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Clemente TM, Angara RK, Gilk SD. Establishing the intracellular niche of obligate intracellular vacuolar pathogens. Front Cell Infect Microbiol 2023; 13:1206037. [PMID: 37645379 PMCID: PMC10461009 DOI: 10.3389/fcimb.2023.1206037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
Obligate intracellular pathogens occupy one of two niches - free in the host cell cytoplasm or confined in a membrane-bound vacuole. Pathogens occupying membrane-bound vacuoles are sequestered from the innate immune system and have an extra layer of protection from antimicrobial drugs. However, this lifestyle presents several challenges. First, the bacteria must obtain membrane or membrane components to support vacuole expansion and provide space for the increasing bacteria numbers during the log phase of replication. Second, the vacuole microenvironment must be suitable for the unique metabolic needs of the pathogen. Third, as most obligate intracellular bacterial pathogens have undergone genomic reduction and are not capable of full metabolic independence, the bacteria must have mechanisms to obtain essential nutrients and resources from the host cell. Finally, because they are separated from the host cell by the vacuole membrane, the bacteria must possess mechanisms to manipulate the host cell, typically through a specialized secretion system which crosses the vacuole membrane. While there are common themes, each bacterial pathogen utilizes unique approach to establishing and maintaining their intracellular niches. In this review, we focus on the vacuole-bound intracellular niches of Anaplasma phagocytophilum, Ehrlichia chaffeensis, Chlamydia trachomatis, and Coxiella burnetii.
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Affiliation(s)
| | | | - Stacey D. Gilk
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
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Clemente TM, Augusto L, Angara RK, Gilk SD. Coxiella burnetii actively blocks IL-17-induced oxidative stress in macrophages. bioRxiv 2023:2023.03.15.532774. [PMID: 36993319 PMCID: PMC10055185 DOI: 10.1101/2023.03.15.532774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Coxiella burnetii is a highly infectious pathogen that causes Q fever, a leading cause of culture-negative endocarditis. Coxiella first targets alveolar macrophages and forms a phagolysosome-like compartment called the Coxiella-Containing Vacuole (CCV). Successful host cell infection requires the Type 4B Secretion System (T4BSS), which translocates bacterial effector proteins across the CCV membrane into the host cytoplasm, where they manipulate numerous cell processes. Our prior transcriptional studies revealed that Coxiella T4BSS blocks IL-17 signaling in macrophages. Given that IL-17 is known to protect against pulmonary pathogens, we hypothesize that C. burnetii T4BSS downregulates intracellular IL-17 signaling to evade the host immune response and promote bacterial pathogenesis. Using a stable IL-17 promoter reporter cell line, we confirmed that Coxiella T4BSS blocks IL-17 transcription activation. Assessment of the phosphorylation state of NF-κB, MAPK, and JNK revealed that Coxiella downregulates IL-17 activation of these proteins. Using ACT1 knockdown and IL-17RA or TRAF6 knockout cells, we next determined that IL17RA-ACT1-TRAF6 pathway is essential for the IL-17 bactericidal effect in macrophages. In addition, macrophages stimulated with IL-17 generate higher levels of reactive oxygen species, which is likely connected to the bactericidal effect of IL-17. However, C. burnetii T4SS effector proteins block the IL-17-mediated oxidative stress, suggesting that Coxiella blocks IL-17 signaling to avoid direct killing by the macrophages.
