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Veras PST, Descoteaux A, Colombo MI, de Menezes JPB. Editorial: Early events during host cell-pathogen interaction, volume II. Front Cell Infect Microbiol 2024; 14:1364415. [PMID: 38299115 PMCID: PMC10827853 DOI: 10.3389/fcimb.2024.1364415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 01/08/2024] [Indexed: 02/02/2024] Open
Affiliation(s)
- Patricia S. T. Veras
- Laboratory of Host - Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Albert Descoteaux
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Sante´ Biotechnologie, Laval, QC, Canada
| | - Maria Isabel Colombo
- Instituto de Histología y Embriología de Mendoza (IHEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Juliana P. B. de Menezes
- Laboratory of Host - Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
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Luz Y, Rebouças A, Bernardes CPOS, Rossi EA, Machado TS, Souza BSF, Brodskyn CI, Veras PST, dos Santos WLC, de Menezes JPB. Leishmania infection alters macrophage and dendritic cell migration in a three-dimensional environment. Front Cell Dev Biol 2023; 11:1206049. [PMID: 37576604 PMCID: PMC10416637 DOI: 10.3389/fcell.2023.1206049] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/18/2023] [Indexed: 08/15/2023] Open
Abstract
Background: Leishmaniasis results in a wide spectrum of clinical manifestations, ranging from skin lesions at the site of infection to disseminated lesions in internal organs, such as the spleen and liver. While the ability of Leishmania-infected host cells to migrate may be important to lesion distribution and parasite dissemination, the underlying mechanisms and the accompanying role of host cells remain poorly understood. Previously published work has shown that Leishmania infection inhibits macrophage migration in a 2-dimensional (2D) environment by altering actin dynamics and impairing the expression of proteins involved in plasma membrane-extracellular matrix interactions. Although it was shown that L. infantum induces the 2D migration of dendritic cells, in vivo cell migration primarily occurs in 3-dimensional (3D) environments. The present study aimed to investigate the migration of macrophages and dendritic cells infected by Leishmania using a 3-dimensional environment, as well as shed light on the mechanisms involved in this process. Methods: Following the infection of murine bone marrow-derived macrophages (BMDM), human macrophages and human dendritic cells by L. amazonensis, L. braziliensis, or L. infantum, cellular migration, the formation of adhesion complexes and actin polymerization were evaluated. Results: Our results indicate that Leishmania infection inhibited 3D migration in both BMDM and human macrophages. Reduced expression of proteins involved in adhesion complex formation and alterations in actin dynamics were also observed in Leishmania-infected macrophages. By contrast, increased human dendritic cell migration in a 3D environment was found to be associated with enhanced adhesion complex formation and increased actin dynamics. Conclusion: Taken together, our results show that Leishmania infection inhibits macrophage 3D migration, while enhancing dendritic 3D migration by altering actin dynamics and the expression of proteins involved in plasma membrane extracellular matrix interactions, suggesting a potential association between dendritic cells and disease visceralization.
