Ex vivo intervertebral disc cultures: degeneration-induction methods and their implications for clinical translation.

Because low back pain is frequently a result of intervertebral disc degeneration (IVDD), strategies to regenerate or repair the IVD are currently being investigated. Often, ex vivo disc cultures of non-human IVD organs or tissue explants are used that usually do not exhibit natural IVDD. Therefore, degenerative changes mimicking those reported in human IVDD need to be induced. To support researchers in selecting ex vivo disc cultures, a systematic search was performed for them and their potential use for studying human IVDD reviewed. Five degeneration induction categories (proinflammatory cytokines, injury/damage, degenerative loading, enzyme, and other) were identified in 129 studies across 7 species. Methods to induce degeneration are diverse and can induce mild to severe degenerative changes that progress over time, as described for human IVDD. The induced degenerative changes are model-specific and there is no "one-fits-all" IVDD induction method. Nevertheless, specific aspects of human IVDD can be well mimicked. Currently, spontaneously degenerated disc cultures from large animals capture human IVDD in most aspects. Combinatorial approaches of several induction methods using discs derived from large animals are promising to recapitulate pathological changes on several levels, such as cellular behaviour, extracellular matrix composition, and biomechanical function, and therefore better mimic human IVDD. Future disc culture setups might increase in complexity, and mimic human IVDD even better. As ex vivo disc cultures have the potential to reduce and even replace animal trials, especially during preclinical development, advancement of such models is highly relevant for more efficient and cost-effective clinical translation from bench-to-bedside.

Mesenchymal stem cell secretome decreases the inflammatory response in annulus fibrosus organ cultures.

Mesenchymal stem/stromal cell (MSC)-based therapies have been proposed for back pain and disc degeneration, despite limited knowledge on their mechanism of action. The impact of MSCs/their secretome on annulus fibrosus (AF) cells and tissue was analysed in bovine AF organ cultures (AF-OCs) exposed to upper-physiological cyclic tensile strain (CTS, 9 %, 1 Hz, 3 h/d) and interleukin (IL)-1ß in a custom-made device. A 4 d treatment of the CTS + IL-1ß-stimulated AF-OCs with MSC secretome downregulated the expression of inflammation markers [IL-6, IL-8, prostaglandin-endoperoxide synthase 2 (PTGS2)], complement system regulators [cluster of differentiation (CD)46, CD55, CD59] and matrix metalloproteinase 1 but also of tissue inhibitors of metalloproteinases (TIMP-1, TIMP-2) and collagen type I. At the protein level, it was confirmed that IL-6, MMP-3 and collagen content was decreased in AF-OCs treated with the MSC secretome compared to the CTS + IL-1ß stimulation alone. 9 d after treatment, a biomechanical peel-force test showed that the annular adhesive strength was significantly decreased by the MSC secretome treatment. Overall, MSC secretome had a stronger impact on AF tissue than MSCs in co-culture. The secretome contributed to a decrease in the inflammatory and catabolic status of AF cells activated by CTS + IL-1ß and played a role in the regulation of the complement system. However, it also contributed to a decrease in collagen at the gene/protein level and in AF mechanical strength compared to the CTS + IL-1ß stimulation alone. Therefore, the use of MSC secretome requires further investigation regarding its influence on disc matrix properties.

Time course and management of key adverse events during the randomized phase III SOLAR-1 study of PI3K inhibitor alpelisib plus fulvestrant in patients with HR-positive advanced breast cancer.