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Affiliation(s)
- Tatiana M Clemente
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, US
| | - Leonardo Augusto
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, US
| | - Rajendra K Angara
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, US
| | - Stacey D Gilk
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, US
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Davis MD, Clemente TM, Giddings OK, Ross K, Cunningham RS, Smith L, Simpson E, Liu Y, Kloepfer K, Ramsey IS, Zhao Y, Robinson CM, Gilk SD, Gaston B. A Treatment to Eliminate SARS-CoV-2 Replication in Human Airway Epithelial Cells Is Safe for Inhalation as an Aerosol in Healthy Human Subjects. Respir Care 2021; 66:113-119. [PMID: 32962996 PMCID: PMC7856523 DOI: 10.4187/respcare.08425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Low airway surface pH is associated with many airway diseases, impairs antimicrobial host defense, and worsens airway inflammation. Inhaled Optate is designed to safely raise airway surface pH and is well tolerated in humans. Raising intracellular pH partially prevents activation of SARS-CoV-2 in primary normal human airway epithelial (NHAE) cells, decreasing viral replication by several mechanisms. METHODS We grew primary NHAE cells from healthy subjects, infected them with SARS-CoV-2 (isolate USA-WA1/2020), and used clinical Optate at concentrations used in humans in vivo to determine whether Optate would prevent viral infection and replication. Cells were pretreated with Optate or placebo prior to infection (multiplicity of infection = 1), and viral replication was determined with plaque assay and nucleocapsid (N) protein levels. Healthy human subjects also inhaled Optate as part of a Phase 2a safety trial. RESULTS Optate almost completely prevented viral replication at each time point between 24 h and 120 h, relative to placebo, on both plaque assay and N protein expression (P < .001). Mechanistically, Optate inhibited expression of major endosomal trafficking genes and raised NHAE intracellular pH. Optate had no effect on NHAE cell viability at any time point. Inhaled Optate was well tolerated in 10 normal subjects, with no change in lung function, vital signs, or oxygenation. CONCLUSIONS Inhaled Optate may be well suited for a clinical trial in patients with pulmonary SARS-CoV-2 infection. However, it is vitally important for patient safety that formulations designed for inhalation with regard to pH, isotonicity, and osmolality be used. An inhalational treatment that safely prevents SARS-CoV-2 viral replication could be helpful for treating patients with pulmonary SARS-CoV-2 infection.
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Affiliation(s)
- Michael D Davis
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine
- Division of Pulmonology, Allergy and Sleep Medicine, Riley Hospital for Children, Indianapolis, Indiana
| | - Tatiana M Clemente
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Olivia K Giddings
- Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, Cleveland, Ohio
| | - Kristie Ross
- Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, Cleveland, Ohio
| | - Rebekah S Cunningham
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine
| | - Laura Smith
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine
| | - Edward Simpson
- Center for Computational Biology and Informatics, Indiana University School of Medicine, Indianapolis, Indiana
- Department of BioHealth Informatics, School of Informatics and Computing, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
| | - Yunlong Liu
- Center for Computational Biology and Informatics, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kirsten Kloepfer
- Division of Pulmonology, Allergy and Sleep Medicine, Riley Hospital for Children, Indianapolis, Indiana
| | - I Scott Ramsey
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Yi Zhao
- Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Christopher M Robinson
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Stacey D Gilk
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Benjamin Gaston
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine.
- Division of Pulmonology, Allergy and Sleep Medicine, Riley Hospital for Children, Indianapolis, Indiana
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Samanta D, Clemente TM, Schuler BE, Gilk SD. Coxiella burnetii Type 4B Secretion System-dependent manipulation of endolysosomal maturation is required for bacterial growth. PLoS Pathog 2019; 15:e1007855. [PMID: 31869379 PMCID: PMC6953889 DOI: 10.1371/journal.ppat.1007855] [Citation(s) in RCA: 17] [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: 05/15/2019] [Revised: 01/10/2020] [Accepted: 12/05/2019] [Indexed: 01/24/2023] Open
Abstract
