Capsule production promotes Group B Streptococcus intestinal colonization.

Late-onset disease is the most common clinical presentation of Group B Streptococcus (GBS) infection during infancy, and gastrointestinal (GI) colonization is an important precursor. Previously, we described a murine model of postnatal GBS GI colonization that resulted in sustained colonization and progression to invasive disease. Capsular polysaccharide is an important GBS virulence factor. Vaccines based on a subset of capsular serotypes are in clinical trials. However, little is known regarding the role of specific GBS capsular serotypes in GI colonization. We examined the role of GBS capsule in GI colonization using capsule-producing and acapsular strains derived from GBS strain A909 (serotype Ia) in a murine model. Using isogenic GBS strains differing only in capsular serotypes, we explored the role of specific serotypes in GI colonization by determining competitive indices during cocolonization. We found that GBS A909 colonizes the murine GI tract without causing invasive disease. In monocolonization experiments, there was colonization persistence with the capsule-producing strain (100%) compared to the acapsular mutant strain (13%). In cocolonization experiments, the capsule-producing strain outcompeted its isogenic acapsular mutant, with a geometric mean competitive index of 8, 95% confidence interval (CI) [1.7, 38.9] in the colon at 7 days post-colonization. A909 expressing its native serotype Ia capsule outcompeted an isogenic mutant that expresses serotype III capsule, with a geometric mean competitive index of 2.5, 95% CI [1.2, 5.1] in the colon at 7 days post-colonization. Thus, polysaccharide capsule production enhances GBS GI colonization in vivo. In an A909 genetic background, the production of a serotype Ia capsule provides a competitive advantage over an isogenic strain producing type III capsule. The murine model is a valuable tool to understand the role of GBS capsule types in GI colonization. IMPORTANCE The establishment of GBS intestinal colonization is believed to be a critical precursor to late-onset disease in neonates, which has a significant impact on neurodevelopment outcomes in this population. Our prior work described a murine model of postnatal Group B Streptococcus (GBS) acquisition and invasive disease. Using this model, we explored the importance of GBS polysaccharide capsule production on gastrointestinal colonization. We found that the expression of capsule (compared to isogenic acapsular strains) provides an advantage in intestinal colonization and, importantly, that capsule type Ia has an advantage over capsule type III in a GBS A909 strain background. We speculate that specific serotypes may differ in colonization fitness, which may play a role in serotype distribution in neonatal disease.

Host inflammatory dynamics reveal placental immune modulation by Group B Streptococcus during pregnancy.

Group B Streptococcus (GBS) is a pathobiont that can ascend to the placenta and cause adverse pregnancy outcomes, in part through production of the toxin ß-hemolysin/cytolysin (ß-h/c). Innate immune cells have been implicated in the response to GBS infection, but the impact of ß-h/c on their response is poorly defined. We show that GBS modulates innate immune cell states by subversion of host inflammation through ß-h/c, allowing worse outcomes. We used an ascending mouse model of GBS infection to measure placental cell state changes over time following infection with a ß-h/c-deficient and isogenic wild type GBS strain. Transcriptomic analysis suggests that ß-h/c-producing GBS elicit a worse phenotype through suppression of host inflammatory signaling in placental macrophages and neutrophils, and comparison of human placental macrophages infected with the same strains recapitulates these results. Our findings have implications for identification of new targets in GBS disease to support host defense against pathogenic challenge.

Pilot Study Investigating Brain Natriuretic Peptide, Troponin, Galectin-3, and miRNA-126a-5p as Biomarkers of Persistent Pulmonary Hypertension in Neonates with Hypoxic-Ischemic Injury Receiving Therapeutic Hypothermia.

