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Jamil Al-Obaidi MM, Desa MNM. Understanding the mechanisms underlying the disruption of the blood-brain barrier in parasitic infections. J Neurosci Res 2024; 102. [PMID: 38284852 DOI: 10.1002/jnr.25288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/16/2023] [Accepted: 12/09/2023] [Indexed: 01/30/2024]
Abstract
Parasites have a significant impact on the neurological, cognitive, and mental well-being of humans, with a global population of over 1 billion individuals affected. The pathogenesis of central nervous system (CNS) injury in parasitic diseases remains limited, and prevention and control of parasitic CNS infections remain significant areas of research. Parasites, encompassing both unicellular and multicellular organisms, have intricate life cycles and possess the ability to infect a diverse range of hosts, including the human population. Parasitic illnesses that impact the central and peripheral nervous systems are a significant contributor to morbidity and mortality in low- to middle-income nations. The precise pathways through which neurotropic parasites infiltrate the CNS by crossing the blood-brain barrier (BBB) and cause neurological harm remain incompletely understood. Investigating brain infections caused by parasites is closely linked to studying neuroinflammation and cerebral impairment. The exact molecular and cellular mechanisms involved in this process remain incomplete, but understanding the exact mechanisms could provide insight into their pathogenesis and potentially reveal novel therapeutic targets. This review paper explores the underlying mechanisms involved in the development of neurological disorders caused by parasites, including parasite-derived elements, host immune responses, and modifications in tight junctions (TJs) proteins.
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Affiliation(s)
- Mazen M Jamil Al-Obaidi
- University of Technology and Applied Sciences, Rustaq College of Education, Science Department (Biology Unit), Rrustaq, Sultante of Oman
| | - Mohd Nasir Mohd Desa
- Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
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2
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Romo ML, Osorio R, Toledo A, Carrillo-Mezo R, Valdez R, Romano MC, Sciutto E, Fragoso G, Fleury A. Low responsiveness of peripheral lymphocytes in extraparenchymal neurocysticercosis. PLoS Negl Trop Dis 2023; 17:e0011386. [PMID: 37262055 DOI: 10.1371/journal.pntd.0011386] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 05/16/2023] [Indexed: 06/03/2023] Open
Abstract
BACKGROUND The morbidity and mortality of extraparenchymal neurocysticercosis (EP-NC) remain high and effectiveness of current medical treatment is suboptimal. Various factors have been implicated in the severity of EP-NC and in the poor response to treatment, but the possible role of host immune and endocrine systems has not yet been examined thoroughly. METHODOLOGY/PRINCIPAL FINDINGS 42 participants with EP-NC before receiving standard treatment and 25 healthy controls were included in the study. Treatment response was assessed by comparing pre/post treatment parasite volumes from 3D MRI. Prior to treatment among participants with EP-NC, specific stimulation induced an increased specific proliferative response accompanied by a significant increase in IL-4, NK, NKT, Bregs and Tregs cells, whereas in healthy controls, specific stimulation induced a significant increase in IL-1β, IL-5, CCL5, IL-6, TNF-α, NK and Bregs cells. Significant differences between participants with EP-NC and healthy controls in the specific inflammatory response were observed. Participants with EP-NC prior to treatment had significantly weaker responses of proinflammatory cytokines (IL-6, TNF-α) and NK cells, and stronger IL-4 response. Anthelmintic treatment did not promote significant peripheral immunological changes at any time, although inflammation was sustained in the cerebrospinal fluid. Serum estradiol concentration significantly decreased after anthelmintic treatment among males, and cortisol correlated negatively with IL-6 and positively with IFN-γ levels. No pre-treatment immunologic or endocrinologic parameters were significantly associated with response to treatment. CONCLUSION/SIGNIFICANCE Prior to anthelmintic treatment, EP-NC was characterized by low lymphocyte reactivity accompanied by a regulatory response, which may be involved in the lack of peripheral immunological changes during and after treatment, although a central inflammatory response was present. This weak specific peripheral response could favor the chronicity of the infection and the poor response to treatment. Our findings highlight the need for new anti-inflammatory treatment focused on the central nervous system with less systemic immunosuppressive effects.
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Affiliation(s)
- Matthew L Romo
- Department of Epidemiology & Biostatistics, CUNY Graduate School of Public Health and Health Policy, City University of New York, New York, United States of America
| | - Rocio Osorio
- Unidad de Neuro inflamación, Departamento de Medicina Genómica y Toxicología ambiental, Instituto de Investigación Biomédicas, Universidad Nacional Autónoma de México (UNAM) / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, México
- Neurocysticercosis Clinic, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, México
| | - Andrea Toledo
- Unidad de Neuro inflamación, Departamento de Medicina Genómica y Toxicología ambiental, Instituto de Investigación Biomédicas, Universidad Nacional Autónoma de México (UNAM) / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, México
- División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Roger Carrillo-Mezo
- Neuroradiology Department, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, México
| | - Ricardo Valdez
- CINVESTAV, Departamento de Fisiología, Biofísica y Neurociencias, México
| | - Marta C Romano
- CINVESTAV, Departamento de Fisiología, Biofísica y Neurociencias, México
| | - Edda Sciutto
- Departamento de Inmunología, Instituto de Investigación Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - Gladis Fragoso
- Departamento de Inmunología, Instituto de Investigación Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - Agnès Fleury
- Unidad de Neuro inflamación, Departamento de Medicina Genómica y Toxicología ambiental, Instituto de Investigación Biomédicas, Universidad Nacional Autónoma de México (UNAM) / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, México
- Neurocysticercosis Clinic, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, México
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3
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Steyn TJS, Awala AN, de Lange A, Raimondo JV. What Causes Seizures in Neurocysticercosis? Epilepsy Curr 2022; 23:105-112. [PMID: 37122403 PMCID: PMC10131564 DOI: 10.1177/15357597221137418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Neurocysticercosis (NCC) is the most prevalent parasitic infection of the central nervous system. It is caused by the presence of larvae of the cestode Taenia solium in the brain. The most common symptom of NCC is seizures, and it is widely considered the world’s leading cause of preventable epilepsy. Despite the prevalence and impact of NCC, a thorough, mechanistic understanding of seizure generation is still lacking. In this review, we address the question “What causes seizures in NCC?” by summarizing and discussing the major theories that seek to explain the seizurogenic and epileptogenic processes in this disorder. In addition, we highlight the potential for recent advances in disease modeling to help accelerate progress in this area.
