1
|
Vellozo NS, Matos-Silva TC, Lopes MF. Immunopathogenesis in Trypanosoma cruzi infection: a role for suppressed macrophages and apoptotic cells. Front Immunol 2023; 14:1244071. [PMID: 37662946 PMCID: PMC10469960 DOI: 10.3389/fimmu.2023.1244071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 08/04/2023] [Indexed: 09/05/2023] Open
Abstract
During Trypanosoma cruzi infection, macrophages phagocytose parasites and remove apoptotic cells through efferocytosis. While macrophage 1 (M1) produces proinflammatory cytokines and NO and fights infection, M2 macrophages are permissive host cells that express arginase 1 and play a role in tissue repair. The regulation of M1 and M2 phenotypes might either induce or impair macrophage-mediated immunity towards parasite control or persistence in chronic Chagas disease. Here, we highlight a key role of macrophage activation in early immune responses to T. cruzi that prevent escalating parasitemia, heart parasitism, and mortality during acute infection. We will discuss the mechanisms of macrophage activation and deactivation, such as T cell cytokines and efferocytosis, and how to improve macrophage-mediated immunity to prevent parasite persistence, inflammation, and the development of chagasic cardiomyopathy. Potential vaccines or therapy must enhance early T cell-macrophage crosstalk and parasite control to restrain the pathogenic outcomes of parasite-induced inflammation in the heart.
Collapse
Affiliation(s)
| | | | - Marcela F. Lopes
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| |
Collapse
|
2
|
Gómez-Olarte S, Bolaños NI, Cuéllar A, Puerta CJ, González JM. Diminished mitogen-induced T cell proliferation by Trypanosoma cruzi antigens associated with antigen-presenting cell modulation and CD3 signaling. Cell Immunol 2020; 348:103974. [DOI: 10.1016/j.cellimm.2019.103974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/10/2019] [Accepted: 08/30/2019] [Indexed: 12/12/2022]
|
3
|
Stempin CC, Rojas Marquez JD, Ana Y, Cerban FM. GRAIL and Otubain-1 are Related to T Cell Hyporesponsiveness during Trypanosoma cruzi Infection. PLoS Negl Trop Dis 2017; 11:e0005307. [PMID: 28114324 PMCID: PMC5289611 DOI: 10.1371/journal.pntd.0005307] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 02/02/2017] [Accepted: 01/06/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Trypanosoma cruzi infection is associated with severe T cell unresponsiveness to antigens and mitogens and is characterized by decreased IL-2 synthesis. In addition, the acquisition of the anergic phenotype is correlated with upregulation of "gene related to anergy in lymphocytes" (GRAIL) protein in CD4 T cells. We therefore sought to examine the role of GRAIL in CD4 T cell proliferation during T. cruzi infection. METHODOLOGY/PRINCIPAL FINDINGS Balb/c mice were infected intraperitoneally with 500 blood-derived trypomastigotes of Tulahuen strain, and spleen cells from control non-infected or infected animals were obtained. CD4 T cell proliferation was assessed by CFSE staining, and the expression of GRAIL in splenic T cells was measured by real-time PCR, flow cytometry and Western blot. We found increased GRAIL expression at the early stages of infection, coinciding with the peak of parasitemia, with these findings correlating with impaired proliferation and poor IL-2 and IFN-γ secretion in response to plate-bound antibodies. In addition, we showed that the expression of GRAIL E3-ubiquitin ligase in CD4 T cells during the acute phase of infection was complemented by a high expression of inhibitory receptors such as PD-1 and CTLA-4. We demonstrated that GRAIL expression during infection was modulated by the mammalian target of the rapamycin (mTOR) pathway, since addition of IL-2 or CTLA-4 blockade in splenocytes from mice 21 days post infection led to a reduction in GRAIL expression. Furthermore, addition of IL-2 was able to activate the mTOR pathway, inducing Otubain-1 expression, which mediated GRAIL degradation and improved T cell proliferation. CONCLUSIONS We hypothesize that GRAIL expression induced by the parasite may be maintained by the increased expression of inhibitory molecules, which blocked mTOR activation and IL-2 secretion. Consequently, the GRAIL regulator Otubain-1 was not expressed and GRAIL maintained the brake on T cell proliferation. Our findings reveal a novel association between increased GRAIL expression and impaired CD4 T cell proliferation during Trypanosoma cruzi infection.
