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Mansueto P, Vitale G, Di Lorenzo G, Rini GB, Mansueto S, Cillari E. Immunopathology of Leishmaniasis: An Update. Int J Immunopathol Pharmacol 2016; 20:435-45. [PMID: 17880757 DOI: 10.1177/039463200702000302] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Leishmaniasis represents a severe, increasing, public health problem. The perspective of its control is highly dependent on research progress, on therapeutic manipulations of the immune system, and on vaccine development. There is a correlation between the clinical outcome of Leishmania infection and the cytokine response profile. While a protective immune response against Leishmania has been clearly identified to be related to the influence of a type-1 response and IFN-γ production, the precise role of T helper (TH) 2 cytokines in non-healing infections requires further exploration. IL-4 and IL-13 (TH2 cytokines) can promote disease progression in cutaneous leishmaniasis, whereas IL-4 would appear to enhance protective type-1 responses in visceral leishmaniasis. Thus, the TH1/TH2 paradigm of resistance/susceptibility to intracellular parasites is probably an oversimplification of a more complicated network of regulatory/counter regulatory interactions. Moreover, the presence of antigen specific regulatory T cell subsets may provide an environment that contributes to the balance between TH1 and TH2 cells. Finally, the involvement of CD8+ T cells has been described, but the modality of their function in this kind of infection has not been so far elucidated.
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Affiliation(s)
- P Mansueto
- Dipartimento di Medicina Clinica e delle Patologie Emergenti, University of Palermo, Palermo, Italy
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2
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Bandyopadhyay S, Kar Mahapatra S, Paul Chowdhury B, Kumar Jha M, Das S, Halder K, Bhattacharyya Majumdar S, Saha B, Majumdar S. Toll-Like Receptor 2 Targeted Rectification of Impaired CD8⁺ T Cell Functions in Experimental Leishmania donovani Infection Reinstates Host Protection. PLoS One 2015; 10:e0142800. [PMID: 26559815 PMCID: PMC4641719 DOI: 10.1371/journal.pone.0142800] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/27/2015] [Indexed: 12/29/2022] Open
Abstract
Leishmania donovani, a protozoan parasite, causes the disease visceral leishmanisis (VL), characterized by inappropriate CD8+ T-cell activation. Therefore, we examined whether the Toll-like Receptor 2 (TLR2) ligand Ara-LAM, a cell wall glycolipid from non-pathogenic Mycobacterium smegmatis, would restore CD8+ T-cell function during VL. We observed that by efficient upregulation of TLR2 signaling-mediated NF-κB translocation and MAPK signaling in CD8+ T-cells (CD25+CD28+IL-12R+IFN-γR+), Ara-LAM triggered signaling resulted in the activation of T-bet, which in turn, induced transcription favourable histone modification at the IFN-γ, perforin, granzyme-B promoter regions in CD8+ T-cells. Thus, we conclude that Ara-LAM induced efficient activation of effector CD8+ T-cells by upregulating the expression of IFN-γ, perforin and granzyme-B in an NF-κB and MAPK induced T-bet dependent manner in VL.
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Affiliation(s)
| | | | | | | | - Shibali Das
- The Division of Molecular Medicine, Bose Institute, Kolkata, India
| | - Kuntal Halder
- The Division of Molecular Medicine, Bose Institute, Kolkata, India
| | | | - Bhaskar Saha
- National Centre for Cell Science, Ganeshkhind, Pune, India
| | - Subrata Majumdar
- The Division of Molecular Medicine, Bose Institute, Kolkata, India
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3
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Alteration of sFAS and sFAS ligand expression during canine visceral leishmaniosis. Vet Parasitol 2014; 205:417-23. [PMID: 25260330 DOI: 10.1016/j.vetpar.2014.09.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 09/02/2014] [Accepted: 09/07/2014] [Indexed: 12/29/2022]
Abstract
Visceral leishmaniosis (VL) is caused by intracellular parasites of the genus Leishmania that affect humans and several animal species. Dogs are one of the main urban reservoirs of Leishmania infantum and play a central role in the transmission cycle to humans via sandflies. CD3+ cells apoptosis is involved in the immune response in VL. Dysregulation of apoptosis has been implicated in various disease states. An important regulator of apoptosis is the FAS-FAS-associated death domain protein (cluster of differentiation 95 - CD95) and FASL-FAS ligand protein (cluster of differentiation 178 - CD178) system involved in the down-regulation of immune reactions and in T cell-mediated cytotoxicity. FAS is a member of the tumor necrosis factor (TNF) receptor super family, which can be expressed in transmembrane or soluble forms. The soluble levels of FAS (sFAS), FASL (sFASL) and active Caspase-3, this last related to apoptotic cascade, were investigated in the spleen of 19 symptomatic dogs presenting moderate VL and 6 healthy dogs, determined by ELISA assay. The splenic parasite load was determined by real-time PCR monitoring of amplification of the intergenic internal transcribed spacer (ITS1) gene of parasite rRNA. sFAS levels were lower (p<0.05). sFASL and active Caspase-3 levels were higher (p<0.05) in dogs with VL compared with controls. Negative correlation was observed between parasite burden and sFASL levels. The increase in sFASL could be related to the mechanism involved in the elimination of the parasite.