Upon host cell infection, the obligate intracellular bacterium Coxiella burnetii resides and multiplies within the Coxiella–Containing Vacuole (CCV). The nascent CCV progresses through the endosomal maturation pathway into a phagolysosome, acquiring endosomal and lysosomal markers, as well as acidic pH and active proteases and hydrolases. Approximately 24–48 hours post infection, heterotypic fusion between the CCV and host endosomes/lysosomes leads to CCV expansion and bacterial replication in the mature CCV. Initial CCV acidification is required to activate C. burnetii metabolism and the Type 4B Secretion System (T4BSS), which secretes effector proteins required for CCV maturation. However, we found that the mature CCV is less acidic (pH~5.2) than lysosomes (pH~4.8). Further, inducing CCV acidification to pH~4.8 causes C. burnetii lysis, suggesting C. burnetii actively regulates pH of the mature CCV. Because heterotypic fusion with host endosomes/lysosomes may influence CCV pH, we investigated endosomal maturation in cells infected with wildtype (WT) or T4BSS mutant (ΔdotA) C. burnetii. In WT-infected cells, we observed a significant decrease in proteolytically active, LAMP1-positive endolysosomal vesicles, compared to mock or ΔdotA-infected cells. Using a ratiometric assay to measure endosomal pH, we determined that the average pH of terminal endosomes in WT-infected cells was pH~5.8, compared to pH~4.75 in mock and ΔdotA-infected cells. While endosomes progressively acidified from the periphery (pH~5.5) to the perinuclear area (pH~4.7) in both mock and ΔdotA-infected cells, endosomes did not acidify beyond pH~5.2 in WT-infected cells. Finally, increasing lysosomal biogenesis by overexpressing the transcription factor EB resulted in smaller, more proteolytically active CCVs and a significant decrease in C. burnetii growth, indicating host lysosomes are detrimental to C. burnetii. Overall, our data suggest that C. burnetii inhibits endosomal maturation to reduce the number of proteolytically active lysosomes available for heterotypic fusion with the CCV, possibly as a mechanism to regulate CCV pH. The obligate intracellular bacterium Coxiella burnetii causes human Q fever, which manifests as a flu-like illness but can develop into a life-threatening and difficult to treat endocarditis. C. burnetii, in contrast to many other intracellular bacteria, thrives within a lysosome-like vacuole in host cells. However, we previously found that the C. burnetii vacuole is not as acidic as lysosomes and increased acidification kills the bacteria, suggesting that C. burnetii regulates the pH of its vacuole. Here, we discovered that C. burnetii blocks endolysosomal maturation and acidification during host cell infection, resulting in fewer lysosomes in the host cell. Moreover, increasing lysosomes in the host cells inhibited C. burnetii growth. Together, our study suggests that C. burnetii regulates vacuole acidity and blocks endosomal maturation in order to produce a permissive intracellular niche.
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Affiliation(s)
- Dhritiman Samanta
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Tatiana M. Clemente
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Baleigh E. Schuler
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Stacey D. Gilk
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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Samanta D, Mulye M, Clemente TM, Justis AV, Gilk SD. Manipulation of Host Cholesterol by Obligate Intracellular Bacteria. Front Cell Infect Microbiol 2017; 7:165. [PMID: 28529926 PMCID: PMC5418226 DOI: 10.3389/fcimb.2017.00165] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 04/18/2017] [Indexed: 12/29/2022] Open
Abstract
Cholesterol is a multifunctional lipid that plays important metabolic and structural roles in the eukaryotic cell. Despite having diverse lifestyles, the obligate intracellular bacterial pathogens Chlamydia, Coxiella, Anaplasma, Ehrlichia, and Rickettsia all target cholesterol during host cell colonization as a potential source of membrane, as well as a means to manipulate host cell signaling and trafficking. To promote host cell entry, these pathogens utilize cholesterol-rich microdomains known as lipid rafts, which serve as organizational and functional platforms for host signaling pathways involved in phagocytosis. Once a pathogen gains entrance to the intracellular space, it can manipulate host cholesterol trafficking pathways to access nutrient-rich vesicles or acquire membrane components for the bacteria or bacteria-containing vacuole. To acquire cholesterol, these pathogens specifically target host cholesterol metabolism, uptake, efflux, and storage. In this review, we examine the strategies obligate intracellular bacterial pathogens employ to manipulate cholesterol during host cell colonization. Understanding how obligate intracellular pathogens target and use host cholesterol provides critical insight into the host-pathogen relationship.
