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da Silva DS, Teixeira LAC, Beghini DG, Ferreira ATDS, Pinho MDBM, Rosa PS, Ribeiro MR, Freire MDC, Hacker MA, Nery JADC, Pessolani MCV, Tovar AMF, Sarno EN, Perales J, Bozza FA, Esquenazi D, Monteiro RQ, Lara FA. Blood coagulation abnormalities in multibacillary leprosy patients. PLoS Negl Trop Dis 2018; 12:e0006214. [PMID: 29565968 PMCID: PMC5863944 DOI: 10.1371/journal.pntd.0006214] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/05/2018] [Indexed: 12/27/2022] Open
Abstract
Background Leprosy is a chronic dermato-neurological disease caused by Mycobacterium leprae infection. In 2016, more than 200,000 new cases of leprosy were detected around the world, representing the most frequent cause of infectious irreversible deformities and disabilities. Principal findings In the present work, we demonstrate a consistent procoagulant profile on 40 reactional and non-reactional multibacillary leprosy patients. A retrospective analysis in search of signs of coagulation abnormalities among 638 leprosy patients identified 35 leprosy patients (5.48%) which displayed a characteristic lipid-like clot formed between blood clot and serum during serum harvesting, herein named ‘leprosum clot’. Most of these patients (n = 16, 45.7%) belonged to the lepromatous leprosy pole of the disease. In addition, formation of the leprosum clot was directly correlated with increased plasma levels of soluble tissue factor and von Willebrand factor. High performance thin layer chromatography demonstrated a high content of neutral lipids in the leprosum clot, and proteomic analysis demonstrated that the leprosum clot presented in these patients is highly enriched in fibrin. Remarkably, differential 2D-proteomics analysis between leprosum clots and control clots identified two proteins present only in leprosy patients clots: complement component 3 and 4 and inter-alpha-trypsin inhibitor family heavy chain-related protein (IHRP). In agreement with those observations we demonstrated that M. leprae induces hepatocytes release of IHRP in vitro. Conclusions We demonstrated that leprosy MB patients develop a procoagulant status due to high levels of plasmatic fibrinogen, anti-cardiolipin antibodies, von Willebrand factor and soluble tissue factor. We propose that some of these components, fibrinogen for example, presents potential as predictive biomarkers of leprosy reactions, generating tools for earlier diagnosis and treatment of these events. Hemostatic illnesses are frequently associated with acute and chronic infections. In the present work we demonstrated that leprosy patients developed hemostatic abnormalities, like the formation of an atypical lipid clot mass during sera harvesting, a phenomenon previously observed and never unraveled. We characterize the nature of the “leprosum clot”, formed during a protrombotic state developed by some patients. During the proteomic analysis of the leprosum clot we discovered a set of potential serum biomarkers to leprosy reactional episodes diagnosis, which at this moment is based only in clinical features. Taking together, our data suggest that leprosy patients are suffering from a procoagulant status, being beneficiated by the introduction of routine coagulation tests during their treatment, which will aloud physicians to prevent some of the acute clinical symptoms related with superficial vein thrombosis such as cyanosis and tissue necrosis observed during severe cases of leprosy reactional episodes.
