IRF8 Mutations and Human Dendritic-Cell Immunodeficiency

BACKGROUND The genetic analysis of human primary immunodeficiencies has defined the contribution of specific cell populations and molecular pathways in the host defense against infection. Disseminated infection caused by bacille Calmette-Guerin (BCG) vaccines is an early manifestation of primary immunodeficiencies, such as severe combined immunodeficiency. In many affected persons, the cause of disseminated BCG disease is unexplained. METHODS We evaluated an infant presenting with features of severe immunodeficiency, including early-onset disseminated BCG disease, who required hematopoietic stem-cell transplantation. We also studied two otherwise healthy subjects with a history of disseminated but curable BCG disease in childhood. We characterized the monocyte and dendritic-cell compartments in these three subjects and sequenced candidate genes in which mutations could plausibly confer susceptibility to BCG disease. RESULTS We detected two distinct disease-causing mutations affecting interferon regulatory factor 8 (IRF8). Both K108E and T80A mutations impair IRF8 transcriptional activity by disrupting the interaction between IRF8 and DNA. The K108E variant was associated with an autosomal recessive severe immunodeficiency with a complete lack of circulating monocytes and dendritic cells. The T80A variant was associated with an autosomal dominant, milder immunodeficiency and a selective depletion of CD11c+CD1c+ circulating dendritic cells. CONCLUSIONS These findings define a class of human primary immunodeficiencies that affect the differentiation of mononuclear phagocytes. They also show that human IRF8 is critical for the development of monocytes and dendritic cells and for antimycobacterial immunity. (Funded by the Medical Research Council and others.)

Selective Inner Hair Cell Loss in Prematurity: A Temporal Bone Study of Infants from a Neonatal Intensive Care Unit

Premature birth is a well-known risk factor for sensorineural hearing loss in general and auditory neuropathy in particular. However, relatively little is known about the underlying causes, in part because there are so few relevant histopathological studies. Here, we report on the analysis of hair cell loss patterns in 54 temporal bones from premature infants and a control group of 46 bones from full-term infants, all of whom spent time in the neonatal intensive care unit at the Hospital de Nios in San Jose, Costa Rica, between 1977 and 1993. The prevalence of significant hair cell loss was higher in the preterm group than the full-term group (41% vs. 28%, respectively). The most striking finding was the frequency of selective inner hair cell loss, an extremely rare histopathological pattern, in the preterm vs. the full-term babies (27% vs. 3%, respectively). The findings suggest that a common cause of non-genetic auditory neuropathy is selective loss of inner hair cells rather than primary damage to the cochlear nerve.

A premenopausal woman with virilization secondary to an ovarian Leydig cell tumor

Background. A 33-year-old woman presented to an endocrinology clinic with a 5-year history of secondary amenorrhea. 2 years before presentation, she had noticed progressively worsening signs of virilization. Investigations. Measurement of levels of serum free and total testosterone, androstenedione, dehydroepiandrosterone sulfate and gonadotropins; transvaginal ultrasonography, abdominal and pelvic MRI and (18)F-fluorodeoxyglucose PET imaging. Diagnosis. Virilization secondary to an ovarian Leydig cell tumor. Management. The patient underwent a left salpingo-oophorectomy that confirmed the diagnosis of a unilateral Leydig cell tumor. Complete normalization of androgens and gonadotropin levels was achieved after surgery.

Water deficit and ABA application on leaf gas exchange and flavonoid content in marigold (Calendula officinalis L.)

Water deficit and ABA application on leaf gas exchange and flavonoid content in marigold (Calendula officinalis L.).The goal of this study was to evaluate the effects of water deficit and abscisic acid (ABA) application on physiological parameters and flavonoid production in marigold plant. The experiment was performed under nursery conditions with potted plants. It was tested water deficit by withholding water (control - diary irrigation, 3, 6 and 9 days without irrigation) followed by 3 ABA concentrations (0, 10 e 100 mu M) applied in the beginning of blooming. It was evaluated the relative water content and the leaf gas exchange using a portable infrared gas analyzer (A: net photosynthesis, gs: stomatal conductance, E: transpiration, Ci: CO(2) intercellular concentration and EUA: water use efficiency). At the end of 9 days of water deficit there were significant decreases in all the characteristics evaluated, independent of ABA application. This suggests that the main effect of ABA was to cause a reduction on gs which was accompanied of a reduction in A, only when the plants were submitted to the water deficit. There was no significant difference among the levels of water deficit tested in relation to the total flavonoid content in inflorescences. However, ABA restricted the flavonoids biosynthesis both in control plant and stressed plants.

