RESUMEN
Although the semi-invariant natural killer T cells (iNKT) are a small subpopulation of cells in the peripheral blood, they are presumed to play a role in early stages of infection against various pathogens, including protozoa. This work investigates the activation status and cytokine profile of iNKT cells during human Leishmania infantum and Leishmania braziliensis infection. We studied iNKT cells in patients with symptomatic active visceral leishmaniasis (AVL) (n = 8), patients with symptomatic active cutaneous leishmaniasis (ACL) (n = 13), negative endemic controls (NEC) (n = 6) and non-endemic controls (NonEC) (n = 6), with and without total Leishmania antigen stimulus (TLA). The number of iNKT cells in the peripheral blood of patients with ACL and AVL unaltered in relation to control groups. Moreover, the iNKT cells from ACL showed a hyperactivation profile compared to patients with AVL. Additionally, TLA induced IFN-gamma production in iNKT cells from patients with ACL, while in iNKT of patients with AVL, TLA induced a decrease in this cytokine. Higher IL-17 and IL-10 production by iNKT cells from patients with ACL were also observed compared to all other groups. There were no changes in iNKT IL-10-producing cells in AVL after TLA stimulation. However, TLA induced increase in IL-10 in iNKT cells in patients with ACL. These findings suggest that, although iNKT cells showed distinct profiles in patients with ACL and AVL, they play a dual role in immune modulation in both Leishmania infections.
Asunto(s)
Plasticidad de la Célula/inmunología , Leishmania braziliensis/inmunología , Leishmania infantum/inmunología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Visceral/inmunología , Células T Asesinas Naturales/inmunología , Adulto , Antígenos de Protozoos/inmunología , Femenino , Humanos , Interferón gamma/inmunología , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Leishmaniasis Cutánea/parasitología , Leishmaniasis Visceral/parasitología , Activación de Linfocitos/inmunología , Recuento de Linfocitos , Masculino , Adulto JovenRESUMEN
Chagas disease was discovered more than a hundred years ago, but its pathogenesis is still not completely understood. Autoimmunity is one of the mechanisms shown to contribute to its pathogenesis, which may indicate an important participation of B lymphocytes. Patients with Chagas disease have shown increased percentage of B cells producing IL-10. However, there are no reports of the phenotypic markers of B cells producing IL-10 in patients with Chagas disease. For the first time in the literature, we evaluated the phenotypic profile of distinct markers of B cells from peripheral blood of noninfected individuals and patients with Chagas disease. Our results showed that patients with Chagas disease had a higher expression of CD21 and CD24 on the surface of CD19+ B cells, while CD43 and CD23 were expressed equally in all groups. Moreover, the expression of MHC-II (HLA-DR), CD80, CD86, caspase-3, granzyme B and intracellular IL-10 and TGF-ß by CD19+ B cells was higher in patients with Chagas disease. The results of IL-10 production within CD19+ CD5+ CD1d+ B cells showed a higher percentage of this cytokine in patients with Chagas disease. Thus, our data bring a new knowledge about distinct markers of B cells in immune responses of Chagas disease.
