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Toxoplasma gondii SAG1 targeting host cell S100A6 for parasite invasion and host immunity. iScience 2021; 24:103514. [PMID: 34950858 PMCID: PMC8671940 DOI: 10.1016/j.isci.2021.103514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/21/2021] [Accepted: 11/22/2021] [Indexed: 11/23/2022] Open
Abstract
Toxoplasma gondii surface antigen 1 (TgSAG1) is a surface protein of tachyzoites, which plays a crucial role in toxoplasma gondii infection and host cell immune regulation. However, how TgSAG1 regulates these processes remains elucidated. We utilized the biotin ligase -TurboID fusion with TgSAG1 to identify the host proteins interacting with TgSAG1, and identified that S100A6 was co-localized with TgSAG1 when T. gondii attached to the host cell. S100A6, either knocking down or blocking its functional epitopes resulted in inhibited parasites invasion. Meanwhile, S100A6 overexpression in host cells promoted T. gondii infection. We further verified that TgSAG1 could inhibit the interaction of host cell vimentin with S100A6 for cytoskeleton organization during T. gondii invasion. As an immunogen, TgSAG1 could promote the secretion of tumor necrosis factor alpha (TNF-α) through S100A6-Vimentin/PKCθ-NF-κB signaling pathway. In summary, our findings revealed a mechanism for how TgSAG1 functioned in parasitic invasion and host immune regulation. TgSAG1 interacts with host protein S100A6 then regulates T. gondii infection TgSAG1 could regulate binding vimentin with S100A6 during T. gondii infection TgSAG1 regulate TNFα secretion through S100A6-vimentin/PKCθ-NF-κB signaling pathway
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Toxoplasma gondii GRA28 Is Required for Placenta-Specific Induction of the Regulatory Chemokine CCL22 in Human and Mouse. mBio 2021; 12:e0159121. [PMID: 34781732 PMCID: PMC8593671 DOI: 10.1128/mbio.01591-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii is an intracellular protozoan pathogen of humans that can cross the placenta and result in adverse pregnancy outcomes and long-term birth defects. The mechanisms used by T. gondii to cross the placenta are unknown, but complex interactions with the host immune response are likely to play a role in dictating infection outcomes during pregnancy. Prior work showed that T. gondii infection dramatically and specifically increases the secretion of the immunomodulatory chemokine CCL22 in human placental cells during infection. Given the important role of this chemokine during pregnancy, we hypothesized that CCL22 induction was driven by a specific T. gondii-secreted effector. Using a combination of bioinformatics and molecular genetics, we have now identified T. gondii GRA28 as the gene product required for CCL22 induction. GRA28 is secreted into the host cell, where it localizes to the nucleus, and deletion of the GRA28 gene results in reduced CCL22 placental cells as well as a human monocyte cell line. The impact of GRA28 on CCL22 production is also conserved in mouse immune and placental cells both in vitro and in vivo. Moreover, parasites lacking GRA28 are impaired in their ability to disseminate throughout the animal, suggesting a link between CCL22 induction and the ability of the parasite to cause disease. Overall, these data demonstrate a clear function for GRA28 in altering the immunomodulatory landscape during infection of both placental and peripheral immune cells and show a clear impact of this immunomodulation on infection outcome. IMPORTANCE Toxoplasma gondii is a globally ubiquitous pathogen that can cause severe disease in HIV/AIDS patients and can also cross the placenta and infect the developing fetus. We have found that placental and immune cells infected with T. gondii secrete significant amounts of a chemokine (called CCL22) that is critical for immune tolerance during pregnancy. In order to better understand whether this is a response by the host or a process that is driven by the parasite, we have identified a T. gondii gene that is absolutely required to induce CCL22 production in human cells, indicating that CCL22 production is a process driven almost entirely by the parasite rather than the host. Consistent with its role in immune tolerance, we also found that T. gondii parasites lacking this gene are less able to proliferate and disseminate throughout the host. Taken together, these data illustrate a direct relationship between CCL22 levels in the infected host and a key parasite effector and provide an interesting example of how T. gondii can directly modulate host signaling pathways in order to facilitate its growth and dissemination.
