Mesenchymal stromal cell infusion modulates systemic immunological responses in stable COPD patients: a phase I pilot study To the Editor: Chronic obstructive pulmonary disease (COPD) is a leading cause of global morbidity and mortality due to limited therapeutic options for the persistent pulmonary and systemic inflammation that characterises this condition [1]. Recently, pre-clinical studies of mesenchymal stromal cells (MSCs) in COPD demonstrate efficacy in alleviating inflammation and reducing emphysema following either systemic or intra-tracheal administration [2, 3]. Human trials have demonstrated that MSCs did not improve spirometry following their administration to COPD patients; however, it was reported that C-reactive protein (CRP), a marker for systemic inflammation, was reduced 1-3 months after infusion. Earlier time-points were not assessed in detail in these trials, which limits further investigation of these changes [4, 5]. Identifying the fate of intravenously infused MSCs and the potential implications of their biodistribution, as well as short-term MSC-induced systemic changes that were not explored in previous trials will better delineate the utility of MSC treatment for COPD. The study was approved by the Royal Perth Hospital ethics committee (approval number EC2012/103) and all patients had provided written informed consent. A single site, phase I study (Australian clinical trials registry number 12614000731695) was conducted to determine MSC biodistribution, inflammatory and clinical endpoints following systemic MSC infusion in a cohort (n=9) of mild to very severe stable COPD patients (n=1 Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I, n=2 GOLD II, n=3 GOLD III, n=3 GOLD IV). All recruited patients had not experienced an exacerbation for at least 3 months prior to trial commencement with no change in regular medications. Patients received two infusions of low passage (p4-5) allogeneic bone marrow-derived MSCs of approximately 2×10 6 MSCs per kg, 1 week apart, with the first infusion comprising radiolabelled cells and the second infusion using unlabelled cells. MSCs used for the first infusion were labelled with indium-111, a low energy radioisotope with a half-life of 68 h to enable tracking across several days. Labelled MSCs were able to adequately suppress peripheral blood mononuclear cell (PBMC) proliferation in vitro compared to unlabelled MSC (p>0.05) and retained regular morphological characteristics. Safety and hospitalisations attributed to acute exacerbations of COPD were monitored up to 1 year later. Wilcoxon matched pairs tests were used for comparison of pre-and post-infusion levels of cell subsets and circulating plasma biomarkers. MSC infusion showed no attributable adverse side-effects and was well tolerated. Following infusion, indium-111 was detected in the lung within 30 min by computed tomography (CT) scan and remained detectable after 24 h, after which uptake was detected in the liver, spleen and bone marrow up to 7 days after infusion (figure 1a ...

Steroid-refractory acute graft versus host disease (AGVHD) and chronic graft versus host disease (CGVHD) after allogeneic haematopoietic stem cell transplantation are major causes of morbidity and mortality. We undertook a phase I trial in patients with steroid-refractory AGVHD and CGVHD utilising bone marrow-derived mesenchymal stromal cells (MSC). Additionally, all refractory patients were treated with etanercept concomitantly. The primary end point was safety, and secondary end points were best response achieved and overall survival. A median of two infusions per patient were administered. The response rate overall for AGVHD was complete in seven, partial in four and no response in one patient. Of the seven patients who achieved a complete response, six are alive. The actuarial survival for the overall group of AGVHD was 55% at 30 months. Two patients with CGVHD achieved complete response with two partial responses and three with no response. The survival for those with AGVHD who achieved a complete response compared with those who did not was significant (p = 0.03). We identified no early or late safety issues in the nineteen patients. In view of the poor outlook for steroid-refractory AGVHD, further trials are warranted of MSC with steroid therapy, at the onset of AGVHD before steroid resistance.

SummaryThe epidermal growth factor receptor (EGFR) plays an important role in the development and progression of prostate cancer and its overexpression is associated with decreased survival. With progression, prostate cancer cells switch from epidermal growth factor (EGF) to transforming growth factor α (TGF-α) synthesis, which contributes to autocrine growth and unrestrained proliferation. To define the molecular mechanisms involved in the regulation of EGFR expression by EGF and TGF-α we studied three human prostate cancer cell lines, androgen-responsive (LNCaP) and -unresponsive (DU145 and PC3). Here we show that TGF-α stabilized EGFR mRNA two-to threefold in all three cell lines, whilst EGF stabilized EGFR mRNA ~ twofold in LNCaP and DU145 cells, but not in PC3 cells. Both ligands increased EGFR transcription in LNCaP and DU145 cells, with less effect in PC3 cells. In all three cell lines EGF reduced total EGFR protein levels more than TGF-α, but this was associated with a greater increase in de novo protein synthesis with EGF compared to TGF-α. Only EGF, however, shortened EGFR protein stability (half-life decreased from 5 h to 120 min), resulting in rapid disappearance of newly synthesized EGFR protein. Both ligands increased total LNCaP and DU145 cell numbers. These studies demonstrate that the EGF-and TGF-α-induced upregulation of EGFR mRNA and protein in human prostate cancer cell lines is complex and occurs at multiple, transcriptional and post-transcriptional levels. Taken together, these data provide novel insight into the molecular mechanisms by which TGF-α would preferentially maintain an autocrine loop in human prostate cancer cells. Furthermore, this work suggests that in human prostate cancer cells ligand-specific differential intracellular trafficking of the EGFR plays a major role in regulating its expression.