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Affiliation(s)
- Débora Santos da Silva
- Lab. of Cellular Microbiology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | - Daniela Gois Beghini
- Lab. of Toxinology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | | | | | | | | | - Mariana Andrea Hacker
- Lab. of Leprosy, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | | | - Ana Maria Freire Tovar
- Lab. of Conjunctive Tissue, Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Euzenir Nunes Sarno
- Lab. of Leprosy, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Jonas Perales
- Lab. of Toxinology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Fernando Augusto Bozza
- Department of Critical Care, National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Danuza Esquenazi
- Lab. of Leprosy, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Robson Queiroz Monteiro
- Lab. of Hemostasis and Poisons, Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Flavio Alves Lara
- Lab. of Cellular Microbiology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- * E-mail:
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CD1a and Factor XIIIa Immunohistochemistry in Leprosy: A Possible Role of Dendritic Cells in the Pathogenesis of Mycobacterium leprae Infection. Am J Dermatopathol 2009; 31:527-31. [PMID: 19590423 DOI: 10.1097/dad.0b013e31819f1997] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hostetter J, Zhang W, Simutis F. Mycobacterium avium subspecies paratuberculosis infection of cattle does not diminish peripheral blood-derived macrophage mycobactericidal activity. Immunol Lett 2006; 107:76-9. [PMID: 16884783 DOI: 10.1016/j.imlet.2006.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 06/13/2006] [Accepted: 06/15/2006] [Indexed: 10/24/2022]
Abstract
Ruminants infected with Mycobacterium avium subspecies paratuberculosis consistently develop a multibacillary form of disease that is centered on the ileum. Mechanisms responsible for failure of macrophage function during multibacillary disease are incompletely characterized. Our data suggest that mycobactericidal functions are present, and potentially enhanced, in monocyte-derived macrophages from M. avium subsp. paratuberculosis infected cattle. Addition of CD4(+) T cells from infected animals to autologous in vitro infected macrophages did not increase bacterial killing. In contrast, CD4(+) T cells from non-infected animals did increase bacterial killing in autologous macrophages. In macrophages from both infected and non-infected cattle, bacterial killing appeared to be independent of interferon-gamma (IFN-gamma) and nitric oxide production.
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Affiliation(s)
- J Hostetter
- Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, 50011, USA.
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Berger ST, Griffin FT. A comparison of ovine monocyte-derived macrophage function following infection with Mycobacterium avium ssp. avium and Mycobacterium avium ssp. paratuberculosis. Immunol Cell Biol 2006; 84:349-56. [PMID: 16509826 DOI: 10.1111/j.1440-1711.2006.01431.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mycobacterium avium ssp. paratuberculosis causes Johne's disease in ruminants, whereas the antigenically and genetically similar subspecies Mycobacterium avium ssp. avium is less virulent. In this study, we compared one strain of each subspecies for its ability to survive, induce cytokines, suppress MHC class I and II expression and induce apoptosis or necrosis in ovine monocyte-derived macrophages. Both subspecies survived intracellularly and induced the secretion of IL-10. Low levels of TNF-alpha were detected after infection with both subspecies at 4 h. IL-12 was not upregulated after infection. Downregulation of MHC class I and II was evident in response to infection with both M. avium ssp. avium and M. avium ssp. paratuberculosis. No significant cytotoxicity was detectable in ovine macrophages after the addition of bacteria. M. avium ssp. paratuberculosis induced slightly more apoptosis than M. avium ssp. avium. Still the overall rate of apoptosis was very low and both subspecies suppressed LPS-induced macrophage apoptosis.
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Affiliation(s)
- Sven T Berger
- Disease Research Laboratory, Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
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Huang W, O'Keefe RJ, Schwarz EM. Exposure to receptor-activator of NFkappaB ligand renders pre-osteoclasts resistant to IFN-gamma by inducing terminal differentiation. Arthritis Res Ther 2003; 5:R49-59. [PMID: 12716453 PMCID: PMC154432 DOI: 10.1186/ar612] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2002] [Revised: 10/11/2002] [Accepted: 10/14/2002] [Indexed: 01/14/2023] Open
Abstract
While it has been established that IFN-gamma is a strong activator of macrophages and a potent inhibitor of osteoclastogenesis in vitro, it is also known that this cytokine is produced in particular settings of inflammatory bone loss, such as infection and psoriatic arthritis. Because of the different kinetics between rapid IFN-gamma macrophage activation (<24 hours) and the slower receptor-activator of NFkappaB ligand (RANKL) osteoclast differentiation (7 days), we postulated that IFN-gamma would have different effects on early-stage and late-stage osteoclast precursors. In RAW264.7 cells and primary splenocyte cultures, pretreatment with RANKL rendered these cells resistant to maximally anti-osteoclastogenic doses of IFN-gamma. These cells were also resistant to IFN-gamma-induced nitric oxide production, morphological change, and surface upregulation of CD11b and receptor-activator of NFkappaB, suggesting that early exposure of osteoclast precursors to RANKL induces a broad resistance to the cellular effects of IFN-gamma. Changes in STAT1 activation did not correlate with this resistance, as IFN-gamma activated STAT1 equally in both early-stage and late-stage pre-osteoclasts. Furthermore, we failed to observe changes in TRAF6 expression following IFN-gamma treatment in pre-osteoclasts. Together these data support a model of inflammatory bone loss in which early exposure to RANKL can prime osteoclast precursors to form in the presence of high levels of IFN-gamma using mechanisms independent of the signal molecules STAT1 and TRAF6.