Collapse
Affiliation(s)
- Cinthia C. Stempin
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Medina Allende y Haya de la Torre, Ciudad Universitaria, Córdoba, Argentina
| | - Jorge D. Rojas Marquez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Medina Allende y Haya de la Torre, Ciudad Universitaria, Córdoba, Argentina
| | - Yamile Ana
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Medina Allende y Haya de la Torre, Ciudad Universitaria, Córdoba, Argentina
| | - Fabio M. Cerban
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Medina Allende y Haya de la Torre, Ciudad Universitaria, Córdoba, Argentina
- * E-mail:
| |
Collapse
|
4
|
Cardillo F, de Pinho RT, Antas PRZ, Mengel J. Immunity and immune modulation in Trypanosoma cruzi infection. Pathog Dis 2015; 73:ftv082. [PMID: 26438729 DOI: 10.1093/femspd/ftv082] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2015] [Indexed: 12/28/2022] Open
Abstract
Chagas disease is caused by the protozoan Trypanosoma cruzi. The parasite reaches the secondary lymphoid organs, the heart, skeletal muscles, neurons in the intestine and esophagus among other tissues. The disease is characterized by mega syndromes, which may affect the esophagus, the colon and the heart, in about 30% of infected people. The clinical manifestations associated with T. cruzi infection during the chronic phase of the disease are dependent on complex interactions between the parasite and the host tissues, particularly the lymphoid system that may either result in a balanced relationship with no disease or in an unbalanced relationship that follows an inflammatory response to parasite antigens and associated tissues in some of the host organs and/or by an autoimmune response to host antigens. This review discusses the findings that support the notion of an integrated immune response, considering the innate and adaptive arms of the immune system in the control of parasite numbers and also the mechanisms proposed to regulate the immune response in order to tolerate the remaining parasite load, during the chronic phase of infection. This knowledge is fundamental to the understanding of the disease progression and is essential for the development of novel therapies and vaccine strategies.
Collapse
Affiliation(s)
- Fabíola Cardillo
- Oswaldo Cruz Foundation, Bahia, Rua Waldemar Falcão 121, Salvador 40295-001, Brazil
| | - Rosa Teixeira de Pinho
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, Brazil
| | - Paulo Renato Zuquim Antas
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, Brazil
| | - José Mengel
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, Brazil Faculty of Medicine of Petropolis, FMP-FASE, 25680-120, Petrópolis, Rio de Janeiro, Brazil
| |
Collapse
|
5
|
Selenium promotes T-cell response to TCR-stimulation and ConA, but not PHA in primary porcine splenocytes. PLoS One 2012; 7:e35375. [PMID: 22530011 PMCID: PMC3328446 DOI: 10.1371/journal.pone.0035375] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 03/15/2012] [Indexed: 11/19/2022] Open
Abstract
There is controversy in the literature over whether the selenium (Se) influences cellular immune responses, and the mechanisms possibly underlying these effects are unclear. In this study, the effects of Se on T-cell proliferation and IL-2 production were studied in primary porcine splenocytes. Splenocytes were treated with different mitogens in the presence of 0.5-4 µmol/L sodium selenite. Se significantly promoted T-cell receptor (TCR) or concanavalin A (ConA)-induced T-cell proliferation and IL-2 production but failed to regulate T-cell response to phytohemagglutinin (PHA). In addition, Se significantly increased the levels of cytosolic glutathione peroxidase (GPx1) and thioredoxin reductase 1 (TR1) mRNA, the activity of GPx1 and the concentration of reduced glutathione (GSH) in the unstimulated, or activated splenocytes. These results indicated that Se improved the redox status in all splenocytes, including unstimulated, TCR, ConA and PHA -stimulated, but only TCR and ConA-induced T-cell activation was affected by the redox status. N-acetylcysteine (NAC), a pharmacological antioxidant, increased T-cell proliferation and IL-2 production by TCR and ConA stimulated splenocytes but had no effect on the response to PHA in primary porcine splenocytes confirming that PHA-induced T-cell activation is insensitive to the redox status. We conclude that Se promotes GPx1 and TR1 expression and increases antioxidative capacity in porcine splenocytes, which enhances TCR or ConA -induced T-cell activation but not PHA-induced T-cell activation. The different susceptibilities to Se between the TCR, ConA and PHA -induced T-cell activation may help to explain the controversy in the literature over whether or not Se boosts immune responses.
