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Wang YJ, Chen CH, Chen JW, Lin WC. Commensals Serve as Natural Barriers to Mammalian Cells during Acanthamoeba castellanii Invasion. Microbiol Spectr 2021; 9:e0051221. [PMID: 34935418 PMCID: PMC8693914 DOI: 10.1128/spectrum.00512-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 11/02/2021] [Indexed: 12/23/2022] Open
Abstract
Acanthamoeba castellanii is a free-living, pathogenic ameba found in the soil and water. It invades the body through ulcerated skin, the nasal passages, and eyes and can cause blinding keratitis and granulomatous encephalitis. However, the mechanisms underlying the opportunistic pathogenesis of A. castellanii remain unclear. In this study, we observed that commensal bacteria significantly reduced the cytotoxicity of the ameba on mammalian cells. This effect occurred in the presence of both Gram-positive and Gram-negative commensals. Additionally, commensals mitigated the disruption of cell junctions. Ex vivo experiments on mouse eyeballs further showed that the commensals protected the corneal epithelial layer. Together, these findings indicate that A. castellanii is pathogenic to individuals with a dysbiosis of the microbiota at infection sites, further highlighting the role of commensals as a natural barrier during parasite invasion. IMPORTANCE Acanthamoeba castellanii, an opportunistic protozoan widely present in the environment, can cause Acanthamoeba keratitis and encephalitis in humans. However, only a few reports describe how the ameba acts as an opportunistic pathogen. Our study showed that the normal microbiota interfered with the cytotoxicity of Acanthamoeba, persevered during Acanthamoeba invasion, and reduced corneal epithelium peeling in the mouse eyeball model. This suggests that commensals may act as a natural barrier against Acanthamoeba invasion. In future, individuals who suffer from Acanthamoeba keratitis should be examined for microbiota absence or dysbiosis to reduce the incidence of Acanthamoeba infection in clinical settings.
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Affiliation(s)
- Yu-Jen Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Clinical Laboratory, Chest Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Chun-Hsien Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jenn-Wei Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Chen Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Xu JB, Zhang YL, Huang J, Lu SJ, Sun Q, Chen PX, Jiang P, Qiu ZE, Jiang FN, Zhu YX, Lai DH, Zhong WD, Lun ZR, Zhou WL. Increased intracellular Cl - concentration mediates Trichomonas vaginalis-induced inflammation in the human vaginal epithelium. Int J Parasitol 2019; 49:697-704. [PMID: 31254529 DOI: 10.1016/j.ijpara.2019.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/01/2019] [Accepted: 04/03/2019] [Indexed: 11/15/2022]
Abstract
Trichomonas vaginalis is a primary urogenital parasite that causes trichomoniasis, a common sexually transmitted disease. As the first line of host defense, vaginal epithelial cells play critical roles in orchestrating vaginal innate immunity and modulate intracellular Cl- homeostasis via the cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel that plays positive roles in regulating nuclear factor-κB (NF-κB) signalling. However, the association between T. vaginalis infection and intracellular Cl- disequilibrium remains elusive. This study showed that after T. vaginalis infection, CFTR was markedly down-regulated by cysteine proteases in vaginal epithelial cells. The intracellular Cl- concentration ([Cl-]i) was consequently elevated, leading to NF-κB signalling activation via serum- and glucocorticoid-inducible kinase-1. Moreover, heightened [Cl-]i and activated NF-κB signalling could be sustained in a positive feedback regulatory manner resulting from decreased intracellular cAMP through NF-κB-mediated up-regulation of phosphodiesterase 4. The results conclusively revealed that the intracellular Cl- of the human vaginal epithelium could be dynamically modulated by T. vaginalis, which contributed to mediation of epithelial inflammation in the human vagina.
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Affiliation(s)
- Jian-Bang Xu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yi-Lin Zhang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jiehong Huang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shen-Jiao Lu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Qing Sun
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Peng-Xiao Chen
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ping Jiang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhuo-Er Qiu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Fu-Neng Jiang
- Department of Urology, Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, China
| | - Yun-Xin Zhu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - De-Hua Lai
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wei-De Zhong
- Department of Urology, Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Zhao-Rong Lun
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China.
| | - Wen-Liang Zhou
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China.
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Rodgers FH, Gendrin M, Wyer CAS, Christophides GK. Microbiota-induced peritrophic matrix regulates midgut homeostasis and prevents systemic infection of malaria vector mosquitoes. PLoS Pathog 2017; 13:e1006391. [PMID: 28545061 PMCID: PMC5448818 DOI: 10.1371/journal.ppat.1006391] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/30/2017] [Accepted: 04/28/2017] [Indexed: 12/22/2022] Open
Abstract
Manipulation of the mosquito gut microbiota can lay the foundations for novel methods for disease transmission control. Mosquito blood feeding triggers a significant, transient increase of the gut microbiota, but little is known about the mechanisms by which the mosquito controls this bacterial growth whilst limiting inflammation of the gut epithelium. Here, we investigate the gut epithelial response to the changing microbiota load upon blood feeding in the malaria vector Anopheles coluzzii. We show that the synthesis and integrity of the peritrophic matrix, which physically separates the gut epithelium from its luminal contents, is microbiota dependent. We reveal that the peritrophic matrix limits the growth and persistence of Enterobacteriaceae within the gut, whilst preventing seeding of a systemic infection. Our results demonstrate that the peritrophic matrix is a key regulator of mosquito gut homeostasis and establish functional analogies between this and the mucus layers of the mammalian gastrointestinal tract. When a female mosquito takes a blood meal from a human, the bacteria residing within its gut grow significantly. Following a blood meal, female mosquitoes produce a barrier within their gut, known as the peritrophic matrix, which physically separates the blood meal from the cells of the epithelium. Here, we show that the presence of bacteria in the gut is required for the synthesis of the peritrophic matrix. By experimentally disrupting this barrier, we find that this structure plays a role in limiting the extent to which bacteria of one particular family are able to grow and persist in the mosquito gut. We also find that the peritrophic matrix ensures that bacteria remain within the gut, preventing them from invading the mosquito body cavity. These results will be useful in designing disease control strategies that depend on the ability of bacteria to colonize and persist in relevant tissues in the mosquito host.
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Affiliation(s)
- Faye H. Rodgers
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Mathilde Gendrin
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Claudia A. S. Wyer
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - George K. Christophides
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail:
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Pakpour N, Camp L, Smithers HM, Wang B, Tu Z, Nadler SA, Luckhart S. Protein kinase C-dependent signaling controls the midgut epithelial barrier to malaria parasite infection in anopheline mosquitoes. PLoS One 2013; 8:e76535. [PMID: 24146884 PMCID: PMC3795702 DOI: 10.1371/journal.pone.0076535] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 09/01/2013] [Indexed: 11/19/2022] Open
Abstract
Anopheline mosquitoes are the primary vectors of parasites in the genus Plasmodium, the causative agents of malaria. Malaria parasites undergo a series of complex transformations upon ingestion by the mosquito host. During this process, the physical barrier of the midgut epithelium, along with innate immune defenses, functionally restrict parasite development. Although these defenses have been studied for some time, the regulatory factors that control them are poorly understood. The protein kinase C (PKC) gene family consists of serine/threonine kinases that serve as central signaling molecules and regulators of a broad spectrum of cellular processes including epithelial barrier function and immunity. Indeed, PKCs are highly conserved, ranging from 7 isoforms in Drosophila to 16 isoforms in mammals, yet none have been identified in mosquitoes. Despite conservation of the PKC gene family and their potential as targets for transmission-blocking strategies for malaria, no direct connections between PKCs, the mosquito immune response or epithelial barrier integrity are known. Here, we identify and characterize six PKC gene family members--PKCδ, PKCε, PKCζ, PKD, PKN, and an indeterminate conventional PKC--in Anopheles gambiae and Anopheles stephensi. Sequence and phylogenetic analyses of the anopheline PKCs support most subfamily assignments. All six PKCs are expressed in the midgut epithelia of A. gambiae and A. stephensi post-blood feeding, indicating availability for signaling in a tissue that is critical for malaria parasite development. Although inhibition of PKC enzymatic activity decreased NF-κB-regulated anti-microbial peptide expression in mosquito cells in vitro, PKC inhibition had no effect on expression of a panel of immune genes in the midgut epithelium in vivo. PKC inhibition did, however, significantly increase midgut barrier integrity and decrease development of P. falciparum oocysts in A. stephensi, suggesting that PKC-dependent signaling is a negative regulator of epithelial barrier function and a potential new target for transmission-blocking strategies.