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CD4+FOXP3+ cells produce IL-10 in the spleens of dogs with visceral leishmaniasis. Vet Parasitol 2014; 202:313-8. [PMID: 24703254 DOI: 10.1016/j.vetpar.2014.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 02/18/2014] [Accepted: 03/05/2014] [Indexed: 11/23/2022]
Abstract
Visceral Leishmaniasis (VL) is caused by intracellular parasites of the genus Leishmania that affect humans and several animal species. Dogs are one of the main urban reservoirs of the parasite and play a central role in the transmission cycle to humans via sandflies. Studies concerning the immune response in dogs with VL have demonstrated that protective immunity is associated with cellular immune response, while disease progression is associated with humoral response and IL-10 and TGF-β production. The study aimed to evaluate IL-10 and TGF-β production by regulatory T (Treg) cells in the blood and spleen of dogs naturally infected by Leishmania spp. and correlate this with parasite load. Five healthy dogs and 29 dogs with proven infection were selected for the study group. Real-time PCR was used to quantify parasite load and confirm infection by Leishmania spp. Treg cells producing IL-10 and TGF-β were quantified using flow cytometry. An increase in IL-10 production by Treg cells was verified in the spleen of dogs naturally infected by Leishmania spp. Concurrently, a decrease in the total number of T cells in these dogs was verified compared with healthy dogs. No association was determined between parasite load and the percentage of spleen Treg cells producing IL-10 and TGF-β. These findings suggest that Treg cells are an important source of IL-10 in the spleen, participating in immune response modulation, while the reduced percentage of these cells in infected dogs could be attributed to persistent immune activation.
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Pereira-Manfro WF, Ribeiro-Gomes FL, Filardy AA, Vellozo NS, Guillermo LVC, Silva EM, Siegel RM, Dosreis GA, Lopes MF. Inhibition of caspase-8 activity promotes protective Th1- and Th2-mediated immunity to Leishmania major infection. J Leukoc Biol 2013; 95:347-55. [PMID: 24072877 DOI: 10.1189/jlb.0912463] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We investigated how apoptosis pathways mediated by death receptors and caspase-8 affect cytokine responses and immunity to Leishmania major parasites. Splenic CD4 T cells undergo activation-induced apoptosis, and blockade of FasL-Fas interaction increased IFN-γ and IL-4 cytokine responses to L. major antigens. To block death receptor-induced death, we used mice expressing a T cell-restricted transgene for vFLIP. Inhibition of caspase-8 activation in vFLIP mice enhanced Th1 and Th2 cytokine responses to L. major infection, even in the Th1-prone B6 background. We also observed increased NO production by splenocytes from vFLIP mice upon T cell activation. Despite an exacerbated Th2 response, vFLIP mice controlled better L. major infection, with reduced lesions and lower parasite loads compared with WT mice. Moreover, injection of anti-IL-4 mAb in infected vFLIP mice disrupted control of parasite infection. Therefore, blockade of caspase-8 activity in T cells improves immunity to L. major infection by promoting increased Th1 and Th2 responses.
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Affiliation(s)
- Wânia F Pereira-Manfro
- 5.Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, RJ, 21941-902, Brazil.
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Silva KLO, Melo LM, Perosso J, Oliveira BB, Santos PSPD, Eugênio FDR, Lima VMFD. CD95 (FAS) and CD178 (FASL) induce the apoptosis of CD4+ and CD8+ cells isolated from the peripheral blood and spleen of dogs naturally infected with Leishmania spp. Vet Parasitol 2013; 197:470-6. [PMID: 23920055 DOI: 10.1016/j.vetpar.2013.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 06/17/2013] [Accepted: 07/06/2013] [Indexed: 12/19/2022]
Abstract
Infected dogs are urban reservoirs of Leishmania chagasi, which is a causative agent of visceral leishmaniasis (VL). Dogs exhibit immune suppression during the course of this disease, and lymphocyte apoptosis is involved in this process. To investigate apoptosis and the expression levels of FAS-FAS-associated death domain protein (CD95 or APO-1), FASL-FAS ligand protein (CD178), and TRAIL-TNF-related apoptosis-inducing ligand (CD253) receptors in peripheral blood mononuclear cells and spleen leukocytes from 38 symptomatic dogs with moderate VL and 25 healthy dogs were evaluated by flow cytometry. The apoptosis rate of blood and splenic CD4+ and CD8+ cells was higher in infected dogs than in healthy dogs. The expression levels of FAS and FASL in blood and splenic CD4+ cells were lower in infected dogs than in healthy dogs. FAS expression in CD8+ cells was higher in infected dogs than in healthy dogs; in contrast, FASL expression was lower in infected dogs. The expression of the TRAIL receptor increased only in splenic CD8+ cells from infected dogs. The FAS and FAS-L blocking antibodies confirmed the importance of these receptors in apoptosis. Our results enhance the current understanding of the immune response in dogs infected with L. chagasi, facilitating the future development of therapeutic interventions to reduce lymphocyte depletion.