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Affiliation(s)
- Yasmin Luz
- Laboratory of Host—Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Amanda Rebouças
- Laboratory of Host—Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | | | - Erik A. Rossi
- Center for Biotechnology and Cell Therapy, São Rafael Hospital, Salvador, Brazil
| | - Taíse S. Machado
- Laboratory of Host—Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Bruno S. F. Souza
- Center for Biotechnology and Cell Therapy, São Rafael Hospital, Salvador, Brazil
- D’Or Institute for Research and Education, Salvador, Brazil
- Laboratory of Tissue Engineering and Immunopharmacology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Claudia Ida Brodskyn
- Laboratory of Host—Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Patricia S. T. Veras
- Laboratory of Host—Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | | | - Juliana P. B. de Menezes
- Laboratory of Host—Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
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Luz YDS, Paixão AR, Bernardes CPOS, da Silva TS, Tavares NM, Brodskyn CI, Veras PST, de Menezes JPB. Cell Migration and Cell Adhesion Assays to Investigate Leishmania-Host Cell Interaction. J Vis Exp 2021. [PMID: 34424251 DOI: 10.3791/62461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Leishmania is an intracellular protozoan parasite that causes a broad spectrum of clinical manifestations, ranging from self-resolving localized cutaneous lesions to a highly fatal visceral form of the disease. An estimated 12 million people worldwide are currently infected, and another 350 million face risk of infection. It is known that host cells infected by Leishmania parasites, such as macrophages or dendritic cells, can migrate to different host tissues, yet how migration contributes to parasite dissemination and homing remains poorly understood. Therefore, assessing these parasites' ability to modulate host cell response, adhesion, and migration will shed light on mechanisms involved in disease dissemination and visceralization. Cellular migration is a complex process in which cells undergo polarization and protrusion, allowing them to migrate. This process, regulated by actin and tubulin-based microtubule dynamics, involves different factors, including the modulation of cellular adhesion to the substrate. Cellular adhesion and migration processes have been investigated using several models. Here, we describe a method to characterize the migratory aspects of host cells during Leishmania infection. This detailed protocol presents the differentiation and infection of dendritic cells, the analysis of host cell motility and migration, and the formation of adhesion complexes and actin dynamics. This in vitro protocol aims to further elucidate mechanisms involved in Leishmania dissemination within vertebrate host tissues and can also be modified and applied to other cell migration studies.
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Affiliation(s)
- Yasmin da Silva Luz
- Laboratory of Host - Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
| | - Amanda R Paixão
- Laboratory of Host - Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
| | | | | | | | - Claudia I Brodskyn
- Laboratory of Host - Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
| | - Patricia S T Veras
- Laboratory of Host - Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
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Paixão AR, Dias BRS, Palma LC, Tavares NM, Brodskyn CI, de Menezes JPB, Veras PST. Investigating the Phagocytosis of Leishmania using Confocal Microscopy. J Vis Exp 2021. [PMID: 34398153 DOI: 10.3791/62459] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Phagocytosis is an orchestrated process that involves distinct steps: recognition, binding, and internalization. Professional phagocytes take up Leishmania parasites by phagocytosis, consisting of recognizing ligands on parasite surfaces by multiple host cell receptors. Binding of Leishmania to macrophage membranes occurs through complement receptor type 1 (CR1) and complement receptor type 3 (CR3) and Pattern Recognition Receptors. Lipophosphoglycan (LPG) and 63 kDa glycoprotein (gp63) are the main ligands involved in macrophage-Leishmania interactions. Following the initial recognition of parasite ligands by host cell receptors, parasites become internalized, survive, and multiply within parasitophorous vacuoles. The maturation process of Leishmania-induced vacuoles involves the acquisition of molecules from intracellular vesicles, including monomeric G protein Rab 5 and Rab 7, lysosomal associated membrane protein 1 (LAMP-1), lysosomal associated membrane protein 2 (LAMP-2), and microtubule-associated protein 1A/1B-light chain 3 (LC3). Here, we describe methods to evaluate the early events occurring during Leishmania interaction with the host cells using confocal microscopy, including (i) binding (ii) internalization, and (iii) phagosome maturation. By adding to the body of knowledge surrounding these determinants of infection outcome, we hope to improve the understanding of the pathogenesis of Leishmania infection and support the eventual search for novel chemotherapeutic targets.
