Nirsevimab binding-site conservation in respiratory syncytial virus fusion glycoprotein worldwide between 1956 and 2021: an analysis of observational study sequencing data.

BACKGROUND: Nirsevimab is an extended half-life monoclonal antibody to the respiratory syncytial virus (RSV) fusion protein that has been developed to protect infants for an entire RSV season. Previous studies have shown that the nirsevimab binding site is highly conserved. However, investigations of the geotemporal evolution of potential escape variants in recent (ie, 2015-2021) RSV seasons have been minimal. Here, we examine prospective RSV surveillance data to assess the geotemporal prevalence of RSV A and B, and functionally characterise the effect of the nirsevimab binding-site substitutions identified between 2015 and 2021. METHODS: We assessed the geotemporal prevalence of RSV A and B and nirsevimab binding-site conservation between 2015 and 2021 from three prospective RSV molecular surveillance studies (the US-based OUTSMART-RSV, the global INFORM-RSV, and a pilot study in South Africa). Nirsevimab binding-site substitutions were assessed in an RSV microneutralisation susceptibility assay. We contextualised our findings by assessing fusion-protein sequence diversity from 1956 to 2021 relative to other respiratory-virus envelope glycoproteins using RSV fusion protein sequences published in NCBI GenBank. FINDINGS: We identified 5675 RSV A and RSV B fusion protein sequences (2875 RSV A and 2800 RSV B) from the three surveillance studies (2015-2021). Nearly all (25 [100%] of 25 positions of RSV A fusion proteins and 22 [88%] of 25 positions of RSV B fusion proteins) amino acids within the nirsevimab binding site remained highly conserved between 2015 and 2021. A highly prevalent (ie, >40·0% of all sequences) nirsevimab binding-site Ile206Met:Gln209Arg RSV B polymorphism arose between 2016 and 2021. Nirsevimab neutralised a diverse set of recombinant RSV viruses, including new variants containing binding-site substitutions. RSV B variants with reduced susceptibility to nirsevimab neutralisation were detected at low frequencies (ie, prevalence <1·0%) between 2015 and 2021. We used 3626 RSV fusion-protein sequences published in NCBI GenBank between 1956 and 2021 (2024 RSV and 1602 RSV B) to show that the RSV fusion protein had lower genetic diversity than influenza haemagglutinin and SARS-CoV-2 spike proteins. INTERPRETATION: The nirsevimab binding site was highly conserved between 1956 and 2021. Nirsevimab escape variants were rare and have not increased over time. FUNDING: AstraZeneca and Sanofi.

Engraftment of Bacteria after Fecal Microbiota Transplantation Is Dependent on Both Frequency of Dosing and Duration of Preparative Antibiotic Regimen.

The gut microbiota has emerged as a key mediator of human physiology, and germ-free mice have been essential in demonstrating a role for the microbiome in disease. Preclinical models using conventional mice offer the advantage of working with a mature immune system. However, optimal protocols for fecal microbiota transplant (FMT) engraftment in conventional mice are yet to be established. Conventional BALB/c mice were randomized to receive 3-day (3d) or 3-week (3w) antibiotic (ABX) regimen in their drinking water followed by 1 or 5-daily FMTs from a human donor. Fecal samples were collected longitudinally and characterized using 16S ribosomal RNA (rRNA) sequencing. Semi-targeted metabolomic profiling of fecal samples was also done with liquid chromatography-mass spectrometry (LC-MS). Lastly, we sought to confirm our findings in BKS mice. Recovery of baseline diversity scores were greatest in the 3d groups, driven by re-emergence of mouse commensal microbiota, whereas the most resemblance to donor microbiota was seen in the 3w + 5-FMT group. Amplicon sequence variants (ASVs) that were linked to the input material (human ASVs) engrafted to a significantly greater extent when compared to mouse ASVs in the 3-week groups but not the 3-day groups. Lastly, comparison of metabolomic profiles revealed distinct functional profiles by ABX regimen. These results indicate successful model optimization and emphasize the importance of ABX duration and frequency of FMT dosing; the most stable and reliable colonization by donor ASVs was seen in the 3wk + 5-FMT group.

PD-L1+ neutrophils contribute to injury-induced infection susceptibility.