We describe successful immunotherapy of murine AIDS (MAIDS) in C57BL/6J mice based on the elimination of replicating CD4+ regulator T cells. We demonstrate that a single injection of the antimitotic drug vinblastine (Vb) given 14 days postinfection (p.i.) with LP-BM5 can prevent MAIDS progression. Treatment with anti-CD4 mAb at 14 days p.i. is similarly able to prevent MAIDS. Treatment at other time points with Vb or anti-CD4 mAb is ineffective. The effect is based on ablation of a replicating dominantly suppressive CD4+ T cell population, as indicated by adoptive transfer and in vivo depletion experiments using mAbs against CD4 as well as combinations of mAbs against the known regulatory cell surface markers CD25, GITR, and CTLA-4. Cell surface marker analysis shows a population of CD4+CD25+ cells arising shortly before day 14 p.i. Cytokine analyses show a peak in IL-10 production from day 12 to day 16 p.i. MAIDS-infected mice also have CD4+ T cells with significantly higher expression levels of CD38 and particularly CD69, which have been demonstrated to be regulator T cell markers in the Friend retroviral model. The immunotherapy appears to prevent disease progression, although no protection against reinfection with LP-BM5 is generated. These data define a new therapy for murine retroviral infection, which has potential for use in other diseases where T regulator cell-mediated immunosuppression plays a role in the disease process.

Members of the genus Brucella are known worldwide as pathogens of wildlife and livestock and are the most common organisms of zoonotic infection in humans. In general, brucellae exhibit a range of host specificity in animals that has led to the identification of at least seven Brucella species. The genomes of the various Brucella species are highly conserved, which makes the differentiation of species highly challenging. However, we found single-nucleotide polymorphisms (SNPs) in housekeeping and other genes that differentiated the seven main Brucella species or clades and thus enabled us to develop real-time PCR assays based around these SNPs. Screening of a diverse panel of 338 diverse isolates with these assays correctly identified each isolate with its previously determined Brucella clade. Six of the seven clade-specific assays detected DNA concentrations of less than 10 fg, indicating a high level of sensitivity. This SNP-based approach places samples into a phylogenetic framework, allowing reliable comparisons to be made among the lineages of clonal bacteria and providing a solid basis for genotyping. These PCR assays provide a rapid and highly sensitive method of differentiating the major Brucella groups that will be valuable for clinical and forensic applications.Brucella spp. are pathogenic bacteria that infect a wide variety of mammalian hosts worldwide, often causing reproductive failure. The genus Brucella has classically been divided into six species based on host specificity, including B. abortus (cattle and bison), B. melitensis (goats and sheep), B. suis (pigs), B. canis (dogs), B. neotomae (desert woodrat), and B. ovis (sheep) (12). Two new species have been discovered recently in marine mammals (B. cetaceae in dolphins and whales and B. pinnipediae in seals) (10). Taxonomic limits of the marine clade, however, are not fully defined, and this group may represent one to three species (8, 18). B. abortus, B. melitensis, B. suis, and B. canis are well-characterized zoonotic pathogens, annually infecting Ͼ500,000 people worldwide (26). In the United States, the first three of these species are defined as select agents due to their pathogenicity and potential use as biological weapons (11).Despite host-based segregation, Brucella spp. have proven challenging to differentiate using molecular techniques. Brucella genomes are highly conserved, with Ͼ90% homology among species based on DNA-DNA hybridization (35), identical 16S rRNA sequences among all species (15), and Ͼ90% of genes sharing Ͼ98% sequence identity (16,27). Serological methods and biochemical testing of isolates allow differentiation of species and biovars. However, PCR-based methods have been used increasingly due to their accuracy, sensitivity, and speed of identification and the ability to work with DNA as opposed to highly infectious live cultures. A wide array of genetic polymorphisms can be assayed for the differentiation of Brucella spp., including the insertion element IS711 (2, 3, 29, 31) and genes of outer membrane proteins (7,...