BACKGROUND: Alpelisib (α-selective phosphatidylinositol 3-kinase inhibitor) plus fulvestrant is approved in multiple countries for men and postmenopausal women with PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer following progression on or after endocrine therapy. A detailed understanding of alpelisib's safety profile should inform adverse event (AE) management and enhance patient care. PATIENTS AND METHODS: AEs in the phase III SOLAR-1 trial were assessed in patients with and without PIK3CA mutations. The impact of protocol-specified AE-management recommendations was evaluated, including an amendment to optimize hyperglycemia and rash management. RESULTS: Patients were randomly assigned to receive fulvestrant plus alpelisib (n = 284) or placebo (n = 287). The most common grade 3/4 AEs with alpelisib were hyperglycemia (grade 3, 32.7%; grade 4, 3.9%), rash (grade 3, 9.9%), and diarrhea (grade 3, 6.7%). Median time to onset of grade ≥3 toxicity was 15 days (hyperglycemia, based on fasting plasma glucose), 13 days (rash), and 139 days (diarrhea). Metformin alone or in combination with other antidiabetic agents was used by most patients (87.1%) with hyperglycemia. Preventive anti-rash medication resulted in lower incidence (any grade, 26.7% versus 64.1%) and severity of rash (grade 3, 11.6% versus 22.7%) versus no preventative medication. Discontinuations due to grade ≥3 AEs were lower following more-detailed AE management guidelines (7.9% versus 18.1% previously). Patients with PIK3CA mutations had a median alpelisib dose intensity of 248 mg/day. Median progression-free survival with alpelisib was 12.5 and 9.6 months for alpelisib dose intensities of ≥248 mg/day and <248 mg/day, respectively, compared with 5.8 months with placebo. CONCLUSIONS: Hyperglycemia and rash occurred early during alpelisib treatment, while diarrhea occurred at a later time point. Early identification, prevention, and intervention, including concomitant medications and alpelisib dose modifications, resulted in less severe toxicities. Reductions in treatment discontinuations and improved progression-free survival at higher alpelisib dose intensities support the need for optimal AE management. CLINICALTRIALS. GOV ID: NCT02437318.

Controlled and Tunable Loading and Release of Vesicles by Using Gigahertz Acoustics.

Controllable exchange of molecules between the interior and the external environment of vesicles is critical in drug delivery and micro/nano-reactors. While many approaches exist to trigger release from vesicles, controlled loading remains a challenge. Herein, we show that gigahertz acoustic streaming generated by a nanoelectromechanical resonator can control the loading and release of cargo into and from vesicles. Polymer-shelled vesicles showed loading and release of molecules both in solution and on a solid substrate. We observed deformation of individual giant unilamellar vesicles and propose that the shear stress generated by gigahertz acoustic streaming induces the formation of transient nanopores, with diameters on the order of 100 nm, in the vesicle membranes. This provides a non-invasive method to control material exchange across membranes of different types of vesicles, which could allow site-specific release of therapeutics and controlled loading into cells, as well as tunable microreactors.

Reversible Stabilization of Vesicles: Redox-Responsive Polymer Nanocontainers for Intracellular Delivery.

We present the self-assembly of redox-responsive polymer nanocontainers comprising a cyclodextrin vesicle core and a thin reductively cleavable polymer shell anchored via host-guest recognition on the vesicle surface. The nanocontainers are of uniform size, show high stability, and selectively respond to a mild reductive trigger as revealed by dynamic light scattering, transmission electron microscopy, atomic force microscopy, a quantitative thiol assay, and fluorescence spectroscopy. Live cell imaging experiments demonstrate a specific redox-responsive release and cytoplasmic delivery of encapsulated hydrophilic payloads, such as the pH-probe pyranine, and the fungal toxin phalloidin. Our results show the high potential of these stimulus-responsive nanocontainers for cell biological applications requiring a controlled delivery.

Cyclic tensile stress of human annulus fibrosus cells induces MAPK activation: involvement in proinflammatory gene expression.