The underlying mechanisms contributing to injury-induced infection susceptibility remain poorly understood. Here, we describe a rapid increase in neutrophil cell numbers in the lungs following induction of thermal injury. These neutrophils expressed elevated levels of programmed death ligand 1 (PD-L1) and exhibited altered gene expression profiles indicative of a reparative population. Upon injury, neutrophils migrate from the bone marrow to the skin but transiently arrest in the lung vasculature. Arrested neutrophils interact with programmed cell death protein 1 (PD-1) on lung endothelial cells. A period of susceptibility to infection is linked to PD-L1+ neutrophil accumulation in the lung. Systemic treatment of injured animals with an anti-PD-L1 antibody prevented neutrophil accumulation in the lung and reduced susceptibility to infection but augmented skin healing, resulting in increased epidermal growth. This work provides evidence that injury promotes changes to neutrophils that are important for wound healing but contribute to infection susceptibility.

Safety and clinical activity of intratumoral MEDI9197 alone and in combination with durvalumab and/or palliative radiation therapy in patients with advanced solid tumors.

BACKGROUND: MEDI9197 is an intratumorally administered toll-like receptor 7 and 8 agonist. In mice, MEDI9197 modulated antitumor immune responses, inhibited tumor growth and increased survival. This first-time-in-human, phase 1 study evaluated MEDI9197 with or without the programmed cell death ligand-1 (PD-L1) inhibitor durvalumab and/or palliative radiation therapy (RT) for advanced solid tumors. PATIENTS AND METHODS: Eligible patients had at least one cutaneous, subcutaneous, or deep-seated lesion suitable for intratumoral (IT) injection. Dose escalation used a standard 3+3 design. Patients received IT MEDI9197 0.005-0.055 mg with or without RT (part 1), or IT MEDI9197 0.005 or 0.012 mg plus durvalumab 1500 mg intravenous with or without RT (part 3), in 4-week cycles. Primary endpoints were safety and tolerability. Secondary endpoints included pharmacokinetics, pharmacodynamics, and objective response based on Response Evaluation Criteria for Solid Tumors version 1.1. Exploratory endpoints included tumor and peripheral biomarkers that correlate with biological activity or predict response. RESULTS: From November 2015 to March 2018, part 1 enrolled 35 patients and part 3 enrolled 17 patients; five in part 1 and 2 in part 3 received RT. The maximum tolerated dose of MEDI9197 monotherapy was 0.037 mg, with dose-limiting toxicity (DLT) of cytokine release syndrome in two patients (one grade 3, one grade 4) and 0.012 mg in combination with durvalumab 1500 mg with DLT of MEDI9197-related hemorrhagic shock in one patient (grade 5) following liver metastasis rupture after two cycles of MEDI9197. Across parts 1 and 3, the most frequent MEDI9197-related adverse events (AEs) of any grade were fever (56%), fatigue (31%), and nausea (21%). The most frequent MEDI9197-related grade ≥3 events were decreased lymphocytes (15%), neutrophils (10%), and white cell counts (10%). MEDI9197 increased tumoral CD8+ and PD-L1+ cells, inducing type 1 and 2 interferons and Th1 response. There were no objective clinical responses; 10 patients in part 1 and 3 patients in part 3 had stable disease ≥8 weeks. CONCLUSION: IT MEDI9197 was feasible for subcutaneous/cutaneous lesions but AEs precluded its use in deep-seated lesions. Although no patients responded, MEDI9197 induced systemic and intratumoral immune activation, indicating potential value in combination regimens in other patient populations. TRIAL REGISTRATION NUMBER: NCT02556463.

Patrolling Alveolar Macrophages Conceal Bacteria from the Immune System to Maintain Homeostasis.

During respiration, humans breathe in more than 10,000 liters of non-sterile air daily, allowing some pathogens access to alveoli. Interestingly, alveoli outnumber alveolar macrophages (AMs), which favors alveoli devoid of AMs. If AMs, like most tissue macrophages, are sessile, then this numerical advantage would be exploited by pathogens unless neutrophils from the blood stream intervened. However, this would translate to omnipresent persistent inflammation. Developing in vivo real-time intravital imaging of alveoli revealed AMs crawling in and between alveoli using the pores of Kohn. Importantly, these macrophages sensed, chemotaxed, and, with high efficiency, phagocytosed inhaled bacterial pathogens such as P. aeruginosa and S. aureus, cloaking the bacteria from neutrophils. Impairing AM chemotaxis toward bacteria induced superfluous neutrophil recruitment, leading to inappropriate inflammation and injury. In a disease context, influenza A virus infection impaired AM crawling via the type II interferon signaling pathway, and this greatly increased secondary bacterial co-infection.

