Control of lupus activity during pregnancy via the engagement of IgG sialylation: novel crosstalk between IgG sialylation and pDC functions / 医学前沿

Immunoglobulin (IgG) glycosylation affects the effector functions of IgG in a myriad of biological processes and has been closely associated with numerous autoimmune diseases, including systemic lupus erythematosus (SLE), thus underlining the pathogenic role of glycosylation aberration in autoimmunity. This study aims to explore the relationship between IgG sialylation patterns and lupus pregnancy. Relative to that in serum samples from the control cohort, IgG sialylation level was aberrantly downregulated in serum samples from the SLE cohort at four stages (from preconception to the third trimester of pregnancy) and was significantly associated with lupus activity and fetal loss during lupus pregnancy. The type I interferon signature of pregnant patients with SLE was negatively correlated with the level of IgG sialylation. The lack of sialylation dampened the ability of IgG to suppress the functions of plasmacytoid dendritic cells (pDCs). RNA-seq analysis further revealed that the expression of genes associated with the spleen tyrosine kinase (SYK) signaling pathway significantly differed between IgG- and deSia-IgG-treated pDCs. This finding was confirmed by the attenuation of the ability to phosphorylate SYK and BLNK in deSia-IgG. Finally, the coculture of pDCs isolated from pregnant patients with SLE with IgG/deSia-IgG demonstrated the sialylation-dependent anti-inflammatory function of IgG. Our findings suggested that IgG influences lupus activity through regulating pDCs function via the modulation of the SYK pathway in a sialic acid-dependent manner.

Different distribution patterns of plasmacytoid dendritic cells in discoid lupus erythematosus and lichen planopilaris demonstrated by CD123 immunostaining

Abstract Background: Clinical and histological features may overlap between lichen planopilaris-associated and discoid lupus erythematosus-associated scarring alopecia. Objectives: The aim of this study was to demonstrate the cutaneous infiltration of plasmacytoid dendritic cells and to compare their distribution pattern in discoid lupus erythematosus and lichen planopilaris. Methods: Twenty-four cases of discoid lupus erythematosus and 30 cases of lichen planopilaris were examined for immunostaining of the CD123 marker. The percentage and distribution pattern of plasmacytoid dendritic cells and the presence of the plasmacytoid dendritic cells clusters were evaluted in the samples. Results: The number of plasmacytoid dendritic cells was higher in the discoid lupus erythematosus specimens. Aggregations of 10 cells or more (large cluster) were observed in half of the discoid lupus erythematosus specimens and only 2 lichen planopilaris, with 50% sensitivity and 93% specificity for differentiating discoid lupus erythematosus from lichen planopilaris. Study limitations: Incidence and prevalence of discoid lupus erythematosus-associated scarring alopecia in the scalp are low, so the samples size of our study was small. Conclusions: We suggest that a plasmacytoid dendritic cells cluster of 10 cells or more is highly specific for distinguishing discoid lupus erythematosus from lichen planopilaris. It also appears that CD123 immunolabeling is valuable in both active and late stages of the disease.

Aspects of Langerhans cells and TNF-α in the cutaneous immunity of anogenital warts

Abstract Background: Anogenital warts are the leading sexually transmitted infection in patients seeking care at specialized clinics. They may display a vast array of forms, according to the interaction of the virus with the host's immunity. Cellular immunity is the epithelium's main form of defense against the virus, involving an active participation of the Langerhans cells and pro-inflammatory cytokines such as TNF-α. Objective: To assess the epithelial immune response of anogenital warts in males, according to the number of lesions presented. Methods: This is a prospective, cross-sectional study carried out at the dermatology outpatient clinic in a tertiary hospital. We included male patients over 18 years of age without comorbidities who had anogenital condylomata and no previous treatments.In order to evaluate the local epithelial immunity, the lesions were quantified, then removed and employed in CD1a immunohistochemistry assays for assessing the morphometry and morphology of Langerhans cells; TNF-α; reaction was used for determining cytokine positivity in the epithelium. Results: 48 patients were included in the study. There was no statistically significant difference as to the number of Langerhans cells, in their morphology, or the presence of TNF-α. However, patients presenting with more Langerhans cells in the lesions had cells with a star-like and dendritic morphology, whereas in those with a lower cell count had cells with a rounded morphology and no dendrites (p < 0.001). Study limitations: Small number of patients analyzed. Conclusion: There was no difference in epithelial immunity between patients having few or many anogenital condyloma lesions as measured by the morphology and morphometry of Langerhans cells and TNF-α; positivity. Such an assessment employing immunity markers differing from the usual ones is expected to yield useful results.