OBJECTIVE: To study the role of mitogen-activated protein kinases (MAPKs) in human annulus fibrosus (AF) cells subjected to cyclic tensile stress (CTS). DESIGN: An in vitro system for CTS studies was established using AF cultures on fibronectin-coated silicone dishes. MAPK phosphorylation was studied by western analysis, while gene expression was followed by qRT-PCR. DNA synthesis was assessed by both tritiated thymidine incorporation and flow cytometry, and collagen synthesis using tritiated proline incorporation and the protease-free collagenase method. RESULTS: All three MAPKs studied, i.e., ERK, SAPK/JNK, and p38 were found to be phosphorylated immediately after CTS application within physiological range. A second wave of phosphorylation appeared at later time points. MAPK activation was elevated at higher CTS magnitudes, but independent of the frequency. CTS did not stimulate DNA synthesis neither extracellular matrix turnover, but it stimulated the proinflammatory genes, COX-2, IL-6, and IL-8. This stimulation was more intense at the highest magnitude (8%) tested and at the median frequency (1 Hz) and time interval (12 h). Blocking of ERK, SAPK/JNK, and p38 MAPK inhibited the CTS-induced stimulation of COX-2 and IL-8, while IL-6 expression was mediated only by SAPK/JNK and p38 MAPK. CONCLUSIONS: We have described for the first time the activation of MAPKs in human AF cells in response to CTS and showed that it drives an inflammatory reaction. These observations shed light on the mechanisms of intervertebral disc (IVD) cell responses to mechanical stress, contributing to the understanding of disc pathophysiology and possibly to the design of novel therapeutic interventions.

Partial PTEN deletion is linked to poor prognosis in breast cancer.

BACKGROUND: Deletions of chromosome 10q23, including the PTEN (phosphatase and tensin homolog) locus, are known to occur in breast cancer, but systematic analyses of its clinical relevance are lacking. METHODS: We thus analyzed a tissue microarray (TMA) with 2,197 breast cancers by fluorescence in-situ hybridization (FISH) using a PTEN-specific probe. RESULTS: PTEN deletions were detected in 19% of no special type, 9% of lobular, 4% of tubular cancers and 46% in carcinomas with medullary features. 98.7% of deletions were heterozygous and only 1.3% were homozygous. PTEN deletion was significantly linked to advanced tumor stage (p=0.0054), high-grade (p<0.0001), high tumor cell proliferation (Ki67 Labeling Index; p<0.0001), and shortened overall survival (p=0.0090). PTEN deletions were inversely associated with features of luminal type breast cancers (ER/PR positivity; p<0.0001 each, and CCND1 amplification; p=0.0020). PTEN deletions were also strongly linked to amplification of genes involved in the PTEN/AKT pathway such as MYC (p=0.0430) and HER2 (p=0.0065). Remarkably the combined analysis of MYC, HER2, CCND1 and PTEN aberrations suggested that aberrations of multiple PTEN/AKT pathway genes have a strong additive effect on breast cancer prognosis. While cancers with one of these aberrations behaved only marginally different from cancers with none, disease outcome was markedly worse in cancers with two or more aberrations as compared to those with only one aberration (p=0.0002). In addition, the particularly poor prognosis of patients with HER2 amplification and PTEN deletions challenges the concept of PTEN deletions interfering with trastuzumab therapy. CONCLUSION: PTEN deletion occurs in a relevant fraction of breast cancers, and is linked to aggressive tumor behavior. Reduced PTEN function cooperates with MYC and HER2 activation in conferring aggressive phenotype to cancer cells.

[Analysis of workplace health promotion and its effect on work ability and health-related quality of life in a medium-sized business]. / Analyse der Arbeitsfähigkeit und gesundheitsbezogenen Lebensqualität im Rahmen bewegungsbezogener Maßnahmen der betrieblichen Gesundheitsförderung in einem mittelständischen Unternehmen.

This study analyses the effect of workplace health promotion on work ability and health-related quality of life in white-collar and blue-collar workers in a medium-sized business. The intervention group contains 75 subjects with a mean age of 36.6±10.63 years (55 men, 20 women). The participation rate is 47%. White-collar workers show improvement in their health-related quality of life regarding physical and psychological aspects and work ability. Physically inactive employees show improvement in their health-related quality of life regarding physical and psychological aspects as well as context. Active employees only show significant improvement in terms of work ability. In conclusion, the promotion of exercise in the context of occupational health promotion has a positive effect on quality of life and work ability of employees and, thus, is a benefit for both the individual as well as the business itself.