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Affiliation(s)
- Teresa Julieta Simões Steyn
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Western Cape, South Africa
| | - Amalia Naita Awala
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Western Cape, South Africa
| | - Anja de Lange
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Western Cape, South Africa
| | - Joseph Valentino Raimondo
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Western Cape, South Africa
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4
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Garcia HH, Verastegui MR, Arroyo G, Bustos JA, Gilman RH. New animal models of neurocysticercosis can help understand epileptogenesis in neuroinfection. Front Mol Neurosci 2022; 15:1039083. [PMID: 36466808 PMCID: PMC9708716 DOI: 10.3389/fnmol.2022.1039083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/27/2022] [Indexed: 11/18/2022] Open
Affiliation(s)
- Hector H. Garcia
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru,Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru,Asociación Benéfica PRISMA, Lima, Peru,*Correspondence: Hector H. Garcia
| | - Manuela R. Verastegui
- Alberto Cazorla School of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Gianfranco Arroyo
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru,Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Javier A. Bustos
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru,Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Robert H. Gilman
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
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5
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Idro R, Ogwang R, Barragan A, Raimondo JV, Masocha W. Neuroimmunology of Common Parasitic Infections in Africa. Front Immunol 2022; 13:791488. [PMID: 35222377 PMCID: PMC8866860 DOI: 10.3389/fimmu.2022.791488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
Parasitic infections of the central nervous system are an important cause of morbidity and mortality in Africa. The neurological, cognitive, and psychiatric sequelae of these infections result from a complex interplay between the parasites and the host inflammatory response. Here we review some of the diseases caused by selected parasitic organisms known to infect the nervous system including Plasmodium falciparum, Toxoplasma gondii, Trypanosoma brucei spp., and Taenia solium species. For each parasite, we describe the geographical distribution, prevalence, life cycle, and typical clinical symptoms of infection and pathogenesis. We pay particular attention to how the parasites infect the brain and the interaction between each organism and the host immune system. We describe how an understanding of these processes may guide optimal diagnostic and therapeutic strategies to treat these disorders. Finally, we highlight current gaps in our understanding of disease pathophysiology and call for increased interrogation of these often-neglected disorders of the nervous system.
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Affiliation(s)
- Richard Idro
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Rodney Ogwang
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda.,Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Antonio Barragan
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Joseph Valentino Raimondo
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Willias Masocha
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Safat, Kuwait
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6
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Abstract
Neurocysticercosis is the most common disease of the nervous system caused by a parasite. Ophthalmological manifestations of cysticercosis typically are due to direct intraorbital or intraocular involvement, parenchymal brainstem involvement, or secondary to hydrocephalus or increased intracranial pressure. We describe a patient with a unilateral fourth nerve palsy, a rare presentation of neurocyticercosis.
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7
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Hydrocephalus in Neurocysticercosis: Challenges for Clinical Practice and Basic Research Perspectives. World Neurosurg 2019; 126:264-271. [DOI: 10.1016/j.wneu.2019.03.071] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 11/19/2022]
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8
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Toledo A, Osorio R, Matus C, Martinez Lopez Y, Ramirez Cruz N, Sciutto E, Fragoso G, Arauz A, Carrillo-Mezo R, Fleury A. Human Extraparenchymal Neurocysticercosis: The Control of Inflammation Favors the Host…but Also the Parasite. Front Immunol 2018; 9:2652. [PMID: 30505305 PMCID: PMC6250850 DOI: 10.3389/fimmu.2018.02652] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/26/2018] [Indexed: 12/14/2022] Open
Affiliation(s)
- Andrea Toledo
- Unidad de Neuroinflamación, Instituto de Investigaciones Biomédicas, UNAM/ Facultad de Medicina UNAM / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico
| | - Rocio Osorio
- Unidad de Neuroinflamación, Instituto de Investigaciones Biomédicas, UNAM/ Facultad de Medicina UNAM / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico
| | - Carlos Matus
- Unidad de Neuroinflamación, Instituto de Investigaciones Biomédicas, UNAM/ Facultad de Medicina UNAM / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico
| | - Yazmin Martinez Lopez
- Unidad de Neuroinflamación, Instituto de Investigaciones Biomédicas, UNAM/ Facultad de Medicina UNAM / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico
| | - Nancy Ramirez Cruz
- Unidad de Neuroinflamación, Instituto de Investigaciones Biomédicas, UNAM/ Facultad de Medicina UNAM / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico
| | - Edda Sciutto
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, UNAM, Ciudad de México, Mexico
| | - Gladis Fragoso
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, UNAM, Ciudad de México, Mexico
| | - Antonio Arauz
- Clínica de Enfermedad Vascular, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico
| | - Roger Carrillo-Mezo
- Departamento de Neurorradiología, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico
| | - Agnès Fleury
- Unidad de Neuroinflamación, Instituto de Investigaciones Biomédicas, UNAM/ Facultad de Medicina UNAM / Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico.,Clínica de Neurocisticercosis, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, Mexico
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9
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Abstract
Neurocysticercosis (NCC) occurs following brain infection by larvae of the cestode Taenia solium. It is the leading cause of preventable epilepsy worldwide and therefore constitutes a critical health challenge with significant global relevance. Despite this, much is still unknown about many key pathogenic aspects of the disease, including how cerebral infection with T. solium results in the development of seizures. Over the past century, valuable mechanistic insights have been generated using both clinical studies and animal models. In this review, we critically assess model systems for investigating disease processes in NCC. We explore the respective strengths and weaknesses of each model and summarize how they have contributed to current knowledge of the disease. We call for the continued development of animal models of NCC, with a focus on novel strategies for understanding this debilitating but often neglected disorder.
