Allogeneic apoptotic thymocyte-stimulated dendritic cells expand functional regulatory T cells

P>Dendritic cells (DCs) play an important role in the clearance of apoptotic cells. The removal of apoptotic cells leads to peripheral tolerance, although their role is still not clear. We show that the uptake of apoptotic thymocytes by DCs converts these cells into tolerogenic DCs resistant to maturation by lipopolysaccharide, modulating the production of interleukin-12 and up-regulating the expression of transforming growth factor-beta(1) latency associated peptide. We also observed that DCs pulsed with apoptotic cells in the allogeneic context were more efficient in the expansion of regulatory T cells (Tregs), and that this expansion requires contact between DCs and the T cell. The Tregs sorted from in vitro culture suppressed the proliferation of splenocytes in vitro in a specific and non-specific manner. In the in vivo model, the transfer of CD4+ CD25- cells to Nude mice induced autoimmunity, with cell infiltrate found in the stomach, colon, liver and kidneys. The co-transfer of CD4+ CD25- and CD4+ CD25+ prevented the presence of cell infiltrates in several organs and increased the total cell count in lymph nodes. Our data indicate that apoptotic cells have an important role in peripheral tolerance via induction of tolerogenic DCs and CD4+ CD25+ Foxp3+ cells that present regulatory functions.

In vivo infection by Trypanosoma cruzi: The conserved FLY domain of the gp85/trans-sialidase family potentiates host infection

Trypanosoma cruzi is a protozoan parasite that infects vertebrates, causing in humans a pathological condition known as Chagas` disease. The infection of host cells by T. cruzi involves a vast collection of molecules, including a family of 85 kDa GPI-anchored glycoproteins belonging to the gp85/trans-sialidase superfamily, which contains a conserved cell-binding sequence (VTVXNVFLYNR) known as FLY, for short. Herein, it is shown that BALB/c mice administered with a single dose (1 mu g/animal, intraperitoneally) of FLY-synthetic peptide are more susceptible to infection by T. cruzi, with increased systemic parasitaemia (2-fold) and mortality. Higher tissue parasitism was observed in bladder (7.6-fold), heart (3-fold) and small intestine (3.6-fold). Moreover, an intense inflammatory response and increment of CD4(+) T cells (1.7-fold) were detected in the heart of FLY-primed and infected animals, with a 5-fold relative increase of CD4(+)CD25(+)FoxP3(+) T (Treg) cells. Mice treated with anti-CD25 antibodies prior to infection, showed a decrease in parasitaemia in the FLY model employed. In conclusion, the results suggest that FLY facilitates in vivo infection by T. cruzi and concurs with other factors to improve parasite survival to such an extent that might influence the progression of pathology in Chagas` disease.

Intranasal vaccination with proinsulin DNA induces regulatory CD4+ T cells that prevent experimental autoimmune diabetes

Insulin, an autoantigen in type 1 diabetes, when administered mucosally to diabetes-prone NOD mice induces regulatory T cells (T_reg) that protect against diabetes. Compared with protein, Ag encoded as DNA has potential advantages as a therapeutic agent. We found that intranasal vaccination of NOD mice with plasmid DNA encoding mouse proinsulin II-induced CD4⁺ T_reg that suppressed diabetes development, both after adoptive cotransfer with "diabetogenic" spleen cells and after transfer into NOD mice given cyclophosphamide to accelerate diabetes onset. In contrast to prototypic CD4⁺CD25⁺ T_reg, CD4⁺ T_reg induced by proinsulin DNA were both CD25⁺ and CD25^– and not defined by markers such as glucocorticoid-induced TNFR-related protein (GITR), CD103, or Foxp3. Intriguingly, despite induction of T_reg and reduced islet inflammation, diabetes incidence in proinsulin DNA-treated mice was unchanged. However, diabetes was prevented when DNA vaccination was performed under the cover of CD40 ligand blockade, known to prevent priming of CTL by mucosal Ag. Thus, intranasal vaccination with proinsulin DNA has therapeutic potential to prevent diabetes, as demonstrated by induction of protective T_reg, but further modifications are required to improve its efficacy, which could be compromised by concomitant induction of pathogenic immunity.