Increased Levels of Circulating Endothelial Progenitor Cells in Human T-cell Lymphotropic Virus Type I Carriers

Background and Aims. HTLV-I-transformed T cells secrete biologically active forms of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF). In addition, HTLV-I-transformed cells have a high capacity of adhesion to endothelial cells. Methods. We measured the circulating endothelial progenitor cells (EPCs) and mature endothelial cells (MECs) by flow cytometry in 27 HTLV-I carriers in comparison to 30 healthy, age- and gender-matched subjects. All subjects had HTLV-I positivity confirmed by Western blot and/or polymerase chain reaction (PCR). The numbers of different subpopulations of EPCs and MECSs were evaluated by four-color flow cytometry using a panel of monoclonal antibodies. All reactions were done in duplicate to confirm reproducibility of the results. Results. The median age of all 27 HTLV-I carriers enrolled in this study was 45 years (range: 27-65 years); 11(41%) were male and 16 (59%) were female. The median age of the 30 healthy subjects in the control group was 45.5 years (range: 20-63 years); 11 (36.6%) were male and 19 (63.4%) were female. The number of EPCs was significantly higher in HTLV-I carriers (median 0.8288 cells/mu L, range: 0.0920-3.3176 cells/mu L) as compared to control group (median 0.4905 cells/mu L, range: 0.0000-1.5660 cells/mu L) (p = 0.035). In contrast, the median of the MECs in the HTLV-I carriers was 0.6380 cells/mu L (range: 0.0473-5.7618 cells/mu L) and 0.4950 cells/mu L (range: 0.0000-4.0896 cells/mu L) in the control group, with no statistical difference (p = 0.697). Conclusions. We demonstrated that EPCs, but not MECs, are increased in the peripheral blood of HTLV-I carriers. (C) 2011 IMSS. Published by Elsevier Inc.

Acute hyperglycemia rapidly stimulates VEGF mRNA translation in the kidney. Role of angiotensin type 2 receptor (AT2)

Angiotensin II (Ang II) and vascular endothelial growth factor (VEGF) are important mediators of kidney injury in diabetes. Acute hyperglycemia increased synthesis of intrarenal Ang I and Ang II and resulted in activation of both Ang II receptors, AT1 and AT2, in the kidney. Losartan (specific AT1 antagonist) or PD123319 (specific AT2 antagonist) did not affect hyperglycemia but prevented activation of renal AT1 and AT2, respectively. In murine renal cortex, acute hyperglycemia increased VEGF protein but not mRNA content after 24 h, which suggested translational regulation. Blockade of AT2, but not AT1, prevented increase in VEGF synthesis by inhibiting translation of VEGF mRNA in renal cortex. Acute hyperglycemia increased VEGF expression in wild type but not in AT2 knockout mice. Binding of heterogeneous nuclear ribonucleoprotein K to VEGF mRNA, which stimulates its translation, was prevented by blockade of AT2, but not AT1. The Akt-mTOR-p70(S6K) signaling pathway, involved in the activation of mRNA translation, was activated in hyperglycemic kidneys and was blocked by the AT2 antagonist. Elongation phase is an important step of mRNA translation that is controlled by elongation factor 1A (eEF1A) and 2 (eEF2). Expression of eEF1A and activity of eEF2 was higher in kidney cortex from hyperglycemic mice and only the AT2 antagonist prevented these changes. To assess selectivity of translational control of VEGF expression, we measured expression of fibronectin (FN) and laminin beta 1 (lam beta 1): acute hyperglycemia increased FN expression at both protein and mRNA levels, indicating transcriptional control, and did not affect the expression of lam beta 1. To confirm results obtained with PD123319, we induced hyperglycemia in AT2 knockout mice and found that in the absence of AT2, translational control of VEGF expression by hyperglycemia was abolished. Our data show that acute hyperglycemia stimulates Ang II synthesis in murine kidney cortex, this leads to AT2 activation and stimulation of VEGF mRNA translation, via the Akt-mTOR-p70(S6K) signaling pathway. Our data show that exclusive translational control of protein expression in the kidney by acute hyperglycemia is not a general phenomenon, but do not prove that it is restricted to VEGF. (C) 2010 Elsevier Inc. All rights reserved.