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Chen XQ, Elsheikha HM, Hu RS, Hu GX, Guo SL, Zhou CX, Zhu XQ. Hepatic Metabolomics Investigation in Acute and Chronic Murine Toxoplasmosis. Front Cell Infect Microbiol 2018; 8:189. [PMID: 29922602 PMCID: PMC5996072 DOI: 10.3389/fcimb.2018.00189] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 05/17/2018] [Indexed: 11/29/2022] Open
Abstract
Toxoplasma gondii poses a great threat to human health, with no approved vaccine available for the treatment of T. gondii infection. T. gondii infections are not limited to the brain, and may also affect other organs especially the liver. Identification of host liver molecules or pathways involved in T. gondii replication process may lead to the discovery of novel anti-T. gondii targets. Here, we analyzed the metabolic profile of the liver of mice on 11 and 30 days postinfection (dpi) with type II T. gondii Pru strain. Global metabolomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified 389 significant metabolites from acutely infected mice; and 368 from chronically infected mice, when compared with control mice. Multivariate statistical analysis revealed distinct metabolic signatures from acutely infected, chronically infected and control mice. Infection influenced several metabolic processes, in particular those for lipids and amino acids. Metabolic pathways, such as steroid hormone biosynthesis, primary bile acid biosynthesis, bile secretion, and biosynthesis of unsaturated fatty acids were perturbed during the whole infection process, particularly during the acute stage of infection. The present results provide insight into hepatic metabolic changes that occur in BALB/c mice during acute and chronic T. gondii infection.
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Affiliation(s)
- Xiao-Qing 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.,College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, United Kingdom
| | - Rui-Si Hu
- 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
| | - Gui-Xue Hu
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Shu-Ling Guo
- Department of Parasitology, Shandong University School of Basic Medicine, Jinan, China
| | - Chun-Xue Zhou
- Department of Parasitology, Shandong University School of Basic Medicine, Jinan, 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
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Borges IP, Silva MF, Santiago FM, de Faria LS, Júnior ÁF, da Silva RJ, Costa MS, de Freitas V, Yoneyama KAG, Ferro EAV, Lopes DS, Rodrigues RS, de Melo Rodrigues V. Antiparasitic effects induced by polyclonal IgY antibodies anti-phospholipase A2 from Bothrops pauloensis venom. Int J Biol Macromol 2018; 112:333-342. [DOI: 10.1016/j.ijbiomac.2018.01.178] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/25/2018] [Accepted: 01/27/2018] [Indexed: 02/07/2023]
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Wilson SK, Knoll LJ. Patatin-like phospholipases in microbial infections with emerging roles in fatty acid metabolism and immune regulation by Apicomplexa. Mol Microbiol 2017; 107:34-46. [PMID: 29090840 DOI: 10.1111/mmi.13871] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 10/23/2017] [Accepted: 10/26/2017] [Indexed: 12/22/2022]
Abstract
Emerging lipidomic technologies have enabled researchers to dissect the complex roles of phospholipases in lipid metabolism, cellular signaling and immune regulation. Host phospholipase products are involved in stimulating and resolving the inflammatory response to pathogens. While many pathogen-derived phospholipases also manipulate the immune response, they have recently been shown to be involved in lipid remodeling and scavenging during replication. Animal and plant hosts as well as many pathogens contain a family of patatin-like phospholipases, which have been shown to have phospholipase A2 activity. Proteins containing patatin-like phospholipase domains have been identified in protozoan parasites within the Apicomplexa phylum. These parasites are the causative agents of some of the most widespread human diseases. Malaria, caused by Plasmodium spp., kills nearly half a million people worldwide each year. Toxoplasma and Cryptosporidium infect millions of people each year with lethal consequences in immunocompromised populations. Parasite-derived patatin-like phospholipases are likely effective drug targets and progress in the tools available to the Apicomplexan field will allow for a closer look at the interplay of lipid metabolism and immune regulation during host infection.