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Affiliation(s)
- Nazzy Pakpour
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Lauren Camp
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
| | - Hannah M. Smithers
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Bo Wang
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Zhijian Tu
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Steven A. Nadler
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
| | - Shirley Luckhart
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
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Guo A, Cai J, Gong W, Yan H, Luo X, Tian G, Zhang S, Zhang H, Zhu G, Cai X. Transcriptome analysis in chicken cecal epithelia upon infection by Eimeria tenella in vivo. PLoS One 2013; 8:e64236. [PMID: 23737974 PMCID: PMC3667848 DOI: 10.1371/journal.pone.0064236] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 04/10/2013] [Indexed: 11/25/2022] Open
Abstract
Coccidiosis, caused by various Eimeria species, is a major parasitic disease in chickens. However, our understanding on how chickens respond to coccidian infection is highly limited at both molecular and cellular levels. The present study employed the Affymetrix chicken genome array and performed transcriptome analysis on chicken cecal epithelia in response to infection for 4.5 days in vivo by the cecal-specific species E. tenella. By Significance Analysis of Microarrays (SAM), we have identified 7,099 probe sets with q-values at <0.05, in which 4,033 and 3,066 genes were found to be up- or down-regulated in response to parasite infection. The reliability of the microarray data were validated by real-time qRT-PCR of 20 genes with varied fold changes in expression (i.e., correlation coefficient between microarray and qRT-PCR datasets: R (2) = 0.8773, p<0.0001). Gene ontology analysis, KEGG pathway mapping and manual annotations of regulated genes indicated that up-regulated genes were mainly involved in immunity/defense, responses to various stimuli, apoptosis/cell death and differentiation, signal transduction and extracellular matrix (ECM), whereas down-regulated genes were mainly encoding general metabolic enzymes, membrane components, and some transporters. Chickens mustered complex cecal eipthelia molecular and immunological responses in response to E. tenella infection, which included pathways involved in cytokine production and interactions, natural killer cell mediated cytotoxicity, and intestinal IgA production. In response to the pathogenesis and damage caused by infection, chicken cecal epithelia reduced general metabolism, DNA replication and repair, protein degradation, and mitochondrial functions.
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Affiliation(s)
- Aijiang Guo
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Institute of Veterinary Research, China Academy of Agricultural Sciences, Lanzhou, China
| | - Jianping Cai
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Institute of Veterinary Research, China Academy of Agricultural Sciences, Lanzhou, China
| | - Wei Gong
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Institute of Veterinary Research, China Academy of Agricultural Sciences, Lanzhou, China
| | - Hongbin Yan
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Institute of Veterinary Research, China Academy of Agricultural Sciences, Lanzhou, China
| | - Xuenong Luo
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Institute of Veterinary Research, China Academy of Agricultural Sciences, Lanzhou, China
| | - Guangfu Tian
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Institute of Veterinary Research, China Academy of Agricultural Sciences, Lanzhou, China
| | - Shaohua Zhang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Institute of Veterinary Research, China Academy of Agricultural Sciences, Lanzhou, China
| | - Haili Zhang
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Guan Zhu
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
- Adjunct Professorship, Institute of Genetics, College of Life Science, Zhejiang University, Hangzhou, China
| | - Xuepeng Cai
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Institute of Veterinary Research, China Academy of Agricultural Sciences, Lanzhou, China
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Zhang S, Jian F, Zhao G, Huang L, Zhang L, Ning C, Wang R, Qi M, Xiao L. Chick embryo tracheal organ: a new and effective in vitro culture model for Cryptosporidium baileyi. Vet Parasitol 2012; 188:376-81. [PMID: 22520234 DOI: 10.1016/j.vetpar.2012.03.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 03/23/2012] [Accepted: 03/28/2012] [Indexed: 11/19/2022]
Abstract
In the present study, chick embryo tracheal organ (TOCs) was used to cultivate oocysts or sporozoites of Cryptosporidium baileyi. Approximately 5 × 10(4) sporozoites and oocysts mixture for group I; 5 × 10(5), 1 × 10(6), 2 × 10(6) purified sporozoites for group II, group III and group IV, respectively, were inoculated into respective chick embryo tracheal rings maintained in RPMI 1640 supplemented with 5% heat-inactivated FBS, and cultivated in each well of the 24-well culture plate at 40°C and 5% CO(2). The tracheal rings in four experimental groups (I-IV) were successfully infected with C. baileyi, and different stages of parasites were also observed under light and electron microscopy. Parasite infection and cytological alterations were noted as early as PI 72 h. The Cryptosporidium were seen attached to the edge of the tracheal epithelium, with more number of parasites in group I than that in group II, group III and group IV. The moderate nuclear swelling and chromatin margination were also detected, and the normal vertical orientation and basilar location of the nuclei of the epithelial cells were almost lost. C. baileyi that has been passed by TOCs exhibited similar immunity and molecular features with parasites before intratracheal inoculation. These results suggest that chick embryo tracheal organ is a new and effective in vitro culture model for C. baileyi and other respiratory pathogens.
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Affiliation(s)
- Sumei Zhang
- The College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, China
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Dezfuli BS, Giari L, Lui A, Lorenzoni M, Noga EJ. Mast cell responses to Ergasilus (Copepoda), a gill ectoparasite of sea bream. Fish Shellfish Immunol 2011; 30:1087-1094. [PMID: 21316458 DOI: 10.1016/j.fsi.2011.02.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 02/04/2011] [Accepted: 02/06/2011] [Indexed: 05/30/2023]
Abstract
Immunocytochemical, light microscopy and ultrastructural studies were conducted on gill of sea bream, Sparus aurata L., naturally parasitized with the important parasitic copepod Ergasilus sp. to assess pathology and cellular responses. Thirty-seven S. aurata were examined from a fish farm; 26 (70%) were parasitized, with infection intensity ranging from 3 to 55 parasites per fish. Hosts were divided into two groups, lightly infected fish (<15 parasites per fish) and heavily infected fish (>15 parasites per fish). In histological sections, the copepod encircled gill lamellae with its second antennae, compressed the epithelium, provoked hyperplasia and hemorrhage, occluded arteries and often caused lamellar disruption. Fusion of the secondary lamellae due to epithelial hyperplasia was common in all infected fish; heavily infected fish showed more intense branchial inflammation. In both healthy and infected fish, mast cells (MCs) were free within the connective tissue inside and outside the blood vessels of the primary lamellae and made close contact with vascular endothelial cells, mucous cells and rodlet cells (RCs). MCs were irregular in shape with a cytoplasm filled by numerous electron-dense, membrane-bound granules. Immunostaining of primary and secondary gill filaments with an antibody against the antimicrobial peptide (AMP) piscidin 3 (anti-piscidin 3 antibody, anti-HAGR) revealed a subpopulation of MCs that were positive. These MCs were more abundant in gills of heavily infected fish than in either lightly infected or uninfected fish (ANOVA, P<0.05). Our report documents the response of gill to ectoparasite infection and provides further evidence that mast cells and their AMPs may play a role in responding to branchial ectoparasite infections.
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Affiliation(s)
- Bahram S Dezfuli
- Department of Biology & Evolution, University of Ferrara, St. Borsari 46, 44123 Ferrara, Italy.
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Gupta L, Noh JY, Jo YH, Oh SH, Kumar S, Noh MY, Lee YS, Cha SJ, Seo SJ, Kim I, Han YS, Barillas-Mury C. Apolipophorin-III mediates antiplasmodial epithelial responses in Anopheles gambiae (G3) mosquitoes. PLoS One 2010; 5:e15410. [PMID: 21072214 PMCID: PMC2970580 DOI: 10.1371/journal.pone.0015410] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 09/06/2010] [Indexed: 11/18/2022] Open
Abstract
Background Apolipophorin-III (ApoLp-III) is known to play an important role in lipid transport and innate immunity in lepidopteran insects. However, there is no evidence of involvement of ApoLp-IIIs in the immune responses of dipteran insects such as Drosophila and mosquitoes. Methodology/Principal Findings We report the molecular and functional characterization of An. gambiae apolipophorin-III (AgApoLp-III). Mosquito ApoLp-IIIs have diverged extensively from those of lepidopteran insects; however, the predicted tertiary structure of AgApoLp-III is similar to that of Manduca sexta (tobacco hornworm). We found that AgApoLp-III mRNA expression is strongly induced in the midgut of An. gambiae (G3 strain) mosquitoes in response to Plasmodium berghei infection. Furthermore, immunofluorescence stainings revealed that high levels of AgApoLp-III protein accumulate in the cytoplasm of Plasmodium-invaded cells and AgApoLp-III silencing increases the intensity of P. berghei infection by five fold. Conclusion There are broad differences in the midgut epithelial responses to Plasmodium invasion between An. gambiae strains. In the G3 strain of An. gambiae AgApoLp-III participates in midgut epithelial defense responses that limit Plasmodium infection.