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Affiliation(s)
- Kathlenn Liezbeth Oliveira Silva
- Department of Clinic, Surgery and Animal Reproduction, Laboratory of Cellular Immunology, School of Veterinary Science of the São Paulo State University (Faculdade de Medicina Veterinária da Universidade Estadual Paulista "Júlio de Mesquita Filho", FMVA/UNESP), Rua Clóvis Pestana, 793, Araçatuba, São Paulo 16050-680, Brazil
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7
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Verçosa BLA, Melo MN, Puerto HLD, Mendonça IL, Vasconcelos AC. Apoptosis, inflammatory response and parasite load in skin of Leishmania (Leishmania) chagasi naturally infected dogs: A histomorphometric analysis. Vet Parasitol 2012; 189:162-70. [DOI: 10.1016/j.vetpar.2012.04.035] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 04/20/2012] [Accepted: 04/27/2012] [Indexed: 10/28/2022]
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8
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Happi AN, Milner DA, Antia RE. Blood and Tissue Leukocyte Apoptosis inTrypanosoma bruceiInfected Rats. ACTA ACUST UNITED AC 2012. [DOI: 10.4303/jnp/n120101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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de Lima VMF, Fattori KR, de Souza F, Eugênio FR, dos Santos PSP, Rozza DB, Machado GF. Apoptosis in T lymphocytes from spleen tissue and peripheral blood of L. (L.) chagasi naturally infected dogs. Vet Parasitol 2011; 184:147-53. [PMID: 21899954 DOI: 10.1016/j.vetpar.2011.08.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 08/10/2011] [Accepted: 08/12/2011] [Indexed: 11/28/2022]
Abstract
Dogs are the main domestic reservoirs of L. (L.) chagasi. Once in the vertebrate host, the parasite may cause visceral leishmaniasis, which can also be transmitted to humans. Infected symptomatic dogs show disorganization in the white pulp in spleen tissue and a reduction in T lymphocytes in peripheral blood. To investigate whether apoptosis is involved in white pulp disorganization and diminished T cell counts in peripheral blood, apoptotic T cells from the spleen and peripheral blood of dogs naturally infected with L. (L.) chagasi and presenting clinical manifestations were quantified and compared with healthy dogs. Thirteen symptomatic adult dogs infected by L. (L.) chagasi and six healthy dogs from a nonendemic area (controls) were included in the study. Samples from spleen and peripheral blood were used to quantify apoptosis in CD3 lymphocytes by flow cytometry using Anexin V and Multicaspase kits; the results were compared using the Mann Whitney test. The percentage of total T cells was lower in Leishmania infected dogs compared to healthy controls (P<0.05). Apoptosis levels in T cells from PBMC and spleen were higher in infected dogs than in controls (P<0.05). The least squares method test was used to determine the effect between the degree of structural organization of spleen white pulp and the percentage of apoptosis in the spleen. A significant effect on the level of white pulp morphological disorganization and percentage of apoptosis in spleen T cells was observed (F=20.45; P=0.0014). These data suggest that apoptosis is an important for the immunopathogenesis of canine visceral leishmaniasis.
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Affiliation(s)
- Valéria Marçal Felix de Lima
- Departamento de Clinica, Cirurgia e Reprodução Animal, Faculdade de Medicina Veterinária, Universidade Estadual Paulista, Rua Clóvis Pestana, 793, ZIP 16050-400 Araçatuba, São Paulo, Brazil.
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Guillermo LVC, Pereira WF, De Meis J, Ribeiro-Gomes FL, Silva EM, Kroll-Palhares K, Takiya CM, Lopes MF. Targeting caspases in intracellular protozoan infections. Immunopharmacol Immunotoxicol 2010; 31:159-73. [PMID: 18785049 DOI: 10.1080/08923970802332164] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Caspases are cysteine aspartases acting either as initiators (caspases 8, 9, and 10) or executioners (caspases 3, 6, and 7) to induce programmed cell death by apoptosis. Parasite infections by certain intracellular protozoans increase host cell life span by targeting caspase activation. Conversely, caspase activation, followed by apoptosis of lymphocytes and other cells, prevents effective immune responses to chronic parasite infection. Here we discuss how pharmacological inhibition of caspases might affect the immunity to protozoan infections, by either blocking or delaying apoptosis.