Análise de células dendríticas, mastócitos e vascularização na doença periodontal biofilme induzida em idosos / Analysis of dendritic cells, mast cells and vasculature in biofilm-induced periodontal disease in the elderly

A microbiota e o sistema imune do idoso apresentam algumas alterações, favorecendo ao aparecimento de infecções e doenças inflamatórias. A doença periodontal é um exemplo, permeando entre fase imediata e tardia, pode ter alterações em sua evolução com o envelhecimento humano. Compreender a doença periodontal e sua relação com o ciclo da vida é importante para a prevenção, tratamento e cura. Este estudo tem como objetivo avaliar a quantidade de mastócitos (triptase), células dendríticas imaturas (CD1a), células dendríticas maduras (CD83) e vasos sanguíneos (CD34) em 154 tecidos periodontais saudáveis e doentes (27 idosos e 127 adultos). Foi utilizada a técnica de imunoistoquímica através da imunomarcação do CD1a, CD83, triptase e CD34, sendo contabilizados em 5 campos de maior número de células positivas, no aumento de 1000x. Para o CD34, ainda foram calculadas a área e o perímetro microvascular para todos os vasos sanguíneos presentes, e dos vasos com presença do endotélio vascular alto. Não houve diferença na imunomarcação das células dendríticas, dos mastócitos e na quantidade de vasos sanguíneos nos tecidos gengivais, entre os casos de gengiva clinicamente saudável, gengivite induzida por biofilme e periodontite estágios II, III e IV, avaliando isoladamente os grupos etários: adultos e idosos. As células dendríticas imaturas são mais numerosas no idoso com o quadro clínico de gengivite e periodontite. Os adultos com gengivite induzida por biofilme possuem maior quantidade de vasos sanguíneos que o grupo idoso. A área microvascular e o perímetro microvascular dos vasos sanguíneos com o endotélio vascular alto apresentaram maiores nos idosos nos casos de gengivite. Este estudo concluiu que nesta amostra não houve diferença na quantidade de células dendríticas imaturas e maduras, mastócitos na doença periodontal dentro dos grupos etário, porém as células dendríticas imaturas estão mais presentes no idoso podendo estar relacionado a algum decréscimo funcional. Em relação aos vasos sanguíneos, há presença de HEVs em adultos e idosos, não havendo diferença entre os diagnósticos. Nos idosos com gengivite há um aumento da área microvascular e perímetro microvascular, necessitando de estudos que justifiquem esta diferença (AU).

The elderly's microbiota and immune system show some changes, favoring the onset of infections and inflammatory diseases. Periodontal disease is an example, permeating between immediate and adaptative stages, it can have changes in its evolution with human aging. Understanding periodontal disease and its relationship with the life cycle is important for prevention, treatment and cure. This study aims to assess the amount of mast cells (tryptase), immature dendritic cells (CD1a), mature dendritic cells (CD83) and blood vessels (CD34) in 154 healthy and sick periodontal tissues (27 elderly and 127 adults). The immunohistochemistry technique was used through the immunostaining of CD1a, CD83, tryptase and CD34, being counted in 5 fields with a greater number of positive cells, in the 1000x increase. For CD34, the microvascular area and perimeter were also calculated for all blood vessels present, and for vessels with the presence of high vascular endothelium. There was no difference in the immunostaining of dendritic cells, mast cells and the amount of blood vessels in the gingival tissues, between cases of clinically healthy gingiva, biofilm-induced gingivitis and stages II, III and IV periodontitis, evaluating the age groups: adults and elderly. Immature dendritic cells are more numerous in the elderly with the clinical picture of gingivitis and periodontitis. Adults with biofilm-induced gingivitis have a greater amount of blood vessels than the elderly group. The microvascular area and the microvascular perimeter of the blood vessels with the high vascular endothelium were larger in the elderly in cases of gingivitis. This study concluded that in this sample there was no difference in the amount of immature and mature dendritic cells, mast cells in periodontal disease within the age groups, however, immature dendritic cells are more present in the elderly and may be related to some functional decrease. Regarding blood vessels, there are HEVs in adults and the elderly, with no difference between diagnoses. In the elderly with gingivitis there is an increase in the microvascular area and microvascular perimeter, requiring studies that justify this difference (AU).