Peripheral lymph nodes contain migratory and resident innate lymphoid cell populations.

Tissue residency is considered a defining feature of the innate lymphoid cell (ILC) populations located within mucosal and adipose tissues. ILCs are also present within all lymphoid tissues, but whether ILCs migrate between lymphoid and nonlymphoid sites and in what context is poorly understood. To determine whether migratory ILCs exist within peripheral lymph nodes (LNs), we labeled all cells within the brachial LN (bLN) of transgenic mice expressing a photoconvertible fluorescent protein by direct exposure to light. Tracking of cellular changes in the labeled LN revealed the gradual migration of new ILCs into the tissue, balanced by egress of ILCs dependent on sphingosine-1-phosphate receptors. Most of the migratory ILCs were ILC1s, entering LNs directly from the circulation in a CD62L- and CCR7-dependent manner and thus behaving like conventional natural killer (cNK) cells. Upon egress, both ILC1s and cNK cells were found to recirculate through peripheral LNs. A distinct population of migratory ILC2s were detected in the LN, but most of the ILC3s were tissue resident. Functionally, both migratory and resident ILC1s within LNs were able to rapidly produce IFN-γ to support the generation of robust TH1 T cell responses after immunization. Thus, migratory and resident ILC populations exist within peripheral LNs, with ILC1s, akin to cNK cells, able to traffic into these tissues where they can contribute to the initiation of adaptive immunity.

Humanised effector-null FcγRIIA antibody inhibits immune complex-mediated proinflammatory responses.

OBJECTIVE: Immune complexes (ICs) play a critical role in the pathology of autoimmune diseases. The aim of this study was to generate and characterise a first-in-class anti-FcγRIIA antibody (Ab) VIB9600 (previously known as MEDI9600) that blocks IgG immune complex-mediated cellular activation for clinical development. METHODS: VIB9600 was humanised and optimised from the IV.3 Ab. Binding affinity and specificity were determined by Biacore and ELISA. Confocal microscopy, Flow Cytometry-based assays and binding competition assays were used to assess the mode of action of the antibody. In vitro cell-based assays were used to demonstrate suppression of IC-mediated inflammatory responses. In vivo target suppression and efficacy was demonstrated in FcγRIIA-transgenic mice. Single-dose pharmacokinetic (PK)/pharmacodynamic study multiple dose Good Laboratory Practice (GLP) toxicity studies were conducted in non-human primates. RESULTS: We generated a humanised effector-deficient anti-FcγRIIA antibody (VIB9600) that potently blocks autoantibody and IC-mediated proinflammatory responses. VIB9600 suppresses FcγRIIA activation by blocking ligand engagement and by internalising FcγRIIA from the cell surface. VIB9600 inhibits IC-induced type I interferons from plasmacytoid dendritic cells (involved in SLE), antineutrophil cytoplasmic antibody (ANCA)-induced production of reactive oxygen species by neutrophils (involved in ANCA-associated vasculitis) and IC-induced tumour necrosis factor α and interleukin-6 production (involved in rheumatoid arthritis). In FcγRIIA transgenic mice, VIB9600 suppressed antiplatelet antibody-induced thrombocytopaenia, acute anti-GBM Ab-induced nephritis and anticollagen Ab-induced arthritis. VIB9600 also exhibited favourable PK and safety profiles in cynomolgus monkey studies. CONCLUSIONS: VIB9600 is a specific humanised antibody antagonist of FcγRIIA with null effector function that warrants further clinical development for the treatment of IC-mediated diseases.

Baseline Plasma Cell Gene Signature Predicts Improvement in Systemic Sclerosis Skin Scores Following Treatment With Inebilizumab (MEDI-551) and Correlates With Disease Activity in Systemic Lupus Erythematosus and Chronic Obstructive Pulmonary Disease.