OBJECTIVE: The objective was to evaluate the utility of brain natriuretic peptide (BNP), troponin, galectin-3 (Gal-3), and microRNA (miRNA)-126a-5p as screening biomarkers for persistent pulmonary hypertension of the newborn (PPHN) by comparing expression in serum of infants with hypoxic-ischemic injury that develop PPHN to those that do not. STUDY DESIGN: This was a prospective, observational pilot study including neonates with hypoxic-ischemic injury undergoing therapeutic hypothermia (TH) at two regional perinatal medical centers. PPHN in this population was diagnosed clinically and confirmed by echocardiogram. Serial measurements of biomarkers were performed from 6 to 96 hours post-TH initiation in 40 patients. RESULTS: Of 40 infants in the study, 10 (25%) developed PPHN and 30 (75%) did not. Baseline demographics and hemodynamics were similar between the groups. Patients with PPHN had a significantly higher need for vasopressors compared with patients without PPHN (70 vs. 27%, p = 0.007). Mean serum BNP and troponin levels were significantly higher in the PPHN group peaking at 12 to 24 hours and decreasing following PPHN treatment initiation. miRNA-126a-5p expression was increased in patients with PPHN compared with patients without, with statistical significance detected at 12 hours (p = 0.005) and 96 hours (p = 0.01). Mean circulating Gal-3 levels were not statistically different between the two groups; however, Gal-3 was elevated in all patients with hypoxic-ischemic injury on TH compared with healthy infants from prior studies. CONCLUSION: BNP and troponin are readily available, low-cost biomarkers that showed significant serial elevations in the PPHN group of the study and, thus, may have value in screening for PPHN in the setting of hypoxic-ischemic encephalopathy (HIE). Gal-3 was elevated in all patients with HIE and may be a useful biomarker of hypoxic injury in infants being evaluated for TH. Elevations in miRNA-126a-5p were not consistently seen in this study. Larger studies are required to establish an association between PPHN and these biomarkers in patients with and without HIE. KEY POINTS: · Serum biomarkers of persistent pulmonary hypertension of the newborn. · Serum biomarkers of hypoxic-ischemic injury.

Effects of Inhaled Iloprost for the Management of Persistent Pulmonary Hypertension of the Newborn.

OBJECTIVE: The study aimed to evaluate the effects of inhaled iloprost on oxygenation indices in neonates with persistent pulmonary hypertension of the newborn (PPHN). STUDY DESIGN: We conducted a retrospective chart review of 30 patients with PPHN from January 2014 to November 2018, who did not respond to inhaled nitric oxide (iNO) alone and received inhaled iloprost. Twenty-two patients met the inclusion criteria and eight patients were excluded from the study (complex cardiac disease and extreme prematurity). Patients were categorized as responders or nonresponders (patients who required extracorporeal membrane oxygenation or died). Oxygenation index, mean airway pressure (MAP), and arterial partial pressure of oxygen (PaO2) were recorded. RESULTS: Among a total of 22 patients who were included in the study, 10 were classified as nonresponders as they required either extracorporeal membrane oxygenation or died. Gestational age and gender did not differ between responders and nonresponders. The median PaO2 was lower (37 vs. 42 mm Hg; p < 0.05) and median MAP was higher (20 vs. 17 cm H2O; p < 0.02) in nonresponders compared with responders just prior to initiating iloprost. Iloprost responders had a significant increase in median PaO2 and decrease in median oxygenation index in the 24 hours after initiating treatment (p < 0.05), with no significant change in required mean airway pressure over that same period. There was no change in vasopressor use or clinically significant worsening of platelets count, liver, and kidney functions after initiating iloprost. CONCLUSION: Inhaled iloprost is well tolerated and seems to have beneficial effects in improving oxygenation indices in neonates with PPHN who do not respond to iNO. There is a need of well-designed prospective trials to further ascertain the benefits of using inhaled iloprost as an adjunct treatment in neonates with PPHN who do not respond to iNO alone. KEY POINTS: · Inhaled iloprost seems to have beneficial effects in improving oxygenation indices in PPHN.. · Inhaled iloprost is generally well tolerated in newborns with PPHN.. · There is a need for prospective randomized controlled trials to further ascertain the benefits of using inhaled iloprost..

Association of SARS-CoV-2 placental histopathology findings with maternal-fetal comorbidities and severity of COVID-19 hypoxia.