Collapse
|
6
|
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.
Collapse
Affiliation(s)
- Landi V C Guillermo
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Mucin AgC10 from Trypanosoma cruzi Interferes with L-selectin-mediated monocyte adhesion. Infect Immun 2010; 78:1260-8. [PMID: 20065025 DOI: 10.1128/iai.00794-09] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The protozoan parasite Trypanosoma cruzi has evolved sophisticated systems to evade the immune response. An important requirement for a productive immune response is recruitment of the appropriate immune cells from the bloodstream to the sites of infection. Here, we show that a mucin expressed and secreted by the metacyclic infective form of T. cruzi, AgC10, is able to interfere with L-selectin-mediated monocyte adhesion. Thus, incubation of U937 monocytic cells stably expressing L-selectin (U937LAM) with AgC10 strongly reduced their adhesion on P-selectin under flow, which is dependent on L-selectin. This treatment also results in a significant inhibition by AgC10 of U937LAM and human primary monocyte adhesion to activated vascular endothelium. This effect was specific for L-selectin, because vascular cell adhesion molecule 1 (VCAM-1)-mediated adhesion was not affected by AgC10 pretreatment. This effect of AgC10 is likely due to its ability to induce L-selectin shedding from the monocyte membrane, since pharmacologic blocking of this shedding prevents AgC10 activity. This is the first description of a mechanism that prevents leukocyte adhesion to the endothelium by a parasite and represents a new potential countermeasure to evade the generation of a correct immune response.
Collapse
|
8
|
Pinto ACH, Caetano LC, Levy AMA, Fernandes RD, Santos CD, do Prado JC. Experimental Chagas' disease in orchiectomized Calomys callosus infected with the CM strain of Trypanosoma cruzi. Exp Parasitol 2009; 124:147-52. [PMID: 19698712 DOI: 10.1016/j.exppara.2009.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 08/07/2009] [Accepted: 08/15/2009] [Indexed: 11/24/2022]
Abstract
The incidence and progression of disorders associated with an unbalanced immune response has among many factors the gender as a contributory factor. The aims of this work were to evaluate the effects of orchiectomy and the immune response during the experimental Trypanosoma cruzi infection. Young adult, male Calomys callous were i.p. inoculated with 1 x 10(5) blood trypomastigotes of the CM strain of T. cruzi and divided in groups: Control, Sham and Castrated. Castrated group displayed significantly lower values for prostate and seminal vesicle weights indicating a drastic drop of testosterone plasmatic levels. Orchiectomized animals also displayed lesser number of blood parasites, enhanced lytic antibody percentage, splenocyte proliferation and NO concentration when compared to its sham and control counterparts, indicating that steroid gonadal ablation actually influences immune response triggering a more efficient cellular and humoral response which led animals to become more resistant against T. cruzi infection.
Collapse
|
9
|
de Meis J, Ferreira LMS, Guillermo LVC, Silva EM, Dosreis GA, Lopes MF. Apoptosis differentially regulates mesenteric and subcutaneous lymph node immune responses to Trypanosoma cruzi. Eur J Immunol 2008; 38:139-46. [PMID: 18085669 DOI: 10.1002/eji.200737582] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Infection with Trypanosoma cruzi causes expansion of subcutaneous (SLN) and atrophy of mesenteric (MLN) lymph nodes. Here we show that excision of MLN increased parasitemia in T. cruzi-infected mice. We then studied how apoptosis of MLN cells affects immune responses to infection. T cell apoptosis increased in the MLN compared to SLN in T. cruzi-infected mice. Absolute numbers of naïve T cells decreased, and activated T cells failed to accumulate in MLN during infection. In addition, activated T cells from MLN produced less IL-2, IFN-gamma, IL-4, and IL-10 than T cells from SLN. Treatment with IL-4 or with caspase-9 inhibitor increased the recovery of viable T cells in vitro. Treatment with caspase-9 inhibitor also increased the production of cytokines by MLN T cells from infected mice. Moreover, injection of a pan caspase inhibitor prevented MLN atrophy during T. cruzi infection. Caspase-9, but not caspase-8, inhibitor also reduced MLN atrophy and increased the recovery of naïve and activated T cells from MLN. These findings indicate that caspase-mediated apoptosis and defective cytokine production are implicated in MLN atrophy and affect immune responses to T. cruzi infection.