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Affiliation(s)
- Willis Huang
- The Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA.
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Weiss DJ, Evanson OA, McClenahan DJ, Abrahamsen MS, Walcheck BK. Regulation of expression of major histocompatibility antigens by bovine macrophages infected with Mycobacterium avium subsp. paratuberculosis or Mycobacterium avium subsp. avium. Infect Immun 2001; 69:1002-8. [PMID: 11159996 PMCID: PMC97980 DOI: 10.1128/iai.69.2.1002-1008.2001] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium avium subsp. paratuberculosis and Mycobacterium avium subsp. avium are antigenically and genetically very similar organisms; however, they differ markedly in their virulence for cattle. We evaluated the capacity of bovine macrophages infected with M. avium subsp. paratuberculosis or M. avium subsp. avium to express major histocompatibility complex (MHC) class I and class II antigens on their surface and to interact with primed autologous lymphocytes. Our results indicate that infection of bovine macrophages with M. avium subsp. paratuberculosis promoted the downregulation of MHC class I and class II molecules on the macrophage surface within 24 and 12 h, respectively. Alternatively, MHC class II expression by M. avium subsp. avium-infected macrophages was not detected until 24 h after infection, and the magnitude of the decrease was smaller. Decreased MHC class I expression by M. avium subsp. avium-infected macrophages was not detected. Unlike M. avium subsp. paratuberculosis-infected macrophages, M. avium subsp. avium-infected macrophages upregulated MHC class I and class II expression after activation by gamma interferon or tumor necrosis factor alpha. Further, M. avium subsp. avium-infected macrophages were lysed by primed autologous lymphocytes, whereas M. avium subsp. paratuberculosis-infected macrophages were not. Overall, the results support the hypothesis that the difference in the virulence of M. avium subsp. paratuberculosis and M. avium subsp. avium for cattle is dependent on a difference in the capacity of the organisms to suppress mycobacterial antigen presentation to T lymphocytes.
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Affiliation(s)
- D J Weiss
- Department of Veterinary PathoBiology, University of Minnesota, St. Paul, Minnesota 55108, USA.
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Moura AC, Mariano M. Lipids from Mycobacterium leprae cell wall suppress T-cell activation in vivo and in vitro. Immunol Suppl 1997; 92:429-36. [PMID: 9497483 PMCID: PMC1364147 DOI: 10.1046/j.1365-2567.1997.00366.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The influence of Mycobacterium leprae cell wall lipids on lymphocyte functions has been investigated in vivo (delayed-type hypersensitivity) and in vitro. The inflammatory response has been earlier evaluated by the mouse footpad oedema model and the delipidated mycobacteria evoked a mild but significant inflammatory response. Herein a higher level of hypersensitivity reaction was observed with delipidated bacilli than with the intact mycobacteria. The lipids obtained from the extract of M. leprae external cell wall were used to prepare liposomes, which have not been shown to be toxic to lymphocytes. The method of lipidic extraction and the sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the lipid fraction did not reveal any trace of proteins. Thin-layer chromatography of this extract detected four different bands with an apolar character, suggestive of mycolic and fatty acids. These same M. leprae liposomes potently suppressed lymph node cells, as well CD4+ and CD8+ T-cell lines, and an antigen-specific T-cell clone (T 4-9) proliferation, even under potent stimulus. Cholesterol-choline liposomes, unrelated to M. leprae liposomes, used as a control in the biological assays showed no significant effect on lymphoblastic activity, which points to the specificity of M. leprae lipids. These data demonstrated that M. leprae cell wall lipids induce immune suppression in mice without causing any membrane alteration in T cells as assessed throughout kinetic studies in vitro. This fact is closely related to the down-regulating effect induced by M. leprae lipids which we have previously observed in macrophage functions in vivo and in vitro. Although this lipidic fraction showed a suppressive action on T lymphocytes in vitro (proliferation) and in vivo (delayed-type hypersensitivity), its possible significance in the establishment of a specific immune response to M. leprae must be further investigated.