Asunto(s)
Linfocitos B/inmunología , Enfermedad de Chagas/inmunología , Adulto , Antígenos CD/análisis , Linfocitos B/metabolismo , Biomarcadores/análisis , Caspasa 3/metabolismo , Enfermedad de Chagas/metabolismo , Femenino , Antígenos HLA-DR/inmunología , Antígenos HLA-DR/metabolismo , Humanos , Inmunofenotipificación , Interleucina-10/biosíntesis , Interleucina-10/inmunología , Masculino , Persona de Mediana Edad , Factor de Crecimiento Transformador beta/metabolismo , Trypanosoma cruzi/inmunologíaRESUMEN
Leishmaniasis is an important tropical disease composed of several clinical forms that adversely affect millions of people globally. Critical cells involved in the host-Leishmania interaction are monocytes and macrophages, which act to protect against infections due to their ability to both control intracellular infections and regulate the subsequent adaptive immune response. Both soluble factors and cell surface receptors are keys in directing the immune response following interaction with pathogens such as Leishmania. Toll-like receptors (TLRs) have an essential role in immune responses against infections, but little is known about their role in human infection with Leishmania braziliensis. In this work, we evaluated peripheral blood CD14+ monocytes for the expression of immunoregulatory cytokines, co-stimulatory molecules and TLR9 from cutaneous leishmaniasis patients infected with L. braziliensis and noninfected individuals. Our results showed that patients present decreased expression of co-stimulatory molecules such as CD80 and CD86 following culture with media alone or after stimulus with soluble Leishmania antigen. Interestingly, TLR9 expression was higher after culture with soluble Leishmania antigen (SLA), suggesting a role of this molecule in immunoregulation of active disease. Lastly, higher frequencies of TLR9+ monocytes were correlated with greater lesion size. These findings demonstrate a peripheral monocytes profile compatible with important immunoregulatory potential.
Asunto(s)
Leishmania braziliensis/inmunología , Leishmaniasis Cutánea/inmunología , Leucocitos Mononucleares/inmunología , Monocitos/inmunología , Receptor Toll-Like 9/inmunología , Inmunidad Adaptativa/inmunología , Adolescente , Adulto , Antígenos de Protozoos/inmunología , Antígeno B7-1/sangre , Antígeno B7-2/sangre , Antígenos CD40/sangre , Citocinas/sangre , Citometría de Flujo , Humanos , Leishmaniasis Cutánea/sangre , Leishmaniasis Cutánea/parasitología , Leishmaniasis Cutánea/patología , Leucocitos Mononucleares/patología , Persona de Mediana Edad , Monocitos/parasitología , Receptor Toll-Like 9/sangre , Adulto JovenRESUMEN
Immunoregulatory mechanisms are important to control the intense immune activity induced in Chagas disease. We evaluated the phenotypic profile and the mechanisms by which Treg cells function in patients with the indeterminate (IND) and cardiac (CARD) clinical forms of Chagas disease. The frequency of Foxp3(+)CD25(high) CD4(+)-T cells is augmented and correlated with the maintenance of a better cardiac function in IND. Treg cells from IND present suppressive activity, although the mechanism is not IL-10 or CTLA-4 dependent and are able to produce augmented levels of IL-17, IL-10 and granzyme B being its frequency correlated with percentage of Annexin V(+) CD4(+)-cells. In contrast, CARD presents higher frequency of IL-6(+), IFN-gamma(+), TNF-alpha(+) and CTLA-4(+) Treg-cells than IND. Thus, our data suggest that Treg cells have an important role in controlling the exacerbated immune response and morbidity in Trypanosoma cruzi infection, probably modulating the cytokine environment and/or killing effector cells.