Melanoacanthoma: a potential pitfall of reflectance confocal microscopy

Abstract Melanoacanthoma is a rare variant of seborrheic keratosis, which is notable for dark pigmentation and fast radial growth, making it difficult to distinguish from melanoma. Histologically, it is characterized by proliferation of keratinocytes and dendritic melanocytes. The authors report a scalp lesion, fast growing, suspected by dermoscopy and confocal microscopy examination, with dendritic cells distributed throughout the lesion. Based on these findings, it was not possible to classify this lesion as clearly benign, so it was excised. Histopathologic evaluation and immunostain were consistent with melanoacanthoma.

Neoplasia blástica de células dendríticas plasmocitoides variante leucemia aguda: reporte de un caso / Blastic plasmacytoid dendritic cell neoplasm variant acute leukemia: case report

RESUMEN La neoplasia blástica de células dendríticas plasmocitoides (NBCDP) es una malignidad hematológica poco frecuente y generalmente agresiva, por lo cual se requiere su reconocimiento precoz. A continuación, se describe el curso clínico prolongado de un paciente masculino de 60 años con NBCDP procedente de Venezuela, en cuyos hallazgos más relevantes destacó la presencia de lesiones cutáneas, organomegalias, infiltración de la médula ósea y del sistema nervioso central. Posterior al diagnóstico se indicó quimioterapia sistémica, no obstante, el paciente falleció por complicaciones respiratorias durante la fase de inducción del tratamiento. En esta enfermedad es necesario establecer el diagnóstico diferencial con trastornos linfoproliferativos, leucemias linfoides y mieloides agudas, constituyendo el análisis morfológico de las células neoplásicas un aspecto importante para una adecuada orientación diagnóstica.

ABSTRACT Blastic plasmacytoid dendritic cell blast neoplasm (BPDCN) is a rare and generally aggressive hematologic malignancy, requiring early recognition. Below is a description of the prolonged clinical course of a 60-year-old male patient with BPDCN from Venezuela, whose most relevant findings highlighted the presence of skin lesions, organomegaly, infiltration of the bone marrow and central nervous system. Systemic chemotherapy was prescribed after diagnosis; however, the patient died of respiratory complications during the induction phase of treatment. In this disease, it is necessary to establish the differential diagnosis with lymphoproliferative disorders, acute lymphoid and myeloid leukemias. The morphological analysis of neoplastic cells is, thus, an important aspect toward proper diagnostic guidance.

Dendritic cells and their relation to apical peridontitis

Abstract: The purpose of this manuscript was to re-discuss apical periodontitis, apical biofilm, and its possible relationship with dendritic cells (DC). DCs are potent regulators of the immune system and their function is divided into three categories that involve the presentation of antigens: the presentation of antigens and activation of T cells; a not well established category suggested that DCs induce and maintain immunological tolerance; and the maintenance of the immune memory in conjunction with B cells. DCs in periapical inflammatory lesions are composed of at least two subpopulations that can be distinguished on the basis of ultrastructure and phenotype. These populations might differ in lineage, state of maturation, differentiation, activation, and/or function. The authors hereby analyzed the root apexes of teeth under SEM, after performing apicoectomy due to the failure of conventional endodontic treatment. Microbial biofilm with multispecies and areas of resorption with the presence of Howship lacunae, and images suggestive of denditric cells could be observed. The presence of DCs in periapical lesion could be an indication of the severity of the lesion, with a constant presence of antigen in the periradicular region.

Neoplasia blástica de células dendríticas plasmocitoides: casos clínicos / Blastic plasmacytoid dendritic cell neoplasm: report of three cases

Blastic plasmacytoid dendritic cell neoplasm is a rare hematological malignancy derived from immature plasmacytoid dendritic cells. The tumor cells have an immature blastic appearance, and diagnosis is based on the expression of CD4, CD56 y CD123 in the absence of other lymphoid, natural killer, or myeloid antigens. The majority of affected individuals are older people with a mean age of 66 years. Male to female ratio is approximately 3:1. Common presentation includes cutaneous lesions followed by tumor dissemination. Treatment with conventional chemotherapy is ineffective and allogeneic hematopoietic stem cell transplantation is required to achieve remission. We report three male patients, aged 23, 27 and 51 years with the disease. All had multiple, infiltrated pink plaques and nodules on the skin of their face, neck and thorax, measuring 1 to 12 cm in diameter. All tumors were histologically characterized by a monotonous proliferation of medium size cells with blastic features. Tumor cells were positive for CD123, CD56, CD4 and CD7 in all cases. After a mean of follow-up of 14.6 months, one patient died of the disease, one patient is alive and the disease relapsed after 17 months of remission and one patient is alive with no evidence of the disease.