Collapse
Affiliation(s)
- Juliana de Meis
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
| | | | | | | | | | | |
Collapse
|
10
|
Goñi O, Alcaide P, Fresno M. Immunosuppression during acute Trypanosoma cruzi infection: involvement of Ly6G (Gr1(+))CD11b(+ )immature myeloid suppressor cells. Int Immunol 2002; 14:1125-34. [PMID: 12356678 DOI: 10.1093/intimm/dxf076] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Trypanosoma cruzi infection is associated with a severe unresponsiveness of spleen cells (SC) to antigens and mitogens. A high production of NO by concanavalin A (Con A)-stimulated SC from infected but not from control mice was observed. Neutralization of endogenous IFN-gamma production or treatment with NO synthase (NOS) inhibitor, L-N-monomethyl-arginine, blocked Con A-induced NO production and greatly restored proliferation by SC from infected mice. This was confirmed by using IFN-gammaR(-/-) and inducible NOS (iNOS)(-/- )knockout mice, since unresponsiveness to mitogens of SC from those infected mice was much less pronounced than in control littermates. Interestingly, SC unresponsiveness was associated with a huge increase in CD11b(+) cells that express Ly-6G (Gr1)(+) and other immature myeloid markers These cells were absent in infected IFN-gammaR(-/-) spleens. Purified immature Gr1(+)CD11b(+) cells produced NO and expressed iNOS upon IFN-gamma treatment, and were able to inhibit T cell proliferation. In addition, depletion of myeloid CD11b(+ )cells abrogated NO production and restored mitogen-induced proliferation, but not IL-2 synthesis, in SC from infected mice. IL-2 production and CD25 cell surface expression by mitogen-activated T cells were greatly depressed in SC from IFN-gammaR(-/-) and iNOS(-/- )mice, confirming that Gr1(+)CD11b(+) cells were not involved in their down-regulation. In contrast, IL-5, tumor necrosis factor and IFN-gamma production, and CD69 expression by T cells were not depressed in infected SC. The results indicate the existence of an immunosuppressive mechanism during T. cruzi infection, mediated through IFN-gamma-dependent NO secretion by immature Ly-6G (Gr1)(+)CD11b(+ )myeloid cells.
Collapse
Affiliation(s)
- Oscar Goñi
- Centro de Biología Molecular (CSIC-UAM), Universidad Autónoma de Madrid, Cantoblanco, Madrid 28049, Spain
| | | | | |
Collapse
|
11
|
Zuñiga E, Motran C, Montes CL, Diaz FL, Bocco JL, Gruppi A. Trypanosoma cruzi-induced immunosuppression: B cells undergo spontaneous apoptosis and lipopolysaccharide (LPS) arrests their proliferation during acute infection. Clin Exp Immunol 2000; 119:507-15. [PMID: 10691924 PMCID: PMC1905583 DOI: 10.1046/j.1365-2249.2000.01150.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Acute infection with Trypanosoma cruzi is characterized by multiple manifestations of immunosuppression of both cellular and humoral responses. B cells isolated at the acute stage of infection have shown marked impairment in their response to polyclonal activators in vitro. The present work aims at studying the B cell compartment in the context of acute T. cruzi infection to provide evidence for B cell activation, spontaneous apoptosis and arrest of the cell cycle upon mitogenic stimulation as a mechanism underlying B cell hyporesponse. We found that B cells from acutely infected mice, which fail to respond to the mitogen LPS, showed spontaneous proliferation and production of IgM, indicating a high level of B cell activation. Furthermore, these activated B cells also exhibited an increase in Fas expression and apoptosis in cultures without an exogenous stimulus. On the other hand, B cells from early acute and chronic infected mice did not present activation or apoptosis, and were able to respond properly to the mitogen. Upon in vitro stimulation with LPS, B cells from hyporesponder mice failed to progress through the cell cycle (G0/G1 arrest), nor did they increase the levels of apoptosis. These results indicate that B cell apoptosis and cell cycle arrest could be the mechanisms that control intense B cell expansion, but at the same time could be delaying the emergence of a specific immune response against the parasite.