Asunto(s)
Enfermedad de Chagas/inmunología , Citocinas/inmunología , Factores de Transcripción Forkhead/inmunología , Subunidad alfa del Receptor de Interleucina-2/inmunología , Linfocitos T Reguladores/inmunología , Adulto , Anciano , Antígeno CTLA-4/inmunología , Antígeno CTLA-4/metabolismo , Proliferación Celular , Células Cultivadas , Enfermedad de Chagas/metabolismo , Enfermedad de Chagas/parasitología , Citocinas/metabolismo , Ecocardiografía , Citometría de Flujo , Factores de Transcripción Forkhead/metabolismo , Pruebas de Función Cardíaca , Humanos , Interferón gamma/inmunología , Interferón gamma/metabolismo , Interleucina-10/inmunología , Interleucina-10/metabolismo , Interleucina-17/inmunología , Interleucina-17/metabolismo , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Interleucina-6/inmunología , Interleucina-6/metabolismo , Recuento de Linfocitos , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Linfocitos T Reguladores/metabolismo , Trypanosoma cruzi/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Although the pathophysiology of Chagas disease is not completely understood, it is widely accepted that involvement of the immune response is critical in determining the outcome of the disease. In this context, CD4⺠T cells may play an important role in generating different mechanisms of protection. In addition to effector and regulatory functions, CD4⺠T cells may be also involved with lytic activities against the parasite and may have a relevant role on control of the infection. In this study, we have evaluated CD4⺠T cells expressing cytotoxic and apoptosis markers in response to Trypanossoma cruzi infection in indeterminate (IND) and cardiac (CARD) patients with Chagas disease and non-infected individuals (NI). Our data demonstrated that: (1) CD4⺠T cells presented higher ex vivo granzyme B expression in patients with Chagas disease compared with healthy individuals and that antigen induced a greater granzyme B expression in IND patients; (2) CD95L expression in CD4⺠CD95⺠T cells from IND patients is higher than in CARD and NI; (3) IND and CARD patients had an increased frequency of caspase-3 after in vitro stimulation and also expressed a high frequency of annexinV⺠7ADD⺠within CD4⺠T cells; (4) Lastly, a positive correlation was seen between cytotoxic molecules and CD45RO memory marker in CD4⺠T cells and between caspase-3 and CD95L within CD4⺠CD95⺠T cells. These results suggest new insights into the functional competence of CD4⺠T cells among the different clinical forms of Chagas disease, which will lead to a better understanding of their influence during immune responses against T. cruzi.
Asunto(s)
Apoptosis/inmunología , Linfocitos T CD4-Positivos/inmunología , Enfermedad de Chagas/inmunología , Subgrupos de Linfocitos T/inmunología , Adulto , Anciano , Animales , Biomarcadores/análisis , Linfocitos T CD4-Positivos/metabolismo , Enfermedad de Chagas/complicaciones , Enfermedad de Chagas/metabolismo , Citotoxicidad Inmunológica/inmunología , Femenino , Citometría de Flujo , Granzimas/inmunología , Granzimas/metabolismo , Cardiopatías/etiología , Cardiopatías/inmunología , Humanos , Proteína 1 de la Membrana Asociada a los Lisosomas/inmunología , Proteína 1 de la Membrana Asociada a los Lisosomas/metabolismo , Masculino , Persona de Mediana Edad , Subgrupos de Linfocitos T/metabolismo , Trypanosoma cruzi/inmunologíaRESUMEN
Leishmaniasis is caused by infection with the protozoan parasite, Leishmania, that parasitizes human cells, and the cellular immune response is essential for controlling infection. In order to measure the host T cell response to Leishmania infection, we have measured the expansion, activation state and functional potential of specific T cells as identified by their T cell receptor Vß region expression. In a group of cutaneous leishmaniasis (CL) patients, we evaluated these characteristics in nine different T cell subpopulations as identified by their Vß region expression, before and after specific Leishmania antigen stimulation. Our results show: (1) an increase in CD4(+) T cells expressing Vß 5·2 and Vß 24 in CL compared to controls; (2) a Leishmania antigen-induced increase in CD4(+) T cells expressing Vß 5·2, 11, 12 and 17; (3) a profile of previous activation of CD4(+) Vß 5·2-, 11- and 24-positive T cells, with higher expression of CD45RO, HLA-DR, interferon-γ, tumour necrosis factor-α and interleukin-10 compared to other Vß-expressing subpopulations; (4) a positive correlation between higher frequencies of CD4(+) Vß5·2(+) T cells and larger lesions; and (5) biased homing of CD4(+) T cells expressing Vß 5·2 to the lesion site. Given that CL disease involves a level of pathology (ulcerated lesions) and is often followed by long-lived protection and cure, the identification of specific subpopulations active in this form of disease could allow for the discovery of immunodominant Leishmania antigens important for triggering efficient host responses against the parasite, or identify cell populations most involved in pathology.