OBJECTIVE: B cells impact the progression of systemic sclerosis (SSc; scleroderma) through multiple pathogenic mechanisms. CD19 inhibition in mice reduced skin thickness, collagen production, and autoantibody levels, consistent with CD19 expression on plasma cells (PCs), the source of antibody production. PC depletion could effectively reduce collagen deposition and inflammation in SSc; therefore, we investigated the effects of PC depletion on SSc disease activity. METHODS: A PC gene signature was evaluated in SSc skin biopsy samples in 2 phase I clinical trials. We assessed microarray data from tissue from public studies of chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), dermatomyositis (DM), systemic lupus erythematosus (SLE), and atopic dermatitis, as well as blood from a phase IIb clinical trial in SLE. RESULTS: The PC signature was elevated in SSc skin specimens compared to healthy donor skin (P = 2.28 × 10-6 ) and correlated with the baseline modified Rodnan skin thickness score (MRSS) (r = 0.64, P = 0.0004). Patients with a high PC signature at baseline showed greater improvement in the MRSS (mean ± SD change 35 ± 16%; P = 6.30 × 10-4 ) following anti-CD19 treatment with inebilizumab (MEDI-551) than did patients with a low PC signature at baseline (mean ± SD change 8 ± 12%; P = 0.104). The PC signature was overexpressed in tissue from patients with SLE, DM, COPD, interstitial lung disease, and IPF relative to controls (all fold change >2; P < 0.001). The PC signature also differed significantly between SLE patients with mild-to-moderate disease and those with severe disease (SLE Disease Activity Index cutoff at 10) (fold change 1.44; P = 3.90 × 10-3 ) and correlated significantly with the degree of emphysema in COPD (r = 0.53, P = 7.55 × 10-8 ). CONCLUSION: Our results support the notion that PCs have a role in the pathogenesis of SSc and other autoimmune or pulmonary indications. An elevated pretreatment PC signature was associated with increased benefit from MEDI-551 in SSc.

Interferon Gamma Messenger RNA Signature in Tumor Biopsies Predicts Outcomes in Patients with Non-Small Cell Lung Carcinoma or Urothelial Cancer Treated with Durvalumab.

Purpose: To identify a predictive biomarker for durvalumab, an anti-programmed death ligand 1 (PD-L1) mAb.Experimental Design: RNA sequencing of 97 advanced-stage non-small cell lung carcinoma (NSCLC) biopsies from a nonrandomized phase Ib/II clinical trial (1108/NCT01693562) were profiled to identify a predictive signature; 62 locally advanced or metastatic urothelial cancer tumors from the same study were profiled to confirm predictive utility of the signature. Thirty NSCLC patients provided pre- and posttreatment tumors for messenger RNA (mRNA) analysis. NSCLC with ≥25% tumor cells and urothelial cancer with ≥25% tumor or immune cells stained for PD-L1 at any intensity were scored PD-L1 positive (PD-L1+). Kaplan-Meier and Cox proportional hazards analyses were used to adjust for gender, age, prior therapies, histology, ECOG status, liver metastasis, and smoking. Tumor mutation burden (TMB) was calculated using data from The Cancer Genome Atlas (TCGA).Results: In the NSCLC discovery set, a four-gene IFNγ-positive (IFNγ+) signature comprising IFNγ, CD274, LAG3, and CXCL9 was associated with higher overall response rates, longer median progression-free survival, and overall survival compared with signature-low patients. IFNγ+-signature NSCLC patients had improved survival regardless of IHC PD-L1 status. These associations were replicated in a urothelial cancer cohort. The IFNγ+ signature was induced 2-fold (P = 0.003) by durvalumab after 8 weeks of therapy in patients with NSCLC, and baseline signature was associated with TMB but not survival in TCGA data.Conclusions: The IFNγ+ mRNA signature may assist in identifying patients with improved outcomes with durvalumab, independent of PD-L1 assessed by IHC. Clin Cancer Res; 24(16); 3857-66. ©2018 AACR.

IL-21 drives expansion and plasma cell differentiation of autoreactive CD11chiT-bet+ B cells in SLE.

Although the aetiology of systemic lupus erythematosus (SLE) is unclear, dysregulated B cell responses have been implicated. Here we show that an unusual CD11chiT-bet+ B cell subset, with a unique expression profile including chemokine receptors consistent with migration to target tissues, is expanded in SLE patients, present in nephrotic kidney, enriched for autoreactive specificities and correlates with defined clinical manifestations. IL-21 can potently induce CD11chiT-bet+ B cells and promote the differentiation of these cells into Ig-secreting autoreactive plasma cells. While murine studies have identified a role for T-bet-expressing B cells in autoimmunity, this study describes and exemplifies the importance of CD11chiT-bet+ B cells in human SLE.