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Affiliation(s)
- Amanda R Paixão
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
| | - Beatriz R S Dias
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
| | - Luana C Palma
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
| | - Natália M Tavares
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
| | - Cláudia I Brodskyn
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute
| | | | - Patricia S T Veras
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute; National Institute of Science and Technology of Tropical Diseases - National Council for Scientific Research and Development (CNPq);
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Dias BRS, de Souza CS, Almeida NDJ, Lima JGB, Fukutani KF, Dos Santos TBS, França-Cost J, Brodskyn CI, de Menezes JPB, Colombo MI, Veras PST. Autophagic Induction Greatly Enhances Leishmania major Intracellular Survival Compared to Leishmania amazonensis in CBA/j-Infected Macrophages. Front Microbiol 2018; 9:1890. [PMID: 30158914 PMCID: PMC6104192 DOI: 10.3389/fmicb.2018.01890] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [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: 03/25/2018] [Accepted: 07/27/2018] [Indexed: 12/29/2022] Open
Abstract
CBA mouse macrophages control Leishmania major infection yet are permissive to Leishmania amazonensis. Few studies have been conducted to assess the role played by autophagy in Leishmania infection. Therefore, we assessed whether the autophagic response of infected macrophages may account for the differential behavior of these two parasite strains. After 24 h of infection, the LC3-II/Act ratio increased in both L. amazonensis- and L. major-infected macrophages compared to uninfected controls, but less than in chloroquine-treated cells. This suggests that L. amazonensis and L. major activate autophagy in infected macrophages, without altering the autophagic flux. Furthermore, L. major-infected cells exhibited higher percentages of DQ-BSA-labeled parasitophorous vacuoles (50%) than those infected by L. amazonensis (25%). However, L. major- and L. amazonensis-induced parasitophorous vacuoles accumulated LysoTracker similarly, indicating that the acidity in both compartment was equivalent. At as early as 30 min, endogenous LC3 was recruited to both L. amazonensis- and L. major-induced parasitophorous vacuoles, while after 24 h a greater percentage of LC3 positive vacuoles was observed in L. amazonensis-infected cells (42.36%) compared to those infected by L. major (18.10%). Noteworthy, principal component analysis (PCA) and an hierarchical cluster analysis completely discriminated L. major-infected macrophages from L. amazonensis-infected cells accordingly to infection intensity and autophagic features of parasite-induced vacuoles. Then, we evaluated whether the modulation of autophagy exerted an influence on parasite infection in macrophages. No significant changes were observed in both infection rate or parasite load in macrophages treated with the autophagic inhibitors wortmannin, chloroquine or VPS34-IN1, as well as with the autophagic inducers rapamycin or physiological starvation, in comparison to untreated control cells. Interestingly, both autophagic inducers enhanced intracellular L. amazonensis and L. major viability, while the pharmacological inhibition of autophagy exerted no effects on intracellular parasite viability. We also demonstrated that autophagy induction reduced NO production by L. amazonensis- and L. major-infected macrophages but not alters arginase activity. These findings provide evidence that although L. amazonensis-induced parasitophorous vacuoles recruit LC3 more markedly, L. amazonensis and L. major similarly activate the autophagic pathway in CBA macrophages. Interestingly, the exogenous induction of autophagy favors L. major intracellular viability to a greater extent than L. amazonensis related to a reduction in the levels of NO.
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Affiliation(s)
- Beatriz R S Dias
- Laboratory of Parasite-Host Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Carina S de Souza
- Laboratory of Parasite-Host Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Niara de Jesus Almeida
- Laboratory of Parasite-Host Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - José G B Lima
- Laboratory of Parasite-Host Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Kiyoshi F Fukutani
- Laboratory of Inflammation and Biomarkers, Gonçalo Moniz Institute, Salvador, Brazil
| | - Thiale B S Dos Santos
- Laboratory of Inflammation and Biomarkers, Gonçalo Moniz Institute, Salvador, Brazil
| | - Jaqueline França-Cost
- Laboratory of Inflammation and Biomarkers, Gonçalo Moniz Institute, Salvador, Brazil.,Department of Biointeraction, Federal University of Bahia, Salvador, Brazil
| | - Claudia I Brodskyn
- Laboratory of Parasite-Host Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Juliana P B de Menezes
- Laboratory of Parasite-Host Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
| | - Maria I Colombo
- Laboratory of Cellular and Molecular Biology, Institute of Histology and Embryology-CONICET, National University of Cuyo, Mendoza, Argentina
| | - Patricia S T Veras
- Laboratory of Parasite-Host Interaction and Epidemiology, Gonçalo Moniz Institute, Salvador, Brazil
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Guedes CES, Lima JGB, Helfer E, Veras PST, Viallat A. Encapsulation of Living Leishmania Promastigotes in Artificial Lipid Vacuoles. PLoS One 2015; 10:e0134925. [PMID: 26241746 PMCID: PMC4524717 DOI: 10.1371/journal.pone.0134925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 07/16/2015] [Indexed: 11/19/2022] Open
Abstract
After phagocytosis by mammalian macrophages, promastigote forms of Leishmania parasites settle inside intracellular parasitophorous vacuoles (PVs) in which they transform into amastigote forms and replicate. Here, using a variant of the 'inverted emulsion' method, we succeeded in encapsulating living L. amazonensis parasites in giant artificial liposomes that serve as model PVs. We were able to control the size of liposomes, the pH and the composition of their internal volume, and the number of internalized parasites per liposome. L. amazonensis promastigotes encapsulated in liposomes filled with RPMI-Dextran solution at pH 7.5 or 6.5 survived up to 96 h at 24°C. At 37°C and pH 5.5, parasites survived 48h. This method paves the way to identifying certain effectors secreted by the parasite and to unraveling specific mechanisms of fusion between the PV and intracellular vesicles of the host cell. This method will also facilitate the study of the temporal evolution of biophysical properties of the PV during its maturation.