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Affiliation(s)
- Lalita Gupta
- Mosquito Immunity and Vector Competence Unit, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Ju Young Noh
- Department of Agricultural Biology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
| | - Yong Hun Jo
- Department of Agricultural Biology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
| | - Seung Han Oh
- Department of Agricultural Biology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
| | - Sanjeev Kumar
- Mosquito Immunity and Vector Competence Unit, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Mi Young Noh
- Department of Agricultural Biology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
| | - Yong Seok Lee
- Department of Parasitology, College of Medicine and Frontier Inje Research for Science and Technology, Inje University, Busan, Korea
| | - Sung-Jae Cha
- Johns Hopkins School of Public Health, Department of Molecular Microbiology and Immunology and Malaria Research Institute, Baltimore, Maryland, United States of America
| | - Sook Jae Seo
- Division of Applied Life Science, Gyeongsang National University, Jinju, Korea
| | - Iksoo Kim
- Department of Agricultural Biology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
| | - Yeon Soo Han
- Department of Agricultural Biology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
- * E-mail: (YSH); (CB-M)
| | - Carolina Barillas-Mury
- Mosquito Immunity and Vector Competence Unit, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail: (YSH); (CB-M)
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Paperna I. New species of Choleoeimeria (Apicomplexa: Eimeriidae), coccidia of bile-bladders of reptiles, illustrating a multiplicity of host cell-parasite interrelations. Parassitologia 2007; 49:81-95. [PMID: 18412050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Oocyst characteristics and histological features of the endogenous development of bile-bladder coccidia of the genus Choleoeimeria Paperna and Landsberg, 1989 are described and the main features for species differentiation are discussed for the following new species: C. allogamae n. sp. from Agama sp., Cameroon, West Africa; C. allogehyrae n. sp. from Gehyra australis, Magnetic Island (type) and mainland N Queensland, Australia; C. boulii n. sp. from Gehyra variegata, SW Queensland, Australia; C. calotesi n. sp. from Calotes mystaceus, Xiang-Mai, Thailand; C. heteronotis n. sp. from Heteronotia binoei, N Queensland, Australia; C. lygosomis n. sp. from Lygosoma buringi, Kon-Kaen, Thailand; C. sylvatica n. sp. from Carlia rhomboidalis, N Queensland, Australia, and C. xiangmaii n. sp. from Hemidactylus frenatus, Xiang-Mai, Thailand. Oocyst characteristic of Choleoeimeria are also reported from Oedura castelnaui, N Queensland. The described species demonstrate a diversity of associations with the bile-bladder epithelial lining, from a single parasite in a single hypertrophic host cell to multiple infections inducing the hypertrophied cells to form stratified layers, or merge into branched clumps.
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Affiliation(s)
- I Paperna
- Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences of the Hebrew University of Jerusalem, Rehovot 76-100, Israel.
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Siden-Kiamos I, Ecker A, Nybäck S, Louis C, Sinden RE, Billker O. Plasmodium berghei calcium-dependent protein kinase 3 is required for ookinete gliding motility and mosquito midgut invasion. Mol Microbiol 2006; 60:1355-63. [PMID: 16796674 PMCID: PMC1513514 DOI: 10.1111/j.1365-2958.2006.05189.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Apicomplexan parasites critically depend on a unique form of gliding motility to colonize their hosts and to invade cells. Gliding requires different stage and species-specific transmembrane adhesins, which interact with an intracellular motor complex shared across parasite stages and species. How gliding is regulated by extracellular factors and intracellular signalling mechanisms is largely unknown, but current evidence suggests an important role for cytosolic calcium as a second messenger. Studying a Plasmodium berghei gene deletion mutant, we here provide evidence that a calcium-dependent protein kinase, CDPK3, has an important function in regulating motility of the ookinete in the mosquito midgut. We show that a cdpk3– parasite clone produces morphologically normal ookinetes, which fail to engage the midgut epithelium, due to a marked reduction in their ability to glide productively, resulting in marked reduction in malaria transmission to the mosquito. The mutant was successfully complemented with an episomally maintained cdpk3 gene, restoring mosquito transmission to wild-type level. cdpk3– ookinetes maintain their full genetic differentiation potential when microinjected into the mosquito haemocoel and cdpk3– sporozoites produced in this way are motile and infectious, suggesting an ookinete-limited essential function for CDPK3.
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Affiliation(s)
- Inga Siden-Kiamos
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College LondonLondon SW7 2AZ, UK
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology – HellasVassilika Vouton, PO Box 1527, 71110 Heraklion, Crete, Greece
| | - Andrea Ecker
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College LondonLondon SW7 2AZ, UK
| | - Saga Nybäck
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College LondonLondon SW7 2AZ, UK
| | - Christos Louis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology – HellasVassilika Vouton, PO Box 1527, 71110 Heraklion, Crete, Greece
- Department of Biology, University of Crete71110 Heraklion, Crete, Greece
| | - Robert E Sinden
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College LondonLondon SW7 2AZ, UK
| | - Oliver Billker
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College LondonLondon SW7 2AZ, UK
- For correspondence. E-mail ; Tel. (+44) 207 594 5461; Fax (+44) 207 594 5424
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Hong S, Lee CS, Seo KY, Seong GJ, Hong YJ. Effects of topical antiglaucoma application on conjunctival impression cytology specimens. Am J Ophthalmol 2006; 142:185-6. [PMID: 16815281 DOI: 10.1016/j.ajo.2006.02.056] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 02/08/2006] [Accepted: 02/09/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE To evaluate the changes in conjunctival impression cytology specimens from patients receiving various topical antiglaucoma medications. DESIGN Cross-sectional comparative study. METHODS Impression cytology specimens were obtained from the eyes taking no topical medication (n = 20) and from the eyes taking various antiglaucoma medications (timolol n = 34; latanoprost n = 40; dorzolamide n = 32; timolol + latanoprost n = 30; timolol + dorzolamide n = 34). Specimens were graded on a scale of zero to three according to Nelson's method. RESULTS Cytology scores were significantly higher in the medication group than the control group. Mean cytology scores of the control, timolol, latanoprost, dorzolamide, timolol + latanoprost, and timolol + dorzolamide group were 0.20, 1.62, 2.00, 1.75, 2.13, and 2.44, respectively. Among the medication groups, cytology scores were significantly lower in the monotherapy group than the fixed-combination therapy group. CONCLUSIONS Various topical antiglaucoma medications induce a significant degree of squamous metaplasia. Conjunctival surface could be altered after the long-term use of antiglaucoma medication.
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Affiliation(s)
- Samin Hong
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
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13
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Werneck-Silva AL, Alvares EP, Gama P, Damião AOMC, Osaki LH, Ogias D, Sipahi AM. Intestinal damage in strongyloidiasis: the imbalance between cell death and proliferation. Dig Dis Sci 2006; 51:1063-9. [PMID: 16865572 DOI: 10.1007/s10620-006-8010-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Accepted: 07/14/2005] [Indexed: 12/25/2022]
Abstract
Strongyloidiasis is an endemic tropical parasitosis caused by Strongyloides stercoralis that also affects immigrants in nontropical countries. The nematode colonizes the duodenum and upper jejunum, inducing mucosal alterations. Because integrity is essential for a functional barrier, we aimed to study apoptosis and proliferation in the small bowel epithelium infected with S. stercoralis. We evaluated 23 patients and 17 controls. Apoptotic cells were detected by TUNEL and M30 immunolabelling, whereas proliferation was scored by Ki67 immunostaining and mitotic counting. Infection increased apoptotic indices in duodenum and jejunum (P < 0.001). Conversely, it decreased cell proliferation in both segments (P < 0.001). Our results showed that intestinal strongyloidiasis promotes an imbalance between cell death and proliferation. This is the first evidence of disruption of the epithelial kinetics with S. stercoralis infection, though the mechanisms remain unclear. Furthermore, our results support the idea that strongyloidiasis disturbs the mucosal integrity and can compromise the intestinal barrier.
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Affiliation(s)
- Ana Luiza Werneck-Silva
- Department of Gastroenterology, School of Medicine, Laboratory of Investigation (LIM 07), University of São Paulo, São Paulo, Brazil
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14
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Masini d'Avila-Levy C, de Almeida Dias F, Nogueira de Melo AC, Martins JL, De Carvalho Santos Lopes AH, Souza Dos Santos AL, Vermelho AB, Branquinha MH. Insights into the role of gp63-like proteins in lower trypanosomatids. FEMS Microbiol Lett 2006; 254:149-56. [PMID: 16451193 DOI: 10.1111/j.1574-6968.2005.00022.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Any actual understanding of trypanosomatids in general requires a comprehensive analysis of the less-specialized species as thorough as our knowledge of the more specialized Leishmania and Trypanosoma. In this context, we have shown by antibody cross-reactivity that purified extracellular metallopeptidases from Phytomonas françai, Crithidia deanei (cured strain) and Crithidia guilhermei share common epitopes with the leishmanial gp63. Flow cytometry and fluorescence microscopy analyses indicated the presence of gp63-like molecules on the cell surface of these lower trypanosomatids. Binding assays with explanted guts of Aedes aegypti incubated with purified gp63 and the pretreatment of trypanosomatids with anti-gp63 antibodies indicated that the gp63-like molecules are involved in the adhesive process of these trypanosomatids to the A. aegypti gut wall. In addition, our results indicate for the first time that the gp63-like molecule binds to a polypeptide of 50 kDa on the A. aegypti gut epithelium extract.
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Affiliation(s)
- Claudia Masini d'Avila-Levy
- Departamento de Microbiologia Geral, Instituto de Microbiologia Prof. Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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15
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Rogers-Lowery CL, Dimock RV. Encapsulation of attached ectoparasitic glochidia larvae of freshwater mussels by epithelial tissue on fins of naive and resistant host fish. Biol Bull 2006; 210:51-63. [PMID: 16501064 DOI: 10.2307/4134536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
To metamorphose into juveniles and subsequently mature into adults, the glochidia larvae of freshwater mussels in the order Unionoida must temporarily parasitize the gills, fins, or other external structures of fish. Once attached to the fish, the glochidium is encapsulated by host fish epithelial tissue. The migration of epithelial cells of the bluegill sunfish Lepomis macrochirus over glochidia of Utterbackia imbecillis was examined by time-lapse video microscopy, and the morphology was examined by scanning electron microscopy. Initially, the leading edge epithelial cells migrating over the larvae became rounded and the cells moved as a sheet until the attached glochidium was completely covered. Cyst formation on host fish that had been repeatedly exposed to mussel larvae was significantly delayed and morphologically irregular compared to that on naïve fish. Cyst formation on other species of fish that are less successful as hosts was examined. In general, it took longer for glochidia to become encapsulated on these less suitable potential hosts. The delay and irregularities in cyst formation on resistant fish and nonhost fish species may result in increased mortality and reduced success of metamorphosis of glochidia.