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10
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Carmen-Orozco RP, Dávila-Villacorta DG, Cauna Y, Bernal-Teran EG, Bitterfeld L, Sutherland GL, Chile N, Céliz RH, Ferrufino-Schmidt MC, Gavídia CM, Sterling CR, García HH, Gilman RH, Verástegui MR. Blood-brain barrier disruption and angiogenesis in a rat model for neurocysticercosis. J Neurosci Res 2018; 97:137-148. [PMID: 30315659 DOI: 10.1002/jnr.24335] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 12/13/2022]
Abstract
Neurocysticercosis (NCC) is a helminth infection affecting the central nervous system caused by the larval stage (cysticercus) of Taenia solium. Since vascular alteration and blood-brain barrier (BBB) disruption contribute to NCC pathology, it is postulated that angiogenesis could contribute to the pathology of this disease. This study used a rat model for NCC and evaluated the expression of two angiogenic factors called vascular endothelial growth factor (VEGF-A) and fibroblast growth factor (FGF2). Also, two markers for BBB disruption, the endothelial barrier antigen and immunoglobulin G, were evaluated using immunohistochemical and immunofluorescence techniques. Brain vasculature changes, BBB disruption, and overexpression of angiogenesis markers surrounding viable cysts were observed. Both VEGF-A and FGF2 were overexpressed in the tissue surrounding the cysticerci, and VEGF-A was overexpressed in astrocytes. Vessels showed decreased immunoreactivity to endothelial barrier antigen marker and an extensive staining for IgG was found in the tissues surrounding the cysts. Additionally, an endothelial cell tube formation assay using human umbilical vein endothelial cells showed that excretory and secretory antigens of T. solium cysticerci induce the formation of these tubes. This in vitro model supports the hypothesis that angiogenesis in NCC might be caused by the parasite itself, as opposed to the host inflammatory responses alone. In conclusion, brain vasculature changes, BBB disruption, and overexpression of angiogenesis markers surrounding viable cysts were observed. This study also demonstrates that cysticerci excretory-secretory processes alone can stimulate angiogenesis.
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Affiliation(s)
- Rogger P Carmen-Orozco
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Danitza G Dávila-Villacorta
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Yudith Cauna
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Edson G Bernal-Teran
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Leandra Bitterfeld
- The Department of International Health, Bloomberg School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, Maryland
| | - Graham L Sutherland
- The Department of International Health, Bloomberg School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, Maryland
| | - Nancy Chile
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Rensson H Céliz
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - María C Ferrufino-Schmidt
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Cesar M Gavídia
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Charles R Sterling
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
| | - Héctor H García
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú.,Cysticercosis Unit, Instituto de Nacional Ciencias Neurológicas, Lima, Perú
| | - Robert H Gilman
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú.,The Department of International Health, Bloomberg School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, Maryland.,Asociación Benéfica PRISMA, Lima, Perú
| | - Manuela Renee Verástegui
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
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11
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Alroy KA, Arroyo G, Gilman RH, Gonzales-Gustavson E, Gallegos L, Gavidia CM, Verastegui M, Rodriguez S, Lopez T, Gomez-Puerta LA, Alroy J, Garcia HH, Gonzalez AE, For The Cysticercosis Working Group In Peru. Carotid Taenia solium Oncosphere Infection: A Novel Porcine Neurocysticercosis Model. Am J Trop Med Hyg 2018; 99:380-387. [PMID: 29893202 DOI: 10.4269/ajtmh.17-0912] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Neurocysticercosis (NCC), the infection of the human central nervous system (CNS) with larval cysts of Taenia solium causes widespread neurological morbidity. Animal models are crucial for studying the pathophysiology and treatment of NCC. Some drawbacks of current NCC models include differences in the pathogenesis of the model and wild-type parasite, low rates of infection efficiency and lack of reproducibility. We describe a novel porcine model that recreates infection in the CNS with high efficiency. Activated oncospheres, either in a high (45,000-50,000) or low (10,000) dose were inoculated in the common carotid artery of 12 pigs by ultrasound-guided catheterization. Following oncosphere injection, either a high (30 mL) or low (1-3 mL) volume of saline flush was also administered. Cyst burden in the CNS was evaluated independently according to oncosphere dose and flush volume. Neurocysticercosis was achieved in 8/12 (66.7%) pigs. Cyst burden in the CNS of pigs was higher in the high versus the low oncosphere dose category (median: 4.5; interquartile ranges [IQR]: 1-8 and median: 1; IQR: 0-4, respectively) and in the high versus the low flush volume category (median 5.5; IQR: 1-8 and median: 1; IQR: 0-2, respectively), although not statistically different. All cysts in the CNS were viable, whereas both viable and degenerated cysts were found in the musculature. Carotid injection of activated oncospheres in pigs is effective in reproducing NCC. Oncosphere entry into the CNS by way of vasculature mimics wild-type infection, and provides a useful alternative for future investigations on the pathogenesis and antiparasitic treatment of NCC.