BubbleTree: an intuitive visualization to elucidate tumoral aneuploidy and clonality using next generation sequencing data.

Tumors are characterized by properties of genetic instability, heterogeneity, and significant oligoclonality. Elucidating this intratumoral heterogeneity is challenging but important. In this study, we propose a framework, BubbleTree, to characterize the tumor clonality using next generation sequencing (NGS) data. BubbleTree simultaneously elucidates the complexity of a tumor biopsy, estimating cancerous cell purity, tumor ploidy, allele-specific copy number, and clonality and represents this in an intuitive graph. We further developed a three-step heuristic method to automate the interpretation of the BubbleTree graph, using a divide-and-conquer strategy. In this study, we demonstrated the performance of BubbleTree with comparisons to similar commonly used tools such as THetA2, ABSOLUTE, AbsCN-seq and ASCAT, using both simulated and patient-derived data. BubbleTree outperformed these tools, particularly in identifying tumor subclonal populations and polyploidy. We further demonstrated BubbleTree's utility in tracking clonality changes from patients' primary to metastatic tumor and dating somatic single nucleotide and copy number variants along the tumor clonal evolution. Overall, the BubbleTree graph and corresponding model is a powerful approach to provide a comprehensive spectrum of the heterogeneous tumor karyotype in human tumors. BubbleTree is R-based and freely available to the research community (https://www.bioconductor.org/packages/release/bioc/html/BubbleTree.html).

Synergistic actions of blocking angiopoietin-2 and tumor necrosis factor-α in suppressing remodeling of blood vessels and lymphatics in airway inflammation.

Remodeling of blood vessels and lymphatics are prominent features of sustained inflammation. Angiopoietin-2 (Ang2)/Tie2 receptor signaling and tumor necrosis factor-α (TNF)/TNF receptor signaling are known to contribute to these changes in airway inflammation after Mycoplasma pulmonis infection in mice. We determined whether Ang2 and TNF are both essential for the remodeling on blood vessels and lymphatics, and thereby influence the actions of one another. Their respective contributions to the initial stage of vascular remodeling and sprouting lymphangiogenesis were examined by comparing the effects of function-blocking antibodies to Ang2 or TNF, given individually or together during the first week after infection. As indices of efficacy, vascular enlargement, endothelial leakiness, venular marker expression, pericyte changes, and lymphatic vessel sprouting were assessed. Inhibition of Ang2 or TNF alone reduced the remodeling of blood vessels and lymphatics, but inhibition of both together completely prevented these changes. Genome-wide analysis of changes in gene expression revealed synergistic actions of the antibody combination over a broad range of genes and signaling pathways involved in inflammatory responses. These findings demonstrate that Ang2 and TNF are essential and synergistic drivers of remodeling of blood vessels and lymphatics during the initial stage of inflammation after infection. Inhibition of Ang2 and TNF together results in widespread suppression of the inflammatory response.

Germinal center reentries of BCL2-overexpressing B cells drive follicular lymphoma progression.

It has recently been demonstrated that memory B cells can reenter and reengage germinal center (GC) reactions, opening the possibility that multi-hit lymphomagenesis gradually occurs throughout life during successive immunological challenges. Here, we investigated this scenario in follicular lymphoma (FL), an indolent GC-derived malignancy. We developed a mouse model that recapitulates the FL hallmark t(14;18) translocation, which results in constitutive activation of antiapoptotic protein B cell lymphoma 2 (BCL2) in a subset of B cells, and applied a combination of molecular and immunofluorescence approaches to track normal and t(14;18)(+) memory B cells in human and BCL2-overexpressing B cells in murine lymphoid tissues. BCL2-overexpressing B cells required multiple GC transits before acquiring FL-associated developmental arrest and presenting as GC B cells with constitutive activation-induced cytidine deaminase (AID) mutator activity. Moreover, multiple reentries into the GC were necessary for the progression to advanced precursor stages of FL. Together, our results demonstrate that protracted subversion of immune dynamics contributes to early dissemination and progression of t(14;18)(+) precursors and shapes the systemic presentation of FL patients.

MEDI-573, alone or in combination with mammalian target of rapamycin inhibitors, targets the insulin-like growth factor pathway in sarcomas.