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Affiliation(s)
- Sarah K Wilson
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Laura J Knoll
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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Chen XQ, Zhou CX, Elsheikha HM, He S, Hu GX, Zhu XQ. Profiling of the perturbed metabolomic state of mouse spleen during acute and chronic toxoplasmosis. Parasit Vectors 2017; 10:339. [PMID: 28720125 PMCID: PMC5516376 DOI: 10.1186/s13071-017-2282-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 07/10/2017] [Indexed: 01/13/2023] Open
Abstract
Background Toxoplasma gondii, a common opportunistic protozoan, is a leading cause of illness and mortality among immunosuppressed individuals and during congenital infections. Current therapeutic strategies for toxoplasmosis are not fully effective at curtailing disease progression in these cases. Given the parasite ability to influence host immunity and metabolism, understanding of the metabolic alterations in the host’s immune organs during T. gondii infection may enhance the understanding of the molecular mechanisms that define the pathophysiology of T. gondii infection. Methods We investigated the global metabolic changes in the spleen of BALB/c mice at early and late stage of infection with T. gondii using LC-MS/MS-based metabolomics. Multivariate data analysis methods, principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA), were used to identify metabolites that are influenced by T. gondii infection. Results Multivariate analyses clearly separated the metabolites of spleen of infected and control mice. A total of 132 differential metabolites were identified, 23 metabolites from acutely infected versus control mice and 109 metabolites from chronically infected versus control mice. Lipids, hormones, lactones, acids, peptides, antibiotics, alkaloids and natural toxins were the most influenced chemical groups. There were 12 shared differential metabolites between acutely infected versus control mice and chronically infected versus control mice, of which 4,4-Dimethyl-5alpha-cholesta-8,14,24-trien-3beta-ol was significantly upregulated and ubiquinone-8 was significantly downregulated. Major perturbed metabolic pathways included primary bile acid biosynthesis, steroid hormone biosynthesis, biotin metabolism, and steroid biosynthesis, with arachidonic acid metabolism being the most significantly impacted pathway. These metabolic changes suggest a multifactorial nature of the immunometabolic responses of mouse spleen to T. gondii infection. Conclusions This study demonstrated that T. gondii infection can cause significant metabolomic alterations in the spleen of infected mice. These findings provide new insights into the molecular mechanisms that underpin the pathogenesis of T. gondii infection. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2282-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiao-Qing Chen
- Department of Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin Province, 130118, People's Republic of China.,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, Gansu Province, 730046, People's Republic of China
| | - Chun-Xue Zhou
- 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, Gansu Province, 730046, People's Republic of China.,Department of Parasitology, Shandong University School of Basic Medicine, Jinan, Shandong Province, 250012, People's Republic of China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - Shuai He
- 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, Gansu Province, 730046, People's Republic of China.,College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province, 230036, People's Republic of China
| | - Gui-Xue Hu
- Department of Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin Province, 130118, People's Republic of 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, Gansu Province, 730046, People's Republic of China.
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Cui XZ, Zheng MX, Zhang Y, Liu RL, Yang SS, Li S, Xu ZY, Bai R, Lv QH, Zhao WL. Calcium homeostasis in mitochondrion-mediated apoptosis of chick embryo cecal epithelial cells induced by Eimeria tenella infection. Res Vet Sci 2015; 104:166-73. [PMID: 26850556 DOI: 10.1016/j.rvsc.2015.12.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 11/11/2015] [Accepted: 12/22/2015] [Indexed: 01/28/2023]
Abstract
In this study, the process of Eimeria tenella-induced apoptosis and the effect of calcium homeostasis were investigated in chick embryo cecal epithelial cells. In particular, we examined cytochrome c release into the cytoplasm, mitochondrial permeability transition pore (MPTP) opening, and changes in [Ca(2+)]c and apoptosis in host cells. Apoptosis, MPTP opening, cytochrome c release, and [Ca(2+)]c in host cells increased following infection. This trend was reversed by blocking the increase in [Ca(2+)]c using BAPTA/AM and EGTA (intra- and extracellular chelators of Ca(2+), respectively) and by applying heparin sodium and ryanodine (blockers of the inositol triphosphate and ryanodine receptors of the endoplasmic reticulum, respectively). These results indicate that [Ca(2+)]c plays a significant role in host cell mitochondrial apoptosis, which is induced via modulation of extracellular Ca(2+) levels and endoplasmic reticulum Ca(2+) channels. Thus, agents that restore Ca(2+) homeostasis may be useful for managing E. tenella infection in chickens.