Claudin-7 down-regulation is an important feature in oral squamous cell carcinoma

Aims: Claudins, a large family of essential tight junction (TJ) proteins, are abnormally regulated in human carcinomas, especially claudin-7. The aim of this study was to investigate claudin-7 expression and alterations in oral squamous cell carcinoma (OSCC). Methods and results: Expression of claudin-7 was analysed in 132 cases of OSCC organized in a tissue microarray. Claudin-7 mRNA transcript was evaluated using real-time polymerase chain reaction and the methylation status of the promoter was also assessed. Claudin-7 was negative in 58.3% of the cases. Loss of claudin-7 protein expression was associated with recurrence (P = 0.019), tumour size (P = 0.014), clinical stage of OSCC (P = 0.055) and disease-free survival (P = 0.015). Down-regulation of the claudin-7 mRNA transcripts was observed in 78% of the cases, in accordance with immunoexpression. Analysis of the methylation status of the promoter region of claudin-7 revealed that treatment of O28 cells (that did not express claudin-7 mRNA transcripts) with 5-Aza-2`-Deoxycytidine (5-Aza-dC) led to the re-expression of claudin-7 mRNA transcript. Conclusion: Loss of claudin-7 expression is associated with important subcellular processes in OSCC with impact on clinical parameters.

Systemic chemotherapy-induced microsatellite instability in the mononuclear cell fraction of women with breast cancer can be reproduced in vitro and abrogated by amifostine

Objectives Microsatellite instability (MSI) induction by alkylating agent-based chemotherapy (ACHT) may underlie both tumor resistance to chemotherapy and secondary leukaemias in cancer patients. We investigated if ACHT could induce MSI in tumor-derived plasma-circulating DNA (pfDNA) and in normal peripheral blood mononuclear (PBMN) cells. We also evaluated if amifostine could interfere with this process in an in-vitro model. Methods MSI was determined in pfDNA, PBMN cells and urine cell-free DNA (ufDNA) of 33 breast cancer patients before and after ACHT. MCF-7 cells and PBMN from normal donors were exposed in vitro to melphalan, with or without amifostine. Results We observed at least one MSI event in PBMN cells, pfDNA or ufDNA of 87, 80 and 80% of patients, respectively. In vitro, melphalan induced MSI in both MCF-7 and normal PBMN cells. In PBMN cells, ACHT-induced MSI occurred together with a significant decrease in the expression of the DNA mismatch repair gene hMSH2. Amifostine decreased hMSH2 expression and also prevented MSI induction only in normal PBMN cells. Conclusions ACHT induced MSI in PBMN cells and in tumour-derived pfDNA. Because of its protective effect against ACHT induction of MSI in normal PBMN cells in vitro, amifostine may be a potential agent for preventing secondary leukaemias in patients exposed to ACHT.

Subchronic effects of nasally instilled diesel exhaust particulates on the nasal and airway epithelia in mice

Diesel exhaust is the major source of ultrafine particles released during traffic-related pollution. Subjects with chronic respiratory diseases are at greater risk for exacerbations during exposure to air pollution. This study evaluated the effects of subchronic exposure to a low-dose of diesel exhaust particles (DEP). Sixty male BALB/c mice were divided into two groups: (a) Saline: nasal instillation of saline (n = 30); and (b) DEP: nasal instillation of 30 mu g of DEP/10 mu l of saline (n = 30). Nasal instillations were performed 5 days a week, over 30 and 60 days. Animals were anesthetized with pentobarbital sodium (50 mg/kg intraperitoneal [i.p.]) and sacrificed by exsanguination. Bronchoalveolar lavage (BAL) fluid was performed to evaluate the inflammatory cell count and the concentrations of the interleukin (IL)-4, IL-10, and IL-13 by enzyme-linked immunosorbent assay (ELISA). The gene expression of oligomeric mucus/gel-forming (Muc5ac) was evaluated by real-time polymerase chain reaction (PCR). Histological analysis in the nasal septum and bronchioles was used to evaluate the bronchial and nasal epithelium thickness as well as the acidic and neutral nasal mucus content. The saline group (30 and 60 days) did not show any changes in any of the parameters. However, the instillation of DEP over 60 days increased the expression of Muc5ac in the lungs and the acid mucus content in the nose compared with the 30-day treatment, and it increased the total leukocytes in the BAL and the nasal epithelium thickness compared with saline for 60 days. Cytokines concentrations in the BAL were detectable, with no differences among the groups. Our data suggest that a low-dose of DEP over 60 days induces respiratory tract inflammation.

Neither Molecular Diversity of the Envelope, Immunosuppression Status, Nor Proviral Load Causes Indeterminate HTLV Western Blot Profiles in Samples From Human T-Cell Lymphotropic Virus Type 2 (HTLV-2)-Infected Individuals

Although human T-cell lymphotropic virus type 2 (HTLV-2) is considered of low pathogenicity, serological diagnosis is important for counseling and monitoring. The confirmatory tests most used are Western blot (WB) and PCR. However, in high-risk populations, about 50% of the indeterminate WB were HTLV-2 positives by PCR. The insensitivity of the WB might be due to the use of recombinant proteins of strains that do not circulate in our country. Another possibility may be a high level of immunosuppression, which could lead to low production of virus, resulting in low stimulation of antibody. We found one mutation, proline to serine in the envelope region in the position 184, presented at least 1/3 of the samples, independent the indeterminate WB profile. In conclusion, we found no correlation of immune state, HTLV-2 proviral load, or env diversity in the K55 region and WB indeterminate results. We believe that the only WB kit available in the market is probably more accurate to detect HTLV-1 antibodies, and some improvement for HTLV-2 detection should be done in the future, especially among high-risk population. J. Med. Virol. 82:837-842,2010. (C) 2010 Wiley-Liss, Inc.

