Recrudescence induced by cyclophosphamide of chronic Trypanosoma cruzi infection in mice is influenced by the parasite strain

Pereira, M. E. S.; Santos, Luis Mauro T; Araújo, Márcio Sobreira Silva; Brener, Z.

doi:10.1590/s0074-02761996000100011

Cited by 23 publications

(16 citation statements)

References 10 publications

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“…Reactivation does not occur in all Chagas' disease patients who undergo immunosuppression; it is possible that this may be influenced by the intrinsic characteristics of the particular infecting strain, as has been demonstrated in animal models (289).…”

Section: Diagnostic Methods (I) Parasitological Methodsmentioning

confidence: 99%

Transmission of Tropical and Geographically Restricted Infections during Solid-Organ Transplantation

et al. 2008

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SUMMARY In recent years, the increasing number of donors from different regions of the world is providing a new challenge for the management and selection of suitable donors. This is a worldwide problem in most countries with transplantation programs, especially due to the increase in immigration and international travel. This paper elaborates recommendations regarding the selection criteria for donors from foreign countries who could potentially transmit tropical or geographically restricted infections to solid-organ transplant recipients. For this purpose, an extensive review of the medical literature focusing on viral, fungal, and parasitic infections that could be transmitted during transplantation from donors who have lived or traveled in countries where these infections are endemic has been performed, with special emphasis on tropical and imported infections. The review also includes cases described in the literature as well as risks of transmission during transplantation, microbiological tests available, and recommendations for each infection. A table listing different infectious agents with their geographic distributions and specific recommendations is included.

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Section: Diagnostic Methods (I) Parasitological Methodsmentioning

confidence: 99%

Transmission of Tropical and Geographically Restricted Infections during Solid-Organ Transplantation

et al. 2008

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“…Fresh acute phase with outbreaks of high parasitemia occurred only in 1 of 4 T. cruzi strains. More recently, Pereira et al [52] used cyclophosphamide in eight groups of mice inoculated with T. cruzi strains of dis tinct geographic origin. Again, the variability was present and the percentages of recrudescence in the different groups of mice were 12.9-90.3%.…”

Section: Reactivation O F Chronic Chagas' Diseasementioning

confidence: 99%

Immnunological Control of <i>Trypanosoma cruzi</i> Infection and Pathogenesis of Chagas’ Disease

Brener

Gazzinelli²

1997

Int Arch Allergy Immunol

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296

233

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The major goal of studies on immunity to Trypanosoma cruzi is the understanding of immunological mechanisms involved in resistance to this protozoan as well as the pathogenesis of Chagas’ disease. Different studies have defined CD8+ T lymphocytes, IFN-γ and macrophages as important elements controlling parasite replication during the acute phase of infection. In contrast, during the chronic stage of the disease parasite-specific antibodies that fix complement and lyse the blood from trypomastigotes are thought to be the main effector molecules responsible for maintaining latent infection. In both acute and chronic infection with T. cruzi CD4+ Th1 lymphocytes appear to be the main cells responsible for induction of protective immunity. The immunological mechanisms involved in the pathogenesis of Chagas’ disease are much more controversial. CD8+ lymphocytes are thought to be the main effector cells responsible for cardiac tissue destruction. Although many experiments suggest the involvement of autoimmunity in the pathogenesis of Chagas’ disease, recent studies both in mice and humans indicate a positive association of tissue parasitism, inflammation and severity of pathology induced by T. cruzi. Finally, T. cruzi has emerged as an important opportunistic pathogen in patients infected with HIV and presenting low numbers of CD4+ T lymphocytes. These clinical findings indicate the essential requirement of CD4+ T-helper cells in mediating resistance during chronic Chagas’ disease; however, the effector mechanisms that control the reactivation of chronic infection in vivo are not completely defined.

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“…Moreover, we also demonstrated that despite the polymorphic expression of immunogenic carbohydrate epitope attached to surface molecules of T. cruzi, the pattern of reactivity of these epitopes remained constant and stable in the acute phase and after reactivation of Chagas disease. Pereira et al (1996) reported that different T. cruzi strains react differently to immunosuppressive agents, suggesting that reactivation of chronic infection is influenced by parasite intrinsic characteristics. We utilized parasites belonging to T. cruzi I (G strain), T. cruzi II (Y strain) and T. cruzi VI (CL strain) and observed that each strain Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Studies of experimental Chagas disease led Pereira et al (1996) to suggest that reactivation of chronic T. cruzi infection is strongly influenced by intrinsic parasite characteristics. While it is not clear what factors determine the different clinical forms of the disease, it is believed that they are primarily determined by parasite genetics, as well as host susceptibility.…”

Section: Introductionmentioning

confidence: 99%

Trypanosoma cruzi strains in the Calomys callosus: parasitemia and reaction of intracellular forms with stage-specific antibodies in the acute and chronic phase of infection and after immunosuppression

et al. 2011

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An experimental model for chronic Chagas disease was developed to investigate whether reactivation is influenced by the genetic origin of Trypanosoma cruzi isolates. In addition, we examined whether the distribution of T. cruzi stage-specific epitopes, as defined by monoclonal antibodies (Mab), raised against mammalian-stage parasite forms, exhibited comparable distribution patterns in Calomys callosus myocardium during the acute phase and after reactivation of the infection. Animals were infected with parasites of the G (T. cruzi I), Y (T.cruzi II) or CL strains (T. cruzi VI). Heart sections were labelled with the Mabs 2C2, 1D9, 2B7, 3B9 and 4B9, which react with carbohydrate epitopes on Ssp-4, a major amastigote surface glycoprotein. Mab 1D9 and 2B7 showed polymorphic distributions over amastigotes among animals infected with the G, Y or CL strains. Mab 3B2, which recognises a non-carbohydrate epitope in flagellated forms, showed an active state of parasite dissemination in the myocardium of C. callosus that were infected with Y or CL strains and then immunosuppressed after 6 or 12 months. C. callosus infected with the G strain (T. cruzi I) displayed absence of amastigote nests in the heart after immunosuppression. Our results permit us to suggest that parasites of the G strain may be more sensitive to the immune response, since we could not find either evidence of parasitemia or amastigote nests. Conversely, parasites from the Y and CL strains appeared able to escape the immune response, as evidenced by an inflammatory infiltrate and disseminated infection after immunosuppression.

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Recrudescence induced by cyclophosphamide of chronic Trypanosoma cruzi infection in mice is influenced by the parasite strain

Cited by 23 publications

References 10 publications

Transmission of Tropical and Geographically Restricted Infections during Solid-Organ Transplantation

Transmission of Tropical and Geographically Restricted Infections during Solid-Organ Transplantation

Immnunological Control of <i>Trypanosoma cruzi</i> Infection and Pathogenesis of Chagas’ Disease

Trypanosoma cruzi strains in the Calomys callosus: parasitemia and reaction of intracellular forms with stage-specific antibodies in the acute and chronic phase of infection and after immunosuppression

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