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Affiliation(s)
- A C Moura
- Department of Immunology, University of São Paulo, Brazil
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Alzuherri HM, Little D, Clarke CJ. Altered intestinal macrophage phenotype in ovine paratuberculosis. Res Vet Sci 1997; 63:139-43. [PMID: 9429247 DOI: 10.1016/s0034-5288(97)90007-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The expression of macrophage surface markers that are likely to be important in antigen presentation and cell interactions was examined in normal sheep and those with clinical paratuberculosis. Immunohistological studies demonstrated that intestinal macrophages in diseased sheep expressed MHC class II, LFA-1 and CR4 antigens weakly compared with normal tissues. Reverse transcriptase-polymerase chain reaction analysis of MHC class II mRNA in intestinal whole tissue samples showed no significant difference between control and diseased groups. A reduction in molecules such as MHC class II and LFA-1 on the surface of infected macrophages could have implications for survival of the intracellular mycobacteria and the persistence of infection.
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Affiliation(s)
- H M Alzuherri
- Department of Veterinary Pathology, University of Edinburgh, Roslin, Midlothian
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Affiliation(s)
- C J Clarke
- Department of Veterinary Pathology, University of Edinburgh, Roslin, Midlothian, UK
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Moura AC, Mariano M. Lipids from Mycobacterium leprae cell wall are endowed with an anti-inflammatory property and inhibit macrophage function in vivo. Immunology 1996; 89:613-8. [PMID: 9014830 PMCID: PMC1456573 DOI: 10.1046/j.1365-2567.1996.d01-786.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In general, the majority of bacteria are pre-inflammatory when injected in experimental animals. However, Mycobacterium leprae has no inflammatory effect when injected into mouse footpad, but using the delipidated mycobacteria we observed a mild significant increase in footpad oedema. Other mycobacteria, Mycobacterium bovis-BCG or M. tuberculosis induce a strong paw oedema. Furthermore, M. leprae reduced locally the BCG-induced inflammatory reaction in mouse footpad, whereas delipidated M. leprae did not influence this reaction. Both M. leprae and M. leprae cell wall lipids blocked immune phagocytosis in vivo by inflammatory macrophages (from an induced focus). In contrast delipidated M. leprae stimulated the phagocytosis reaction. Neither intact M. leprae. delipidated M. leprae, nor its lipids had any toxic effect on macrophages or on cell migration. Although M. leprae did not interfere on cell influx and cell type in an induced-inflammatory site, this mycobacterium led to the appearance of a distinct cell population in vivo. The hypothesis is that M. leprae would transform macrophages in epithelioid cells, suggested by morphology analysis of cells by fluorescence-activated cell sorter and observed under optic microscopy.
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Affiliation(s)
- A C Moura
- Department of Immunology, University of Sào Paulo, Brazil
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Tohyama M, Kawakami K, Futenma M, Saito A. Enhancing effect of oxygen radical scavengers on murine macrophage anticryptococcal activity through production of nitric oxide. Clin Exp Immunol 1996; 103:436-41. [PMID: 8608643 PMCID: PMC2200379 DOI: 10.1111/j.1365-2249.1996.tb08299.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We examined the roles of reactive nitrogen intermediates (RNI) and reactive oxygen intermediates (ROI) in interferon-gamma (IFN-gamma)-induced cryptococcostatic activity of murine peritoneal macrophages using N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of RNI synthesis, and superoxide dismutase (SOD) and catalase, oxygen radical scavengers. IFN-gamma-activated macrophages produced nitric oxide (NO) in a dose-dependent manner, as measured by increased nitrite concentration in the culture supernatant. IFN-gamma also enhanced the suppressive effect on cryptococcal growth in a similar dose-dependent manner. The induction of killing activity and NO production by an optimal dose of IFN-gamma (100 U/ml) was virtually suppressed by 500 microM L-NMMA. These results confirmed the importance of the RNI-mediated effector mechanism in anticryptococcal activity of macrophages. SOD and catalase significantly enhanced the cryptococcostatic activity of macrophages induced by a suboptimal dose of IFN-gamma (20 U/ml). The augmenting effect of these reagents was mediated by NO, since they potentiated the production of NO by macrophages and their effects were totally blocked by L-NMMA. Our results indicate that the IFN-gamma-induced anticryptococcal activity of macrophages is dependent mostly on RNI, and suggest that the ROI system down-regulates the effector mechanism for cryptococcostasis by suppressing the RNI system.