A randomized controlled phase II trial of a novel composition of paclitaxel embedded into neutral and cationic lipids targeting tumor endothelial cells in advanced triple-negative breast cancer (TNBC).

BACKGROUND: EndoTAG-1, composed of paclitaxel embedded in liposomal membranes targeting tumor endothelial cells, was evaluated for safety and efficacy in advanced triple-negative breast cancer (TNBC). PATIENTS AND METHODS: One hundred and forty patients were treated with weekly EndoTAG-1 (22 mg/m(2)) plus paclitaxel (70 mg/m(2)), twice weekly EndoTAG-1 (2× 44 mg/m(2)), or weekly paclitaxel (90 mg/m(2)) for greater than or equal to four cycles (3-week treatment + 1-week rest) or until progression/toxicity. Primary end point was progression-free survival (PFS) rate evaluated centrally after four cycles of therapy (week 16). The study was not powered for intergroup comparisons. RESULTS: The PFS rate at week 16 was 59.1% [one-sided 95% CI: 45.6, ∞] on combination treatment, 34.2% [21.6, ∞] on EndoTAG-1, and 48.0% [30.5, ∞] on paclitaxel. Median PFS reached 4.2, 3.4, and 3.7 months, respectively. After complete treatment (week 41 analysis), median overall survival (OS) was 13.0, 11.9, and 13.1 months for the modified Intention-to-Treat (ITT) population and 15.1, 12.5, and 8.9 months for the per-protocol population, respectively. The clinical benefit rate was 53%, 31%, and 36% for the treatment groups. Safety analysis revealed known toxicities of the drugs with slight increases of grade 3/4 neutropenia on combination therapy. CONCLUSION: Treatment of advanced TNBC with a combination of EndoTAG-1 and standard paclitaxel [Taxol® (Bristol-Myers Squibb GmbH), or equivalent generic formulation] was well tolerated and showed antitumor efficacy. The positive trend needs to be confirmed in a randomized phase III trial. STUDY REGISTRATION: European Clinical Trials Database: EudraCT number 2006-002221-23. ClinicalTrials.gov identifier: NCT00448305.

Slow fitness recovery in a codon-modified viral genome.

Extensive synonymous codon modification of viral genomes appears to be an effective way of attenuating strains for use as live vaccines. An assumption of this method is that codon changes have individually small effects, such that codon-attenuated viruses will be slow to evolve back to high fitness (and thus to high virulence). The major capsid gene of the bacterial virus T7 was modified to have varying levels of suboptimal synonymous codons in different constructs, and fitnesses declined linearly with the number of changes. Adaptation of the most extreme design, with 182 codon changes, resulted in a slow fitness recovery by standards of previous experimental evolution with this virus, although fitness effects of substitutions were higher than expected from the average effect of an engineered codon modification. Molecular evolution during recovery was modest, and changes evolved both within the modified gene and outside it. Some changes within the modified gene evolved in parallel across replicates, but with no obvious explanation. Overall, the study supports the premise that codon-modified viruses recover fitness slowly, although the evolution is substantially more rapid than expected from the design principle.

Fibrotic alterations in human annulus fibrosus correlate with progression of intervertebral disc herniation.

BACKGROUND: Intervertebral disc (IVD) herniation is characterized by annulus fibrosus failure (AF) in containing the nucleus pulposus (NP). IVD herniation involves cellular and extracellular matrix (ECM) alterations that have been associated with tissue fibrosis, although still poorly investigated. METHODS: Here, fibrotic alterations in human AF were evaluated, by characterizing the herniated ECM. Human AF samples (herniated lumbar IVD (n = 39, age 24-83) and scoliosis controls (n = 6, age 15-21)) were processed for transmission electron microscopy and histological/immunohistochemical analysis of fibrotic markers. Correlations between the fibrotic markers in AF ECM and the degree of NP containment (protused, contained and uncontained) and patients' age were conducted. RESULTS: Our results demonstrate that with herniation progression, i.e. loss of NP containment, human AF presents less stained area of sulphated glycosaminoglycans and collagen I, being collagen I fibres thinner and disorganized. On the other hand, fibronectin stained area and percentage of α-smooth muscle actin+ cells increase in human AF, while matrix metalloproteinase-12 (MMP12) production and percentage of macrophages (CD68+ cells) remain constant. These structural and biochemical fibrotic alterations observed in human AF with herniation progression occur independently of the age. CONCLUSIONS: The characterization of human AF here conducted evidence the presence of fibrosis in degenerated IVD, while highlighting the importance of considering the herniation progression stage, despite the patients' age, for a better understanding of the mechanisms behind AF failure and IVD herniation.