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Affiliation(s)
- Dhritiman Samanta
- Department of Microbiology and Immunology, Indiana University School of MedicineIndianapolis, IN, USA
| | - Minal Mulye
- Department of Microbiology and Immunology, Indiana University School of MedicineIndianapolis, IN, USA
| | - Tatiana M Clemente
- Department of Microbiology and Immunology, Indiana University School of MedicineIndianapolis, IN, USA
| | - Anna V Justis
- Department of Microbiology and Immunology, Indiana University School of MedicineIndianapolis, IN, USA
| | - Stacey D Gilk
- Department of Microbiology and Immunology, Indiana University School of MedicineIndianapolis, IN, USA
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Rodrigues AA, Notário AFO, Teixeira TL, e Silva RT, Quintal APN, Alves RN, Brígido PC, Siqueira CS, Martins FA, Machado FC, Clemente TM, da Silva AA, Borges BC, Teixeira SC, dos Santos MA, da Silva CV. A high throughput analysis of cytokines and chemokines expression during the course of Trypanosoma cruzi experimental oral infection. Acta Trop 2016; 157:42-53. [PMID: 26827742 DOI: 10.1016/j.actatropica.2016.01.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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: 09/20/2015] [Revised: 12/14/2015] [Accepted: 01/25/2016] [Indexed: 01/28/2023]
Abstract
Trypanosoma cruzi has high biological and biochemical diversity and variable tissue tropism. Here we aimed to verify the kinetics of cytokine and chemokine in situ secretion in animals infected with two distinct T. cruzi strains after oral inoculation. Also, we investigated parasite migration, residence and pathological damage in stomach, heart and spleen. Our results showed that host immune response against T. cruzi infection is an intricate phenomenon that depends on the parasite strain, on the infected organ and on the time point of the infection. We believe that a wide comprehension of host immune response will potentially provide basis for the development of immunotherapeutic strategies in order to clear parasitism and minimize tissue injury. In this context, we find that KC poses as a possible tool to be used.
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Affiliation(s)
- Adele A Rodrigues
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Ana Flávia O Notário
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Thaise L Teixeira
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Rebecca T e Silva
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Amanda P N Quintal
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Rosiane N Alves
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Paula C Brígido
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Carla S Siqueira
- Faculdade de Odontologia, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Flávia A Martins
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Fabrício C Machado
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil; Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil, Brazil
| | - Tatiana M Clemente
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil; Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil, Brazil
| | - Aline A da Silva
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Bruna C Borges
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Samuel C Teixeira
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Marlus A dos Santos
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Claudio V da Silva
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
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Rodrigues AA, Clemente TM, dos Santos MA, Machado FC, Gomes RGB, Moreira HHT, Cruz MC, Brígido PC, dos Santos PCF, Martins FA, Bahia D, Maricato JT, Janini LMR, Reboredo EH, Mortara RA, da Silva CV. A recombinant protein based on Trypanosoma cruzi P21 enhances phagocytosis. PLoS One 2012; 7:e51384. [PMID: 23251513 PMCID: PMC3519637 DOI: 10.1371/journal.pone.0051384] [Citation(s) in RCA: 24] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 11/06/2012] [Indexed: 12/12/2022] Open
Abstract
Background P21 is a secreted protein expressed in all developmental stages of Trypanosoma cruzi. The aim of this study was to determine the effect of the recombinant protein based on P21 (P21-His6) on inflammatory macrophages during phagocytosis. Findings Our results showed that P21-His6 acts as a phagocytosis inducer by binding to CXCR4 chemokine receptor and activating actin polymerization in a way dependent onthe PI3-kinase signaling pathway. Conclusions Thus, our results shed light on the notion that native P21 is a component related to T. cruzi evasion from the immune response and that CXCR4 may be involved in phagocytosis. P21-His6 represents an important experimental control tool to study phagocytosis signaling pathways of different intracellular parasites and particles.
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Affiliation(s)
- Adele A. Rodrigues
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Tatiana M. Clemente
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Marlus A. dos Santos
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Fabrício C. Machado
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Rafael G. B. Gomes
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | | | - Mário C. Cruz
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo, Brazil
| | - Paula C. Brígido
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Paulo C. F. dos Santos
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Flávia A. Martins
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Diana Bahia
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo, Brazil
| | - Juliana T. Maricato
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo, Brazil
| | - Luiz M. R. Janini
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo, Brazil
| | - Eduardo H. Reboredo
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil
| | - Renato A. Mortara
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo, Brazil
| | - Claudio V. da Silva
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
- * E-mail:
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