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16
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Vlachou D, Schlegelmilch T, Christophides GK, Kafatos FC. Functional Genomic Analysis of Midgut Epithelial Responses in Anopheles during Plasmodium Invasion. Curr Biol 2005; 15:1185-95. [PMID: 16005290 DOI: 10.1016/j.cub.2005.06.044] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 06/03/2005] [Accepted: 06/07/2005] [Indexed: 11/17/2022]
Abstract
BACKGROUND The malaria parasite Plasmodium must complete a complex developmental life cycle within Anopheles mosquitoes before it can be transmitted into the human host. One day after mosquito infection, motile ookinetes traverse the midgut epithelium and, after exiting to its basal site facing the hemolymph, develop into oocysts. Previously, we have identified hemolymph factors that can antagonize or promote parasite development. RESULTS We profiled on a genomic scale the transcriptional responses of the A. gambiae midgut to P. berghei and showed that more than 7% of the assessed mosquito transcriptome is differentially regulated during invasion. The profiles suggested that actin- and microtubule-cytoskeleton remodeling is a major response of the epithelium to ookinete penetration. Other responses encompass components of innate immunity, extracellular-matrix remodeling, and apoptosis. RNAi-dependent gene silencing identified both parasite antagonists and agonists among regulators of actin dynamics and revealed that actin polymerization is inhibitory to the invading parasite. Combined transcriptional and reverse-genetic analysis further identified an unexpected dual role of the lipid-trafficking machinery of the hemolymph for both parasite and mosquito-egg development. CONCLUSIONS We conclude that the determinants of malaria-parasite development in Anopheles include components not only of systemic humoral immunity but also of intracellular, local epithelial reactions. These results provide novel mechanistic insights for understanding malaria transmission in the mosquito vector.
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Affiliation(s)
- Dina Vlachou
- European Molecular Biology Laboratory, Heidelberg, Germany
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17
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Gupta L, Kumar S, Han YS, Pimenta PFP, Barillas-Mury C. Midgut epithelial responses of different mosquito-Plasmodium combinations: the actin cone zipper repair mechanism in Aedes aegypti. Proc Natl Acad Sci U S A 2005; 102:4010-5. [PMID: 15753303 PMCID: PMC554815 DOI: 10.1073/pnas.0409642102] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In vivo responses of midgut epithelial cells to ookinete invasion of three different vector-parasite combinations, Aedes aegypti-Plasmodium gallinaceum, Anopheles stephensi-Plasmodium berghei, and A. stephensi-P. gallinaceum, were directly compared by using enzymatic markers and immunofluorescence stainings. Our studies indicate that, in A. aegypti and A. stephensi ookinetes traverse the midgut via an intracellular route and inflict irreversible damage to the invaded cells. These two mosquito species differ, however, in their mechanisms of epithelial repair. A. stephensi detaches damaged cells by an actin-mediated budding-off mechanism when invaded by either P. berghei or P. gallinaceum. In A. aegypti, the midgut epithelium is repaired by a unique actin cone zipper mechanism that involves the formation of a cone-shaped actin aggregate at the base of the cell that closes sequentially, expelling the cellular contents into the midgut lumen as it brings together healthy neighboring cells. Invasion of A. stephensi by P. berghei induced expression of nitric oxide synthase and peroxidase activities, which mediate tyrosine nitration. These enzymes and nitrotyrosine, however, were not induced in the other two vector-parasite combinations examined. These studies indicate that the epithelial responses of different mosquito-parasite combinations are not universal. The implications of these observations to validate animal experimental systems that reflect the biology of natural vectors of human malarias are discussed.
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Affiliation(s)
- Lalita Gupta
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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18
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Bartholomew JL, Ray E, Torell B, Whipple MJ, Heidel JR. Monitoring Ceratomyxa shasta infection during a hatchery rearing cycle: comparison of molecular, serological and histological methods. Dis Aquat Organ 2004; 62:85-92. [PMID: 15648834 DOI: 10.3354/dao062085] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The prevalence of Ceratomyxa shasta infection in production stocks of steelhead Oncorhynchus mykiss and cutthroat trout O. clarki was monitored using a parasite-specific polymerase chain reaction (PCR) assay. For all 4 stocks of fish followed through their 1 yr rearing cycle, C. shasta infection was detected despite their genetic resistance to the disease and the treatment of the incoming water with ozone. Infection was confirmed using serological methods and standard histological procedures, except when prevalence was low (<10%). This suggests that at the lowest infection levels PCR is more sensitive than other methodologies, and can be used as an early indicator of infection. Results of the PCR assay continued to correlate with histological and serological detection as the numbers of parasites and the lesion severity increased over the rearing cycle. For both steelhead and cutthroat trout, early infections were characterized by large numbers of parasites on the epithelial surface, but with little associated inflammation. At release as yearlings, the infection prevalence in all stocks was greater than 90 % and the inflammatory response in many fish was extensive, with tissue necrosis and mucosal damage. Although C. shasta infections no longer result in high mortality at this facility, results of this study indicate that the parasite remains a contributor to low condition indices in these fish, despite their genetic resistance and ozone disinfection of the water supply.
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Affiliation(s)
- Jerri L Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331-3804, USA.
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19
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Lee SJ, Yokoyama H, Ogawa K. Modes of transmission of Glugea plecoglossi (Microspora) via the skin and digestive tract in an experimental infection model using rainbow trout, Oncorhynchus mykiss (Walbaum). J Fish Dis 2004; 27:435-444. [PMID: 15291785 DOI: 10.1111/j.1365-2761.2004.00556.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Glugea plecoglossi (Microspora) is a significant cause of economic loss in cultured ayu, Plecoglossus altivelis, in Japan, due to the unsightly appearance of infected fish harbouring xenomas in the body cavity. Modes of transmission of G. plecoglossi via the skin and digestive tract were studied in an experimental infection model using rainbow trout, Oncorhynchus mykiss. Combined with Uvitex 2B and in situ hybridization (ISH) assays, the early development of G. plecoglossi was successfully traced. Following a bath exposure of fish Uvitex 2B-labelled G. plecoglossi spores were observed to attach to microscopic injuries (trypan blue-positive sites) of fish skin, after which ISH-positive sporoplasms were found to invade the epidermis as early as 5 min post-infection (PI), migrating rapidly to the subdermis. It was also shown that G. plecoglossi entering via the skin does not spread into the internal organs but develops into subdermal xenomas. After rainbow trout were exposed to G. plecoglossi spores by oral intubation, spores germinated in the intestinal lumen, followed by penetration of sporoplasms into the gut mucosal epithelium 5 min PI. In vitro trials determining stimulation factors (fish mucus, changes in pH, digestive enzymes) for the extrusion of the polar tube were inconclusive. The present study indicates that skin wounds and the gut epithelium can be portals of entry of G. plecoglossi and that natural infection in fish seems to occur perorally rather than via the skin.
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Affiliation(s)
- S-J Lee
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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20
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Pemberton AD, Knight PA, Wright SH, Miller HRP. Proteomic analysis of mouse jejunal epithelium and its response to infection with the intestinal nematode,Trichinella spiralis. Proteomics 2004; 4:1101-8. [PMID: 15048991 DOI: 10.1002/pmic.200300658] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Infection with the intestinal nematode Trichinella spiralis induces profound, but stereotypic pathological changes to the epithelium, which are common to many nematode infections. This study describes changes in jejunal epithelial protein expression that reflect these stereotypic responses. Adult male BALB/c mice were infected with T. spiralis, and groups (n = 4) examined on day 14/15 (time of worm rejection) were compared with uninfected controls (n = 4). Jejunal epithelium was harvested and extracted for two-dimensional gel electrophoresis. Tryptic peptide mass fingerprinting was used to create a reference map consisting of a total of 52 landmark spots. Of these, 16 were observed to change in intensity during infection. The changes observed at day 14/15 were of relevance to such mechanisms as lipid utilization and transport (increase in triacylglycerol lipase, and reduction in intestinal fatty acid binding protein) and innate immunity (appearance of intelectin-2). As a result, candidate molecules have been identified for further focused studies on their role in the host response to intestinal nematode infection.
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Affiliation(s)
- Alan D Pemberton
- Division of Veterinary Clinical Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian, UK.
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21
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Abstract
Malaria parasites must complete a complex developmental cycle in an Anopheles mosquito vector before transmission to a vertebrate host. Sexual development of the parasite in the midgut is initiated in the lumen immediately after the mosquito ingests infected blood, and the resulting ookinetes must traverse the surrounding epithelial layer before transforming into oocysts. The innate immune system of the mosquito is activated during midgut invasion, but to date, no evidence has been published identifying mosquito immune genes that affect parasite development. Here, we show by gene silencing that an Anopheles gambiae leucine rich-repeat protein acts as an antagonist and two C-type lectines act as protective agonists on the development of Plasmodium ookinetes to oocysts.