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Affiliation(s)
- M Tohyama
- First Department of Internal Medicine, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan
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Cree IA, Coghill G, Subedi AM, Abbot NC, Butlin SR, Samson PD, Beck JS. Effects of treatment on the histopathology of leprosy. J Clin Pathol 1995; 48:304-7. [PMID: 7615846 PMCID: PMC502545 DOI: 10.1136/jcp.48.4.304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
AIMS To identify the histological changes in leprosy skin lesions over the first few weeks after the start of leprosy treatment and to examine their relationship to reversal reaction. METHODS Sequential skin biopsy during treatment with multiple drug therapy. In this study, a series of 28 patients was studied, from whom two or more biopsies were taken at two week intervals. Fourteen patients had paucibacillary leprosy (PBL) and 14 had multibacillary leprosy (MBL). RESULTS In most cases, granuloma fraction and bacterial index fell during treatment, the bacterial index being less sensitive than the granuloma fraction. Since the biopsies were fixed in buffered formalin and processed through to paraffin wax, little immunohistochemistry was feasible. However, there was strong evidence of immune activation, with increased expression of HLA-DR in the granulomas of MBL and PBL cases: the epidermis also expressed HLA-DR in several patients. Such changes may reflect gamma IFN production from granuloma lymphocytes. Patients with reversal reaction often showed HLA-DR expression on admission which decreased with corticosteroid treatment. CONCLUSIONS The results suggest that activation of cell mediated immunity in leprosy lesions occurs during treatment with multiple drug therapy and may not be restricted to those with clinical evidence of reversal reaction.
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Affiliation(s)
- I A Cree
- Department of Pathology, University of London
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Messick JB, Rikihisa Y. Suppression of Ia antigen expression on gamma interferon treated macrophages infected with Ehrlichia risticii. Vet Immunol Immunopathol 1992; 32:225-41. [PMID: 1632064 DOI: 10.1016/0165-2427(92)90048-u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ehrlichia risticii is an obligate intracellular bacterium of monocytes/macrophages. In this report, using immunofluorescence staining, flow cytometry, and Kolmogorov-Smirnov analysis of histograms, the response of P338D1 and peritoneal macrophages stimulated with recombinant murine interferon-gamma (rIFN-gamma) was examined for the expression of major histocompatibility complex Class II gene product (Ia) and effect of E. risticii infection on induction of Ia surface expression. Maximal expression of Ia by sham-infected P388D1 cells was observed 2 days post rIFN-gamma addition followed by a progressive decline. These stimulatory effects of rIFN-gamma were dose dependent. Relative to sham-infected P388D1 cells, the induction of Ia by rIFN-gamma (200 U ml-1) on E. risticii-infected P388D1 cells was significantly suppressed at each time point tested through Day 5 with maximal suppression of 88% occurring on Day 2. Similarly, the induction of Ia by rIFN-gamma on E. risticii-infected peritoneal macrophages was significantly suppressed by 77% (fluorescent microscopy) when compared to sham-infected peritoneal macrophages. The higher dose of rIFN-gamma (2000 U ml-1) failed to restore Ia surface expression by E. risticii-infected P388D1 cells. The suppression of Ia on P388D1 cells in response to RIFN-gamma was not related to the degree of infection of these cells by E. risticii. A soluble inhibitor substance was not demonstrable in the supernatant from E. risticii-infected cells, nor were inhibitor levels of prostaglandin E2 levels found in the supernatant. Suppression of surface Ia expression on the macrophage suggests a mechanism whereby I. risticii may evade T-lymphocyte recognition, hinder antigen-specific T-lymphocyte activation, and promote their own survival.