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Affiliation(s)
- Carlos E. S. Guedes
- Centro de Pesquisas Gonçalo Moniz, Fiocruz, Laboratório de Patologia e Biointervenção, Rua Waldemar Falcão, 121, Candeal, Salvador, Bahia, Brazil
| | - Jose G. B. Lima
- Centro de Pesquisas Gonçalo Moniz, Fiocruz, Laboratório de Patologia e Biointervenção, Rua Waldemar Falcão, 121, Candeal, Salvador, Bahia, Brazil
| | - Emmanuèle Helfer
- Aix-Marseille Université, CNRS, CINaM UMR 7325, 13288, Marseille, France
| | - Patricia S. T. Veras
- Centro de Pesquisas Gonçalo Moniz, Fiocruz, Laboratório de Patologia e Biointervenção, Rua Waldemar Falcão, 121, Candeal, Salvador, Bahia, Brazil
- * E-mail: (PSTV); (AV)
| | - Annie Viallat
- Aix-Marseille Université, CNRS, CINaM UMR 7325, 13288, Marseille, France
- * E-mail: (PSTV); (AV)
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Santos DM, Petersen ALOA, Celes FS, Borges VM, Veras PST, de Oliveira CI. Chemotherapeutic potential of 17-AAG against cutaneous leishmaniasis caused by Leishmania (Viannia) braziliensis. PLoS Negl Trop Dis 2014; 8:e3275. [PMID: 25340794 PMCID: PMC4207694 DOI: 10.1371/journal.pntd.0003275] [Citation(s) in RCA: 20] [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: 03/11/2014] [Accepted: 09/16/2014] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Leishmaniasis remains a worldwide public health problem. The limited therapeutic options, drug toxicity and reports of resistance, reinforce the need for the development of new treatment options. Previously, we showed that 17-(allylamino)-17-demethoxygeldanamycin (17-AAG), a Heat Shock Protein 90 (HSP90)-specific inhibitor, reduces L. (L.) amazonensis infection in vitro. Herein, we expand the current knowledge on the leishmanicidal activity of 17-AAG against cutaneous leishmaniasis, employing an experimental model of infection with L. (V.) braziliensis. METHODOLOGY/PRINCIPAL FINDINGS Exposure of axenic L. (V.) braziliensis promastigotes to 17-AAG resulted in direct dose-dependent parasite killing. These results were extended to L. (V.) braziliensis-infected macrophages, an effect that was dissociated from the production of nitric oxide (NO), superoxide (O(-2)) or inflammatory mediators such as TNF-α, IL-6 and MCP-1. The leishmanicidal effect was then demonstrated in vivo, employing BALB/c mice infected with L. braziliensis. In this model, 17-AAG treatment resulted in smaller skin lesions and parasite counts were also significantly reduced. Lastly, 17-AAG showed a similar effect to amphotericin B regarding the ability to reduce parasite viability. CONCLUSION/SIGNIFICANCE 17-AAG effectively inhibited the growth of L. braziliensis, both in vitro and in vivo. Given the chronicity of L. (V.) braziliensis infection and its association with mucocutaneous leishmaniasis, 17-AAG can be envisaged as a new chemotherapeutic alternative for cutaneous Leishmaniasis.