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Affiliation(s)
- Landi V C Guillermo
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Taher JH, Al-Mulla Hummadi YMK, Al-Bashir NMT, Al-Araji AS. Lymphocyte phenotyping, using cluster-of-differentiation (CD) markers, in young Iraqi children with visceral leishmaniasis. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2010; 103:671-7. [PMID: 20030991 DOI: 10.1179/000349809x12554106963672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The lymphocytic phenotypes involved in the pathogenesis of visceral leishmaniasis (VL) in Iraqi children have recently been investigated, in a study based on cluster-of-differentiation (CD) markers. Each case of VL investigated was confirmed parasitologically by the observation of amastigotes in a bone-marrow smear. Compared with the values for the healthy children used as controls, a lymphocyte from an untreated VL case was significantly less likely to be CD3+ or CD4+, significantly more likely to be CD8+, and more (but not significantly more) likely to be CD22+. The untreated cases also had significantly lower CD4+/CD8+ ratios than the controls. Among the untreated cases, gender and age had no apparent effect on any of these variables. After 28 days of treatment with sodium stibogluconate, there was a trend towards normalization in the lymphocytic phenotypes of the VL cases, with significant increases in the CD4+/CD8+ ratios and the percentages of lymphocytes that were CD3+ or CD4+, and a significant decrease in the percentages of lymphocytes that were CD22+.
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Affiliation(s)
- J H Taher
- Department of Biology, Babylon University, Hilla, Iraq.
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Pereira WF, Guillermo LVC, Ribeiro-Gomes FL, Lopes MF. Inhibition of caspase-8 activity reduces IFN-gamma expression by T cells from Leishmania major infection. AN ACAD BRAS CIENC 2008; 80:129-36. [PMID: 18345381 DOI: 10.1590/s0001-37652008000100008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Accepted: 08/15/2007] [Indexed: 12/30/2022] Open
Abstract
Following infection with Leishmania major, T cell activation and apoptosis can be detected in draining lymph nodes of C57BL/6-infected mice. We investigated the mechanisms involved in apoptosis and cytokine expression following T cell activation. After two weeks of infection, apoptotic T cells were not detected in draining lymph nodes but activation with anti-CD3 induced apoptosis in both CD4 and CD8 T cells. Treatment with anti-Fas Ligand, caspase-8 or caspase- 9 inhibitors did not block activation-induced T-cell death. We also investigated whether the blockade of caspase-8 activity would affect the expression of type-1 or type-2 cytokines. At early stages of infection, both CD4 and CD8 T cells expressed IFN-gamma upon activation. Treatment with the caspase-8 inhibitor zIETD-fmk (benzyl-oxycarbonyl-Ile- Glu(OMe)-Thr-Asp(OMe)-fluoromethyl ketone) reduced the proportion of CD8 T cells and IFN-gamma expression in both CD4 and CD8 T cells. We conclude that a non apoptotic role of caspase-8 activity may be required for T cell-mediated type-1 responses during L. major infection.
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Affiliation(s)
- Wânia F Pereira
- Centro de Ciências da Saúde, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Dey R, Majumder N, Majumdar SB, Bhattacharjee S, Banerjee S, Roy S, Majumdar S. Induction of Host Protective Th1 Immune Response by Chemokines in Leishmania donovani-infected BALB/c Mice. Scand J Immunol 2007; 66:671-83. [DOI: 10.1111/j.1365-3083.2007.02025.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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DosReis GA, Ribeiro-Gomes FL, Guillermo LVC, Lopes MF. Cross-talk between apoptosis and cytokines in the regulation of parasitic infection. Cytokine Growth Factor Rev 2007; 18:97-105. [PMID: 17337235 DOI: 10.1016/j.cytogfr.2007.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Parasitic diseases have worldwide medical and economical impact. Host T lymphocytes and the cytokines they produce determine the outcome of parasitic infections. Programmed cell death by apoptosis is induced in the course of parasitic infections, and affects cytokine production by removing activated effector T and B cells. In addition, engulfment of apoptotic cells promotes the secretion of cytokines that regulate intracellular replication of protozoan parasites. In this review, we discuss how the cross-talk between apoptosis and cytokines regulates parasitic infection.
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Affiliation(s)
- George A DosReis
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco G, Ilha do Fundão, Rio de Janeiro, RJ 21949-900, Brazil.
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Abstract
Experimental visceral leishmaniasis (VL) caused by infection with Leishmania donovani results in the development of organ-specific immunity in the two main target tissues of infection, the spleen and the liver. The liver is the site of an acute resolving infection associated with the development of inflammatory granulomas around infected Kupffer cells, and resistance to reinfection. Paradoxically, the spleen is an initial site for the generation of cell-mediated immune responses, but ultimately becomes a site of parasite persistence with associated immunopathological changes. These include splenomegaly and a breakdown in tissue architecture that is postulated to contribute to the immunocompromized status of the host. The progressive development of splenic pathology is largely associated with high levels of TNF and interleukin (IL)-10. Follicular dendritic cell (DC) networks are lost, whereas TNF mediates the destruction of marginal zone macrophages and gp38(+) stromal cells, and IL-10 promotes impaired DC migration into T-cell areas with consequent ineffective T-cell priming. Splenic stromal cell function is also altered, promoting the selective development of IL-10-producing DC with immunoregulatory properties. Ultimately, a fine immunological balance determines responses that effectively promote parasite clearance in the liver and those that promote pathology in the spleen, and future investigation aims to separate these responses to offer further means of parasite control in chronically infected VL patients.