MEDI-573 is a human antibody that neutralizes insulin-like growth factor (IGF) I and IGFII. IGFs are overexpressed in multiple types of cancer; their overexpression is a potential mechanism for resistance to IGFI receptor (IGFIR)-targeting therapy. Effects of IGF on cell proliferation, differentiation, and survival are mediated through its binding to and activation of IGFIR or insulin receptor A (IR-A). In this study, we measured the mRNA levels of IGFI, IGFII, and IGFIR in human pediatric sarcoma xenografts, and protein levels in sarcoma cell lines. MEDI-573 potently inhibited in vitro proliferation of sarcoma cell lines, with Ewing sarcoma cell lines being the most sensitive. In addition, MEDI-573 inhibited IGFI- and IGFII-induced sarcoma cell proliferation in vitro. The effect of MEDI-573 on IGF signaling was also examined. Treatment with MEDI-573 markedly reduced levels of pIGFIR, pIR-A, and pAKT and significantly blocked IGFI- and IGFII-induced activation of the IGFIR and AKT pathways. MEDI-573 inhibited the growth of sarcoma xenografts in vivo and inhibition correlated with neutralization of IGFI and IGFII. Combination of MEDI-573 with either rapamycin or AZD2014, another mTOR inhibitor (mTORi), significantly enhanced the antitumor activity of MEDI-573, and this response correlated with modulation of AKT and mTOR signaling. In summary, sarcoma cells respond to autocrine or paracrine growth stimulation by IGFI and IGFII, and inhibition of IGFI and IGFII by MEDI-573 results in significant slowing of tumor growth rate in sarcoma models, particularly in Ewing sarcoma. These data provide evidence for the potential benefits of MEDI-573 and mTORi combinations in patients with Ewing sarcoma.

Inhibition of myogenic microRNAs 1, 133, and 206 by inflammatory cytokines links inflammation and muscle degeneration in adult inflammatory myopathies.

OBJECTIVE: The molecular basis of inflammatory myopathies such as dermatomyositis (DM), polymyositis, and inclusion body myositis, which share the characteristics of chronic muscle inflammation and skeletal muscle wasting, are poorly understood. As such, effective targeted treatments for these diseases are lacking, resulting in critical unmet medical needs for these devastating diseases. The purpose of this study was to identify possible new targets for drug development by exploring the mechanism by which inflammation may play a role in the pathology of the inflammatory myopathies. METHODS: We compared expression levels of inflammatory cytokines and microRNAs (miRNAs) between muscle biopsy samples from patients with inflammatory myopathies and those from donors without myositis. In vitro human and mouse model systems were then used to characterize the role of these cytokines and microRNAs on myoblast-to-myocyte differentiation. RESULTS: We observed increased expression of inflammatory cytokines, including tumor necrosis factor α (TNFα), interferon-α (IFNα), IFNß, and interleukin-1ß, in different subtypes of inflammatory myopathies. We observed decreased expression of microRNA-1 (miR-1), miR-133a, and miR-133b in all of the inflammatory myopathy subtypes we evaluated, as well as decreased expression of miR-206 in DM; these miRNAs are essential for adult skeletal muscle differentiation and maintenance. TNFα was significantly inversely correlated with decreased myogenic miRNA expression in the inflammatory myopathy subtypes. In mechanistic studies, TNFα inhibited the expression of myogenic miRNAs and suppressed the differentiation of C2C12 myoblasts to myocytes/myotubes in an NF-κB-dependent manner. This block in differentiation by TNFα was relieved by overexpression of miR-1, miR-206, or miR-133a/b. CONCLUSION: Taken together, these results provide a new mechanistic link between the action of proinflammatory cytokines and the degenerative pathology of inflammatory myopathies, and suggest therapeutic approaches for these diseases.

The plasma cell signature in autoimmune disease.