Neoplasia de células dendríticas plasmocitoides blásticas con respuesta inicial a quimioterapia y recaída en sistema nervioso central: caso clínico / Blastic plasmacytoid dendritic cell neoplasm with complete clinical remission with chemotherapy and central nervous system relapse: report of one case

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, clinically aggressive hematologic malignancy that most commonly manifests as cutaneous lesions with or without bone marrow involvement and leukemic dissemination. The demonstration of tumor cells with the characteristic immunophenotype with expression of CD56, generally CD4 and dendritic cell antigens (CD123, cyTCL-1, HLA-DR), in the absence of myeloid or lymphoid lineage markers is required for the diagnosis. Responses to chemotherapy are initially satisfactory, with frequent systemic and central nervous system relapses. We report a 24 year-old male with BPDCN, initially diagnosed and treated as non-Hodgkin CD4+ T-cell lymphoma, with initial complete remission who evolved with early central nervous system relapse. A second attempt of chemotherapy failed and the patient died two months later.

Neoplasia blástica de células dendríticas plasmocitoides: reporte de un caso y revisión de la literatura / Plasmacytoid dendritic cell blast neoplasia: case report and literature review

La neoplasia de células blásticas plasmocitoides dendríticas esun linfoma cutáneo poco frecuente y de mal pronóstico, que característicamenteexpresa antígenos CD4 y CD56. Clínicamentepresenta placas o nódulos de coloración violácea, únicos o múltiples.El diagnóstico se confirma con el estudio anatomopatológicoque evidencia células linfoblástica y fenotipo CD4+ y CD56+, conausencia de marcadores para células mieloides, linfoides B y T ycélulas NK. Presentamos el reporte de un caso de un paciente desexo masculino de 65 años de edad y una revisión de la literatura.

Blastic plasmacytoid dendritic cell neoplasm is a rare andhighly aggressive cutaneous lymphoma that characteristicallyexpress CD4 and CD56 antigens. Clinically presents violet colouredplaques or nodules, in a unique or multiple presentation.The diagnosis is confirmed with the anatomophatologic studythat evidence linfoblastic cells with CD4+ and CD56+ phenotype,and no mieloids, linfoids B and T and natural killers cellsmarkers. We present a case report of a 65-years-old male anda literature review.

Estudo da interação entre neutrófilos, células dendríticas humanas e L. braziliensis / Study of the interaction between neutrophils, human dendritic cells and L. braziliensis

Os neutrófilos são essenciais para a resposta imune inata contra uma variedade de patógenos. Eles são capazes de modular a resposta imune através da produção de citocinas e quimiocinas, degranulação e a sua interação direta com outras células no local da infecção, tais como as células dendríticas. A interação entre as células do sistema imune inato é essencial para direcionar a resposta imune adaptativa, a qual é responsável pela eliminação de microrganismos e manutenção de memória imunológica. Objetivo: Este estudo avaliou a interação de neutrófilos humanos com Leishmania braziliensis, através da análise da expressão de moléculas de superfície, liberação de enzimas presentes nos grânulos e produção de espécies reativas de oxigênio (ROS). Também foi avaliada a interação entre neutrófilos humanos infectados e células dendríticas, a fim de se observar o efeito desta interação na indução da ativação das células dendríticas. Metodologia: Os neutrófilos foram purificados a partir do sangue periférico de doadores saudáveis e as células dendríticas foram geradas in vitro. Os neutrófilos foram infectados ou não com L. braziliensis e co-cultivados com as células dendríticas. Em seguida, os sobrenadantes e as células foram coletadas para avaliar a liberação de enzimas, tais como mieloperoxidase (MPO) e metaloproteinase 9 (MMP-9). O fenótipo e a função dos neutrófilos foram analisados através da expressão de Mac-1 (CD18 e CD11b), CD16, CD62-L e produção de ROS...