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Affiliation(s)
- Karen A Alroy
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Gianfranco Arroyo
- School of Public Health and Management, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Robert H Gilman
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | | | - Linda Gallegos
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Cesar M Gavidia
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Manuela Verastegui
- Departments of Pathology, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Silvia Rodriguez
- Microbiology of the School of Science, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Teresa Lopez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Luis A Gomez-Puerta
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Joseph Alroy
- School of Medicine, Tufts University, Boston, Massachusetts
| | - Hector H Garcia
- Microbiology of the School of Science, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Armando E Gonzalez
- Microbiology of the School of Science, Universidad Peruana Cayetano Heredia, Lima, Peru
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12
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Understanding host-parasite relationship: the immune central nervous system microenvironment and its effect on brain infections. Parasitology 2017; 145:988-999. [PMID: 29231805 DOI: 10.1017/s0031182017002189] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The central nervous system (CNS) has been recognized as an immunologically specialized microenvironment, where immune surveillance takes a distinctive character, and where delicate neuronal networks are sustained by anti-inflammatory factors that maintain local homeostasis. However, when a foreign agent such as a parasite establishes in the CNS, a set of immune defences is mounted and several immune molecules are released to promote an array of responses, which ultimately would control the infection and associated damage. Instead, a host-parasite relationship is established, in the context of which a close biochemical coevolution and communication at all organization levels between two complex organisms have developed. The ability of the parasite to establish in its host is associated with several evasion mechanisms to the immune response and its capacity for exploiting host-derived molecules. In this context, the CNS is deeply involved in modulating immune functions, either protective or pathogenic, and possibly in parasitic activity as well, via interactions with evolutionarily conserved molecules such as growth factors, neuropeptides and hormones. This review presents available evidence on some examples of CNS parasitic infections inducing different morbi-mortality grades in low- or middle-income countries, to illustrate how the CNS microenvironment affect pathogen establishment, growth, survival and reproduction in immunocompetent hosts. A better understanding of the influence of the CNS microenvironment on neuroinfections may provide relevant insights into the mechanisms underlying these pathologies.
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13
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TNF-α blockade suppresses pericystic inflammation following anthelmintic treatment in porcine neurocysticercosis. PLoS Negl Trop Dis 2017; 11:e0006059. [PMID: 29190292 PMCID: PMC5708608 DOI: 10.1371/journal.pntd.0006059] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 10/20/2017] [Indexed: 02/06/2023] Open
Abstract
Background Neurocysticercosis (NCC) is an infection of the brain with the larval cyst of the tapeworm, Taenia solium. Cysticidal treatment induces parasite killing resulting in a post inflammatory response and seizures, which generally requires corticosteroid treatment to control inflammation. The nature of this response and how to best control it is unclear. We investigated the anti-inflammatory effects of pretreatment with etanercept (ETN), an anti-tumor necrosis factor agent, or dexamethasone (DEX), a high potency corticosteroid, on the post treatment inflammatory response in naturally infected pigs with neurocysticercosis after a single dose of the cysticidal drug praziquantel (PZQ). Methodology/Principal findings We followed the methods from a previously developed treatment model of NCC in naturally infected swine. The four study groups of infected pigs included 3 groups treated with PZQ on day 0: PZQ-treated alone (100 mg/kg PO; n = 9), pretreated with dexamethasone (DEX, 0.2 mg/kg IM administered on days -1, +1 and +3; n = 6), and pretreated with etanercept (ETN, 25 mg IM per animal on days -7 and 0; n = 6). The fourth group remained untreated (n = 3). As measured by quantitative RT-PCR, ETN pretreatment depressed transcription of a wide range of proinflammatory, regulatory and matrix protease encoding genes at 120 hr post PZQ treatment in capsules of cysts that demonstrated extravasated Evans Blue (EB) (a measure of blood brain barrier dysfunction) compared to animals not receiving ETN. Transcription was significantly depressed for the proinflammatory genes tumor necrosis factor (TNF)-α, and interferon (IFN)-γ; the inflammation regulating genes cytotoxic T-lymphocyte-associated protein (CTLA)4, interleukin (IL)-13 and transforming growth factor (TGF)-β; the tissue remodeling genes matrix metalloprotease (MMP)1 and 9, tissue inhibitors of metalloproteases (TIMP)1 and 2, and the genes regulating endothelial function vascular endothelial growth factor (VEGF)1, angiopoietin (Ang)1, Ang 2, and platelet endothelial cell adhesion molecule (PECAM)-1. In contrast, transcription was only modestly decreased in the DEX pretreated pigs compared to PZQ alone, and only for TNF-α, IL-6, IFN-γ, TGF-β and Ang1. IL-10 was not affected by either ETN or DEX pretreatments. The degree of inflammation, assessed by semi-quantitative inflammatory scores, was modestly decreased in both ETN and DEX pretreated animals compared to PZQ treated pigs whereas cyst damage scores were moderately decreased only in cysts from DEX pretreated pigs. However, the proportion of cysts with EB extravasation was not significantly changed in ETN and DEX pretreated groups. Conclusions/Significance Overall, TNF-α blockade using ETN treatment modulated expression of a large variety of genes that play a role in induction and control of inflammation and structural changes. In contrast the number of inflammatory cells was only moderately decreased suggesting weaker effects on cell migration into the inflammatory capsules surrounding cysts than on release of modulatory molecules. Taken together, these data suggest that TNF-α blockade may provide a viable strategy to manage post-treatment pericystic inflammation that follows antiparasitic therapy for neurocysticercosis. Infection of the brain with larvae of the tapeworm Taenia solium is called neurocysticercosis (NCC), a disease with varied and serious neurological symptoms. Therapy requires antiparasitic drugs and corticosteroids to prevent seizures caused by treatment due to inflammation around dying parasites. The gene expression of the proinflammatory molecule tumor necrosis factor alpha (TNF-α) is increased in NCC. We treated three groups of naturally infected pigs with an antiparasitic drug: one group was also pretreated with an anti-TNF-α inhibitor, the second one with a corticosteroid, and the third was not pretreated. All pigs were infused with Evans blue dye (EB), which leaks where the blood brain barrier is damaged by inflammation around cysts. We compared the expression of several genes involved in inflammation, healing and fibrosis and regulation of vascular function in tissues surrounding cysts. In inflamed samples showing leaked EB, the inhibition of TNF-α suppressed nearly all the genes assessed, and this suppression was significantly stronger than the moderate decrease caused by corticosteroid pretreatment on most of the genes. On microscopic examination, the inflammation observed was slightly decreased with both pretreatments in relation to the group that was not pretreated. We believe that the inflammatory route that includes TNF-α should be further explored in the search for better management of inflammation directed to degenerating cysts.