Exposure and safety of higher doses of recombinant factor VIIa ≥250 µg kg(-1) in individuals with congenital haemophilia complicated by alloantibody inhibitors: the Haemophilia and Thrombosis Research Society Registry experience (2004-2008).

Recombinant factor VIIa (rFVIIa) is a well-established treatment for managing bleeding episodes in individuals with congenital haemophilia complicated by alloantibody inhibitors (CHwI). The safety and efficacy of standard dosing (90-120 µg kg(-1) every 2-3 h) are well-established; however, the desire to optimize therapy with one or more higher doses instead of multiple lower doses has created a need for evidence of the safety and efficacy of such regimens. Analysis of data from the Haemophilia and Thrombosis Research Society (HTRS) Registry was performed on episodes where doses of ≥250 µg kg(-1) were reported. From 2041 rFVIIa-treated bleeds, 172 bleeding episodes were identified in 25 individuals with CHwI who were treated with ≥1 higher doses (≥250 µg kg(-1) , ≥270 µg kg(-1) or ≥300 µg kg(-1) ) of rFVIIa between January 2004 and November 2008. Bleeds occurred in individuals ranging in age from 0.4 to 41.7 years who were predominantly non-Hispanic and white (40%) with haemophilia A (88%). Bleed types most frequently treated with higher doses of rFVIIa were spontaneous (62-65%) or traumatic (27-32%). Bleed locations most frequently treated with higher doses of rFVIIa were joint (60-68%) or muscle (20-25%). A total of 1521 rFVIIa doses were administered (median, three doses per bleed); 26% were 250 µg kg(-1) or higher (initial dose, 82%). Bleeding stopped in 93% (160/172) of bleeds treated with rFVIIa 250 µg kg(-1) or higher. No serious adverse drug-related events or thrombotic complications were reported. This data analysis from the HTRS Registry provides evidence of the safe and effective use of higher doses of rFVIIa (≥250 µg kg(-1) ) in US practice.

Inhibition of interleukin 8 attenuates angiogenesis in bronchogenic carcinoma.

We investigated the role of interleukin 8 (IL-8) in mediating angiogenesis in human bronchogenic carcinoma. Increased quantities of IL-8 were detected in tumor tissue as compared with normal lung tissue. Immunohistochemical staining of tumors revealed primary localization of IL-8 to individual tumor cells and demonstrated the capacity of tumor to elaborate IL-8. Functional studies that used tissue homogenates of tumors demonstrated the induction of both in vitro endothelial cell chemotaxis and in vivo corneal neovascularization. It is important to note that the addition of neutralizing antisera to IL-8 to these assays resulted in the marked and specific attenuation of these responses. Our observations definitively establish IL-8 as a primary mediator of angiogenesis in bronchogenic carcinoma and offer a potential target for immunotherapies against solid malignancies.

Lupus-specific health outcome measure for US patients: the LupusQoL-US version.