Neutrophils are essential in the innate immune response against a variety of pathogens. They are able to modulate immune response by cytokine and chemokine production, release of granules and their direct interaction with other cells at the infection site. Dendritic cells are recruited in response to cytokines and chemokines produced by neutrophils. The interaction between cells of the innate immune system is essential for targeting the adaptive immune response, which is responsible for eliminating microorganisms and the maintenance of immunological memory. Objective: Evaluate the interaction of human neutrophils with Leishmania braziliensis, through the analysis of surface molecule expression, release of granules enzymes and production of reactive oxygen species (ROS). We also evaluated the interaction between human infected neutrophils and dendritic cells, in order to observe the effect of this interaction on dendritic cells. Methodology: Neutrophils were purified from peripheral blood of healthy donors and dendritic cells were generated in vitro. Neutrophils were infected or not with L. braziliensis and cocultured with DC. Afterwards, supernatants and cells were harvested to evaluate the release of granules enzymes, such as myeloperoxidase (MPO) and metalloproteinase 9 (MMP-9). Neutrophils phenotype and function were analyzed by the expression of Mac-1 (CD18 and CD11b), CD16 and ROS production...

Oral chronic graft-versus-host disease: analysis of dendritic cells subpopulations

The graft-versus-host disease is the major cause of morbidity and mortality in patients who have undergone hematopoietic stem cell transplantation. Aiming at contributing to the understanding of the role of myeloid and plasmacytoid dendritic cells, and natural killer cells in chronic graft-versus-host disease, we examined biopsies of jugal mucosa of 26 patients with acute myeloid leukemia who had undergone allogenic hematopoietic stem cell transplantation. Half of these patients developed oral chronic graft-versus-host disease. Microscopic sections were immunohistochemically stained for anti-CD1a, anti-CD123 and anti-CD56. We calculated the number of immunostained cells in the corium per square millimeter and applied the Mann-Whitney test. Results showed a statistically significant increase of myeloid dendritic cells (CD1a+; p=0,02) and natural killer cells (CD56; p=0,04) in patients with oral chronic graft-versus-host disease. CD123 immunostaining showed no statistical difference between groups. It was concluded that myeloid dendritic cells and natural killer cells participate in the development of oral chronic graft-versus-host disease.

Neoplasia de células dentríticas plasmocitoides blásticas y lepra. ¿Asociación o coincidencia? / Blastic plasmacytoid dentritic cell neoplasm and leprosy. Association or coincidence?

La neoplasia de células dendríticas plasmocitoides blásticas es una entidad de baja incidencia originada en las células precursoras de las células dendríticas plasmocitoides o tipo2, anteriormente llamada linfoma de células blásticas NK. Afecta principalmente a adultos entre la quinta y séptima década de la vida, aunque hay casos descritos en niños y adolescentes.Presentamos un paciente masculino de 87 años con este diagnóstico, quienademás presentó baciloscopia intensamente positiva para bacilos de Mycobacterium lepraecon una mejoría importante de las lesiones al instaurar tratamiento para lepra multibacilar...

Redução da inflamação das vias aéreas e da produção de anticorpos IgEatravés do uso de células dendríticas tolerogênicas pulsadas com extrato solúvel de Blomia tropicalis / Reduction in airway inflammation and the production of IgE antibodies through the use of tolerogenic dendritic cells pulsed with soluble extracts of Blomia tropicalis

As alergias afetam cerca de 20 a 30% da população mundial e sua prevalência, bem como a gravidade dos sintomas, tem aumentado nas últimas décadas. As terapias existentes para as desordens do trato respiratório ocorrem por períodos prolongados, apresentam efeitos colaterais, muitas vezes não são efetivas para pacientes graves e dependem do afastamento do alérgeno. Uma alternativa para esses pacientes seria a indução de tolerância imunológica, através da terapia celular com células dendríticas pulsadas com o alérgeno. O presente trabalho objetivou avaliar o efeito de células dendríticas mielóides sensibilizadas in vitro com extrato de B. tropicalis em modelo murino de alergia respiratória. Em modelos experimentais de alergia respiratória, células T auxiliares (Th2)...

Allergies affect about 20-30% of world population and its prevalence and severity of symptoms has increased in recent decades. Existing therapies to respiratory tract disorders are extense, with side effects, not effective for severe patients and depending on the allergen removal. An alternative for these patients is the induction of immune tolerance by cell therapy with dendritic cells pulsed with the allergen. This study aimed to evaluate the effect of myeloid dendritic cells sensitized in vitro with B. tropicalis extract in a murine model of respiratory allergy. In experimental models of respiratory allergy, T helper cells (Th2)...