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Affiliation(s)
- J B Messick
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Ohio State University, Columbus 43210
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Eze MO. Towards more efficacious chemotherapy of trypanosomiasis: combination of alpha-difluoromethylornithine (DFMO) with reactive oxygen generating drugs. Med Hypotheses 1991; 36:246-9. [PMID: 1787820 DOI: 10.1016/0306-9877(91)90142-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Trypanosomiasis (whether African sleeping sickness, or American Chaga's disease) is caused by an infection with a protozoan parasite, i.e. the trypanosome. This carries fatal sequences in the untreated host. Currently available chemotherapeutic drugs (some of which cure by involving reactive oxygen species (ROS] are not optimally adequate. They are toxic as well, and may also be carcinogenic. It is therefore desirable to devise better chemotherapeutic regimens. ROS destroy the parasite, but excess ROS damage host tissue and are potentially carcinogenic. Alpha-difluoromethylornithine (DFMO) inhibits ornithine decarboxylase and so lowers the levels of spermine and spermidine. This singular effect in the parasite inhibits its multiplication, whereas in the host tissue it prevents carcinogenesis by preventing cell proliferation. Thus, combination of ROS-generating drugs with DFMO would be very effective against trypanosomiasis, and would be without cancer risk too. The combination is therefore advocated for chemotherapy of trypanosoma infections. This necessities experimental investigations specifically directed towards establishing the optimally efficacious combination of DFMO with the drugs.
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Affiliation(s)
- M O Eze
- Department of Biochemistry, University of Nigeria, Nsukka
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Eze MO. Avoidance, and inactivation of reactive oxygen species: novel microbial immune evasion strategies. Med Hypotheses 1991; 34:252-5. [PMID: 2062259 DOI: 10.1016/0306-9877(91)90219-o] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A prominent aspect of host cell-mediated immune (CMI) reactions leading to the clearance of infections is the production of one or more reactive oxygen species (ROS) such as superoxide (O2-), hydrogen peroxide (H2O2), hydroxyl radical (OH.), and hypohalite (e.g., OC1-). These ROS are usually produced by phagocytes. A number of chemotherapeutic agents also produce ROS in the process of their curative mechanisms. In a variety of infections, these ROS constitute a formidable arsenal in the clearance of the infection. In some cases, the excess ROS could also cause tissue damage. Evidence is herewith presented that pathogenic intracellular microorganisms, in order to enhance their survival as well as effective virulence within the host, have evolved novel strategies in the nature of avoidance, or inhibition of ROS production by phagocytes, or neutralization of already produced ROS. It is advocated that more in depth studies be undertaken in these respects in order to be able to exploit these phenomena in the production of more efficacious chemotherapeutic agents and anti-pathogen vaccines.
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Affiliation(s)
- M O Eze
- Department of Biochemistry, University of Nigeria, Nsukka
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Marolia J, Robinson P, Mahadevan PR. A complex component modulating immune-deficient cells in leprosy patients leading to loss of viability of Mycobacterium leprae--a possible vaccine. Clin Exp Immunol 1990; 79:7-14. [PMID: 2154348 PMCID: PMC1534713 DOI: 10.1111/j.1365-2249.1990.tb05119.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Macrophages from peripheral blood of leprosy patients, both multi-bacillary and paucibacillary are unable to kill phagocytosed Mycobacterium leprae due to their inability to produce superoxide (O2-) and hydroxyl radicals (OH.). The macrophages from healthy individuals are able to kill M. leprae along with release of O2- and OH. radicals. The deficiency in the macrophages of both types of leprosy patients is removed by activation of these cells when exposed to a culture supernatant obtained after stimulation of peripheral blood mononuclear cells from the same patients with delipidified cell components of M. leprae which are most likely cell wall proteins. The activation of macrophages also leads to recognition of whole live M. leprae as an antigen by cells from lepromatous patients. This activation of the phagocytes by delipidified cell components is blocked by cyclosporin A, indicating the possible role of several steps involved in immune activation of cells. The observations thus indicate the significant ability of delipidified cell components to eliminate the deficiencies in the macrophages from leprosy patients and restore them to behave like the cells from healthy individuals. Considering all these, it is suggested that delipidified cell components could be potential modulators, and are probably capable of functioning as a vaccine for leprosy.
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Affiliation(s)
- J Marolia
- Foundation for Medical Research, Bombay, India
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