OBJECTIVE: SARS-CoV-2 is known to impact multiple organ systems, with growing data to suggest the potential for placental infection and resultant pathology. Understanding how maternal COVID-19 disease can affect placental histopathology has been limited by small study cohorts with mild disease, review by multiple pathologists, and potential confounding by maternal-fetal comorbidities that can also influence placental findings. This study aims to identify pathologic placental findings associated with COVID-19 disease and severity, as well as to distinguish them from changes related to coexisting maternal-fetal comorbidities. METHODS: This is an observational study of 61 pregnant women with confirmed SARS-CoV-2 infection who delivered and had a placental histological evaluation at NYU Langone Health between March 19, 2020 and June 30, 2020. Primary outcomes were the prevalence of placental histopathologic features and their association with maternal-fetal comorbidities and severity of COVID-19 related hypoxia. Analysis was performed using Fisher's exact test and t-test with p < 0.05 considered significant. RESULTS: Sixty-one placentas were included in the study cohort, 71% from pregnancies complicated by at least one maternal-fetal comorbidity. Twenty-five percent of placentas were small for gestational age and 77% exhibited at least one feature of maternal vascular malperfusion. None of the histopathologic features in the examined placentas were associated with the presence of any specific maternal-fetal comorbidity. Thirteen percent of the cohort required maternal respiratory support for COVID-19 related hypoxia. Villous trophoblast necrosis was associated with maternal supplemental oxygen requirement (67 vs. 33%, p = 0.04) and intubation (67 vs. 33%, p = 0.01). CONCLUSION: In pregnancies complicated by COVID-19 disease, there was a high prevalence of placental histopathologic changes identified, particularly features of maternal vascular malperfusion, which could not be attributed solely to the presence of maternal-fetal comorbidities. The significantly increased prevalence of villous trophoblast necrosis in women needing respiratory support suggests a connection to the severity of COVID-19 illness.

The Impact of Circulating Antibody on Group B Streptococcus Intestinal Colonization and Invasive Disease.

Gastrointestinal (GI) colonization with group B Streptococcus (GBS) is an important precursor to late-onset (LO) disease in infants. The host-pathogen interactions that mediate progression to invasive disease remain unknown due, in part, to a paucity of robust model systems. Passively acquired maternal GBS-specific antibodies protect newborns from early-onset disease, yet their impact on GI colonization and LO disease is unexplored. Using murine models of both perinatal and postnatal GBS acquisition, we assessed the kinetics of GBS GI colonization, progression to invasive disease, and the role of GBS-specific IgG production in exposed offspring and juvenile mice at age 12 and 14 days, respectively. We defined LO disease as >7 days of life in the perinatal model. We studied the impact of maternal immunization using a whole-cell GBS vaccine on the duration of intestinal colonization and progression to invasive disease after postnatal GBS exposure in offspring. Animals exhibit sustained GI colonization following both perinatal and postnatal exposure to GBS, with 21% and 27%, respectively, developing invasive disease. Intestinal colonization with GBS induces an endogenous IgG response within 20 days of exposure. Maternal vaccination with whole-cell GBS induces production of GBS-specific IgG in dams that is vertically transmitted to their offspring but does not decrease the duration of GBS intestinal colonization or reduce LO mortality following postnatal GBS exposure. Both perinatal and postnatal murine models of GBS acquisition closely recapitulate the human disease state, in which GBS colonizes the intestine and causes LO disease. We demonstrate both endogenous production of anti-GBS IgG in juvenile mice and vertical transfer of antibodies to offspring following maternal vaccination. These models serve as a platform to study critical host-pathogen interactions that mediate LO GBS disease.

Epigenetic therapy inhibits metastases by disrupting premetastatic niches.