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Gutierrez-Loli R, Orrego MA, Sevillano-Quispe OG, Herrera-Arrasco L, Guerra-Giraldez C. MicroRNAs in Taenia solium Neurocysticercosis: Insights as Promising Agents in Host-Parasite Interaction and Their Potential as Biomarkers. Front Microbiol 2017; 8:1905. [PMID: 29033926 PMCID: PMC5626859 DOI: 10.3389/fmicb.2017.01905] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 09/19/2017] [Indexed: 12/21/2022] Open
Abstract
MicroRNAs (miRNAs) are short, endogenous, non-coding, single-stranded RNAs involved in post-transcriptional gene regulation. Although, several miRNAs have been identified in parasitic helminths, there is little information about their identification and function in Taenia. Furthermore, the impact of miRNAs in neurocysticercosis, the brain infection caused by larvae of Taenia solium is still unknown. During chronic infection, T. solium may activate numerous mechanisms aimed to modulate host immune responses. Helminthic miRNAs might also have effects on host mRNA expression and thus play an important role regulating host-parasite interactions. Also, the diagnosis of this disease is difficult and it usually requires neuroimaging and confirmatory serology. Since miRNAs are stable when released, they can be detected in body fluids and therefore have potential to diagnose infection, determine parasite burden, and ascertain effectiveness of treatment or disease progression, for instance. This review discusses the potential roles of miRNAs in T. solium infection, including regulation of host-parasite relationships and their eventual use as diagnostic or disease biomarkers. Additionally, we summarize the bioinformatics resources available for identification of T. solium miRNAs and prediction of their targets.
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Affiliation(s)
- Renzo Gutierrez-Loli
- Neurocysticercosis Lab, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Miguel A Orrego
- Neurocysticercosis Lab, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Oscar G Sevillano-Quispe
- Neurocysticercosis Lab, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Luis Herrera-Arrasco
- Neurocysticercosis Lab, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Cristina Guerra-Giraldez
- Neurocysticercosis Lab, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
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Marcin Sierra M, Arroyo M, Cadena Torres M, Ramírez Cruz N, García Hernández F, Taboada D, Galicia Martínez Á, Govezensky T, Sciutto E, Toledo A, Fleury A. Extraparenchymal neurocysticercosis: Demographic, clinicoradiological, and inflammatory features. PLoS Negl Trop Dis 2017; 11:e0005646. [PMID: 28599004 PMCID: PMC5479594 DOI: 10.1371/journal.pntd.0005646] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 06/21/2017] [Accepted: 05/17/2017] [Indexed: 12/24/2022] Open
Abstract
Background Extraparenchymal neurocysticercosis (ExPNCC), an infection caused by Taenia solium cysticerci that mainly occurs in the ventricular compartment (Ve) or the basal subarachnoid space (SAb), is more severe but less frequent and much less studied than parenchymal neurocysticercosis (ParNCC). Demographic, clinical, radiological, and lumbar cerebrospinal fluid features of patients affected by ExPNCC are herein described and compared with those of ParNCC patients. Methodology and principal findings 429 patients with a confirmed diagnosis of neurocysticercosis, attending the Instituto Nacional de Neurología y Neurocirugía, a tertiary reference center in Mexico City, from 2000 through 2014, were included. Demographic information, signs and symptoms, radiological patterns, and lumbar cerebrospinal fluid (CSF) laboratory values were retrieved from medical records for all patients. Data were statistically analyzed to assess potential differences depending on cyst location and to determine the effects of age and sex on the disease presentation. In total, 238 ExPNCC and 191 ParNCC patients were included. With respect to parenchymal cysts, extraparenchymal parasites were diagnosed at an older age (P = 0.002), chiefly caused intracranial hypertension (P < 0.0001), were more frequently multiple and vesicular (P < 0.0001), and CSF from these patients showed higher protein concentration and cell count (P < 0.0001). SAb patients were diagnosed at an older age than Ve patients, and showed more frequently seizures, vesicular cysticerci, and higher CSF cellularity. Gender and age modulated some traits of the disease. Conclusions This study evidenced clear clinical, radiological, and inflammatory differences between ExPNCC and ParNCC, and between SAb and Ve patients, and demonstrated that parasite location determines different pathological entities. Neurocysticercosis (NCC) is caused by the establishment of Taenia solium larvae in the human central nervous system. While NCC diagnosis, treatment, and prevention have clearly improved in the last 40 years, the disease still causes significant morbidity and mortality in endemic regions of Latin America, Asia, and Africa. Herein we described demographic, clinical, radiological, and cerebrospinal fluid features of a large series of NCC patients, and evaluated the relevance of parasite location on disease presentation. 191 patients with parenchymal parasites, 125 patients with extraparenchymal cysts, and 113 patients lodging parasites in both locations were included. Our results clearly demonstrated that differences in parasite location actually determines distinct diseases, with wide variations in severity. This is particularly evident when comparing parenchymal with extraparenchymal patients and ventricular with subarachnoid patients. Gender and age also modulate some characteristics of the disease. In conclusion, parasite location is one of the most important features of the disease, which must be considered when approaching an NCC patient.