Collapse
Affiliation(s)
- E Zuñiga
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ala 1 Subsuelo, Pabellón Argentina, Ciudad Universitaria, Córdoba, Argentina
| | | | | | | | | | | |
Collapse
|
12
|
Hölscher C, Köhler G, Müller U, Mossmann H, Schaub GA, Brombacher F. Defective nitric oxide effector functions lead to extreme susceptibility of Trypanosoma cruzi-infected mice deficient in gamma interferon receptor or inducible nitric oxide synthase. Infect Immun 1998; 66:1208-15. [PMID: 9488415 PMCID: PMC108035 DOI: 10.1128/iai.66.3.1208-1215.1998] [Citation(s) in RCA: 191] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/1997] [Accepted: 12/19/1997] [Indexed: 02/06/2023] Open
Abstract
Trypanosoma cruzi, the causative agent of Chagas' disease, induces an innate and adaptive host immune response during the acute phase of infection. These responses were analyzed by comparing mouse lines deficient for the gamma interferon (IFN-gamma) receptor (IFN-gammaR(-/-)) or deficient for inducible nitric oxide synthase (iNOS(-/-)). Both lines were highly susceptible, with similar and dramatically increased parasite burdens and severe histopathology and were incapable of surviving even very low doses, exhibiting similar mortality kinetics. This pathophysiological correlation has a common cause, since both mutant mouse strains were unable to respond to infection by producing nitric oxide (NO) with the consequence that mutant macrophages had impaired trypanocidal activities. These in vivo and subsequent in vitro studies further demonstrated that an IFN-gamma-dependent pathway of iNOS induction is crucial for efficient NO production and mandatory for resisting acute infection with T. cruzi. Despite this defect, both mutant mouse strains had a rather normal proinflammatory cytokine response (interleukin-12 [IL-12], IFN-gamma, IL-6), with the exception of an impaired tumor necrosis factor alpha and IL-1alpha response in IFN-gammaR(-/-) mice, demonstrating that only the latter two cytokines are dependent on IFN-gamma activation. Moreover, polarization of T cells in type 1 and type 2 T-helper (Th1/Th2) and cytotoxic T (Tc1/Tc2) cells as well as T. cruzi-specific antibody responses were normal in IFN-gammaR(-/-) mice, demonstrating that IFN-gamma is not necessary for the promotion of T-cell differentiation and T. cruzi-specific antibody responses.
Collapse
Affiliation(s)
- C Hölscher
- Max Planck Institute for Immunobiology, Freiburg, Germany
| | | | | | | | | | | |
Collapse
|
13
|
Nunes MP, Andrade RM, Lopes MF, DosReis GA. Activation-Induced T Cell Death Exacerbates Trypanosoma cruzi Replication in Macrophages Cocultured with CD4+ T Lymphocytes from Infected Hosts. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.3.1313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Activation-induced cell death (AICD) of CD4+ T lymphocytes was described in infection with Trypanosoma cruzi, but a role for AICD in modulating parasite spread in host cells has not been investigated. In this study, replication of T. cruzi in vitro in murine macrophage (Mφ) monolayers was investigated. Long term (5 to 13 day) replication of infective (trypomastigote) T. cruzi forms was blocked by supernatants from activated (anti-TCR) CD4+ T cells of infected mice or by rIFN-γ. However, when CD4+ T cells from infected mice were cocultured with Mφ and activated by anti-TCR, marked exacerbation of trypomastigote growth in Mφ ensued. The deleterious effect required contact between T cells and infected Mφ. Both anti-Fas and TCR activation killed a proportion of CD4+ T cells. Ly-6 activation did not induce AICD and did not exacerbate parasite growth. However, Fas-mediated killing of T cells before Ly-6 activation led to exacerbated parasite growth. Although a minor population, Fas-susceptible cells were the major source of IFN-γ production by activated T cells. Addition of a neutralizing anti-Fas ligand antibody blocked 50 to 60% of CD4+ T cell AICD and reduced trypomastigote growth in T/Mφ cocultures stimulated by anti-TCR. The results demonstrate that in CD4+ T cells from infected mice, the onset of AICD selectively ablates IFN-γ production and up-regulates parasite replication in Mφ in vitro. These findings suggest a deleterious role for AICD in T. cruzi infection.
Collapse
Affiliation(s)
- Marise P. Nunes
- *Instituto Oswaldo Cruz, FIOCRUZ (Fundaçao Oswaldo Cruz), and
| | - Regis M. Andrade
- †Programa de Imunobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcela F. Lopes
- †Programa de Imunobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - George A. DosReis
- †Programa de Imunobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
14
|
Abstract
Infection of humans with the protozoan Trypanosoma cruzi leads to Chagas disease, or American trypanosomiasis, a disease that affects nearly 20 million people, and constitutes one of the largest socioeconomic burdens in Latin America. Much of the present knowledge on pathogenic mechanisms underlying T. cruzi infection comes from experimental murine models. Here, George A. DosReis reviews recent findings about the features of host cell-mediated immunity against the parasite and possible mechanisms leading to chronic infection.