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Affiliation(s)
- Amanda C Stanley
- Immunology & Infection Laboratory, Queensland Institute of Medical Research, Herston, Queensland, Australia
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Schaumburg F, Hippe D, Vutova P, Lüder CGK. Pro- and anti-apoptotic activities of protozoan parasites. Parasitology 2006; 132 Suppl:S69-85. [PMID: 17018167 DOI: 10.1017/s0031182006000874] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
During infection, programmed cell death, i.e. apoptosis, is an important effector mechanism of innate and adaptive host responses to parasites. In addition, it fulfils essential functions in regulating host immunity and tissue homeostasis. Not surprisingly, however, adaptation of parasitic protozoa to their hosts also involves modulation or even exploitation of cell death in order to facilitate parasite survival in a hostile environment. During recent years, considerable progress has been made in our understanding of apoptosis during parasitic infections and there is now convincing evidence that apoptosis and its modulation by protozoan parasites has a major impact on the parasite-host interaction and on the pathogenesis of disease. This review updates our current knowledge on the diverse functions apoptosis may fulfil during infections with diverse protozoan parasites including apicomplexans, kinetoplastids and amoebae. Furthermore, we also summarize common mechanistic themes of the pro- and anti-apoptotic activities of protozoan parasites. The diverse and complex effects which parasitic protozoa exert on apoptotic cell death within the host highlight fascinating interactions of parasites and their hosts. Importantly, they also stress the importance of further investigations before the modulation of host cell apoptosis can be exploited to combat parasitic infections.
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Affiliation(s)
- F Schaumburg
- Institute for Medical Microbiology, Georg-August-University, Kreuzbergring 57, 37075 Göttingen, Germany
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Ji MJ, Su C, Wang Y, Wu HW, Cai XP, Li GF, Zhu X, Wang XJ, Zhang ZS, Wu GL. Characterization of CD4+ T cell responses in mice infected with Schistosoma japonicum. Acta Biochim Biophys Sin (Shanghai) 2006; 38:327-34. [PMID: 16680373 DOI: 10.1111/j.1745-7270.2006.00169.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
To better understand the interaction between Schistosoma japonicum and its murine host, we characterized the immune response of CD4+ T cells generated during an experimental S. japonicum infection based on different key aspects, from gene expression to cell behavior. Mouse oligonucleotide microarrays were used to compare gene expression profiles of CD4+ T cells from spleens of mice at 0, 3, 6 and 13 weeks post-infection. Flow cytometry analysis was used to determine type 1 and type 2 cytokine-secreting CD4+ T cells, to test apoptosis of CD4+ T cells and to count CD4+CD25+ T cells, a kind of regulatory subpopulation of CD4+ T cells. The percentage of interleukin-4-producing CD4+ T cells was found to be much higher than that of gamma-interferon-producing cells, especially after stimulation with S. japonicum egg antigen, which was consistent with type 1 and type 2 cytokine gene expression in the genechip. Microarray data also showed that S. japonicum induced the increased expression of Th2 response-related genes, whereas some transcripts related to the Th1 responsive pathway were depressed. Flow cytometry analysis showed a marked increase in the apoptotic CD4+ T cells from 6 weeks post-infection and in the ratio of CD4+CD25+ to CD4+ T cells in infected mice after 13 weeks. We therefore concluded that experimental infection of mice with S. japonicum resulted in a Th2-skewed immune response, which was to a great extent monitored by the immune regulatory network, including cytokine cross-modulation, cell apoptosis and the subpopulation of regulatory cells.
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Affiliation(s)
- Min-Jun Ji
- Department of Pathogen Biology, Nanjing Medical University, Nanjing 210029, China
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Potestio M, D'Agostino P, Romano GC, Milano S, Ferlazzo V, Aquino A, Di Bella G, Caruso R, Gambino G, Vitale G, Mansueto S, Cillari E. CD4+ CCR5+ and CD4+ CCR3+ lymphocyte subset and monocyte apoptosis in patients with acute visceral leishmaniasis. Immunology 2004; 113:260-8. [PMID: 15379987 PMCID: PMC1782561 DOI: 10.1111/j.1365-2567.2004.01948.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The potential involvement of apoptosis in the pathogenesis of visceral leishmaniasis (VL) was examined by studying spontaneous and Leishmania antigen (LAg)-induced apoptosis using cryopreserved peripheral blood mononuclear cells (PBMC) of Sicilian patients with VL. Results indicate that monocytes and T lymphocytes from acute VL patients show a significantly higher level of apoptosis compared with that observed in healed subjects. The percentage of apoptotic cells was higher in monocytes than in T lymphocytes. T cells involved in programmed cell death (PCD) were mainly of the CD4(+) phenotype. In particular, the T helper 1-type (Th1) subset, as evaluated by chemokine receptor-5 (CCR5) expression, is involved in this process. Cell death in Th1-type uses a CD95-mediated mechanism. Furthermore, Th1-type CCR5(+) cells are prone to cell suicide in an autocrine or paracrine way, as attested by enhanced expression of CD95L in acute VL patients. The reduction in Th1-type cells by apoptosis was confirmed by the decrease in interferon-gamma secretion. In conclusion, apoptosis of monocytes, CD4(+) and CD4(+) CCR5(+) T cells could be involved in the failure of cell mediated immunity that is responsible for severe immune-depression in VL.