Effects of 60-day bed rest with and without exercise on cellular and humoral immunological parameters

Exercise at regular intervals is assumed to have a positive effect on immune functions. Conversely, after spaceflight and under simulated weightlessness (e.g., bed rest), immune functions can be suppressed. We aimed to assess the effects of simulated weightlessness (Second Berlin BedRest Study; BBR2-2) on immunological parameters and to investigate the effect of exercise (resistive exercise with and without vibration) on these changes. Twenty-four physically and mentally healthy male volunteers (20-45 years) performed resistive vibration exercise (n=7), resistance exercise without vibration (n=8) or no exercise (n=9) within 60 days of bed rest. Blood samples were taken 2 days before bed rest, on days 19 and 60 of bed rest. Composition of immune cells was analyzed by flow cytometry. Cytokines and neuroendocrine parameters were analyzed by Luminex technology and ELISA/RIA in plasma. General changes over time were identified by paired t-test, and exercise-dependent effects by pairwise repeated measurements (analysis of variance (ANOVA)). With all subjects pooled, the number of granulocytes, natural killer T cells, hematopoietic stem cells and CD45RA and CD25 co-expressing T cells increased and the number of monocytes decreased significantly during the study; the concentration of eotaxin decreased significantly. Different impacts of exercise were seen for lymphocytes, B cells, especially the IgD(+) subpopulation of B cells and the concentrations of IP-10, RANTES and DHEA-S. We conclude that prolonged bed rest significantly impacts immune cell populations and cytokine concentrations. Exercise was able to specifically influence different immunological parameters. In summary, our data fit the hypothesis of immunoprotection by exercise and may point toward even superior effects by resistive vibration exercise.Cellular & Molecular Immunology advance online publication, 10 November 2014; doi:10.1038/cmi.2014.106.

Ativação linfocitária durante a cirurgia de revascularização miocárdica : papel da circulação extracorpórea

Introdução: Sabe-se que a cirurgia de revascularização miocárdica está associada com alteração dos mediadores inflamatórios e da função imunitária, com ativação precoce dos linfócitos que poderia ser responsável pela linfopenia e diminuição da atividade dos linfócitos no pós-operatório. A elevação enzimática está diminuída na cirurgia sem circulação extracorpórea mas este achado não está associado a melhor evolução clínica. Nesta tese, testamos a hipótese de que a cirurgia de revascularização miocárdica realizada sem circulação extracorpórea pode levar a uma ativação linfocitária de menor intensidade do que a cirurgia com circulação extracorpórea. Métodos: A resposta da ativação linfocitária foi estudada durante o período trans e pósoperatório em 28 pacientes randomizados para cirurgia de coronária sem circulação extracorpórea (n=13) ou cirurgia convencional com circulação extracorpórea (n=15), utilizando citometria de fluxo para determinar a expressão de CD25, CD26, CD69 e DR em linfócitos T (CD3+) e B (CD19+), em sangue periférico. No mesmo período foram realizadas dosagens de troponina I por quimioluminescência e realizado ecocardiograma uni-bidimensional antes e após a cirurgia. Resultados: Não houve diferença estatisticamente significativa para nenhum dos marcadores de ativação linfocitária quando comparados os grupos operados sem ou com circulação extracorpórea (ANOVA bicaudal para medidas repetidas, p>0,05). Considerando todos os pacientes estudados, houve uma elevação da expressão proporcional de CD25 e CD69 em linfócitos T (CD3+) e B (CD19+). Nos linfócitos T, o valor proporcional médio mais elevado (+ EP) de CD69 foi observado 6 horas após terem sido completadas as anastomoses (+75 + 476%) e CD25 teve uma elevação mais gradual, com o pico de seu valor médio (+48 + 24 %) ocorrendo 24 horas após a revascularização. Em linfócitos B, o pico do valor médio de CD69 (+104 + 269 %) ocorreu também após o fim das anastomoses. CD25 teve seu pico de valor médio (+150 + 773 %) 112 horas após a revascularização e seu último valor medido ainda estava elevado. A expressão de CD26 em linfócitos T teve um aparente declínio nos seus valores proporcionais médios (-42 + 32 %) 12 horas após o fim das anastomoses. Não houve diferença significativa na elevação enzimática entre os dois grupos (teste estatístico >0,05). No ecocardiograma, o grupo operado sem circulação extracorpórea apresentou diminuição do volume diastólico (p=0,001) de da fração de ejeção (P=0,012), enquanto no grupo com circulação extracorpórea, diminuíram os volumes diastólico (p=0,006) e sistólico (p=0,01). Conclusões: 1) Comparando a cirurgia de revascularização miocárdica com circulação extracorpórea, a cirurgia sem circulação extracorpórea não reduz a ativação dos linfócitos. 2) A cirurgia de revascularização miocárdica produz uma ativação precoce dos linfócitos, com aumento da expressão de CD69 e CD25 em linfócitos T (CD3+) e B (CD19+), em sangue periférico. A elevação precoce de CD69, e elevação mais tardia de CD25, pode indicar duas partes de uma seqüência de ativação linfocitária. 3) O comportamento das enzimas cardíacas e dos achados ecocardiográficos não sugere benefício da cirurgia sem circulação extracorpórea sobre o dano miocárdio.