Blastic plasmacytoid dendritic cell neoplasm / Neoplasia blastica de celulas dendriticas plasmocitoides

Blastic plasmacytoid dendritic cell neoplasm is a rare and aggressive hematodermic neoplasia with frequent cutaneous involvement and leukemic dissemination. We report the case of a 76-year-old man with a 2 month history of violaceous nodules and a tumor with stony consistency, located on the head, and mandibular, cervical and supraclavicular lymphadenopathies. Multiple thoracic and abdominal adenopathies were identified on computerized tomography. Flow cytometry analysis of the skin, lymph node and bone marrow biopsies demonstrated the presence of plasmocytoid dendritic cell neoplastic precursor cells (CD4+, CD45+, CD56+ and CD123+ phenotype). After initial clinical and laboratorial complete remission with chemotherapy, the patient died due to relapse of the disease associated with the appearance of a cervical mass with medullary compromise.

A neoplasia blástica de células dendríticas plasmocitóides é uma neoplasia hematodérmica rara, agressiva, com frequente envolvimento cutâneo e disseminação leucêmica. Relatamos o caso de um homem de 76 anos com quadro clínico com 2 meses de evolução caracterizado por nódulos e tumor de tonalidade violácea, de consistência pétrea, localizados na cabeça, e linfadenopatias mandibular, cervicais e supraclaviculares. Identificaram-se múltiplas adenopatias torácicas e abdominais em tomografia computorizada. A análise por citometria de fluxo de biópsias cutânea, ganglionar e óssea demonstrou a presença de precursores neoplásicos das células dendríticas plasmocitóides (fenótipo CD4+, CD45+, CD56+ e CD123+). Após remissão clínica e laboratorial completa inicial com quimioterapia, veio a falecer por recaída da doença associada ao aparecimento de massa cervical com compromisso medular.

Case for diagnosis / Caso para diagnostico

The chondroid syringoma is a rare benign tumor, also called mixed cutaneous tumor by the presence of epithelial and mesenchymal components, consisting of sweat elements in cartilaginous, collagenous, myxoid or osseous stroma, among others. It mainly affects middle-aged men and is characterized by asymptomatic and slowgrowing, dermal or subcutaneous nodules. The most common locations are the head and neck. It is rare on the extremities. There are reports of malignant variants predominantly in women, located on the extremities. We report a case of a female patient with a lesion on the toe, with excellent outcome after surgical treatment.

O siringoma condroide é um tumor benigno, raro, também chamado de tumor misto cutâneo pela presença de componentes epiteliais e mesenquimais, que consistem em elementos sudoríparos em estroma cartilaginoso, colagênico, mixoide ou ósseo, entre outros. Acomete, principalmente, homens de meia-idade e caracteriza-se por nódulos subcutâneos ou dérmicos, assintomáticos e com crescimento lento. As localizações preferenciais são a cabeça e o pescoço, sendo raro nas extremidades. Existem relatos de variantes malignas, com predomínio em mulheres, localizadas nas extremidades. Relatamos um caso em paciente do sexo feminino, com lesão em extremidade e excelente resultado após o tratamento cirúrgico.

Presença de células dendríticas ativadas e das células T CD4+CD25hi na miocardite aguda e crônica da doença de chagas, em camundongos de linhagens resistente e susceptível / Presence of activated dendritic cells and CD4 + CD25hi T cells in acute and chronic myocarditis of Chagas disease in mice resistant and susceptible strains

A doença de Chagas é caracterizada por apresentar duas fases com curso clínico bastante variável. Na fase aguda ocorre uma intensa miocardite, sendo o parasita facilmente detectado no sangue periférico e nos tecidos. A fase crônica cardíaca é caracterizada por uma cardiopatia, com intensa destruição das fibras cardíacas, presença de áreas de fibrose e escassos parasitas. Os mecanismos envolvidos na patogenia dessa miocardite ainda não são muito claros. Acredita-se que as células reguladoras e as células dendríticas estejam envolvidas nesse processo. Para compreender os mecanismos envolvidos, na resposta inflamatória à infecção pelo T. cruzi, resolvemos investigar a participação das células dendríticas, das células reguladoras e o perfil dos linfócitos T CD4+ e CD8+, utilizando duas linhagens de camundongos isogênicos, que apresentam diferentes graus de susceptibilidade a infecção. Em nossos resultados constatamos que os camundongos DBA/1 apresentaram maior sobrevida à fase aguda (90%), mesmo tratando os camundongos A (70%) com benzonidazol por três dias consecutivos, com o intuito de diminuir a carga parasitária prevenindo a alta mortalidade. A resistência dos DBA/1 e a susceptibilidade dos A, a infecção pelo T. cruzi, estaria relacionada ao perfil da resposta inflamatória e regulatória desenvolvida no decorrer da doença. Observamos que os camundongos DBA/1 possuem mais células dendríticas ativadas no baço e coração e mais células T CD4+CD25hi do que os camundongos da linhagem A. Essa diferença do perfil de resposta pode estar provocando uma maior expansão e diferenciação dos linfócitos T CD4+ pelas células dendríticas, levando ao controle da carga parasitaria