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Affiliation(s)
- Mariana Marcin Sierra
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
| | - Mariana Arroyo
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
| | - May Cadena Torres
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
| | - Nancy Ramírez Cruz
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
| | - Fernando García Hernández
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
| | - Diana Taboada
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
| | - Ángeles Galicia Martínez
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
| | - Tzipe Govezensky
- Immunology Department, Instituto de Investigaciones Biomédicas – Universidad Nacional Autónoma de México, México City, México
| | - Edda Sciutto
- Immunology Department, Instituto de Investigaciones Biomédicas – Universidad Nacional Autónoma de México, México City, México
| | - Andrea Toledo
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
| | - Agnès Fleury
- Research Unit on Neuroinflammation, Instituto de Investigaciones Biomédicas - Universidad Nacional Autónoma de México / Facultad de Medicina – Universidad Nacional Autónoma de México / Instituto Nacional de Neurología y Neurocirugía, México City, México
- Neurocysticercosis Clinic, Instituto Nacional de Neurología y Neurocirugía, México City, México
- * E-mail:
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Cangalaya C, Bustos JA, Calcina J, Vargas-Calla A, Mamani J, Suarez D, Arroyo G, Gonzalez AE, Chacaltana J, Guerra-Giraldez C, Mahanty S, Nash TE, García HH. Radiological evolution of porcine neurocysticercosis after combined antiparasitic treatment with praziquantel and albendazole. PLoS Negl Trop Dis 2017; 11:e0005624. [PMID: 28575043 PMCID: PMC5470720 DOI: 10.1371/journal.pntd.0005624] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 06/14/2017] [Accepted: 05/04/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The onset of anthelmintic treatment of neurocysticercosis (NCC) provokes an acute immune response of the host, which in human cases is associated with exacerbation of neurological symptoms. This inflammation can occur at the first days of therapy. So, changes in the brain cysts appearance may be detected by medical imaging. We evaluated radiological changes in the appearance of brain cysts (enhancement and size) on days two and five after the onset of antiparasitic treatment using naturally infected pigs as a model for human NCC. METHODS AND RESULTS Contrast T1-weighted magnetic resonance imaging with gadolinium was performed before and after antiparasitic treatment. Eight NCC-infected pigs were treated with praziquantel plus albendazole and euthanized two (n = 4) and five (n = 4) days after treatment; another group of four infected pigs served as untreated controls. For each lesion, gadolinium enhancement intensity (GEI) and cyst volume were measured at baseline and after antiparasitic treatment. Volume and GEI quantification ratios (post/pre-treatment measures) were used to appraise the effect of treatment. Cysts from untreated pigs showed little variations between their basal and post treatment measures. At days 2 and 5 there were significant increases in GEI ratio compared with the untreated group (1.32 and 1.47 vs 1.01, p = 0.021 and p = 0.021). Cyst volume ratios were significantly lower at days 2 and 5 compared with the untreated group (0.60 and 0.22 vs 0.95, p = 0.04 and p = 0.02). Cysts with lower cyst volume ratios showed more marked post-treatment inflammation, loss of vesicular fluid and cyst wall wrinkling. CONCLUSION/SIGNIFICANCE A significant and drastic reduction of cyst size and increased pericystic enhancement occur in the initial days after antiparasitic treatment as an effect of acute perilesional immune response. These significant changes showed that early anthelmintic efficacy (day two) can be detected using magnetic resonance imaging.
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Affiliation(s)
- Carla Cangalaya
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Facultad de Medicina Humana, Universidad Nacional Mayor de San Marcos, Lima, Peru
- * E-mail:
| | - Javier A. Bustos
- Unidad de Cisticercosis, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Juan Calcina
- Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Ana Vargas-Calla
- Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Javier Mamani
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Diego Suarez
- Facultad de Medicina, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Gianfranco Arroyo
- Unidad de Cisticercosis, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Armando E. Gonzalez
- Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Juan Chacaltana
- Departamento de Diagnóstico por imágenes, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Cristina Guerra-Giraldez
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Siddhartha Mahanty
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Theodore E. Nash
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Héctor H. García
- Unidad de Cisticercosis, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
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Perilesional Inflammation in Neurocysticercosis - Relationship Between Contrast-Enhanced Magnetic Resonance Imaging, Evans Blue Staining and Histopathology in the Pig Model. PLoS Negl Trop Dis 2016; 10:e0004869. [PMID: 27459388 PMCID: PMC4961384 DOI: 10.1371/journal.pntd.0004869] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/30/2016] [Indexed: 11/19/2022] Open
Abstract
Background Disease manifestations in neurocysticercosis (NCC) are frequently due to inflammation of degenerating Taenia solium brain cysts. Exacerbated inflammation post anthelmintic treatment is associated with leakage of the blood brain barrier (BBB) using Evans blue (EB) staining. How well EB extravasation into the brain correlates with magnetic resonance imaging (MRI) using gadolinium (Gd) enhancement as a contrast agent and pericystic inflammation was analyzed in pigs harboring brain cysts of Taenia solium. Methodology/Principal Findings Three groups of 4 naturally infected pigs were assessed. The first and second groups were treated with both praziquantel plus albendazole and sacrificed two and five days post treatment, respectively. A third untreated group remained untreated. Pigs were injected with EB two hours prior to evaluation by Gd-enhanced T1-MRI, and euthanized. The EB staining for each cyst capsule was scored (EB grades were 0: 0%; 1: up to 50%; 2: over 50% but less than 100%; 3: 100%). Similarly, the Gd enhancement around each cyst was qualitatively and quantitatively scored from the MRI. The extent of pericystic inflammation on histology was scored in increasing severity as IS1, IS2, IS3 and IS4. Grade 3 EB staining and enhancement was only seen in treated capsules. Also, treated groups had higher Gd intensity than the untreated group. Grades of enhancement correlated significantly with Gd enhancement intensity. EB staining was correlated with Gd enhancement intensity and with IS4 in the treated groups. These correlations were stronger in internally located cysts compared to superficial cysts in treated groups. Significance EB staining and Gd enhancement strongly correlate. The intensity of enhancement determined by MRI is a good indication of the degree of inflammation. Similarly, EB staining highly correlates with the degree of inflammation and may be applied to study inflammation in the pig model of NCC. Neurocysticercosis (NCC) is a frequent parasitic infection of the human brain in developing countries. The symptomatology of human NCC after antiparasitic treatment is generally related to inflammation. The presence and degree of enhancement after intravascular injection of the contrast agent gadolinium in magnetic resonance imaging (MRI) is commonly considered an evidence of blood brain barrier (BBB) leakage. Experimentally, the presence and degree of extravasation of Evans blue (EB) after intravascular injection into the tissues of the brain is a direct measure of blood brain barrier leakage. The BBB leakage of gadolinium in neurocysticercosis is commonly used as an indirect measure of inflammation but has never been experimentally proven. Here we evaluated the relationship between contrast T1-MRI, EB staining and histology findings in naturally infected pigs. There was a strong correlation between EB staining, contrast MRI and histopathology findings after antiparasitic treatment. This correlation was stronger when cysts were internally located in the brain than in superficial cysts partly located in the subarachnoid space (meninges). Contrast-enhanced MRI is a non invasive tool used in diagnosis and follow up of NCC patients. This study shows that the use of EB staining allows for the same conclusions as when using MRI post-treatment, and that both techniques correlate with histopathology findings. These results support the use of EB staining to study NCC using the porcine model as well as validate MRI enhancement to assess brain inflammation in patients.