Perfil de memória e ativação de linfócitos T na leishmaniose visceral

Visceral leishmaniasis (VL) in Brazil is a disease caused by Leishmania infantum chagasi (L.i.chagasi). The clinical evolution post-infection depends on the vertebrate host immune response, which is genetically mediated. This study aimed to evaluate the immune response of individuals living in endemic area for VL in the state of the Rio Grande do Norte, considering individuals with VL under treatment (n = 9), recovered VL <1 year post treatment (n = 10), > 10 years posttreatment (n = 9), uninfected individuals living in endemic areas (n = 7), individuals that lost DTH response (n=6) and asymptomatic individuals for VL (n=9). Peripheral blood cells were evaluated in the presence and absence of soluble Leishmania antigens (SLA) and ex vivo, to determine activation, presence of regulatory cells and memory cells. The Leishmania parasitemia and anti-Leishmania antibodies were determined respectively by qPCR and ELISA. Cells from individuals with VL under treatment showed less cell activation after stimulation with SLA for the markers CD4/CD69, CD8/CD69 and CD8/CD25 compared with VL post treatment treatment (p <0.001). Apparently uninfected individuals have a higher cell activation than symptomatic VL (p <0.001), with the exception of CD8/CD25 marker (p = 0.6662). On the other hand, in the ex-vivo group, significant differences were observed for CD4/CD69, CD8/CD69 and CD8/CD25 between the 4 groups due to increased cell activation present in cells of individuals symptomatic LV (p <0.001). VL cells under treatment, ex vivo, have a lower percentage of memory cells (CD4/CD45RO and CD8/CD45RO) than individuals VL post-treatment or control group (p = <0.01). Likewise, individuals with symptomatic VL have fewer regulatory cells when stimulated by SLA [CD4/CD25 (p = 0.0022) and CD4/FOXP3 (p = 0.0016)] and in the ex-vivo group (p = 0.0017). Finally, DNA isolated from recovered VL contained Leishmania DNA, supporting the hypothesis of non-sterile clinical cure for Leishmania infection. Recovered VL, even 10 years after treatment have high levels of memory cells, which may be due to the presence of stimulation, either by reexposure to Leishmania or non-sterile cure

Estado nutricional e efeito da vitamina A na resposta imune frente à infecção por Leishmania Infantum

Nutritional status is an important determinant to the response against Leishmania infection, although few studies have characterized the molecular basis for the association found between malnutrition and the disease. Vitamin A supplementation has long been used in developing countries to prevent mortality by diarrheal and respiratory diseases, but there are no studies on the role of vitamin A in Leishmania infection, although we and others have found vitamin A deficiency in visceral Leishmaniasis (VL). Regulatory T cells are induced in vitro by vitamin A metabolites and are considered important cells implicated T CD4+ cell suppression in human VL. This work aimed to examine the correlation of nutritional status and the effect of vitamin A in the response against Leishmania infantum infection. A total of 179 children were studied: 31 had active VL, 33 VL history, 44 were DTH+ and 71 were DTH- and had negative antibody to Leishmania (DTH-/Ac-). Peripheral blood monuclear cells were isolated in a subgroup of 10 active VL and 16 DTH-/Ac- children and cultivated for 20h under 5 different conditions: 1) Medium, 2) Soluble promastigote L. infantum antigens (SLA), 3) All-trans retinoic acid (ATRA), 4) SLA + ATRA and 5) Concanavalin A. T CD4+CD25highFoxp3+, T CD4+CD25-Foxp3- and CD14+ monocytes were stained and studied by flow cytometry for IL-10, TGF-β and IL-17 production. Nutritional status was compromised in VL children, which presented lower BMI/Age and retinol concentrations when compared to healthy controls. We found a negative correlation between nutritional status (measured by BMI/Age and serum retinol) and anti-Leishmania antibodies and acute phase proteins. There was no correlation between nutritional status and parasite load. ATRA presented a dual effect in Treg cells and monocytes: In healthy children (DTH-/Ac-), it induced a regulatory response, increasing IL-10 and TGF-β production; in VL children it modulated the immune response, preventing increased IL-10 production after SLA stimulation. Furthermore, we found a positive correlation between BMI/Age and IL-17 production and negative correlation between serum retinol and IL-10 and TGF-β production in T CD4+CD25highFoxp3+ cells after SLA stimulus. Our results show a potential dual role of vitamin A in the immune system: improvement of regulatory profile during homeostasis and down modulation of IL-10 in Treg cells and monocytes during symptomatic VL. Therefore, the use of vitamin A concomitant to VL therapy might improve recovery from disease status in Leishmania infantum infection