Chagas’diseasse, due to Trypanosoma cruzi infection is characterized by the development of two phases with a variable clinical course. During the acute phase there occurs a severe myocarditis with the parasite being easily detected in peripheral blood and tissues. The chronic cardiac phase is characterized as a chronic cardiopathy, when severe destruction of cardiac myocells and fibrosis are present and parasites are rare. The mechanisms involved in the pathogenesis of this myocarditis are somewhat obscure. It is believed that regulatory and dendritic cells play a role in this process. In an attempt to clarify the mechanisms involved in the inflammatory response to infection with T. cruzi we decided to investigate the participation of dendritic and regulatory cells and of TCD4 and TCD8 lymphocytes, using two strains of isogenic mice , which exhibit different degrees of susceptibility to infection. Our results have shown that the DBA/1 mice presented a higher survival (90%) in the acute phase than the A mice (70%), even when these were treated with Benznidazole for three consecutive days, with the objective of to reduce the parasitemia and the high mortality. Resistance of DBA/1 mice and susceptibility of A mice could be related to the evolution of the inflammatory and regulatory responses, during the infection. It was seen that DBA/1 mice disclosed a higher number of activated dendritic cells in the spleen and heart and a higher number of T CD4+CD25hi than the mice of A strain. This differences of the response could be influencing in the TCD4 differentiation and on the control of parasitic load.

Neoplasia blástica de células dendríticas plasmocitoides: Caso clínico / Blastic plasmocytoid dendritic cell neoplasm: Report of one case

Background: We report a 74 years old male consulting for multiple painless non pruriginous pink plaques and nodules of truncal distribution that appeared 15 days earlier. A skin biopsy disclosed a blastic plasmocytoid dendritic cell neoplasm. A staging CAT scan showed lymphadenopathies located around the trachea and its bifurcation. A bone marrow biopsy did not show tumor infiltration. The patient has been treated with four cycles of cyclophosphamide-doxorubicin-vincristine-prednisone, obtaining a partial remission of the lesions.

Effects of Epstein-Barr virus on the development of dendritic cells derived from cord blood monocytes: an essential role for apoptosis

OBJECTIVE: Epstein-Barr virus (EBV) is a ubiquitous human γ-herpes virus, which can adapt and evade host immune defense. Dendritic cells (DCs) play a pivotal role in the initiation and maintenance of immune responses. This study investigated the effects of EBV on cord blood monocytes derived DCs (CBDC). METHODS: Monocytes were isolated from cord blood and cultured in medium containing recombinant IL-4 and GM-CSF to induce DCs development. B95-8 supernatant was added in monocytes culture medium for EBV infection at day 0. Phenotypic characterization of DCs, apoptotic cells, and mitochondrial membrane potential (MMP) were detected by flow cytometry. The morphology was observed by Hoechst 33258 staining and TUNEL staining, the expression of X-linked inhibitor of apoptosis protein (XIAP) was detected by Western blotting assay and caspase 3, 8 and 9 activity was measured. RESULTS: Phenotypic characterization of DCs was changed in EBV-treated group. Chromatin condensation and DNA fragmentation were observed in EBV induced CBDC apoptosis. In addition, caspase 3, caspase 8, and caspase 9 activation were enhanced in the EBV-treated group. This was accompanied by the loss of MMP. Furthermore, XIAP expression was down-regulated in the EBV-treated group and compared to mock-infected group. CONCLUSION: These results suggested that EBV could inhibit CBDC phenotypic differentiation, and induce CBDC apoptosis in caspase-dependent manner with involvement of the mitochondrial pathway. This might help EBV to evade host immune responses to establish persistent infection.