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Cangalaya C, Zimic M, Marzal M, González AE, Guerra-Giraldez C, Mahanty S, Nash TE, García HH. Inflammation Caused by Praziquantel Treatment Depends on the Location of the Taenia solium Cysticercus in Porcine Neurocysticercosis. PLoS Negl Trop Dis 2015; 9:e0004207. [PMID: 26658257 PMCID: PMC4689503 DOI: 10.1371/journal.pntd.0004207] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 10/12/2015] [Indexed: 12/04/2022] Open
Abstract
Background Neurocysticercosis (NCC), infection of the central nervous system by Taenia solium cysticerci, is a pleomorphic disease. Inflammation around cysticerci is the major cause of disease but is variably present. One factor modulating the inflammatory responses may be the location and characteristics of the brain tissue adjacent to cysticerci. We analyzed and compared the inflammatory responses to cysticerci located in the parenchyma to those in the meninges or cysticerci partially in contact with both the parenchyma and the meninges (corticomeningeal). Methodology/Principal Findings Histological specimens of brain cysticerci (n = 196) from 11 pigs naturally infected with Taenia solium cysticerci were used. Four pigs were sacrificed after 2 days and four after 5 days of a single dose of praziquantel; 3 pigs did not receive treatment. All pigs were intravenously injected with Evans Blue to assess disruption of the blood-brain barrier. The degree of inflammation was estimated by use of a histological score (ISC) based on the extent of the inflammation in the pericystic areas as assessed in an image composed of several photomicrographs taken at 40X amplification. Parenchymal cysticerci provoked a significantly greater level of pericystic inflammation (higher ISC) after antiparasitic treatment compared to meningeal and corticomeningeal cysticerci. ISC of meningeal cysticerci was not significantly affected by treatment. In corticomeningeal cysticerci, the increase in ISC score was correlated to the extent of the cysticercus adjacent to the brain parenchyma. Disruption of the blood-brain barrier was associated with treatment only in parenchymal tissue. Significance Inflammatory response to cysticerci located in the meninges was significantly decreased compared to parenchymal cysticerci. The suboptimal inflammatory response to cysticidal drugs may be the reason subarachnoid NCC is generally refractory to treatment compared to parenchymal NCC. The cystic larvae of the pork tapeworm Taenia solium may affect the human brain causing neurocysticercosis (NCC), a very frequent cause of neurological symptoms in developing countries. The clinical expression and response to treatment of human NCC are related to the location of cysticerci inside (intraparenchymal) or outside the brain parenchyma (extraparenchymal NCC). We used a naturally infected pig model to assess the characteristics of inflammation around brain cysticerci of parenchymal, meningeal and mixed locations. There were no major differences in inflammation without treatment. After antiparasitic treatment with praziquantel, inflammation around parenchymal brain cysticerci increased in comparison to meningeal located cysticerci. Cysticerci partially surrounded by both brain parenchyma and meninges showed increased inflammation in relation to the extent of the cysticercus in the brain parenchyma. The location of cysticerci within the brain is a factor that determines the extent and degree of the immune response following anticysticidal treatment. Similar changes may occur in treated human infections. Our work could contribute to explain the differences in response to antiparasitic treatment in different forms of human neurocysticercosis.
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Affiliation(s)
- Carla Cangalaya
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
- * E-mail:
| | - Mirko Zimic
- Laboratorio de Bioinformática y Biología Molecular, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Miguel Marzal
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Armando E. González
- Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Cristina Guerra-Giraldez
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Siddhartha Mahanty
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Theodore E. Nash
- Laboratorio de Inmunopatología en Neurocisticercosis, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hector H. García
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
- Unidad de Cisticercosis, Instituto Nacional de Ciencias Neurológicas, Lima, Perú
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Mahanty S, Orrego MA, Mayta H, Marzal M, Cangalaya C, Paredes A, Gonzales-Gustavson E, Arroyo G, Gonzalez AE, Guerra-Giraldez C, García HH, Nash TE. Post-treatment vascular leakage and inflammatory responses around brain cysts in porcine neurocysticercosis. PLoS Negl Trop Dis 2015; 9:e0003577. [PMID: 25774662 PMCID: PMC4361613 DOI: 10.1371/journal.pntd.0003577] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 01/29/2015] [Indexed: 11/18/2022] Open
Abstract
Cysticidal treatment of neurocysticercosis, an infection of humans and pig brains with Taenia solium, results in an early inflammatory response directed to cysts causing seizures and focal neurological manifestations. Treatment-induced pericystic inflammation and its association with blood brain barrier (BBB) dysfunction, as determined by Evans blue (EB) extravasation, was studied in infected untreated and anthelmintic-treated pigs. We compared the magnitude and extent of the pericystic inflammation, presence of EB-stained capsules, the level of damage to the parasite, expression of genes for proinflammatory and regulatory cytokines, chemokines, and tissue remodeling by quantitative PCR assays between treated and untreated infected pigs and between EB-stained (blue) and non stained (clear) cysts. Inflammatory scores were higher in pericystic tissues from EB-stained cysts compared to clear cysts from untreated pigs and also from anthelmintic-treated pigs 48 hr and 120 hr after treatment. The degree of inflammation correlated with the severity of cyst wall damage and both increased significantly at 120 hours. Expression levels of the proinflammatory genes for IL-6, IFN-γ, TNF-α were higher in EB-stained cysts compared to clear cysts and unaffected brain tissues, and were generally highest at 120 hr. Additionally, expression of some markers of immunoregulatory activity (IL-10, IL-2Rα) were decreased in EB-stained capsules. An increase in other markers for regulatory T cells (CTLA4, FoxP3) was found, as well as significant increases in expression of two metalloproteases, MMP1 and MMP2 at 48 hr and 120 hr post-treatment. We conclude that the increase in severity of the inflammation caused by treatment is accompanied by both a proinflammatory and a complex regulatory response, largely