Cancer recurrence after surgery remains an unresolved clinical problem1-3. Myeloid cells derived from bone marrow contribute to the formation of the premetastatic microenvironment, which is required for disseminating tumour cells to engraft distant sites4-6. There are currently no effective interventions that prevent the formation of the premetastatic microenvironment6,7. Here we show that, after surgical removal of primary lung, breast and oesophageal cancers, low-dose adjuvant epigenetic therapy disrupts the premetastatic microenvironment and inhibits both the formation and growth of lung metastases through its selective effect on myeloid-derived suppressor cells (MDSCs). In mouse models of pulmonary metastases, MDSCs are key factors in the formation of the premetastatic microenvironment after resection of primary tumours. Adjuvant epigenetic therapy that uses low-dose DNA methyltransferase and histone deacetylase inhibitors, 5-azacytidine and entinostat, disrupts the premetastatic niche by inhibiting the trafficking of MDSCs through the downregulation of CCR2 and CXCR2, and by promoting MDSC differentiation into a more-interstitial macrophage-like phenotype. A decreased accumulation of MDSCs in the premetastatic lung produces longer periods of disease-free survival and increased overall survival, compared with chemotherapy. Our data demonstrate that, even after removal of the primary tumour, MDSCs contribute to the development of premetastatic niches and settlement of residual tumour cells. A combination of low-dose adjuvant epigenetic modifiers that disrupts this premetastatic microenvironment and inhibits metastases may permit an adjuvant approach to cancer therapy.

Comparative Evaluation of Efficacy of Diode Laser and Clinpro XT Varnish for Treatment of Dentin Hypersensitivity: A Randomized Clinical Trial.

CONTEXT: Dentin hypersensitivity (DH) is a very common dilemma and often results in temporary relief by the conventional treatment method. An in vivo comparative study of various methods and materials helps in evaluation of a superior method to provide a long-lasting relief. AIM: The aim of this study was to evaluate the efficacy of diode laser (DL) and Clinpro XT Varnish for managing DH. MATERIALS AND METHODS: This study was a randomized, single-blinded, clinical trial, designed, adhering to the CONSORT (Consolidated Standards of Reporting Trials) Guidelines using DL and fluoride-based varnish for managing DH. A total of 40 teeth were selected from eight patients and randomly divided into two groups. All patients received tactile and air syringe stimulus to assess for DH and a visual analog scale (VAS) was used to obtain readings at baseline, 15min, 1 week, and 3 weeks, posttreatment. Student's t test was used, paired t test was for the intragroups, and unpaired t test was for intergroups. RESULTS: This study showed that the effect of DL and Clinpro XT Varnish results in a significant decrease of DH. However, success decreased gradually over time. CONCLUSION: Clinpro XT Varnish presented superior immediate effect and DL effect tends to become better with time. Hence, both had good results in the end.

The emerging role of epigenetic therapeutics in immuno-oncology.

The past decade has seen the emergence of immunotherapy as a prime approach to cancer treatment, revolutionizing the management of many types of cancer. Despite the promise of immunotherapy, most patients do not have a response or become resistant to treatment. Thus, identifying combinations that potentiate current immunotherapeutic approaches will be crucial. The combination of immune-checkpoint inhibition with epigenetic therapy is one such strategy that is being tested in clinical trials, encompassing a variety of cancer types. Studies have revealed key roles of epigenetic processes in regulating immune cell function and mediating antitumour immunity. These interactions make combined epigenetic therapy and immunotherapy an attractive approach to circumvent the limitations of immunotherapy alone. In this Review, we highlight the basic dynamic mechanisms underlying the synergy between immunotherapy and epigenetic therapies and detail current efforts to translate this knowledge into clinical benefit for patients.

FOSL1 Promotes Kras-induced Lung Cancer through Amphiregulin and Cell Survival Gene Regulation.

The FOSL1/AP-1 transcription factor regulates gene expression, thereby controlling various pathophysiological processes. It is a major effector of RAS-ERK1/2 signaling and is activated in human lung epithelia by tumorigenic stimuli. Recent evidence shows an inverse correlation between FOSL1 expression and the survival of patients with lung cancer and adenocarcinomas; however, its role in lung tumorigenesis remains elusive. In this work, we sought to determine the role of FOSL1 in Kras-induced lung adenocarcinoma in vivo and its downstream effector mechanisms. We used mice expressing the Kras oncogene in the lung with concomitant Fosl1 deletion, Kras-activated murine alveolar epithelial cells (mAECs) with Fosl1 deletion, and KRAS mutant human lung adenocarcinoma (HLAC) cells with FOSL1 deficiency, and performed cell proliferation and gene expression analyses. Mutant Kras induced Fosl1 expression in vitro (mAECs) and in vivo (lung tissue), and mice with Fosl1 deletion showed reduced levels of mutant Kras-induced lung tumorigenesis and survived longer than Fosl1-sufficient mice. Studies with mutant Kras-activated mAECs and KRAS-mutant HLAC cells revealed that FOSL1 regulates mutant KRAS-induced gene expression, thereby controlling cell proliferation and survival. In contrast, FOSL1 depletion in non-KRAS-mutant HLAC cells and nonmalignant human lung epithelia had no effect. Our data support the notion that FOSL1-mediated expression of amphiregulin and apoptotic and antioxidative genes plays a role in regulating HLAC cell proliferation and survival. FOSL1 is a determinant of lung cancer in vivo and regulates HLAC cell proliferation and survival, largely in the context of KRAS mutations. Activation of FOSL1 in adenocarcinomas may be a prognostic marker and potential target for human lung cancer with KRAS mutations.