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Affiliation(s)
- Marcella Potestio
- Department of BioPathology and BioMedical Methodologies, University of Palermo, Palermo, Italy
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Pinheiro RO, Pinto EF, Benedito AB, Lopes UG, Rossi-Bergmann B. The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis. AN ACAD BRAS CIENC 2004; 76:519-27. [PMID: 15334250 DOI: 10.1590/s0001-37652004000300006] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg) but not L. braziliensis promastigotes (LbAg) contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h) and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.
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Affiliation(s)
- Roberta O Pinheiro
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21949-900, Brasil
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Abstract
Leishmaniasis is a disease caused by protozoa of the genus Leishmania, and visceral leishmaniasis is a form in which the inner organs are affected. Since knowledge about immunity in experimental visceral leishmaniasis is poor, we present here a review on immunity and immunosuppression in experimental visceral leishmaniasis in mouse and hamster models. We show the complexity of the mechanisms involved and differences when compared with the cutaneous form of leishmaniasis. Resistance in visceral leishmaniasis involves both CD4+ and CD8+ T cells, and interleukin (IL)-2, interferon (IFN)-gamma, and IL-12, the latter in a mechanism independent of IFN-gamma and linked to transforming growth factor (TGF)-beta production. Susceptibility involves IL-10 but not IL-4, and B cells. In immune animals, upon re-infection, the elements involved in resistance are different, i.e., CD8+ T cells and IL-2. Since one of the immunopathological consequences of active visceral leishmaniasis in humans is suppression of T-cell responses, many studies have been conducted using experimental models. Immunosuppression is mainly Leishmania antigen specific, and T cells, Th2 cells and adherent antigen-presenting cells have been shown to be involved. Interactions of the co-stimulatory molecule family B7-CTLA-4 leading to increased level of TGF-beta as well as apoptosis of CD4+ T cells and inhibition of macrophage apoptosis by Leishmania infection are other components participating in immunosuppression. A better understanding of this complex immune response and the mechanisms of immunosuppression in experimental visceral leishmaniasis will contribute to the study of human disease and to vaccine development.
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Affiliation(s)
- H Goto
- Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical de São Paulo e Departamento de Medicina Preventiva, Faculdade de Medicina, Universidade de São Paulo, Sao Paulo, SP, Brazil.
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Chen L, Rao KVN, He YX, Ramaswamy K. Skin-stage schistosomula of Schistosoma mansoni produce an apoptosis-inducing factor that can cause apoptosis of T cells. J Biol Chem 2002; 277:34329-35. [PMID: 12107158 PMCID: PMC2742670 DOI: 10.1074/jbc.m201344200] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Skin-stage schistosomula of Schistosoma mansoni were found to secrete molecules that are pro-apoptotic for skin T lymphocytes as measured by annexin V staining, caspase-3 activity, caspase-8 activities, and DNA fragmentation. Caspase-8 activities in lymphocytes peaked approximately 8 h and caspase-3 activity peaked approximately 16 h after exposure to the parasite secretions. Subset analysis showed that mainly CD4(+) and CD8(+) cells (but not B cells) were susceptible to the parasite-induced pro-apoptotic effect. In situ staining confirmed the presence of apoptotic T cells around challenge parasites in the skin of naive or immunized animals. Analysis of T cells to identify the potential molecular pathway of the parasite-induced apoptosis showed increases in the expression of Fas, FasL, and the Fas-associated death domain. Blocking of FasL with a fusion protein reversed the parasite-induced apoptosis, suggesting a role for the Fas/FasL-mediated pathway in the parasite-induced T cell apoptosis. Subsequent analyses of the secretions of skin-stage schistosomula identified the pro-apoptotic activity as being associated with a protein of approximately 23 kDa. This protein was termed S. mansoni-derived apoptosis-inducing factor.
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Affiliation(s)
- Lin Chen
- Department of Biomedical Sciences, College of Medicine, University of Illinois, Rockford, Illinois 61107
| | - Kakuturu V. N. Rao
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208
| | - Yi-Xun He
- Department of Biomedical Sciences, College of Medicine, University of Illinois, Rockford, Illinois 61107
| | - Kalyanasundaram Ramaswamy
- Department of Biomedical Sciences, College of Medicine, University of Illinois, Rockford, Illinois 61107
- To whom correspondence and reprint requests should be addressed: Dept. of Biomedical Sciences, College of Medicine, University of Illinois, 1601 Parkview Ave., Rockford, IL 61107. Tel.: 815-395-5696; Fax: 815-395-5666; E-mail:
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Lüder CG, Gross U, Lopes MF. Intracellular protozoan parasites and apoptosis: diverse strategies to modulate parasite-host interactions. Trends Parasitol 2001; 17:480-6. [PMID: 11587962 DOI: 10.1016/s1471-4922(01)02016-5] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Programmed cell death (apoptosis) is an important regulator of the host's response during infection with a variety of intracellular protozoan parasites. Parasitic pathogens have evolved diverse strategies to induce or inhibit host-cell apoptosis, thereby modulating the host's immune response, aiding dissemination within the host or facilitating intracellular survival. Here, we review the molecular and cell-biological mechanisms of the pathogen-induced modulation of host-cell apoptosis and its effects on the parasite-host interaction and the pathogenesis of parasitic diseases. We also discuss the previously unrecognized phenomenon of apoptotic cell death in (unicellular) protozoan parasites and its potential implications.