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Affiliation(s)
- Xiao-zhen Cui
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
| | - Ming-xue Zheng
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China.
| | - Yan Zhang
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
| | - Rui-li Liu
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
| | - Sha-sha Yang
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
| | - Shan Li
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
| | - Zhi-yong Xu
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
| | - Rui Bai
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
| | - Qiang-hua Lv
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
| | - Wen-long Zhao
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi Province 030801, PR China
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Role of gap junctions and hemichannels in parasitic infections. BIOMED RESEARCH INTERNATIONAL 2013; 2013:589130. [PMID: 24236292 PMCID: PMC3819887 DOI: 10.1155/2013/589130] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 08/07/2013] [Accepted: 08/26/2013] [Indexed: 02/06/2023]
Abstract
In vertebrates, connexins (Cxs) and pannexins (Panxs) are proteins that form gap junction channels and/or hemichannels located at cell-cell interfaces and cell surface, respectively. Similar channel types are formed by innexins in invertebrate cells. These channels serve as pathways for cellular communication that coordinate diverse physiologic processes. However, it is known that many acquired and inherited diseases deregulate Cx and/or Panx channels, condition that frequently worsens the pathological state of vertebrates. Recent evidences suggest that Cx and/or Panx hemichannels play a relevant role in bacterial and viral infections. Nonetheless, little is known about the role of Cx- and Panx-based channels in parasitic infections of vertebrates. In this review, available data on changes in Cx and gap junction channel changes induced by parasitic infections are summarized. Additionally, we describe recent findings that suggest possible roles of hemichannels in parasitic infections. Finally, the possibility of new therapeutic designs based on hemichannel blokers is presented.
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Rub A, Arish M, Husain SA, Ahmed N, Akhter Y. Host-lipidome as a potential target of protozoan parasites. Microbes Infect 2013; 15:649-60. [PMID: 23811020 DOI: 10.1016/j.micinf.2013.06.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/13/2013] [Accepted: 06/18/2013] [Indexed: 12/24/2022]
Abstract
Host-lipidome caters parasite interaction by acting as first line of recognition, attachment on the cell surface, intracellular trafficking, and survival of the parasite inside the host cell. Here, we summarize how protozoan parasites exploit host-lipidome by suppressing, augmenting, engulfing, remodeling and metabolizing lipids to achieve successful parasitism inside the host.
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Affiliation(s)
- Abdur Rub
- Infection and Immunity Lab, Department of Biotechnology, Jamia Millia Islamia (A Central University), New Delhi 110025, India.
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Na RH, Zhu GH, Luo JX, Meng XJ, Cui L, Peng HJ, Chen XG, Gomez-Cambronero J. Enzymatically active Rho and Rac small-GTPases are involved in the establishment of the vacuolar membrane after Toxoplasma gondii invasion of host cells. BMC Microbiol 2013; 13:125. [PMID: 23721065 PMCID: PMC3681593 DOI: 10.1186/1471-2180-13-125] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 05/27/2013] [Indexed: 11/10/2022] Open
Abstract
Background GTPases are the family of hydrolases that bind and hydrolyze guanosine triphosphate. The large Immunity-related GTPases and the small GTPase ADP-ribosylation factor-6 in host cells are known to accumulate on the parasitophorous vacuole membrane (PVM) of Toxoplasma gondii and play critical roles in this parasite infection, but these GTPases cannot explain the full extent of infection. Results In this research, RhoA and Rac1 GTPases from the host cell were found to accumulate on the PVM regardless of the virulence of the T. gondii strains after T. gondii invasion, and this accumulation was dependent on their GTPase activity. The real-time micrography of T. gondii tachyzoites invading COS-7 cells overexpressing CFP-RhoA showed that this GTPase was recruited to the PVM at the very beginning of the invasion through the host cell membrane or from the cytosol. Host cell RhoA and Rac1 were also activated after T. gondii tachyzoites invasion, which was needed for host cell cytoskeleton reorganization to facilitate intracellular pathogens invasion. The decisive domains for the RhoA accumulation on the PVM included the GTP/Mg2+ binding site, the mDia effector interaction site, the G1 box, the G2 box and the G5 box, respectively, which were related to the binding of GTP for enzymatic activity and mDia for the regulation of microtubules. The recruited CFP-RhoA on the PVM could not be activated by epithelial growth factor (EGF) and no translocation was observed, unlike the unassociated RhoA in the host cell cytosol that migrated to the cell membrane towards the EGF activation spot. This result supported the hypothesis that the recruited RhoA or Rac1 on the PVM were in the GTP-bound active form. Wild-type RhoA or Rac1 overexpressed cells had almost the same infection rates by T. gondii as the mock-treated cells, while RhoA-N19 or Rac1-N17 transfected cells and RhoA, Rac1 or RhoA + Rac1 siRNA-treated cells showed significantly diminished infection rates compared to mock cells. Conclusions The accumulation of the RhoA and Rac1 on the PVM and the requisite of their normal GTPase activity for efficient invasion implied their involvement and function in T. gondii invasion.
