Hellen Thais Fuzii

Immunopathogenesis of HTLV-1-assoaciated myelopathy/tropical spastic paraparesis (HAM/TSP)

Human T-cell lymphotropic virus type 1 (HTLV-1) is associated with adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Only a limited percentage of infected individuals develop disease in response to the virus while the majority remain asymptomatic, and HAM/TSP is the most common clinical manifestation of the virus. HAM/TSP is an inflammatory disease of the central nervous system (CNS); however, the mechanism by which HTLV-1 induces HAM/TSP is not yet clear. CD4(+) T lymphocytes are the main reservoirs of HTLV-1 in vivo and perform an important role in the immunological response to this retrovirus. This virus-host interaction may provoke changes in the immunological response, such as the enhanced production of inflammatory cytokines and the spontaneous proliferation of T CD4(+) lymphocytes, which are implicated in the pathogenesis of HAM/TSP.

Zika virus disrupts molecular fingerprinting of human neurospheres

Zika virus (ZIKV) has been associated with microcephaly and other brain abnormalities; however, the molecular consequences of ZIKV to human brain development are still not fully understood. Here we describe alterations in human neurospheres derived from induced pluripotent stem (iPS) cells infected with the strain of Zika virus that is circulating in Brazil. Combining proteomics and mRNA transcriptional profiling, over 500 proteins and genes associated with the Brazilian ZIKV infection were found to be differentially expressed. These genes and proteins provide an interactome map, which indicates that ZIKV controls the expression of RNA processing bodies, miRNA biogenesis and splicing factors required for self-replication. It also suggests that impairments in the molecular pathways underpinning cell cycle and neuronal differentiation are caused by ZIKV. These results point to biological mechanisms implicated in brain malformations, which are important to further the understanding of ZIKV infection and can be exploited as therapeutic potential targets to mitigate it.

Prevalência de infecção genital pelo HPV em populações urbana e rural da Amazônia Oriental Brasileira

Foram investigados a prevalencia e os fatores associados a infeccao genital pelo HPV em mulheres de populacao urbana e rural de duas regioes da Amazonia Oriental brasileira. Foi um estudo transversal com 444 mulheres submetidas ao rastreamento para câncer cervical, sendo 233 urbanas e 211 rurais, de janeiro de 2008 a marco de 2010. Coletaram-se amostras da cervice uterina para a pesquisa de DNA do HPV pela PCR. Todas responderam a um formulario epidemiologico. Analise bivariada e por regressao logistica foram empregadas na investigacao dos fatores associados ao HPV. A prevalencia geral de HPV foi de 14,6%. Entre as populacoes, nao houve diferenca significativa, 15% urbana e 14,2% rural. O unico fator de risco explorado no estudo significativamente associado ao HPV foi a situacao conjugal de mulheres residentes na zona rural na faixa de 13 a 25 anos, com maior prevalencia de infeccao entre solteiras, separadas ou viuvas. Conclui-se que, apesar das prevalencias entre as populacoes serem semelhantes, as estrategias preventivas a serem aplicadas seriam especificas para cada populacao.

EGFR signaling downstream of EGF regulates migration, invasion, and MMP secretion of immortalized cells derived from human ameloblastoma.

Ameloblastoma is an odontogenic tumor characterized by local invasiveness and frequent recurrence. The surrounding stroma, composed of different cell types and extracellular matrix (ECM), may influence ameloblastoma invasive behavior. Furthermore, tumor and stromal cells secrete matrix metalloproteases (MMPs), which, in turn, can modulate the matrix and promote the release of ECM-bound growth factors. Among these growth factors, epidermal growth factor (EGF) and its receptor, EGFR, have already been shown to stimulate MMP synthesis, suggesting that an interdependent mechanism, involving MMP activity and growth factors release, may contribute to tumor invasiveness. The aim of this study was to evaluate the effects of the EGF/EGFR signaling pathway on migration, invasion, and MMP activity, in a primary cell line derived from human ameloblastoma. We established and characterized a primary cell line (AME-1) from a human ameloblastoma sample. This cell line was transduced with human papillomavirus type 16 (HPV16) E6/E7 oncogenes, generating the AME-HPV continuous cell line. EGF, MMP2, and MMP9 expression in ameloblastoma biopsies and in the AME-HPV cell line was analyzed by immunohistochemistry and immunofluorescence, respectively. Migratory activity of EGF-treated AME-HPV cells was investigated using monolayer wound assays and Transwell chambers. EGF-induced invasion was assessed in Boyden chambers coated with Matrigel. Conditioned medium from EGF-treated cells was subjected to zymography. EGFR expression in AME-HPV cells was silenced by small interfering RNA (siRNA), to verify the relationship between this receptor and MMP secretion. Ameloblastoma samples and AME-HPV cells expressed EGF, EGFR, MMP2, and MMP9. AME-HPV cells treated with EGF showed increased rates of migration and invasion, as well as enhanced MMP2 and MMP9 activity. EGFR knockdown decreased MMP2 and MMP9 levels in AME-HPV cells. EGFR signaling downstream of EGF probably regulates migration, invasion, and MMP secretion of ameloblastoma-derived cells.

