured with splenocytes from uninfected chickens. Eimeria-specific antibodies and cytokines (gamma interferon [IFN-γ], interleukin-2 [IL-2], and IL-15), derived from E. tenella-primed B and T lymphocytes, respectively, were capable of promoting premature egress of sporozoites from infected host cells. Both egressed parasites and host cells were viable, although the latter showed reduced reinvasion ability. These results suggest a novel, immune-mediated mechanism that the host exploits to interrupt the normal Eimeria life cycle in vivo and thereby block the release of mature parasites into the environment.
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How pathogen-derived cysteine proteases modulate host immune responses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 712:192-207. [PMID: 21660666 PMCID: PMC7123607 DOI: 10.1007/978-1-4419-8414-2_12] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In mammals, cysteine proteases are essential for the induction and development of both innate and adaptive immune responses. These proteases play a role in antigen-and pathogen-recognition and elimination, signal processing and cell homeostasis. Many pathogens also secrete cysteine proteases that often act on the same target proteins as the mammalian proteases and thereby can modulate host immunity from initial recognition to effector mechanisms. Pathogen-derived proteases range from nonspecific proteases that degrade multiple proteins involved in the immune response to enzymes that are very specific in their mode of action. Here, we overview current knowledge of pathogen-derived cysteine proteases that modulate immune responses by altering the normal function of key receptors or pathways in the mammalian immune system.
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Sologub L, Kuehn A, Kern S, Przyborski J, Schillig R, Pradel G. Malaria proteases mediate inside-out egress of gametocytes from red blood cells following parasite transmission to the mosquito. Cell Microbiol 2011; 13:897-912. [DOI: 10.1111/j.1462-5822.2011.01588.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Molecular cloning and characterization of a M17 leucine aminopeptidase of Cryptosporidium parvum. Parasitology 2011; 138:682-90. [DOI: 10.1017/s0031182011000199] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYLeucine aminopeptidases (LAPs) are a group of metalloexopeptidases that catalyse the sequential removal of amino acids from the N-termini of polypeptides or proteins. They play an important role in regulating the balance between catabolism and anabolism in living cells. LAPs of apicomplexa parasitic protozoa have been intensively investigated due to their crucial roles in parasite biology as well as their potentials as drug targets. In this study, we identified an M17 leucine aminopeptidase of Cryptosporidium parvum (CpLAP) and characterized the biochemical properties of the recombinant protein. Multiple sequence alignment of the deduced amino acid sequence of CpLAP with those of other organisms revealed that typical amino acid residues essential for metal binding and active-site formation in M17 LAPs were well conserved in CpLAP. Recombinant CpLAP shared similar biochemical properties such as optimal pH, stability at neutral pHs, and metal-binding characteristics with other characterized LAPs. The enzyme showed a marked preference for Leu and its activity was effectively inhibited by bestatin. These results collectively suggest that CpLAP is a typical member of the M17 LAP family and may play an important role in free amino acid regulation in the parasite.
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Deu E, Leyva MJ, Albrow VE, Rice MJ, Ellman JA, Bogyo M. Functional studies of Plasmodium falciparum dipeptidyl aminopeptidase I using small molecule inhibitors and active site probes. ACTA ACUST UNITED AC 2011; 17:808-19. [PMID: 20797610 DOI: 10.1016/j.chembiol.2010.06.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 06/20/2010] [Accepted: 06/25/2010] [Indexed: 11/26/2022]
Abstract
The widespread resistance of malaria parasites to all affordable drugs has made the identification of new targets urgent. Dipeptidyl aminopeptidases (DPAPs) represent potentially valuable new targets that are involved in hemoglobin degradation (DPAP1) and parasite egress (DPAP3). Here we use activity-based probes to demonstrate that specific inhibition of DPAP1 by a small molecule results in the formation of an immature trophozoite that leads to parasite death. Using computational methods, we designed stable, nonpeptidic covalent inhibitors that kill Plasmodium falciparum at low nanomolar concentrations. These compounds show signs of slowing parasite growth in a murine model of malaria, which suggests that DPAP1 might be a viable antimalarial target. Interestingly, we found that resynthesis and activation of DPAP1 after inhibition is rapid, suggesting that effective drugs would need to sustain DPAP1 inhibition for a period of 2-3 hr.
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Affiliation(s)
- Edgar Deu
- Department of Pathology, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
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de Miguel N, Lustig G, Twu O, Chattopadhyay A, Wohlschlegel JA, Johnson PJ. Proteome analysis of the surface of Trichomonas vaginalis reveals novel proteins and strain-dependent differential expression. Mol Cell Proteomics 2010; 9:1554-66. [PMID: 20467041 DOI: 10.1074/mcp.m000022-mcp201] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The identification of surface proteins on the plasma membrane of pathogens is of fundamental importance in understanding host-pathogen interactions. Surface proteins of the extracellular parasite Trichomonas are implicated in the initial adherence to mucosal tissue and are likely to play a critical role in the long term survival of this pathogen in the urogenital tract. In this study, we used cell surface biotinylation and multidimensional protein identification technology to identify the surface proteome of six strains of Trichomonas vaginalis with differing adherence capacities to vaginal epithelial cells. A combined total of 411 proteins were identified, and of these, 11 were found to be more abundant in adherent strains relative to less adherent parasites. The mRNA levels of five differentially expressed proteins selected for quantitative RT-PCR analysis mirrored their observed protein levels, confirming their up-regulation in highly adherent strains. As proof of principle and to investigate a possible role in pathogenesis for differentially expressed proteins, gain of function experiments were performed using two novel proteins that were among the most highly expressed surface proteins in adherent strains. Overexpression of either of these proteins, TVAG_244130 or TVAG_166850, in a relatively non-adherent strain increased attachment of transfected parasites to vaginal epithelial cells approximately 2.2-fold. These data support a role in adhesion for these abundant surface proteins. Our analyses demonstrate that comprehensive profiling of the cell surface proteome of different parasite strains is an effective approach to identify potential new adhesion factors as well as other surface molecules that may participate in establishing and maintaining infection by this extracellular pathogen.
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Affiliation(s)
- Natalia de Miguel
- Department of Microbiology, University of California, Los Angeles, California 90095-1489, USA
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Castro-Gomes T, Almeida-Campos FR, Calzavara-Silva CE, da Silva RA, Frézard F, Horta MF. Membrane binding requirements for the cytolytic activity ofLeishmania amazonensisleishporin. FEBS Lett 2009; 583:3209-14. [DOI: 10.1016/j.febslet.2009.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 09/02/2009] [Accepted: 09/03/2009] [Indexed: 12/11/2022]
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