BACKGROUND: Patient-reported outcomes are valuable for the management of chronic diseases like systematic lupus erythematosus (SLE), but no measures have been validated for use in US-based patients with SLE. OBJECTIVES: To adapt and assess the validity and reliability of an SLE-specific quality of life (QoL) measure developed in the United Kingdom, the LupusQoL, for use in US-based patients with SLE. METHODS: Debriefing interviews of subjects with SLE guided the language modifications of the tool. The LupusQoL-US, SF-36 and EQ5D were administered. Internal consistency (ICR) and test-retest (TRT) reliability, convergent and discriminative validity were examined. Factor analyses were performed. RESULTS: The mean (SD) age of the 185 subjects with SLE was 42.5 (12.9) years. ICR and TRT of the eight domains ranged from 0.85 to 0.94 and 0.68 to 0.92, respectively. Related domains on the SF-36 correlated with the LupusQoL domains (physical health and physical function r = 0.73, physical health and role physical r = 0.57, emotional health and mental health r = 0.72, emotional health and role emotional r = 0.48, pain and bodily pain r = 0.66, fatigue and vitality r = 0.70, planning and social functioning r = 0.58). Most LupusQoL-US domains could discriminate between subjects with varied disease activity and damage. Principal component analysis disclosed five factors in the US version, with physical function, pain and planning items loading on one factor. CONCLUSIONS: These data provide evidence to support the psychometric properties of the LupusQoL-US, suggesting its utility as an assessment tool for patients with SLE in the USA.

Phenotypic differences in viral immune escape explained by linking within-host dynamics to host-population immunity.

Viruses that do not cause life-long immunity persist by evolving rapidly in response to prevailing host immunity. The immune-escape mutants emerge frequently, displacing or co-circulating with native strains even though mutations conferring immune evasion are often detrimental to viral replication. The epidemiological dynamics of immune-escape in acute-infection viruses with high transmissibility have been interpreted mainly through immunity dynamics at the host population level, despite the fact that immune-escape evolution involves dynamical processes that feedback across the within- and between-host scales. To address this gap, we use a nested model of within- and between-host infection dynamics to examine how the interaction of viral replication rate and cross-immunity imprint host population immunity, which in turn determines viral immune escape. Our explicit consideration of direct and immune-mediated competitive interactions between strains within-hosts revealed three insights pertaining to risk and control of viral immune-escape: (1) replication rate and immune-stimulation deficiencies (i.e., original antigenic sin) act synergistically to increase immune escape, (2) immune-escape mutants with replication deficiencies relative to their wildtype progenitor are most successful under moderate cross-immunity and frequent re-infections, and (3) the immunity profile along short host-transmission chains (local host-network structure) is a key determinant of immune escape.

Photochemical preparation of gold nanoparticle decorated cyclodextrin vesicles with tailored plasmonic properties.

We report a photochemical strategy for the preparation of plasmonic vesicles by the in situ formation of gold nanoparticles at the surface of cyclodextrin host vesicle templates decorated with photoactive guest polymers. Upon irradiation with UV light, these carefully designed polymer shells undergo a Norrish type I reaction to generate reducing radicals for the in situ reduction of gold salts and simultaneously provide a stabilizing matrix allowing for a dense decoration with discrete gold seeds. In a highly controlled growth procedure the gold particle size can be adjusted between 3 and 28 nm resulting in an increasing interparticle plasmonic coupling as revealed by a pronounced redshift of the surface plasmon resonance (SPR) band and an enhanced absorption at wavelengths above 600 nm. This unique combination of cyclodextrin vesicles capable of specifically recognizing guest molecules with a plasmonic particle shell displaying multiple interparticle gaps acting as electromagnetic hotspots shows great potential for surface-enhanced Raman scattering (SERS) applications.

Controlled Cellular Delivery of Amphiphilic Cargo by Redox-Responsive Nanocontainers.