Exogenous Administration of 15d-PGJ(2)-Loaded Nanocapsules Inhibits Bone Resorption in a Mouse Periodontitis Model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação dos parâmetros hematológicos e imunofenotípicos de pacientes com doenças linfoproliferativas crônicas no Rio Grande do Norte

Chronic lymphoproliferative disorders (DLPC) are lymphoid system diseases characterized by the abnormal proliferation of mature lymphocytes that affect B cells, T lymphocytes and NK cells. The aim of the study was to demonstrate the relevance of immunophenotyping by flow cytometry in patients with prolonged lymphocytosis and / or cytomorphological changes compatible with lymphoproliferative diseases. In this study 460 patients (244 men and 216 women) with DLPC were evaluated. Were analyzed by flow cytometry with a panel of monoclonal antibodies consisting of CD3, CD4, CD5, CD8, CD10, CD19, CD22, CD23, CD25, CD38, CD45, CD16/CD56, and HLADR heavy and light chains of immunoglobulins. It also examines information regarding age, gender of patients and laboratory data as leucocytes, cytomorphological analysis, platelet count and hemoglobin determination. The results showed 398 cases of chronic lymphoproliferative disorders and 62 of DLPC B cell lymphoproliferative diseases T. B showed the following distribution : 253 cases of chronic lymphocytic leukemia (CLL), 42 cases of multiple myeloma ( MM ), 37 cases of lymphoma non - Hodgkin lymphoma in leukemic phase (NHL) , 17 cases of pro- B lymphocytic leukemia ( B -PLL), 15 cases of mantle cell lymphoma (MCL ), 12 cases of plasma cell leukemia ( PCL), 9 cases of lymphoma Burkitt (Linf B), 8 cases of leukemia villous cells ( LCV), 3 cases of splenic lymphoma with villous cells (LECV), a case of follicular lymphoma (LF) and a Waldenströn macroglobulinemia ( MW). The diseases source NK / T were 23 cases of peripheral T cell lymphoma (LCTP), 14 cases of T prolymphocytic leukemia (T -PLL), 10 cases of leukemia T of large granular lymphocytes (LGL -T) 9 cases of leukemia cells of adult T (LCTA), 5 cases of Sezary syndrome (SS) and a case of large granular NK leukemia (LGL -NK) lymphocytes. In conclusion, the combined use of the monoclonal antibody panel careful cytomorphological analysis was shown to be essential in immune diagnosis and classification of chronic lymphoproliferative disorders. This study was approved by the IRB - HUOL under number 356 / 09

Perfil imuno-histoquímico do infiltrado inflamatório no front de invasão em carcicomas epidermóides de língua e lábio inferior

The progression of the oral squamous cells carcinomas (OSCCs) seems to suffer influence from related factors to the host, as local and systemic immunologic response, which are essential to the antineoplasic defenses. The purpose of this study was evaluate the local immunity in 30 tongue and 20 lower lip SCC by immunohistochemistry method, utilizing antibodies anti-CD3, CD4, -CD8, -CD25 e -ζ(zeta), which immunoexpressions were compared considering the anatomical localization, the intensity of the inflammatory infiltrate into the front of invasion and metastases. The CD4/CD8+ ratio was calculated for each case and associate with the mentioned variable, being the intensity of the inflammatory infiltrated also compared with the anatomical localization and metastase and for this the cases had been grouped in two categories: (n = 10) absent/scarce inflammatory infiltrate; and (n = 40) moderate/intense infiltrate. Fisher´s exact test was performed (α= 0.05) and it was not observed any significant correlation between these groups with anatomical sites and metastases. With regard to the immunoexpression, the CD3+, CD4+, CD8+ and CD25+ cells count was higher in the lower lip SCCs while the anti-ζimmunomarcation was more evident in the non metastatic cases. Through the statistical analyses, it was verified that the CD3 exhibited positive-significant correlation with the inflammatory infiltrate (p = 0.023). Furthermore, antibodies against CD8 and CD25 cells were also significantly correlated with the inflammatory infiltrate (p = 0.002 and 0.030, respectively) and with the anatomical site (p = 0.004 and p = 0.004) mainly in the lower lip SCCs. CD4/CD8 ratio did not show significant association with metastase nor with anatomical localization. We conclude that the inflammatory infiltrated of the Bryne s (1998) system did not constitute an indicator of aggressiveness in the tongue and lower lip SCCs analyzed and that clinical behavior of the SCCs studied was related in part to the immunohistochemical profile of infiltrated the inflammatory present in tumoral invasion front