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Affiliation(s)
- Ren-Hua Na
- Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong Higher Institutes, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
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Li RW, Schroeder SG. Cytoskeleton remodeling and alterations in smooth muscle contractility in the bovine jejunum during nematode infection. Funct Integr Genomics 2011; 12:35-44. [PMID: 22203460 DOI: 10.1007/s10142-011-0259-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 11/28/2011] [Accepted: 12/05/2011] [Indexed: 11/27/2022]
Abstract
Gastrointestinal nematodes of the genus Cooperia are arguably the most important parasites of cattle. The bovine jejunal transcriptome was characterized in response to Cooperia oncophora infection using RNA-seq technology. Approximately 71% of the 25,670 bovine genes were detected in the jejunal transcriptome. However, 16,552 genes were expressed in all samples tested, probably representing the core component of the transcriptome. Twenty of the most abundant genes accounted for 12.7% of the sequences from the transcriptome. A 164-h infection seemingly induced a minor change in the transcriptome (162 genes). Additionally, a total of 162,412 splice junctions were identified. Among them, 1,164 appeared unique to 1 of the 2 groups: 868 splice junctions were observed only in infected animals, while 278 were only present in all 4 control animals. Biological functions associated with muscle contraction were predominant Gene Ontology terms enriched in the genes differentially expressed by infection. The primary function of two of the four regulatory networks impacted was related to skeletal and muscular systems. A total of 34 pathways were significantly impacted by infection. Several pathways were directly related to host immune responses, such as acute phase response, leukocyte extravasation, and antigen presentation, consistent with previous findings. Calcium signaling and actin cytoskeleton signaling were among the pathways most significantly impacted by infection in the bovine jejunum. Together, these data suggest that smooth muscle hypercontractility may be initiated as a result of a primary C. oncophora infection, which may represent a mechanism for host responses in the jejunum during nematode infection.
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Affiliation(s)
- Robert W Li
- Bovine Functional Genomics Laboratory, Animal and Natural Resources Institute, USDA-ARS, Beltsville, MD 20705, USA.
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Peng HJ, Chen XG, Lindsay DS. A review: Competence, compromise, and concomitance-reaction of the host cell to Toxoplasma gondii infection and development. J Parasitol 2011; 97:620-8. [PMID: 21506833 DOI: 10.1645/ge-2712.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Toxoplasma gondii is an important zoonotic parasite with a worldwide distribution. It infects about one-third of the world's population, causing serious illness in immunosuppressed individuals, fetuses, and infants. Toxoplasma gondii biology within the host cell includes several important phases: (1) active invasion and establishment of a nonfusogenic parasitophorous vacuole in the host cell, (2) extensive modification of the parasitophorous vacuolar membrane for nutrient acquisition, (3) intracellular proliferation by endodyogeny, (4) egress and invasion of new host cells, and (5) stage conversion from tachyzoite to bradyzoite and establishment of chronic infection. During these processes, T. gondii regulates the host cell by modulating morphological, physiological, immunological, genetic, and cellular biological aspects of the host cell. Overall, the infection/development predispositions of T. gondii -host cell interactions overtakes the infection resistance aspects. Upon invasion and development, host cells are modulated to keep a delicate balance between facilitating and eliminating the infection.