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Affiliation(s)
- Mike A Osta
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
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22
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Dubey JP, Ross AD, Fritz D. Clinical Toxoplasma gondii, Hammondia heydorni, and Sarcocystis spp. infections in dogs. Parassitologia 2003; 45:141-6. [PMID: 15267102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Concurrent infections with coccidians Toxoplasma gondii, Sarcocystis spp., and a Hammondia heydorni-like parasite were identified in tissues of three littermate pups on a Kelpie dog breeding farm in Australia. In total, 20 pups in four litters had died following vaccination with an attenuated distemper virus vaccine. Toxoplasma gondii tachyzoites were identified immunohistochemically in tissues of two dogs. Sarcocystis sp. sporocysts were seen in the intestinal lamina propria of two dogs. Asexual and sexual stages of H. heydorni-like parasite were found in enterocytes of the small intestine of two dogs. Ultrastructural development of schizonts and gamonts of this parasite is described. None of the protozoa in these dogs reacted with antibodies to Neospora caninum. Feeding of uncooked tissue of sheep was considered to be the likely source of infection for these coccidians in dogs.
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Affiliation(s)
- J P Dubey
- United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA.
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23
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McDermott JR, Bartram RE, Knight PA, Miller HRP, Garrod DR, Grencis RK. Mast cells disrupt epithelial barrier function during enteric nematode infection. Proc Natl Acad Sci U S A 2003; 100:7761-6. [PMID: 12796512 PMCID: PMC164661 DOI: 10.1073/pnas.1231488100] [Citation(s) in RCA: 260] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2003] [Accepted: 04/14/2003] [Indexed: 12/15/2022] Open
Abstract
We have investigated the influence of mast cells on the barrier function of intestinal epithelium during nematode infection. Trichinella spiralis infection induces a strong type 2 cytokine-mediated inflammation, resulting in a critical mucosal mastocytosis that is known to mediate expulsion of the parasites from the intestine. The host response to infection is also characterized by an increase in mucosal leakiness. We show here that intestinal epithelial permeability is markedly elevated during infection, with kinetics that mirror the adaptive immune response to primary and secondary infection. Furthermore, we have identified degradation of the tight junction protein, occludin, thereby providing a mechanism for increased paracellular permeability during helminth infection. We further demonstrate by using anti-c-kit antibody and IL-9 transgenic mice that mast cells are directly responsible for increasing epithelial paracellular permeability and that mice deficient in a mast cell-specific protease fail to increase intestinal permeability and fail to expel their parasite burden. These results provide the mechanism whereby mucosal mast cells mediate parasite expulsion from the intestine.
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Affiliation(s)
- Jacqueline R McDermott
- School of Biological Sciences, University of Manchester, Manchester M13 9PT, United Kingdom.
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24
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Chen C, Gulati P, French SW. Pathologic quiz case: a patient with acquired immunodeficiency syndrome and an unusual biliary infection. Arch Pathol Lab Med 2003; 127:243-4. [PMID: 12562247 DOI: 10.5858/2003-127-243-pq] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Chen Chen
- Department of Pathology, Harbor-UCLA Medical Center, Torrance 90502, USA.
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25
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Tinsley RC, Cable J, Porter R. Pathological effects of Pseudodiplorchis americanus (Monogenea: Polystomatidae) on the lung epithelium of its host, Scaphiopus couchii. Parasitology 2002; 125:143-53. [PMID: 12211607 DOI: 10.1017/s0031182002001993] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Infection of the desert toad, Scaphiopus couchii, by the monogenean Pseudodiplorchis americanus involves 2 principal sites: post-invasion juveniles reside in the respiratory tract for 1 month before migrating to the urinary bladder where they reach sexual maturity and may live up to 4 years. While previous work has demonstrated the long-term impact on host condition of the blood-feeding adults, this study assesses pathological effects of the short-term pulmonary infection. Lung ultrastructure was compared in toads (i) maintained in captivity for 1 year without invasion, and (ii) experimentally infected with 50-300 juveniles/host, equivalent to burdens in the wild, and examined 23-44 days p.i. Typically, the alveolar lining of S. couchii is composed of a single cell type with characteristics of both Type I and Type II pneumocytes. However, infected lung tissue exhibited an inflammatory reaction with epithelial cell vacuolation, interstitial oedema, and an increase of alveolar exudate, leucocytes and fibrous tissue. Accompanying a post-infection increase in host immune cells in the lungs, there was evidence of reciprocal tegumental damage to the parasites. Lung epithelium of toads free of infection for 1 year exhibited scar tissue representing a residual effect of past infection. The pathological consequences of P. americanus infection therefore have 2 components. Acute lung infection coincides with the host's brief activity season: impaired respiratory function could compromise feeding and accumulation of reserves and hence ability to survive following a 10 month period of hibernation. Additionally, adult toads are normally exposed annually to re-infection and may accumulate chronic lung damage with extended effects on host survival.
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Affiliation(s)
- R C Tinsley
- School of Biological Sciences, University of Bristol, UK.
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26
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Abstract
After oral ingestion, Toxoplasma gondii crosses the intestinal epithelium, disseminates into the deep tissues, and traverses biological barriers such as the placenta and the blood-brain barrier to reach sites where it causes severe pathology. To examine the cellular basis of these processes, migration of T. gondii was studied in vitro using polarized host cell monolayers and extracellular matrix. Transmigration required active parasite motility and the highly virulent type I strains consistently exhibited a superior migratory capacity than the nonvirulent type II and type III strains. Type I strain parasites also demonstrated a greater capacity for transmigration across mouse intestine ex vivo, and directly penetrated into the lamina propria and vascular endothelium. A subpopulation of virulent type I parasites exhibited a long distance migration (LDM) phenotype in vitro, that was not expressed by nonvirulent type II and type III strains. Cloning of parasites expressing the LDM phenotype resulted in substantial increase of migratory capacity in vitro and in vivo. The potential to up-regulate migratory capacity in T. gondii likely plays an important role in establishing new infections and in dissemination upon reactivation of chronic infections.
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Affiliation(s)
- Antonio Barragan
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
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27
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Abstract
Malaria is estimated to cause 0.7 to 2.7 million deaths per year, but the actual figures could be substantially higher owing to under-reporting and difficulties in diagnosis. If no new control measures are developed, the malaria death toll is projected to double in the next 20 years. Efforts to control the disease are hampered by drug resistance in the Plasmodium parasites, insecticide resistance in mosquitoes, and the lack of an effective vaccine. Because mosquitoes are obligatory vectors for malaria transmission, the spread of malaria could be curtailed by rendering them incapable of transmitting parasites. Many of the tools required for the genetic manipulation of mosquito competence for malaria transmission have been developed. Foreign genes can now be introduced into the germ line of both culicine and anopheline mosquitoes, and these transgenes can be expressed in a tissue-specific manner. Here we report on the use of such tools to generate transgenic mosquitoes that express antiparasitic genes in their midgut epithelium, thus rendering them inefficient vectors for the disease. These findings have significant implications for the development of new strategies for malaria control.
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Affiliation(s)
- Junitsu Ito
- Case Western Reserve University, Department of Genetics, 10900 Euclid Avenue, Ohio 44106-4955, USA
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29
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Kettunen H, Tiihonen K, Peuranen S, Saarinen MT, Remus JC. Dietary betaine accumulates in the liver and intestinal tissue and stabilizes the intestinal epithelial structure in healthy and coccidia-infected broiler chicks. Comp Biochem Physiol A Mol Integr Physiol 2001; 130:759-69. [PMID: 11691612 DOI: 10.1016/s1095-6433(01)00410-x] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aim of this experiment was to study the patterns of betaine accumulation into intestinal tissue, liver and plasma of broiler chicks with or without coccidial infection. The chicks were raised on a corn-based, low-betaine diet with or without 1000 ppm betaine supplementation and with or without intestinal microparasite (Eimeria maxima) challenge to the age of 21 days. Plasma, liver, intestinal tissue and digesta of non-challenged (NC) birds and plasma and intestinal tissue of coccidiosis challenged (CC) birds were analysed for betaine content. NC birds were also analyzed for homocysteine in plasma and S-adenosylmethionine (S-AM) in liver. The jejunal epithelium was histologically examined for the presence of coccidia and the crypt-villus ratio was measured. Dietary betaine supplementation decreased the plasma homocysteine concentration but had no effect on liver S-AM of NC birds. The data suggest that chicks on a low-betaine diet accumulate betaine into the intestinal tissue. When the diet was supplemented with betaine, betaine accumulated heavily into liver and to a lesser degree into intestinal tissue. The concentration of betaine in jejunal and ileal digesta was low suggesting that dietary betaine was mainly absorbed from the proximal small intestine. The coccidial challenge decreased the concentration of betaine in the liver, but greatly increased that in the intestinal tissue. The crypt-villus ratio was decreased by the dietary betaine supplementation in healthy and challenged chicks, suggesting that dietary betaine both protects the jejunal villi against coccidial infection and also stabilizes the mucosal structure in healthy broiler chicks. These results support our earlier findings suggesting that betaine is likely to act as an important intestinal osmolyte in broiler chicks.