Epigenetic Therapy Ties MYC Depletion to Reversing Immune Evasion and Treating Lung Cancer.

Combining DNA-demethylating agents (DNA methyltransferase inhibitors [DNMTis]) with histone deacetylase inhibitors (HDACis) holds promise for enhancing cancer immune therapy. Herein, pharmacologic and isoform specificity of HDACis are investigated to guide their addition to a DNMTi, thus devising a new, low-dose, sequential regimen that imparts a robust anti-tumor effect for non-small-cell lung cancer (NSCLC). Using in-vitro-treated NSCLC cell lines, we elucidate an interferon α/ß-based transcriptional program with accompanying upregulation of antigen presentation machinery, mediated in part through double-stranded RNA (dsRNA) induction. This is accompanied by suppression of MYC signaling and an increase in the T cell chemoattractant CCL5. Use of this combination treatment schema in mouse models of NSCLC reverses tumor immune evasion and modulates T cell exhaustion state towards memory and effector T cell phenotypes. Key correlative science metrics emerge for an upcoming clinical trial, testing enhancement of immune checkpoint therapy for NSCLC.

Chronic Cigarette Smoke-Induced Epigenomic Changes Precede Sensitization of Bronchial Epithelial Cells to Single-Step Transformation by KRAS Mutations.

We define how chronic cigarette smoke-induced time-dependent epigenetic alterations can sensitize human bronchial epithelial cells for transformation by a single oncogene. The smoke-induced chromatin changes include initial repressive polycomb marking of genes, later manifesting abnormal DNA methylation by 10 months. At this time, cells exhibit epithelial-to-mesenchymal changes, anchorage-independent growth, and upregulated RAS/MAPK signaling with silencing of hypermethylated genes, which normally inhibit these pathways and are associated with smoking-related non-small cell lung cancer. These cells, in the absence of any driver gene mutations, now transform by introducing a single KRAS mutation and form adenosquamous lung carcinomas in mice. Thus, epigenetic abnormalities may prime for changing oncogene senescence to addiction for a single key oncogene involved in lung cancer initiation.

Recovery and purification of recombinant 503 antigen of Leishmania infantum chagasi using expanded bed adsorption chromatography.

Visceral leishmaniasis, a disease caused by Leishmania infantum chagasi, represents a major public health problem in many areas of the world. However, there is currently no vaccine for human use. The aim of this work was to purify the 503 antigen of Leishmania i. chagasi directly from unclarified Escherichia coli feedstock through expanded bed adsorption (EBA) chromatography. Batch experiments were performed to optimize the adsorption and elution conditions of the antigen onto a STREAMLINE Chelating resin using two central composite rotatable designs (CCRD). The results showed that the optimal binding conditions of the 503 antigen were pH 8.0 in the presence of 2.4 M NaCl. For the elution of the target protein, the optimized conditions included the presence of 600.0 mM imidazole. The adsorption isothermal data of the 503 antigen were fitted to the Langmuir adsorption isotherm. The EBA experiment successfully recovered 59.2% of the 503 antigen from the unclarified E. coli homogenate with a purification factor of 6.0.

Myeloid-specific Fos-related antigen-1 regulates cigarette smoke-induced lung inflammation, not emphysema, in mice.