IL-2, IL-5, TNF-α and IFN-γ mRNA expression in epidermal keratinocytes of systemic lupus erythematosus skin lesions

OBJECTIVE: To analyze cytokine gene expression in keratinocytes from patients with systemic lupus erythematosus (SLE). INTRODUCTION: Keratinocytes represent 95% of epidermal cells and can secrete several cytokines. METHODS: Keratinocytes were obtained by laser microdissection from 21 patients with SLE (10 discoid and 11 acute lesions) at involved and uninvolved sites. All patients were receiving a low/moderate prednisone dose and 18 were receiving chloroquine diphosphate. IL-2, IL-5, TNF-α and IFN-γ gene expression was evaluated by real-time PCR and expressed as the ratio (R) to a pool of skin samples from 12 healthy volunteers. RESULTS: Heterogeneity in cytokine gene expression was found among patients with SLE. Eighteen of 38 valid SLE samples (47%) presented overexpression (R>1) of at least one cytokine. Lesional skin samples tended to show higher cytokine expression than samples from uninvolved skin (p = 0.06). IL-5 and IFN-γ were the most commonly overexpressed cytokines. Samples with cytokine overexpression corresponded to more extensive and severe lesions. Prednisone dose did not differ between samples without cytokine overexpression (15.71±3.45 mg/day) and those with overexpressed cytokines (12.68±5.41 mg/day) (p = 0.216). Samples from all patients not receiving diphosphate chloroquine had at least one overexpressed cytokine. CONCLUSIONS: The heterogeneous keratinocyte cytokine gene expression reflects the complex immunological and inflammatory background in SLE. Patients with severe/extensive skin lesions showed a higher frequency of cytokine gene overexpression. Increased IFN-γ and IL-5 expression suggests that Th1 and Th2 cells are involved in SLE skin inflammation. The possibility that prednisone and antimalarial drugs may have contributed to low cytokine gene expression in some samples cannot be ruled out.

HTLV-1, Immune Response and Autoimmunity

Human T-lymphotropic virus type-1 (HTLV-1) infection is associated with adult T-cell leukemia/lymphoma (ATL). Tropical spastic paraparesis/HTLV-1-associated myelopathy (PET/HAM) is involved in the development of autoimmune diseases including Rheumatoid Arthritis (RA), Systemic Lupus Erythematosus (SLE), and Sjögren’s Syndrome (SS). The development of HTLV-1-driven autoimmunity is hypothesized to rely on molecular mimicry, because virus-like particles can trigger an inflammatory response. However, HTLV-1 modifies the behavior of CD4+ T cells on infection and alters their cytokine production. A previous study showed that in patients infected with HTLV-1, the activity of regulatory CD4+ T cells and their consequent expression of inflammatory and anti-inflammatory cytokines are altered. In this review, we discuss the mechanisms underlying changes in cytokine release leading to the loss of tolerance and development of autoimmunity.

New immunologic pathways in the pathogenesis of leprosy: Role for Th22 cytokines in the polar forms of the disease

To the Editor: Leprosy is an infectious disease caused by Mycobacterium leprae with clinical manifestations that are vastly dependent on the host’s immune response. The role of Th22 cells in the immunopathogenicity of leprosy has yet to be characterized. Thirty-one untreated adults, 19 women and 12 men, were selected for evaluation from the Brazilian state of Para with positive leprosy diagnoses according to World Health Organization and Ridley-Jopling system criteria. Sixteen were defined as tuberculoid and 15 as lepromatous. The study was approved by the Ethics Committee of the Federal do Para University (number 212.969). For immunohistochemical analysis, tissue biopsies were immunostained with monoclonal antibodies against IL-23, IL-22, TNF, and FGFb (fibroblast growth factor basic) (Fig 1). A quantitative analysis was made by randomly selecting 5 visual fields (3400 magnification; 0.0625 mm) using a 10 3 10 reticulated grid. Mann-Whitney and Pearson’s correlation tests were used for univariate analyses with P # .05 considered to be statistically significant. Quantitative analysis revealed a significant difference in IL-22 levels in tissues from patients with polar forms of leprosy (TT 1⁄4 90.39 6 30.18; LL 1⁄4 241.3 6 44.63; P# .0001), with higher levels observed in the lepromatous form with intense staining in vacuoles and globules of infected macrophages. Our results corroborate these observations, in that inactivation of the macrophage lytic response is largely responsible for the increased bacterial dissemination and evasive capacity of M leprae. Therefore, IL-22 expression presents as a possible alternative mechanism for triggering phagolysosomal maturation. In particular, IL-22 can stimulate the expression of