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Affiliation(s)
- H Kettunen
- Danisco Cultor Innovation, Technology Center, Kantvik, Sokeritehtaantie 20, FIN-02460 Kantvik, Finland.
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30
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Abstract
This study was performed to investigate the presence of microorganisms in the epithelial cells of leukoplakia. Frozen sections of 20 specimens of leukoplakia were stained with DNA-binding bisbenzimide Hoechst 33258. As a control, 20 specimens of normal oral mucosa and five specimens of normal skin were used. In all preparations of leukoplakia, small granular fluorescing structures were observed within the cytoplasm of the epithelial cells, predominantly within the cytoplasm of prickle cells, although the amount of the granular structures varied between specimens, layers of the epithelium and even areas of the epithelium within a single section. Less granular structures were observed, or none at all, in the cytoplasm of the epithelial cells of normal mucosa. No structures were observed in the cytoplasm of the epithelium of skin. The results in this study strongly suggest that microorganisms are present in the epithelial cells of oral mucosa, and that they are closely associated with the development of oral leukoplakia. It is postulated that the microorganisms in the epithelial cells could be bacteria, particularly mycoplasmas.
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Affiliation(s)
- H Mizuki
- Department of Oral and Maxillo-Facial Surgery, Oita Medical University, Hasama-machi, 879-5593, Oita, Japan.
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Velásquez JN, Carnevale S, Mariano M, Kuo LH, Caballero A, Chertcoff A, Ibáñez C, Bozzini JP. Isosporosis and unizoite tissue cysts in patients with acquired immunodeficiency syndrome. Hum Pathol 2001; 32:500-5. [PMID: 11381368 DOI: 10.1053/hupa.2001.24326] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Isospora belli, a coccidian parasite in humans, has been described as causing chronic diarrhea and acalculous cholecystitis in patients with the acquired immunodeficiency syndrome (AIDS). Diagnosis can be made at the tissue level in the epithelium of the small bowel and by fecal examination. Disseminated extraintestinal forms are uncommon. We studied 118 adult patients with AIDS and chronic diarrhea using stool analysis and endoscopy with duodenal biopsy specimen collection. These samples were processed by routine histology and transmission electron microscopy. Isosporosis was diagnosed in 8 cases. In 2 of them, unizoite tissue cysts were present in the lamina propria, with negative results in stool materials. The cysts were located within a large parasitophorous vacuole. There were no structural means of differentiating the species level of Isospora based on morphology using light or electron microscopy. We believe further work should be done to determine if unizoite tissue cysts are part of the cycle of I belli or of other species of Isospora that could be pathogenic in immunocompromised hosts.
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Affiliation(s)
- J N Velásquez
- Hospital Municipal de Infecciosas "Dr Francisco Javier Muñiz," ANLIS "Dr Carlos G. Malbrán," Aires, Argentina
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32
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Abstract
Late cutaneous vulvar schistosomiasis (LCVS), which represents the cutaneous response to the deposition of schistosomal ova, is characterized by a range of clinical manifestations. Histopathological descriptions of LCVS have highlighted the hyperplastic epithelial reaction, and a few reports have alluded to the presence of intraepidermal bilharzial ova. Although transepithelial elimination (TEE), a well-known phenomenon whereby the skin rids itself of foreign, potentially dangerous substances, has been documented in a range of infectious processes, it has not been recognized as a distinct process in LCVS. This study not only documents TEE in 23 biopsies of LCVS but also correlates the role of the histopathological inflammatory reaction pattern, density of ova, and pseudoepitheliomatous hyperplasia in the pathogenesis of TEE. The importance of TEE as an additional, hitherto unrecognized mechanism of release and spread of schistosomal ova to the exterior is also highlighted.
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Affiliation(s)
- P K Ramdial
- Department of Anatomical Pathology, School of Pathology and Laboratory Medicine, Nelson R Mandela School of Medicine, University of Natal, Private Bag 7, Congella, 4013, Kwazulu Natal, South Africa
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33
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Yoshinaga T, Nagakura T, Ogawa K, Wakabayashi H. Attachment-inducing capacities of fish tissue extracts on oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae). J Parasitol 2000; 86:214-9. [PMID: 10780535 DOI: 10.1645/0022-3395(2000)086[0214:aicoft]2.0.co;2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
When oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae) were incubated in wells with lyophilized extracts of fish skin epithelia on the bottom, some attached to the well bottom with the haptor unfolded and shed the ciliated epidermal cells. Based on these morphological changes in oncomiracidia, we developed a new assay method to examine the attachment-inducing capacities of various fish extracts for oncomiracidia. Attachment-inducing capacities were found only in extracts of fish skin epithelium and not in other fish extracts. No significant difference in capacities was observed among extracts of skin epithelia of 4 fish species. Wheat germ lectin and concanavalin A suppressed capacities in extracts of skin epithelia of Japanese flounder and yellowtail, respectively. Suppressed capacities were recovered by adding sugars that bound specifically to these lectins. These results indicate that some sugar-related chemical substances that exist specifically in fish epithelium induce the attachment of N. girellae oncomiracidia.
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Affiliation(s)
- T Yoshinaga
- National Research Institute of Aquaculture, Watarai-gun, Mie, Japan
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34
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Gonzalez MS, Nogueira NF, Mello CB, De Souza W, Schaub GA, Azambuja P, Garcia ES. Influence of brain and azadirachtin on Trypanosoma cruzi development in the vector, Rhodnius prolixus. Exp Parasitol 1999; 92:100-8. [PMID: 10366535 DOI: 10.1006/expr.1998.4387] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Studies on the effects of decapitation, head transplantation, azadirachtin, and ecdysone therapy on the ultrastructural organization of the midgut of Rhodnius prolixus, a vector of the protozoan Trypanosoma cruzi, show a distinct effect on the organization of the epithelial cells. When insects are decapitated or treated with azadirachtin, the ultrastructural organiza tion of these compartments changed significantly and drastically blocked the development of T. cruzi infection. In converse experiments, head transplantation or oral therapy with ecdysone significantly re versed the T. cruzi infectivity and reestablished the organization of the stomach and intestine in decapitated or azadirachtin-treated insects. These results indicat that a brain factor, possibly the prothoracicotropic hormone which stimulates ecdysteroid production on the prothoracic glands, may act directly or indirectly on both the midgut cell organiza tion and the intestinal microenvironment, interfering in the trypanosome survival and infection of the vector R. prolixus.
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Affiliation(s)
- M S Gonzalez
- Departamento de Biologia Geral, Instituto de Biologia, Universidade Federal Fluminense, Morro do Valonguinho SIN degrees, Niterói, RJ, CEP 24001-970, Brazil
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35
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Hemmer N, Steinhagen D, Drommer W, Körting W. Changes of intestinal epithelial structure and cell turnover in carp Cyprinus carpio infected with Goussia carpelli (Protozoa: Apicomplexa). Dis Aquat Organ 1998; 34:39-44. [PMID: 9789977 DOI: 10.3354/dao034039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Epithelial cell turnover in the intestine of common carp Cyprinus carpio infected with the coccidian parasite Goussia carpelli (Leger & Stankovitch, 1921) was investigated during laboratory infection using histological and electron microscopical techniques. During the development of the parasite an increased number of mitotic enterocytes, identified by bromodeoxyuridine (BRDU) uptake, were observed at the base of infected mucosal folds. During the merogonic and gamogonic development of the parasite, severe damage to infected epithelium occurred, and concomitantly BRDU-positive cells spread along the mucosal folds. These cells exhibited immature characteristics, including a squamous to cuboidal shape, nuclear apolarity, a high number of ribosomes, and short or reduced microvilli. Contact with adjoining cells was formed by tight junctions and desmosomes, indicating the epithelial origin of these cells. These cells covered gut segments with damaged epithelium within a few days, suggesting a high regenerative capacity of the carp intestine, and this could explain the mild clinical symptoms in fish affected by G. carpelli-coccidiosis. Our study for the first time describes epithelial cell responses to injuries caused by enteric protozoa in piscine hosts.
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Affiliation(s)
- N Hemmer
- Fish Disease Research Unit, School of Veterinary Medicine, Hannover, Germany
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36
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Zieler H, Garon CF, Fischer ER, Shahabuddin M. Adhesion of Plasmodium gallinaceum ookinetes to the Aedes aegypti midgut: sites of parasite attachment and morphological changes in the ookinete. J Eukaryot Microbiol 1998; 45:512-20. [PMID: 9783452 DOI: 10.1111/j.1550-7408.1998.tb05110.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Plasmodium gallinaceum ookinetes adhered to Aedes aegypti midgut epithelia when purified ookinetes and isolated midguts were combined in vitro. Ookinetes preferentially bound to the microvillated luminal surface of the midgut, and they seemed to interact with three types of structures on the midgut surface. First, they adhered to and migrated through a network-like matrix, which we have termed microvilli-associated network, that covers the surface of the microvilli. This network forms on the luminal midgut surface in response to blood or protein meals. Second, the ookinetes bound directly to the microvilli on the surface of the midgut and were occasionally found immersed in the thick microvillar layer. Third, the ookinetes associated with accumulations of vesicular structures found interspersed between the microvillated cells of the midgut. The origin of these vesicular structures is unknown, but they correlated with the surface of midgut cells invaded by ookinetes as observed by TEM. After binding to the midgut, ookinetes underwent extensive morphological changes: they frequently developed one or more annular constrictions, and their surface roughened considerably, suggesting that midgut components remain bound to the parasite surface. Our observations suggest that, in a natural infection, the ookinete interacts in a sequential manner with specific components of the midgut surface. Initial binding to the midgut surface may activate the ookinete and cause morphological changes in preparation for invasion of the midgut cells.