Collapse
Affiliation(s)
- G A DosReis
- Immunobiology Program, Instituto de Biofisica Carlos Chagas Filho da Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco G, Ilha do Fundão, Rio de Janeiro, RJ 21944-970, Brazil
| |
Collapse
|
15
|
Lopes MF, DosReis GA. Trypanosoma cruzi-induced immunosuppression: selective triggering of CD4+ T-cell death by the T-cell receptor-CD3 pathway and not by the CD69 or Ly-6 activation pathway. Infect Immun 1996; 64:1559-64. [PMID: 8613360 PMCID: PMC173961 DOI: 10.1128/iai.64.5.1559-1564.1996] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In a model of experimental Chagas' disease induced with metacyclic forms of Trypanosoma cruzi, CD4+ but not CD8+ T cells undergo T-cell receptor (TCR)-CD3-mediated activation-induced cell death (AICD) in vitro. CD4+ T cells from T. cruzi-infected mice also developed unresponsiveness in proliferative responses to TCR-CD3-mediated stimulation. A linear correlation was found between extent of proliferative unresponsiveness and loss of CD4+ T-cell viability. CD4+ T-cell activation through the CD69 or Ly-6 A/E pathway, on the other hand, did not result in proliferative unresponsiveness compared with controls. Lack of suppression in proliferation assays correlated with lack of AICD by cells stimulated through the CD69 or Ly-6 A/E pathway. Concomitant stimulation through CD69, however, did not rescue CD4+ T cells from CD3-induced death. Flow cytometry study of cells stimulated in vitro showed no defect in interleukin-2 receptor expression by CD4+ T cells from infected donors, which escaped TCR-mediated AICD. In vivo injection of anti-CD3 into acutely infected mice, but not into control mice, led to splenocyte DNA fragmentation and failed to increase splenic CD4+ T-cell numbers. These results show that TCR-CD3-mediated AICD is involved in CD4+ T-cell unresponsiveness in vitro following infection with T. cruzi. In addition, successful activation of these cells through the CD69 and Ly-6 pathways is due to differences in the inability of these stimuli to trigger AICD. Since TCR-CD3-mediated AICD can be induced in vivo in infected mice, these findings may be relevant for the onset of immunological disturbances in the host.
Collapse
MESH Headings
- Animals
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Antigens, Ly/metabolism
- Apoptosis/immunology
- CD3 Complex/metabolism
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/pathology
- Chagas Disease/immunology
- Disease Models, Animal
- Immune Tolerance
- In Vitro Techniques
- Lectins, C-Type
- Lymphocyte Activation
- Male
- Mice
- Mice, Inbred BALB C
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Interleukin-2/metabolism
- Trypanosoma cruzi/growth & development
- Trypanosoma cruzi/immunology
- Trypanosoma cruzi/pathogenicity
Collapse
Affiliation(s)
- M F Lopes
- Department of Immunology, Federal University of Rio de Janeiro, Brazil
| | | |
Collapse
|
16
|
DosReis GA, Fonseca ME, Lopes MF. Programmed T-cell death in experimental chagas disease. ACTA ACUST UNITED AC 1995; 11:391-4. [PMID: 15275405 DOI: 10.1016/0169-4758(95)80011-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In mature T cells, programmed cell death is thought to serve a regulatory function by limiting both the duration and amplitude of immune responses. Programmed cell death might also be involved in immuno-pathogenesis of certain infectious diseases: recent evidence suggests that programmed T-cell death plays an important role in immune suppression during viral infections. In this article, George DosReis, Maria Evangelina Fonseca and Marcela Lopes review their findings on programmed T-cell death in experimental infection induced by the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. They also discuss the differential behavior of CD4(+) and CD8(+) T-cell subsets regarding programmed cell death, and same possible pathogenic aspects of host-parasite interaction, where abnormal or exaggerated programmed T-cell death could be involved.
Collapse
Affiliation(s)
- G A DosReis
- Department of Immunology, Instituto de Microbiologia da Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Brasil.
| | | | | |
Collapse
|