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Affiliation(s)
- C G Lüder
- Department Bacteriology, Georg August University of Göttingen, Kreuzbergring 57, D-37075 Göttingen, Germany.
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Fuhrmann G, Leisser C, Rosenberger G, Grusch M, Huettenbrenner S, Halama T, Mosberger I, Sasgary S, Cerni C, Krupitza G. Cdc25A phosphatase suppresses apoptosis induced by serum deprivation. Oncogene 2001; 20:4542-53. [PMID: 11494150 DOI: 10.1038/sj.onc.1204499] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2001] [Revised: 03/22/2001] [Accepted: 04/02/2001] [Indexed: 01/04/2023]
Abstract
The phosphatase Cdc25A was shown to be a target of the transcription factor c-Myc. Myc-induced apoptosis appeared dependent on Cdc25A expression and Cdc25A over-expression could substitute for Myc-triggered apoptosis. These findings suggested that an important downstream component of Myc-mediated apoptosis was identified. However and in contrast, we recently reported that during TNFalpha-induced apoptosis, which required c-Myc function, Cdc25A was down-regulated in a human carcinoma cell line. We now provide evidence that Cdc25A rendered the non-transformed rat embryonic cell line 423 refractory to apoptosis, which was induced by serum deprivation and in absence of detectable c-myc levels. The survival promoting activity of cdc25A was abolished upon infection of cells with a full-length cdc25A antisense construct. To identify the signaling proteins mediating the survival function of the phosphatase, cdc25A- and akt- over-expressing pooled clones were exposed to selected chemicals, which inhibit or activate key proteins in signaling pathways. Inhibition of apoptosis by SU4984, NF023 and Rapamycin placed Cdc25A and Akt function downstream of FGF.R, PDGF.R, and compensated G-protein- and PP2A- activity. Interestingly, upon treatment with LY-294002, cdc25A- and akt- over-expressing clones exhibited similar apoptotic patterns as control cells, which indicates that neither Akt- nor Cdc25A-mediated survival functions are dependent on PI.3 kinase activity in rat 423 cells. In cdc25A-overexpressing cells increased levels of serine 473 phosphorylated Akt were found, which co-precipitated with Cdc25A and Raf1. Since activation of proteins requires dephosphorylation of particular residues in addition to site-specific phosphorylation, the anti-apoptotic effect of Cdc25A might derive from its participation in a multimeric protein complex with phosphoAkt and Raf1, two prominent components of survival pathways.
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Affiliation(s)
- G Fuhrmann
- Institute of Clinical Pathology, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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Martins GA, Petkova SB, MacHado FS, Kitsis RN, Weiss LM, Wittner M, Tanowitz HB, Silva JS. Fas-FasL interaction modulates nitric oxide production in Trypanosoma cruzi-infected mice. Immunology 2001; 103:122-9. [PMID: 11380700 PMCID: PMC1783222 DOI: 10.1046/j.1365-2567.2001.01216.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2000] [Revised: 11/20/2000] [Accepted: 01/17/2001] [Indexed: 12/15/2022] Open
Abstract
During acute Trypanosoma cruzi infection in mice, many leucocytes undergo apoptosis. Although apoptosis has been ascribed to increased levels of nitric oxide (NO) and Fas-FasL interaction, the importance of this phenomenon in modulating the host response against T. cruzi is unknown. Herein, the role of NO- and Fas-FasL-induced apoptosis in modulating the immune response to T. cruzi was evaluated using mice deficient in Fas expression (MRL/MpJ-Fas lpr) and inducible nitric oxide synthase (iNOS) knockout mice (iNOS-/-). The results showed that besides decreasing apoptosis induction after infection, impairment of the Fas-FasL interaction resulted in decreased NO production, as a consequence of enhanced T helper 2 (Th2) cytokine production. Differently, blockage of NO-induced apoptosis resulted in uncontrolled cytokine production, rather than a biased Th2 cytokine pattern. Together, these results suggested that Fas and FasL-induced apoptosis could be implied in modulation of the immune response against T. cruzi by interfering with cytokine and NO production during the acute phase of the infection.