The specific transport of amphiphilic compounds such as fluorescently labeled phospholipids into cells is a prerequisite for the analysis of highly dynamic cellular processes involving these molecules, e.g., the intracellular distribution and metabolism of phospholipids. However, cellular delivery remains a challenge as it should not affect the physiological integrity and morphology of the cell membrane. To address this, polymer nanocontainers based on redox-responsive cyclodextrin (CD) amphiphiles are prepared, and their potential to deliver fluorescently labeled phospholipids to intracellular membrane compartments is analyzed. It is shown that mixtures of reductively degradable cyclodextrin amphiphiles and different phospholipids form liposome-like vesicles (CD-lipid vesicles, CSSLV) with a homogeneous distribution of each lipid. Host-guest-mediated self-assembly of a cystamine-crosslinked polymer shell on these CSSLV produces polymer-shelled liposomal vesicles (PSSCSSLV) with the unique feature of a redox-sensitive CSSLV core and reductively degradable polymer shell. PSSCSSLV show high stability and a redox-sensitive release of the amphiphilic cargo. Live cell experiments reveal that the novel PSSCSSLV are readily internalized by primary human endothelial cells and that the reductive microenvironment of the cells' endosomes triggers the release of the amphiphilic cargo into the cytosol. Thus, PSSCSSLV represent a highly efficient system to transport lipid-like amphiphilic cargo into the intracellular environment.

Bone marrow transplant-induced alterations in Notch signaling promote pathologic Th17 responses to γ-herpesvirus infection.

Idiopathic pneumonia syndrome (IPS) is a common, often fatal, complication following hematopoietic stem cell transplantation (HSCT) characterized by severe pneumonitis and interstitial fibrosis. Fully reconstituted syngeneic bone marrow transplant (BMT) mice infected with murine γ-herpesvirus-68 develop interleukin-17 (IL-17)-driven pneumonitis and fibrosis, which mimics clinical manifestations of IPS. We found CD103+ and CD11b+ dendritic cells (DCs) are selectively deficient for the Notch ligand, DLL4, following BMT and CD4+ T cells isolated from lungs and spleens of infected BMT mice display Notch signaling defects. Mice transplanted with CD4-Cre-driven dominant-negative Notch transcriptional regulator Mastermind-Like (CD4-Cre-DNMAML (CCD) mice) bone marrow displayed elevated IL-17 and transforming growth factor-ß (TGF ß) in the lungs, a further expansion of T-helper type 17 (Th17) cells, and developed more fibrosis than wild-type (WT)-BMT mice. Culture of BMT lung leukocytes with recombinant Notch ligand, DLL4, restored Notch signaling and decreased production of IL-17. Adoptive transfer of CD11c+ DCs could restore Th1 and limit Th17 in WT-BMT but not CCD-BMT mice, indicating that a specific DC/CD4+ T-cell Notch interaction modulates IL-17 production following reconstitution in syngeneic BMT mice. Given recent clinical observations showing that patients with pulmonary complications post-transplant harbor occult herpesvirus infections, these data provide mechanistic insight and suggest potential therapies for these devastating conditions.

Elevated prostaglandin E2 post-bone marrow transplant mediates interleukin-1ß-related lung injury.

Hematopoietic stem cell transplant (HSCT) treats or cures a variety of hematological and inherited disorders. Unfortunately, patients who undergo HSCT are susceptible to infections by a wide array of opportunistic pathogens. Pseudomonas aeruginosa bacteria can have life-threatening effects in HSCT patients by causing lung pathology that has been linked to high levels of the potent pro-inflammatory cytokine, interleukin-1ß (IL-1ß). Using a murine bone marrow transplant (BMT) model, we show that overexpression of prostaglandin E2 (PGE2) post-BMT signals via EP2 or EP4 to induce cyclic adenosine monophosphate (cAMP), which activates protein kinase A or the exchange protein activated by cAMP (Epac) to induce cAMP response element binding-dependent transcription of IL-1ß leading to exacerbated lung injury in BMT mice. Induction of IL-1ß by PGE2 is time and dose dependent. Interestingly, IL-1ß processing post-P. aeruginosa infection occurs via the enzymatic activity of either caspase-1 or caspase-8. Furthermore, PGE2 can limit autophagy-mediated killing of P. aeruginosa in alveolar macrophages, yet autophagy does not have a role in PGE2-mediated upregulation of IL-1ß. Reducing PGE2 levels with indomethacin improved bacterial clearance and reduced IL-1ß-mediated acute lung injury in P. aeruginosa-infected BMT mice.