T‐helper 17 cytokines expression in leprosy skin lesions

DEAR EDITOR, Until recently, it was believed that T-helper (Th) 1 and Th2 lymphocytes were the only effector cells of the immune response; however, another group of T cells producing cytokines that differ from those observed in the Th1–Th2 model has been identified recently. These cells comprise a third subtype of CD4 effector T-helper called type 17 Th cells, or Th17. Th17 lymphocytes produce interleukin (IL)-17, IL-17F, IL-6, IL-21, IL-22 and tumour necrosis factor-a, which play a role in both tissue inflammation and neutrophil activation. IL-17 is a potent proinflammatory cytokine that exerts effects on a variety of cells. In leprosy, the cytokine profile of the tuberculoid and lepromatous forms (stable forms) has been extensively investigated and is

Immunohistochemical analysis of the expression of cellular transcription NFκB (p65), AP-1 (c-Fos and c-Jun), and JAK/STAT in leprosy ☆ ☆☆

Leprosy is a disease whose clinical spectrum depends on the cytokine patterns produced during the early stages of the immune response. The main objective of this study was to describe the activation pattern of cellular transcription factors and to correlate these factors with the clinical forms of leprosy. Skin samples were obtained from 16 patients with the tuberculoid (TT) form and 14 with the lepromatous (LL) form. The histologic sections were immunostained with anti-c-Fos and anti-c-Jun monoclonal antibodies for investigation of AP-1, anti-NFκB p65 for the study of NFκB, and anti-JAK2, STAT1, STAT3, and STAT4 for investigation of the JAK/STAT pathway. Cells expressing STAT1 were more frequent in the TT form than in LL lesions (P = .0096), in agreement with the protective immunity provided by IFN-γ. STAT4 was also more highly expressed in the TT form than in the LL form (P = .0098). This transcription factor is essential for the development of a Th1 response because it is associated with interleukin-12. NFκB (p65) and STAT4 expression in the TT form showed a strong and significant correlation (r = 0.7556 and P = .0007). A moderate and significant correlation was observed between JAK2 and STAT4 in the TT form (r = 0.6637 and P = .0051), with these factors responding to interleukin-12 in Th1 profiles. The results suggest that STAT1, JAK2, and NFκB, together with STAT4, contribute to the development of cell-mediated immunity, which is able to contain the proliferation of Mycobacterium leprae.

Relationship between growth factors and its implication in the pathogenesis of leprosy.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae which affects the skin and peripheral nervous system. The immune response of the host determines the clinical course of the disease. The tuberculoid form is the result of high cell-mediated immunity characterized by a Th1 response, whereas the lepromatous form is characterized by low cell-mediated immunity and a Th2 humoral response. The neural damage established produces marked changes in the expression of growth factors such as nerve growth factor (NGF) and its receptors (NGF-R). The expression of NGF, associated with the expression of Th1 and Th2 cytokines, might be involved in the tissue damage caused by the bacillus. Therefore, the objective of this study was to correlate the immunoexpression patterns of NGF and NGF-R in the different clinical forms of leprosy, and to associate the findings with the in situ expression of TGF-β and clinical classification of the disease. TGF-β, NGF and NGF-R immunoexpression was analyzed by immunohistochemistry in paraffin-embedded material. Most patients were males with a mean age of 40.7 years. TGF-β levels were significantly higher in the lepromatous forms. No significant difference in the immunoexpression of NGF or NGF-R was observed between the clinical forms, but expression tended to be higher at the lepromatous pole. There was a significant positive correlation between NGF and NGF-R in the different clinical forms of leprosy. A significant positive correlation was observed between NGF, NGF-R and TGF-β. It can be concluded that, even existing evidence on the role of these molecules in the clinical spectrum of leprosy.