Experimental autoimmune encephalomyelitis evolution was not modified by multiple infections with Strongyloides venezuelensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prevention of experimental diabetes by Uncaria tomentosa extract: Th2 polarization, regulatory T cell preservation or both?

Ethnopharmacological relevance: Uncaria tomentosa (Willd.) DC (Rubiaceae) is a species native to the Amazon rainforest and surrounding tropical areas that is endowed with immunomodulatory properties and widely used around the world. In this study we investigated the immunomodulatory potential of Uncaria tomentosa (UT) aqueous-ethanol extract on the progression of immune-mediated diabetes.Materials and methods: C57BL/6 male mice were injected with MLDS (40 mg/kg) and orally treated with UT at 10-400 mg/kg during 21 days. Control groups received MLDS alone or the respective dilution vehicle. Pancreatic mononuclear infiltrate and beta-cell insulin content were analyzed by HE and immunohistochemical staining, respectively, and measured by digital morphometry. Lymphocyte immunophenotyping and cytokine production were determined by flow cytometry analysis.Results: Treating the animals with 50-400 mg/kg of UT caused a significant reduction in the glycemic levels, as well as in the incidence of diabetes. The morphometric analysis of insulitis revealed a clear protective effect. Animals treated with UT at 400 mg/kg presented a higher number of intact islets and a significant inhibition of destructive insulitis. Furthermore, a significant protection against the loss of insulin-secreting presented beta-cells was achieved, as observed by a careful immunohistochemical evaluation. The phenotypic analysis indicated that the groups treated with higher doses (100-400 mg/kg) presented CD4(+) and CD8(+) T-cell values similar to those observed in healthy animals. These same higher doses also increased the number of CD4(+)CD25(+)Foxp3(+) regulatory T-cells. Moreover, the extract modulated the production of Th1 and Th2, with increased levels of IL-4 and IL-5.Conclusions: The extract was effective to prevent the progression of immune-mediated diabetes by distinct pathways. (C) 2011 Elsevier B.V. All rights reserved.

Immune modulation induced by tuberculosis DNA vaccine protects non-obese diabetic mice from diabetes progression

We have described previously the prophylactic and therapeutic effect of a DNA vaccine encoding the Mycobacterium leprae 65 kDa heat shock protein (DNA-HSP65) in experimental murine tuberculosis. However, the high homology of this protein to the corresponding mammalian 60 kDa heat shock protein (Hsp60), together with the CpG motifs in the plasmid vector, could trigger or exacerbate the development of autoimmune diseases. The non-obese diabetic (NOD) mouse develops insulin-dependent diabetes mellitus (IDDM) spontaneously as a consequence of an autoimmune process that leads to destruction of the insulin-producing beta cells of the pancreas. IDDM is characterized by increased T helper 1 (Th1) cell responses toward several autoantigens, including Hsp60, glutamic acid decarboxylase and insulin. In the present study, we evaluated the potential of DNA-HSP65 injection to modulate diabetes in NOD mice. Our results show that DNA-HSP65 or DNA empty vector had no diabetogenic effect and actually protected NOD mice against the development of severe diabetes. However, this effect was more pronounced in DNA-HSP65-injected mice. The protective effect of DNA-HSP65 injection was associated with a clear shift in the cellular infiltration pattern in the pancreas. This change included reduction of CD4(+) and CD8(+) T cells infiltration, appearance of CD25(+) cells influx and an increased staining for interleukin (IL)-10 in the islets. These results show that DNA-HSP65 can protect NOD mice against diabetes and can therefore be considered in the development of new immunotherapeutic strategies.

Caracterização da resposta imune celular pela expressão imunoistoquímica de CD4, CD8, CD28, CD152, CD56 e FOXP3 em carcinoma mamário de fêmeas caninas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)