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Affiliation(s)
- Diego M. Santos
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ), Salvador, Bahia, Brazil
| | | | - Fabiana S. Celes
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ), Salvador, Bahia, Brazil
| | - Valeria M. Borges
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ), Salvador, Bahia, Brazil
- Instituto Nacional de Ciência e Tecnologia de Investigação em Imunologia (iii-INCT), Salvador, Bahia, Brazil
| | - Patricia S. T. Veras
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ), Salvador, Bahia, Brazil
| | - Camila I. de Oliveira
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ), Salvador, Bahia, Brazil
- Instituto Nacional de Ciência e Tecnologia de Investigação em Imunologia (iii-INCT), Salvador, Bahia, Brazil
- * E-mail:
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Almeida TF, Palma LC, Mendez LC, Noronha-Dutra AA, Veras PST. Leishmania amazonensis fails to induce the release of reactive oxygen intermediates by CBA macrophages. Parasite Immunol 2013; 34:492-8. [PMID: 22817661 PMCID: PMC3532614 DOI: 10.1111/j.1365-3024.2012.01384.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
CBA mouse macrophages effectively control Leishmania major infection, yet are permissive to Leishmania amazonensis. It has been established that some Leishmania species are destroyed by reactive oxygen species (ROS). However, other species of Leishmania exhibit resistance to ROS or even down-modulate ROS production. We hypothesized that L. amazonensis–infected macrophages reduce ROS production soon after parasite–cell interaction. Employing a highly sensitive analysis technique based on chemiluminescence, the production of superoxide () and hydrogen peroxide (H2O2) by L. major- or L. amazonensis-infected CBA macrophages were measured. L. major induces macrophages to release levels of 3·5 times higher than in uninfected cells. This production is partially dependent on NADPH oxidase (NOX) type 2. The level of accumulated H2O2 is 20 times higher in L. major-than in L. amazonensis-infected cells. Furthermore, macrophages stimulated with L. amazonensis release amounts of ROS similar to uninfected cells. These findings support previous studies showing that CBA macrophages are effective in controlling L. major infection by a mechanism dependent on both production and H2O2 generation. Furthermore, these data reinforce the notion that L. amazonensis survive inside CBA macrophages by reducing ROS production during the phagocytic process.
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Affiliation(s)
- T F Almeida
- Laboratório de Patologia e Biointervenção do CPqGM-FIOCRUZ, Bahia, Brazil
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Meirelles T, Veras PST, Pitanga TN, Carvalho LCP, Noronha-Dutra AA. I 004 Monocytes Derived Microparticles Characterization: Myeloperoxidase Activity and Their Possible Role in Endothelial Dysfunction. ATHEROSCLEROSIS SUPP 2009. [DOI: 10.1016/s1567-5688(09)71758-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Carvalhal DGF, Barbosa A, D'El-Rei Hermida M, Clarencio J, Pinheiro NF, Veras PST, dos-Santos WLC. The modelling of mononuclear phagocyte-connective tissue adhesion in vitro: application to disclose a specific inhibitory effect of Leishmania infection. Exp Parasitol 2004; 107:189-99. [PMID: 15363945 DOI: 10.1016/j.exppara.2004.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Accepted: 06/14/2004] [Indexed: 01/13/2023]
Abstract
In this work, we have developed an adhesion assay to study interactions between mononuclear phagocytes and connective tissue in vitro and show its potential use to study diseases caused by intracellular microorganisms. The assay reproduces most of the characteristics of macrophage adhesion to connective tissue in vivo, such as: preferential adhesion to inflamed connective tissue, divalent cation and integrin dependence, and up-regulation upon cell activation. The phagocyte adhesion to connective tissue was inhibited by infection with Leishmania (58+/-22%, p < 0.05) and was not affected by infection with Mycobacterium or by endocytosis of latex beads. Manganese partially reverted the loss in adherence produced by Leishmania infection, indicating that the mechanisms regulating the function of integrins are affected by cell infection with Leishmania. This assay might be a useful tool for the study of the mechanisms by which mononuclear phagocytes play a role in the immune-inflammatory response and in the development of lesions.
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Affiliation(s)
- Djalma G F Carvalhal
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Rua Waldemar Falcão 121, 40295-001 Salvador, BA, Brazil
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