Polymorphisms in innate immunity genes and patients response to dendritic cell-based HIV immuno-treatment

Dendritic cells (DCs)-based vaccine was demonstrated to increase HIV specific cellular immune response; however, in some HIV-infected patients, the response to the vaccine resulted to be not effective. In order to understand if the outcome of the vaccination may be influenced by the host`s genome and natural immunity, we studied the innate immune genome of HIV-infected patients previously vaccinated with DCs. We identified 15 SNPs potentially associated with the response to the immuno-treatment and two SNPs significantly associated with the modulation of the response to the DC vaccine: MBL2 rs10824792 and NOS1 rs693534. These two SNPs were also studied in different ethnic groups (Brazilians, African and Caucasian) of HIV-infected, exposed uninfected and unexposed uninfected subjects. The HIV positive Caucasian patients were also characterized by different disease progressions. Our findings suggest that, independently and/or in addition to other variables. the host`s genome could significantly contribute to the modulation of the response to the DC vaccine. (C) 2009 Elsevier Ltd. All rights reserved.

Assessment of disease-free survival in patients with laryngeal squamous cell carcinoma treated with radiotherapy associated or not with chemotherapy

In early stage (I and II) laryngeal squamous cell carcinoma, both surgery and radiotherapy results in significant local and regional control. In advanced tumors (III and IV), radiotherapy alone has local-regional control rates of 32-43%. Aim: To assess disease-free survival in SCC laryngeal carcinoma patients submitted to radiotherapy alone and/or associated with chemotherapy. Materials and Methods: Retrospective study involving 84 cases of laryngeal SCC treated with radiotherapy or chemotherapy together with radiotherapy. Fifty-three cases were treated with intension to cure and 31 because of impossibility to resect the disease. As to clinical stage (CS), 12 were CS I, 15 II, 21 III and 5 IV. In the second group, 11 cases were EC III and 20 IV. Results: Mean age was 60 years, 84.5% were men. Fifty-eight (69.1%) cases had complete response and 26 (30.9%) had persistent or residual disease. Five-year disease-free survival was of 42.5%; 62.5% of the patients with organ preservation indication and 9.75 in the group of irressecable disease. Conclusion: disease-free survival of those patients submitted to radiotherapy because of laryngeal SCC was of 62.5%

Establishment and characterization of human bladder cancer cell lines BexBra1, BexBra2, and BexBra4

Bladder cancer (BC) is the fourth most common cancer in the USA. In Brazil, BC represents 3% of the total existing carcinomas in the population and represents the second highest incidence among urological tumors. The majority of bladder cancer cell lines available were derived from Caucasians and established in the seventies or eighties. Thus, neoplasia development in these cells likely occurred in environment conditions vastly different than today. In the present study, we report the establishment and characterization of three Brazilian bladder cancer cell lines (BexBra1, BexBra2, and BexBra4). These cell lines may be helpful for dissecting the genetic and epigenetic aspects that trigger the progression of BC. Moreover, the development of a Brazilian representative of the disease will allow us to investigate the potential inter-racial differences of malignancy-associated phenotypes in bladder cancer.

A novel human CD4(+) T-cell inducer subset with potent immunostimulatory properties

The complexity of immunoregulation has focused attention on the CD4(+) T ""suppressor"" regulatory cell (T(reg)), which helps maintain balance between immunity and tolerance. An immunoregulatory T-cell population that upon activation amplifies cellular immune responses was described in murine models more than 30 years ago; however, no study has yet identified a naturally occurring T ""inducer"" cell type. Here, we report that the ectoenzyme CD39/NTPDase1 (ecto-nucleoside triphosphate diphosphohydrolase 1) helps to delineate a novel population of human ""inducer"" CD4(+) T cells (T(ind)) that significantly increases the proliferation and cytokine production of responder T cells in a dose-dependent manner. Furthermore, this unique T(ind) subset produces a distinct repertoire of cytokines in comparison to the other CD4(+) T-cell subsets. We propose that this novel CD4(+) T-cell population counterbalances the suppressive activity of suppressor T(reg) in peripheral blood and serves as a calibrator of immunoregulation.