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Affiliation(s)
- Hong-Juan Peng
- Department of Etio-biology, School of Public Health and Tropical Medicine, Southern Medical University, 1838 North Guangzhou Rd, Guangzhou, Guangdong Province 510515, People's Republic of China
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Scheler S, Kitzan M, Fahr A. Cellular uptake and degradation behaviour of biodegradable poly(ethylene glycol-graft-methyl methacrylate) nanoparticles crosslinked with dimethacryloyl hydroxylamine. Int J Pharm 2010; 403:207-18. [PMID: 20969936 DOI: 10.1016/j.ijpharm.2010.10.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 10/11/2010] [Accepted: 10/13/2010] [Indexed: 12/18/2022]
Abstract
Crosslinked polymers with hydrolytically cleavable linkages are highly interesting materials for the design of biodegradable drug carriers. The aim of this study was to investigate if nanoparticles made of such polymers have the potential to be used also for intracellular drug delivery. PEGylated nanoparticles were prepared by copolymerization of methacrylic acid esters and N,O-dimethacryloylhydroxylamine (DMHA). The particles were stable at pH 5.0. At pH 7.4 and 9.0 the degradation covered a time span of about 14 days, following first-order kinetics with higher crosslinked particles degrading slower. Cellular particle uptake and cytotoxicity were tested with L929 mouse fibroblasts. The particle uptake rate was found to correlate linearly with the surface charge and to increase as the zeta potential becomes less negative. Coating of the particle surface with polysorbate 80 drops the internalization rate close to zero and the charge dependence disappears. This indicates the existence of a second effect apart from surface charge. A similar pattern of correlation with zeta potential and coating was also found for the degree of membrane damage while there was no effect of polysorbate on the cell metabolism which increased as the negative charge decreased. It is discussed whether exocytotic processes may explain this behaviour.
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Affiliation(s)
- Stefan Scheler
- Friedrich Schiller University of Jena, Department of Pharmaceutical Technology, Jena, Germany.
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Belton M, Prato FS, Rozanski C, Carson JJL. Effect of 100 mT homogeneous static magnetic field on [Ca2+]c response to ATP in HL-60 cells following GSH depletion. Bioelectromagnetics 2009; 30:322-9. [PMID: 19204977 DOI: 10.1002/bem.20475] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Calcium is an important molecule in a number of biological systems. Often these systems are signal transduction cascades involving molecules such as ATP. ATP activates second messengers which can interact with ion channels on the endoplasmic/sarcoplasmic reticulum resulting in the emptying of the intracellular calcium stores and an increase in cytosolic free calcium concentration ([Ca2+]c). Changes in [Ca2+]c can be influenced by external factors such as a static magnetic field (SMF). One hypothesis suggests that a SMF affects the cells through the radical pair mechanism. By reducing the number of antioxidant molecules like glutathione (GSH), the proportion of free radicals in the cells is increased and may lead to a greater probability of a biological response to a SMF. The purpose of this study was to determine if the [Ca2+]c response to ATP was affected by depletion of GSH by diethylmaleate (DEM) and the absence or presence of a 100 mT homogeneous SMF. Undifferentiated HL-60 cells were loaded with fura-2 AM. [Ca2+]c was measured in real time using a ratiometric fluorescence spectroscopy system. Various (DEM) ranging from 1 to 15 mM were added to deplete GSH. Cells were either exposed to sham or magnetic field (100 mT) for 13 min (780 s) and challenged with 1 microM ATP. The data show that [Ca2+]c was elevated following treatment with DEM with greater [Ca2+]c at higher [DEM]. The [Ca2+]c response to ATP was decreased as the DEM concentration increased. However, there was no effect of a 100 mT SMF on the average [Ca2+]c peak following ATP activation or the full width at half maximum (FWHM) of the [Ca2+]c response and recovery after ATP activation.
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Affiliation(s)
- Michelle Belton
- Imaging Program, Lawson Health Research Institute, London, Ontario, Canada
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