Heightened lung inflammation is a cardinal feature of chronic obstructive pulmonary disease (COPD). Cigarette smoke (CS)-induced macrophage recruitment and activation, accompanied by abnormal secretion of a number of inflammatory cytokines and matrix metalloproteinases, play a major role in the pathophysiology of COPD. The Fos-related antigen-1 (Fra-1) transcription factor differentially regulates several cellular processes that are implicated in COPD, such as inflammation and immune responses, cell proliferation and death, and extracellular remodeling. Although CS stimulates Fra-1 expression in the lung, the precise role of this transcription factor in the regulation of CS-induced lung inflammation in vivo is poorly understood. Here, we report that myeloid-specific Fra-1 signaling is important for CS-induced lung macrophagic inflammatory response. In response to chronic CS exposure, mice with Fra-1 specifically deleted in myeloid cells showed reduced levels of CS-induced lung macrophagic inflammation, accompanied by decreased expression levels of proinflammatory cytokines compared with their wild-type counterparts. Consistent with this result, bone marrow-derived Fra-1-null macrophages treated with CS showed decreased levels of proinflammatory mediators and matrix metalloproteinases. Interestingly, deletion of Fra-1 in myeloid cells did not affect the severity of emphysema. We propose that Fra-1 plays a key role in promoting chronic CS-induced lung macrophagic inflammation in vivo, and that targeting this transcription factor may be useful in dampening persistent lung inflammation in patients with COPD.

Fra-1/AP-1 transcription factor negatively regulates pulmonary fibrosis in vivo.

The Fra-1/AP-1 transcription factor plays a key role in tumor epithelial cell progression; however, its role in pathogenic lung fibrosis remains unclear. In the present study, using a genetic approach (Fra-1 deficient mice), we have demonstrated a novel regulatory (protective) role for Fra-1 in lung fibrosis. We found greater levels of progressive interstitial fibrosis, characterized by increased levels of inflammation, collagen accumulation, and profibrotic and fibrotic gene expression in the lungs of Fra-1(Δ/Δ) mice than in those of Fra-1(+/+) mice following bleomycin treatment. Fra-1 knockdown in human lung epithelial cells caused the upregulation of mesenchymal marker N-cadherin, concomitant with a downregulation of the epithelial phenotype marker E-cadherin, under basal conditions and in response to bleomycin and TGF-ß1. Furthermore, Fra-1 knockdown caused an enhanced expression of type 1 collagen and the downregulation of collagenase (MMP-1 and MMP-13) gene expression in human lung epithelial cells. Collectively, our findings demonstrate that Fra-1 mediates anti-fibrotic effects in the lung through the modulation of proinflammatory, profibrotic and fibrotic gene expression, and suggests that the Fra-1 transcription factor may be a potential target for pulmonary fibrosis, a progressive disorder with poor prognosis and treatment.

Oxidant-induced cell death and Nrf2-dependent antioxidative response are controlled by Fra-1/AP-1.

AP-1 (Jun/Fos) transcription factors play key roles in various biological processes, including cell death. Here we report a novel role for Fra-1 in oxidant-induced cell death controlled by modulating antioxidant gene expression. Fra-1-deficient (Fra-1(Δ/Δ)) mouse embryonic fibroblasts (MEFs) and primary lung fibroblasts (PLFs) were remarkably resistant to H(2)O(2)- and diquat-induced cell death, compared to their wild-type (Fra-1(+/+)) counterparts. Fra-1 deficiency ablated oxidant-induced mitochondrion-dependent apoptosis. Fra-1(Δ/Δ) cells had elevated basal levels of antioxidant enzymes and intracellular glutathione (GSH), which were further stimulated by oxidants. Loss of Fra-1 led to an increased half-life of transcription factor Nrf2 and increased recruitment of this protein to the promoters of antioxidant genes and increased their expression. Depletion of intracellular GSH or RNA interference (RNAi)-mediated knockdown of Nqo1, Hmox1, and Nrf2 restored oxidant-induced cell death in Fra-1(Δ/Δ) cells. Thus, Fra-1 appears to increase susceptibility to oxidants and promotes cell death by attenuating Nrf2-driven antioxidant responses.

The transcription factor encyclopedia.

Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130 mini review articles on pertinent human, mouse and rat TFs. Notable features of the TFe website include a high-quality PDF generator and web API for programmatic data retrieval. TFe aims to rapidly educate scientists about the TFs they encounter through the delivery of succinct summaries written and vetted by experts in the field. TFe is available at http://www.cisreg.ca/tfe.

Genetic disruption of Fra-1 decreases susceptibility to endotoxin-induced acute lung injury and mortality in mice.

The activator protein-1 (AP-1) transcription factor, comprising Jun and Fos family proteins, distinctly regulates various cellular processes, including those involved in inflammation. FOS like antigen 1 (Fra-1), a member of the Fos family, dimerizes with members of the Jun family and regulates gene expression in a context-dependent manner. Although respiratory toxicants are known to stimulate the expression of Fra-1 in the lung, whether Fra-1 promotes or decreases susceptibility to the development and progression of toxicant-induced lung disease in vivo is not well established. To determine the role of Fra-1 in LPS-induced acute lung injury and mortality, we administered LPS either intraperitoneally or intratracheally to Fra-1-sufficient (Fra-11(+/+)) and Fra-1-deficient (Fra-1(Δ/Δ)) mice. LPS-induced mortality, lung injury, inflammation, cytokine measurements, and AP-1 and NF-κB activities were then assessed in these mice. Fra-1(Δ/Δ) mice showed a greater resistance to LPS-induced mortality than did their Fra-1(+/+) counterparts. Consistent with this result, LPS-induced lung injury and inflammatory responses were markedly lower in Fra-1(Δ/Δ) mice than in Fra-1(+/+) mice. Compared with Fra-1(+/+) mice, Fra-1(Δ/Δ) mice showed a reduced influx of neutrophils into the lungs, accompanied by a decreased expression of proinflammatory cytokines in response to treatment with LPS. The decreased inflammatory responses in Fra-1(Δ/Δ) mice coincided with diminished and increased levels of NF-κB and c-Jun/AP-1 binding, respectively. These results demonstrate that Fra-1/AP-1 plays a key role in promoting LPS-induced injury and mortality in mice, and they suggest that targeting (i.e., inhibiting) this transcription factor may be a useful approach to dampening the adverse effects of exposure to endotoxins.

Influence of culture medium on the production of eif antigen from Leishmania chagasi in recombinant Escherichia coli

With the advent of recombinant DNA technology, recombinant protein expression has become an important tool in the study of the structure, function and identification of new proteins, especially those with therapeutic functions. Escherichia coli has been the predominant prokaryote used in genetic engineering studies due to the abundance of information about its metabolism. Despite significant advances in molecular biology and immunology of infections, there are as yet no prophylactic drugs capable of preventing visceral leishmaniasis. It is therefore important to identify specific antigens in order to develop vaccines and diagnostic kits against this disease. The objective of this study was to evaluate the influence of culture medium on the production of eIF antigen from Leishmania chagasi in recombinant Escherichia coli. An induction procedure using IPTG was carried out in a series of trials, to observe the influence of culture medium (2xTY, TB) under expression of the recombinant eIF protein. Results showed that recombinant protein expression was associated to growth and that the highest eIF antigen expression was obtained in the 2xTY medium.

Influence of culture medium on the production of eif antigen from Leishmania chagasi in recombinant Escherichia coli.

With the advent of recombinant DNA technology, recombinant protein expression has become an important tool in the study of the structure, function and identification of new proteins, especially those with therapeutic functions. Escherichia coli has been the predominant prokaryote used in genetic engineering studies due to the abundance of information about its metabolism. Despite significant advances in molecular biology and immunology of infections, there are as yet no prophylactic drugs capable of preventing visceral leishmaniasis. It is therefore important to identify specific antigens in order to develop vaccines and diagnostic kits against this disease. The objective of this study was to evaluate the influence of culture medium on the production of eIF antigen from Leishmania chagasi in recombinant Escherichia coli. An induction procedure using IPTG was carried out in a series of trials, to observe the influence of culture medium (2xTY, TB) under expression of the recombinant eIF protein. Results showed that recombinant protein expression was associated to growth and that the highest eIF antigen expression was obtained in the 2xTY medium.