OBJECTIVE: Production of pathogenic autoantibodies by self-reactive plasma cells (PCs) is a hallmark of autoimmune diseases. We undertook this study to investigate the prevalence of PCs and their relationship to known pathogenic pathways to increase our understanding of the role of PCs in disease progression and treatment response. METHODS: We developed a sensitive gene expression-based method to overcome the challenges of measuring PCs using flow cytometry. Whole-genome microarray analysis of sorted cellular fractions identified a panel of genes, IGHA1, IGJ, IGKC, IGKV4-1, and TNFRSF17, expressed predominantly in PCs. The sensitivity of the PC signature score created from the combined expression levels of these genes was assessed through ex vivo experiments with sorted cells. This PC gene expression signature was used for monitoring changes in PC levels following anti-CD19 therapy, for evaluating the relationship between PCs and other autoimmune disease-related genes, and for estimating PC levels in affected blood and tissue from patients with multiple autoimmune diseases. RESULTS: The PC signature was highly sensitive and capable of detecting a change in as few as 360 PCs. The PC signature was reduced more than 90% in scleroderma patients following anti-CD19 treatment, and this reduction was highly correlated (r = 0.80) with inhibition of collagen gene expression. Evaluation of multiple autoimmune diseases revealed that 30-35% of lupus and rheumatoid arthritis patients had increased levels of PCs. CONCLUSION: This newly developed PC signature provides a robust and accurate method of measuring PC levels in the clinic. Our results highlight subsets of patients across multiple autoimmune diseases who may benefit from PC-depleting therapy.

MicroRNA-206 induces G1 arrest in melanoma by inhibition of CDK4 and Cyclin D.

Expression profiling of microRNAs in melanoma lesional skin biopsies compared with normal donor skin biopsies, as well as melanoma cell lines compared with normal melanocytes, revealed that hsa-miR-206 was down-regulated in melanoma (-75.4-fold, P = 1.7 × 10(-4)). MiR-206 has been implicated in a large number of cancers, including breast, lung, colorectal, ovarian, and prostate cancers; however, its role in tumor development remains largely unknown, its biologic function is poorly characterized, and its targets affecting cancer cells are largely unknown. MiR-206 reduced growth and migration/invasion of multiple melanoma cell lines. Bioinformatics identified cell cycle genes CDK2, CDK4, Cyclin C, and Cyclin D1 as strong candidate targets. Western blots and 3'UTR reporter gene assays revealed that miR-206 inhibited translation of CDK4, Cyclin D1, and Cyclin C. Additionally, hsa-miR-206 transfection induced G1 arrest in multiple melanoma cell lines. These observations support hsa-miR-206 as a tumor suppressor in melanoma and identify Cyclin C, Cyclin D1, and CDK4 as miR-206 targets.

Neutralization of interferon-alpha/beta-inducible genes and downstream effect in a phase I trial of an anti-interferon-alpha monoclonal antibody in systemic lupus erythematosus.

OBJECTIVE: Type I interferons (IFNs) play an important role in the pathogenesis of systemic lupus erythematosus (SLE). This phase Ia trial was undertaken to evaluate the safety, pharmacokinetics, and immunogenicity of anti-IFNalpha monoclonal antibody (mAb) therapy in SLE. During the trial, we also examined whether overexpression of an IFNalpha/beta-inducible gene signature in whole blood could serve as a pharmacodynamic biomarker to evaluate IFNalpha neutralization and investigated downstream effects of neutralizing IFNalpha on BAFF and other key signaling pathways, i.e., granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-10 (IL-10), tumor necrosis factor alpha (TNFalpha), and IL-1beta, in SLE. METHODS: Affymetrix Human Genome U133 Plus 2.0 microarrays were used to profile whole blood and lesional skin of patients receiving standard therapy for mild to moderate SLE. Selected IFNalpha/beta-inducible proteins were analyzed by immunohistochemistry. RESULTS: With the study treatment, we observed anti-IFNalpha mAb-specific and dose-dependent inhibition of overexpression of IFNalpha/beta-inducible genes in whole blood and skin lesions from SLE patients, at both the transcript and the protein levels. In SLE patients with overexpression of messenger RNA for BAFF, TNFalpha, IL-10, IL-1beta, GM-CSF, and their respective inducible gene signatures in whole blood and/or skin lesions, we observed a general trend toward suppression of the expression of these genes and/or gene signatures upon treatment with anti-IFNalpha mAb. CONCLUSION: IFNalpha/beta-inducible gene signatures in whole blood are effective pharmacodynamic biomarkers to evaluate anti-IFNalpha mAb therapy in SLE. Anti-IFNalpha mAb can neutralize overexpression of IFNalpha/beta-inducible genes in whole blood and lesional skin from SLE patients and has profound effects on signaling pathways that may be downstream of IFNalpha in SLE.