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Affiliation(s)
- H Zieler
- Medical Entomology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0425, USA
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37
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el-Mansy A, Molnár K. Extrapiscine development of Myxobolus drjagini Akhmerov, 1954 (Myxosporea: Myxobolidae) in oligochaete alternative hosts. Acta Vet Hung 1998; 45:427-38. [PMID: 9557320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The extrapiscine development of Myxobolus drjagini, a myxosporean parasite of the head, operculum and buccal cavity of the silver carp (Hypophthalmichthys molitrix), was studied in experimentally infected oligochaetes, Tubifex tubifex. After infection of uninfected tubificids with mature spores of M. drajagini, development of actinosporean stages was first observed by light microscopy 27 days after infection. Triactinomyxon stages of M. drjagini emerged from the worms after 91 days of intraoligochaete development. In histological sections, early pansporocysts were found in the gut epithelium of the experimental oligochaetes 42 days after infection. Mature pansporocysts, each containing 8 triactinomyxons, appeared 79 days after infection. After rupture of the epithelial cell and the pansporocyst, free actinosporean stages were found in the gut lumen of the oligochaete. Actinosporean stages released from oligochaetes appeared in the water 91 days after infection. They were floating in the water and showed a typical triactinomyxon form. Each triactinomyxon had three pyriform polar capsules, a sporoplasm with 14 secondary cells inside the spore body, a moderately long style and slightly bent, trifurcated, conically ending tails. The total length of the triactinomyxon measured approximately 198 microns. The prevalence of infection in 51 oligochaetes proved to be 9.8%. No infection was found in the control oligochaetes.
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Affiliation(s)
- A el-Mansy
- Veterinary Medical Research Institute, Hungarian Academy of Sciences, Budapest, Hungary
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38
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Renesto P, Sansonetti PJ, Guillén N. Interaction between Entamoeba histolytica and intestinal epithelial cells involves a CD44 cross-reactive protein expressed on the parasite surface. Infect Immun 1997; 65:4330-3. [PMID: 9317044 PMCID: PMC175620 DOI: 10.1128/iai.65.10.4330-4333.1997] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This study shows that Entamoeba histolytica binds hyaluronic acid. The binding molecule was identified as an 80-kDa membrane protein and was recognized by anti-CD44 monoclonal antibodies. These data indicate that a CD44 cross-reacting adherence molecule is expressed on E. histolytica.
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Affiliation(s)
- P Renesto
- Unité de Pathogénie Microbienne Moléculaire, Institut National de la Santé et de la Recherche Médicale U389, Institut Pasteur, Paris, France.
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39
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Forney JR, Yang S, Healey MC. Synergistic anticryptosporidial potential of the combination alpha-1-antitrypsin and paromomycin. Antimicrob Agents Chemother 1997; 41:2006-8. [PMID: 9303402 PMCID: PMC164053 DOI: 10.1128/aac.41.9.2006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The combined effect of the serine protease inhibitor alpha-1-antitrypsin (AAT) and the aminoglycoside paromomycin on Cryptosporidium parvum infection in vitro was investigated. AAT and paromomycin were mixed with C. parvum oocysts as either single or combined treatments and used to inoculate epithelial cell cultures. Single- and combined-treatment groups had significantly lower (P < 0.01) parasite numbers than untreated controls. The mean fractional inhibitory concentration indices suggested significant synergistic activity.
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Affiliation(s)
- J R Forney
- Department of Biology, College of Science, Utah State University, Logan 84322-5600, USA
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40
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Abstract
BACKGROUND & AIMS The four principal types of intestinal epithelial cells are derived from multipotent stem cells. Currently, there is no information on factors that regulate commitment of stem cells to differentiate along one lineage vs. another. The aim of our study was to investigate the role of T cells in the regulation of small intestinal goblet cell hyperplasia in mice infected with the parasite Trichinella spiralis. METHODS NIH mice were infected with T. spiralis, and intestinal goblet cells and cytokine response were studied. Interferon gamma and interleukin 5 were used as candidate T helper (Th)1 and Th2 cytokines, respectively. Adoptive transfer experiments were also performed. RESULTS Small intestinal goblet cell hyperplasia occurred 8 days after infection with T. spiralis. Th1-type cells were predominant in the mesenteric lymph nodes early in the course of infection, with a switch to Th2-predominant cells around the time of goblet cell hyperplasia. Transfer of Th2-enriched mesenteric lymph node cells further enhanced goblet cell hyperplasia in recipient mice. Neutralization of interleukin 5 activity did not affect T. spiralis-induced goblet cell hyperplasia. CONCLUSIONS Small intestinal goblet cell hyperplasia in T. spiralis-infected mice is probably regulated by Th2 cells. We postulate that Th2-derived factors (other than interleukin 5) induce stem cells to differentiate preferentially along the goblet cell lineage.
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Affiliation(s)
- N Ishikawa
- Division of Gastroenterology, University of Nottingham, England
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41
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Spano F, Puri C, Ranucci L, Putignani L, Crisanti A. Cloning of the entire COWP gene of Cryptosporidium parvum and ultrastructural localization of the protein during sexual parasite development. Parasitology 1997; 114 ( Pt 5):427-37. [PMID: 9149414 DOI: 10.1017/s0031182096008761] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Molecular cloning and immunoelectron microscopy have been used to clone the full-length gene encoding Cryptosporidium parvum oocyst wall protein (COWP) and to analyse at the ultrastructural level the expression and localization of COWP during development in the gut. COWP is 1622 amino acids long, has a typical leader peptide and consists of 2 amino acidic domains each containing distinct repeated elements possibly originating from a common ancestral precursor. Electron microscopy localized COWP in a large cytoplasmic inclusion and in the wall-forming bodies of early and late macrogametes, respectively. Ultrastructural analysis of double-walled sporulating and mature oocysts indicated that COWP is selectively localized in the inner layer of the oocyst wall. This study provides the first localization at the ultrastructural level of a cloned coccidian oocyst wall protein.
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Affiliation(s)
- F Spano
- Istituto di Parassitologia, Università di Roma La Sapienza, Italy
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42
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Verdon R, Keusch GT, Tzipori S, Grubman SA, Jefferson DM, Ward HD. An in vitro model of infection of human biliary epithelial cells by Cryptosporidium parvum. J Infect Dis 1997; 175:1268-72. [PMID: 9129102 DOI: 10.1086/593695] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Cryptosporidium parvum infection in the immunosuppressed host is frequently complicated by biliary tract involvement. The recent production of human biliary epithelial cell lines was exploited to develop an in vitro model of biliary cryptosporidiosis. Infection with C. parvum oocysts was detected by IFA and ELISA and confirmed by transmission electron microscopy. Inoculation of monolayers with 10(4) to 5 X 10(5) oocysts/well resulted in a dose-dependent increase in infection. Time-course experiments showed that the number of parasitic stages was maximal at 18-24 h after inoculation. Infection was significantly enhanced by bile at concentrations of 50 and 100 microg/mL and inhibited by 400 microg/mL paromomycin. Infection of human biliary cells with C. parvum can be consistently achieved and monitored by use of IFA or ELISA. This system will be of use in evaluating mechanisms of C. parvum infection and response to therapeutic agents in biliary cryptosporidiosis.
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Affiliation(s)
- R Verdon
- Department of Medicine, New England Medical Center, Boston, Massachusetts 02111, USA
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43
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Maya A, Jayaraman K, Balakrishnan A. Necrosis of lung epithelial cells by filarial parasitic protein via an early induction of c-H-ras and TNF alpha expression. Cell Biol Int 1997; 21:273-80. [PMID: 9243802 DOI: 10.1006/cbir.1997.0139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The direct interaction of filarial proteins with lung epithelial cells was examined to determine the possible mechanism of inducing cell death, an event that is observed in patients with tropical pulmonary eosinophilia. Exposure of lung epithelial cells to filarial parasitic proteins, Brugia malayi (BmA), Setaria digitata (Sd), and recombinant filarial protein (pGT 7) in vitro for more than 2 days, causes the appearance of DNA fragments both in the cytoplasm and culture supernatants, while no fragmentation was observed in the untreated controls. The release of DNA fragments both in the cytoplasm and the culture supernatants simultaneously, indicates that cell death is induced by a necrotic event rather than apoptosis. Fluorescent-labelled studies also indicate the fragmentation of DNA increasing in a time-dependent manner. Normal cellular function is controlled through several oncogenes. The modulation of specific proto-oncogenes like myc, ras and TNF alpha during exposure to filarial parasitic proteins reveal elevated levels of expression of ras and TNF alpha as early as 2 hours, implicating their involvement prior to DNA fragmentation leading to pathogenesis.