limited to pericystic tissues with compromised vascular integrity. Because treatment induced inflammation occurs in porcine NCC similar to that in human cases, this model can be used to investigate mechanisms involved in host damaging inflammatory responses and agents or modalities that may control damaging post treatment inflammation. Neurocysticercosis is caused by infection of the brain with the larval (cyst) stage of the tape worm Taenia solium in humans and pigs. Antiparasitic drug treatment is compromised by worsening of neurological symptoms during therapy due to reactive inflammation triggered by the dying parasite. The immune mechanisms that cause this inflammation are poorly understood. In this study, we investigated the nature of inflammation after treatment in pigs naturally infected with T. solium cysts. Evans blue dye injected into infected pigs marks areas in the brain where the normally impermeable capillaries have become more permeable, allowing damaging cells and molecules to leak out into the brain. By microscopy and measurement of gene expression for inflammation-inducing immune mediators, we show that inflammation in the brain tissues around cysts is more severe with increased vessel leakage. Furthermore, the levels of these mediators increased after antiparasitic drug treatment. A significant implication of these findings is that it may be possible to inhibit the inflammation around parasites using drugs or biologics that inhibit these inflammatory pathways and, thereby, reduce local brain damage during treatment. These observations may also be applicable to other inflammatory conditions that affect the brain.
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Affiliation(s)
- Siddhartha Mahanty
- Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Laboratory of Immunopathology, Universidad Peruana Cayetano Heredia, Lima, Peru
- * E-mail:
| | - Miguel Angel Orrego
- Laboratory of Immunopathology, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Holger Mayta
- Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Miguel Marzal
- Laboratory of Immunopathology, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Carla Cangalaya
- Laboratory of Immunopathology, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Adriana Paredes
- Laboratory of Immunopathology, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Gianfranco Arroyo
- Faculty of Veterinary Sciences, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Armando E. Gonzalez
- Faculty of Veterinary Sciences, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Cristina Guerra-Giraldez
- Laboratory of Immunopathology, Universidad Peruana Cayetano Heredia, Lima, Peru
- Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Hector H. García
- Laboratory of Immunopathology, Universidad Peruana Cayetano Heredia, Lima, Peru
- Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Theodore E. Nash
- Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Laboratory of Immunopathology, Universidad Peruana Cayetano Heredia, Lima, Peru
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Garcia HH, Rodriguez S, Friedland JS. Immunology of Taenia solium taeniasis and human cysticercosis. Parasite Immunol 2014; 36:388-96. [PMID: 24962350 DOI: 10.1111/pim.12126] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 06/18/2014] [Indexed: 01/08/2023]
Abstract
The life cycle of Taenia solium, the pork tapeworm, is continuously closed in many rural settings in developing countries when free roaming pigs ingest human stools containing T. solium eggs and develop cysticercosis, and humans ingest pork infected with cystic larvae and develop intestinal taeniasis, or may also accidentally acquire cysticercosis by faecal-oral contamination. Cysticercosis of the human nervous system, neurocysticercosis, is a major cause of seizures and other neurological morbidity in most of the world. The dynamics of exposure, infection and disease as well as the location of parasites result in a complex interaction which involves immune evasion mechanisms and involutive or progressive disease along time. Moreover, existing data are limited by the relative lack of animal models. This manuscript revises the available information on the immunology of human taeniasis and cysticercosis.
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Affiliation(s)
- H H Garcia
- Department of Microbiology, School of Sciences and Center for Global Health - Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru; Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
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Evans blue staining reveals vascular leakage associated with focal areas of host-parasite interaction in brains of pigs infected with Taenia solium. PLoS One 2014; 9:e97321. [PMID: 24915533 PMCID: PMC4051593 DOI: 10.1371/journal.pone.0097321] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 04/18/2014] [Indexed: 11/19/2022] Open
Abstract
Cysticidal drug treatment of viable Taenia solium brain parenchymal cysts leads to an acute pericystic host inflammatory response and blood brain barrier breakdown (BBB), commonly resulting in seizures. Naturally infected pigs, untreated or treated one time with praziquantel were sacrificed at 48 hr and 120 hr following the injection of Evans blue (EB) to assess the effect of treatment on larval parasites and surrounding tissue. Examination of harvested non encapsulated muscle cysts unexpectedly revealed one or more small, focal round region(s) of Evans blue dye infiltration (REBI) on the surface of otherwise non dye-stained muscle cysts. Histopathological analysis of REBI revealed focal areas of eosinophil-rich inflammatory infiltrates that migrated from the capsule into the tegument and internal structures of the parasite. In addition some encapsulated brain cysts, in which the presence of REBI could not be directly assessed, showed histopathology identical to that of the REBI. Muscle cysts with REBI were more frequent in pigs that had received praziquantel (6.6% of 3736 cysts; n = 6 pigs) than in those that were untreated (0.2% of 3172 cysts; n = 2 pigs). Similar results were found in the brain, where 20.7% of 29 cysts showed histopathology identical to muscle REBI cysts in praziquantel-treated pigs compared to the 4.3% of 47 cysts in untreated pigs. Closer examination of REBI infiltrates showed that EB was taken up only by eosinophils, a major component of the cellular infiltrates, which likely explains persistence of EB in the REBI. REBI likely represent early damaging host responses to T. solium cysts and highlight the focal nature of this initial host response and the importance of eosinophils at sites of host-parasite interaction. These findings suggest new avenues for immunomodulation to reduce inflammatory side effects of anthelmintic therapy.
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