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Affiliation(s)
- G A Martins
- Department of Immunology, School of Medicine of Ribeirão Preto-USP, Ribeirão Preto, São Paulo, Brazil
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Alexander CE, Kaye PM, Engwerda CR. CD95 is required for the early control of parasite burden in the liver of Leishmania donovani-infected mice. Eur J Immunol 2001; 31:1199-210. [PMID: 11298345 DOI: 10.1002/1521-4141(200104)31:4<1199::aid-immu1199>3.0.co;2-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In this study we show an increased incidence of T cell apoptosis in the liver and spleen of mice infected with Leishmania donovani. T cells from L. donovani-infected mice were found to be increasingly susceptible to CD95-mediated apoptosis in vitro, compared to controls. To test if suboptimal T cell function resulting from CD95-mediated apoptosis contributes to sustained parasite burden in L. donovani parasitized mice, B6.gld mice (lacking functional CD95 ligand) were infected with L. donovani. Surprisingly, at four different time points no difference in levels of T cell apoptosis in the spleen and liver was found between these mice and controls following intravenous delivery of L. donovani amastigotes, indicating that the CD95 / CD95L interaction is not essential for T cell apoptosis in the L. donovani-infected liver and spleen. However, B6.gld mice were increasingly susceptible to L. donovani infection, associated with less efficient granuloma formation in the liver and uncontrolled parasite growth in the spleen. Late in infection (day 56 post-infection), B6.gld mice had higher numbers of IFN-gamma-producing CD4(+) T cells in the liver and spleen, indicating a role for CD95 signaling in the homeostasis of this subset of cytokine-producing T cells in L. donovani-parasitized mice. Adoptive transfer of CD4(+) and CD8(+) T cells into recombinase activating gene 1 knockout (RAG-1(- / -)) recipients, revealed that CD95L expressed on CD4(+) T cells contributes to early control of L. donovani infection in the liver via mechanisms that are independent of granuloma formation and induction of apoptosis. These results indicate important roles for CD95 and CD95L that are unrelated to regulation of apoptosis in the early control of L. donovani infection.
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Affiliation(s)
- C E Alexander
- The Department of Infectious and Tropical Diseases, The London School of Hygiene and Tropical Medicine, London, GB
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Morford LA, Dix AR, Brooks WH, Roszman TL. Apoptotic elimination of peripheral T lymphocytes in patients with primary intracranial tumors. J Neurosurg 1999; 91:935-46. [PMID: 10584838 DOI: 10.3171/jns.1999.91.6.0935] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Patients with gliomas exhibit severe T lymphopenia during the course of the disease. This study was conducted to determine the mechanism(s) responsible for the lymphopenia. METHODS Using two-color fluorescent staining techniques, the authors show that significant numbers of T cells undergo apoptosis in the peripheral blood of patients with gliomas. To determine whether a glioma-derived factor(s) induces this apoptosis, rosette-purified T cells obtained from healthy donors were treated with glioma cell culture supernatant (GCCS) and examined for apoptosis. It is demonstrated that treatment of normal T cells with GCCS induced apoptosis only with concurrent stimulation of the T-cell receptor/CD3 complex. The addition of neutralizing antibodies to interleukin (IL)-10, IL-4, transforming growth factor alpha, or tumor necrosis factor-beta (lymphotoxin) did not rescue these T cells from apoptosis. Experiments were also conducted in which the degree of monocyte involvement in the induction of T-cell apoptosis was explored. The U937 cells were pretreated for 20 hours with a 1:20 dilution of GCCS. After the removal of GCCS, the U937 cells were cultured in transwell assays with stimulated T cells. Although control U937 cells did not induce apoptosis of the activated T cells, GCCS-pretreated U937 cells induced appreciable apoptosis in normal, stimulated T-cell cultures. CONCLUSIONS These data indicate that one mechanism by which gliomas cause immunosuppressive effects is the induction of monocytes to release soluble factors that promote activated T-cell apoptosis. The loss of activated T cells leads to T lymphopenia and contributes to the deficiencies in cell-mediated immunity that have been observed during testing of glioma patients' immune function.
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Affiliation(s)
- L A Morford
- Department of Microbiology and Immunology, University of Kentucky Medical Center, Lexington 40536-0084, USA
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Dix AR, Brooks WH, Roszman TL, Morford LA. Immune defects observed in patients with primary malignant brain tumors. J Neuroimmunol 1999; 100:216-32. [PMID: 10695732 DOI: 10.1016/s0165-5728(99)00203-9] [Citation(s) in RCA: 223] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Malignant glioblastomas (gliomas) account for approximately one third of all diagnosed brain tumors. Yet, a decade of research has made little progress in advancing the treatment of these tumors. In part this lack of progress is linked to the challenge of discovering how glial tumors are capable of both modulating host immune function and neutralizing immune-based therapies. Patients with gliomas exhibit a broad suppression of cell-mediated immunity. The impaired cell-mediated immunity observed in patients with gliomas appears to result from immunosuppressive factor(s) secreted by the tumor. This article reviews what has been elucidated about the immune defects of patients harboring glioma and the glioma-derived factors which mediate this immunosuppression. A model involving systemic cytokine dysregulation is presented to suggest how the immune defects arise in these individuals.
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Affiliation(s)
- A R Dix
- Department of Microbiology and Immunology, University of Kentucky Medical Center, Lexington 40536-0084, USA
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