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Affiliation(s)
- A Maya
- Centre for Biotechnology, Anna University, Madras, India
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44
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Affiliation(s)
- G P Cowley
- Department of Histopathology, University College London Medical School, UK
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45
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Abstract
Pneumocystis carinii lipids are similar to host lipids, but it is not known if some of these lipids are acquired from host cells. The ability of P. carinii to incorporate a fluorescent fatty acid analogue (Bodipy-C12) was analyzed, the metabolism of the incorporated lipid by P. carinii was characterized, and lipid transfer from human alveolar epithelial cells (A549) to P. carinii was investigated. Both P. carinii and A549 cells incorporated exogenous Bodipy-C12 in a concentration-dependent manner. Biochemical analysis of labeled P. carinii revealed incorporation of Bodipy-C12 into complex lipid classes. Incubation of unlabeled P. carinii with Bodipy-C12-labeled A549 cells demonstrated lipid transfer to P. carinii, a process facilitated by attachment. These data suggest that P. carinii can incorporate and modify an exogenous fluorescent lipid. The observed transfer of lipid from A549 cells to P. carinii provides important insight into the interaction of this organism with alveolar epithelial cells.
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Affiliation(s)
- S T Furlong
- Division of Rheumatology and Immunology, Brigham and Women's Hospital, Boston, Massachusetts, USA
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46
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Chen WJ, Chow CY, Wu ST. Ultrastructure of infection, development and gametocyst formation of Ascogregarina taiwanensis (Apicomplexa: Lecudinidae) in its mosquito host, Aedes albopictus (Diptera: Culicidae). J Eukaryot Microbiol 1997; 44:101-8. [PMID: 9190261 DOI: 10.1111/j.1550-7408.1997.tb05945.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The life history of the protozoan parasite Ascogregarina taiwanensis in mosquito larvae (Aedes albopictus, collected in southern Taiwan) was shown to consist of two consecutive stages--intracellular and extracellular. Light microscopy showed that most trophozoites moved into the Malpighian tubules and developed into giant trophozoites during the first day pupa. The locomotion may be associated with bristle-like ridges of the trophozoite. The stage for sexual reproduction, i.e., the gamete, was then formed by segmentation of the giant trophozoite and twisting off the anucleate extremities of the body. Sexual reproduction occurred via fertilization by fusion of two resulting gametes, presumably two opposed sexes. The fused gametes finally generate the formation of the gametocyst, within which oocysts develop by budding from the cytoplasmic mass. This type of sexual reproduction has not been reported previously in any gregarine protozoa. We here proposed it as a new hypothesis for further elucidation of the protozoan reproduction.
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Affiliation(s)
- W J Chen
- Department of Parasitology, Chang Gung College of Medicine and Technology, Kwei-San, Tao-Yuan, Taiwan
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47
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Abstract
Acanthamoeba keratitis is a sight-threatening corneal infection. In a recent study, the saccharide mannose has been shown to inhibit the binding of Acanthamoeba organisms to the epithelium of the cornea (L. D. Morton, G. L. McLaughlin, and H. E. Whiteley, Infect. Immun. 59:3819-3822, 1991). In an attempt to determine the molecular mechanism by which acanthamoebae adhere to the surface of the cornea, the present study was designed to determine whether Acanthamoeba castellanii derived from an infected human cornea (i) binds to mannose-containing glycoproteins (mannose-GPs) of corneal epithelium and (ii) expresses one or more mannose-binding proteins. Mannose-GPs of primary cell cultures of rabbit corneal epithelium were isolated by using three different agarose-conjugated, mannose-specific lectins. By electrophoresis blot-overlay assays, 35S-labeled acanthamoebae were shown to bind to mannose-GPs of corneal epithelium and to a neoglycoprotein, mannose-bovine serum albumin (mannose-BSA). 35S-labeled acanthamoebae also bound to microtiter wells coated with mannose-BSA in a concentration-dependent manner. The binding of amoebae to mannose-GPs was blocked by free methyl-alpha-D-mannopyranoside. The parasites did not bind to galactose-BSA or to many other proteins lacking mannose residues. A membrane-associated mannose-binding protein (136 kDa) of A. castellanii was isolated by affinity chromatography of detergent extracts of unlabeled parasites and of cell surface biotin-labeled parasites on a p-aminophenyl alpha-D-mannopyranoside-agarose column. The affinity-purified protein of the amoeba was shown to bind specifically to mannose-BSA. In summary, a mannose-binding protein is present on the surface membranes of Acanthamoeba, and corneal epithelial cells express Acanthamoeba-reactive GPs. One of the mechanisms of Acanthamoeba adhesion to the corneal surface may involve interactions between the mannose-binding protein of Acanthamoeba and mannose-GPs on the surface of corneal epithelium.
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Affiliation(s)
- Z Yang
- The New England Eye Center, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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48
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Modha J, Roberts MC, Kennedy MW, Kusel JR. Induction of surface fluidity in Trichinella spiralis larvae during penetration of the host intestine: simulation by cyclic AMP in vitro. Parasitology 1997; 114 ( Pt 1):71-7. [PMID: 9011076 DOI: 10.1017/s0031182096008025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The lateral diffusion (DL) properties of the fluorescent lipid probe 5-N (octadecanoyl) aminofluorescein (AF18) inserted into the surface of muscle-stage larvae of Trichinella spiralis were investigated by fluorescence recovery after photo-bleaching. AF18 was not free to diffuse laterally in dormant larvae, and this remained unchanged after larval activation in vitro with trypsin and bile. However, a significant increase in surface fluidity of the probe was demonstrated (%R = 74.5; DL = 11.5 x 10(-9) cm2/sec) when larvae invaded intestinal epithelial tissue following oral infection of mice. Membrane-permeant photoactivatable caged cyclic AMP was used to analyse the putative mechanism responsible for this increase in lateral diffusion in the parasite surface. Although incubation of larvae with 1-50 microM caged cAMP had no effect on surface fluidity, incubation with 100 microM caged cAMP induced a substantial increase in the lateral mobility of AF18 (%R = 64.3; DL = 8.3 x 10(-11) cm2/sec) immediately following photo-activation of the caged messenger. This induced fluidity, however, was transient and the larval surface reverted to immobility within 15 min. These observations constitute the first reported measurement of the fluid properties of the surface of intracellular parasites, the first demonstration of the parasite surface fluidity altering as a result of host cell invasion and the first indication of a mechanism underlying changes in surface fluidity in parasitic helminths.
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Affiliation(s)
- J Modha
- Division of Biochemistry and Molecular Biology, University of Glasgow, UK
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49
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Molnár K, Székely C. An unusual location for Ergasilus sieboldi Nordmann (Copepoda, Ergasilidae) on the operculum and base of pectoral fins of the pikeperch (Stizostedion lucioperca L.). Acta Vet Hung 1997; 45:165-75. [PMID: 9270139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ergasilus sieboldi infestation of the pikeperch (Stizostedion lucioperca) is extremely common in Lake Balaton. In the summer and autumn, these parasitic copepods have high prevalence and intensity on pikeperch of more than 20 cm body length. Typically, Ergasilus establish themselves in the folds on the external surface of the operculum and on the base of the pectoral fins, and only a small proportion cling to the gill filaments. Infestation is rare and of low intensity in pikeperch of less than 20 cm body length. The Volga pikeperch (Stizostedion volgense) has low-intensity infestation irrespective of age. The lesions caused by copepods present on the operculum are restricted to the epithelium even if infestation is intensive.
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Affiliation(s)
- K Molnár
- Veterinary Medical Research Institute, Hungarian Academy of Sciences, Budapest, Hungary
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Forney JR, Yang S, Du C, Healey MC. Efficacy of serine protease inhibitors against Cryptosporidium parvum infection in a bovine fallopian tube epithelial cell culture system. J Parasitol 1996; 82:638-40. [PMID: 8691375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The anticryptosporidial potential of the protease inhibitors alpha-1-antitrypsin (AAT), antipain, aprotinin, leupeptin, methoxysuccinyl-ala-ala-pro-valine chloromethylketone (MAAPVCK), soybean trypsin inhibitor (SBTI), and phenylmethylsulfonyl fluoride (PMSF) was evaluated in a bovine fallopian tube epithelial (BFTE) cell culture system. Protease inhibitor concentrations of 5, 10, 50, 100, and 500 micrograms/ ml (PMSF at 1, 2, and 3 mM) in RPMI medium were mixed with Cryptosporidium parvum oocysts and used to inoculate BFTE cell monolayers. At 24 hr postinoculation (candlejar/37 C), cells were rinsed with RPMI medium, fixed in methanol, and stained with Giemsa. Parasites were enumerated in cell monolayers by brightfield microscopy. The mean number of parasites counted in each protease inhibitor treatment group was expressed as a percentage of the mean number of parasites counted in an infection control group. Leupeptin and SBTI reduced parasite numbers to 40-50% of the control mean at 500 micrograms/ml: AAT, antipain, and aprotinin reduced parasite numbers to 10-15% at the same concentration. PMSF reduced parasite numbers to 40% of the control mean at 3 mM. MAAPVCK did not significantly inhibit cryptosporidial infection. These findings suggest that a protease component of C. parvum may be essential for host cell infection.
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Affiliation(s)
- J R Forney
- Department of Biology, College of Science, Utah State University, Logan 84322-5305, USA
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