Bernett Lee

Citrullinated peptide dendritic cell immunotherapy in HLA risk genotype-positive rheumatoid arthritis patients.

Citrullinated peptide-exposed DCs induced immune regulatory effects in HLA risk genotype–positive RA patients. Immunotherapy out of joint Autoantibodies to anti–citrullinated peptides (ACPA) are found in most patients with rheumatoid arthritis (RA), especially those with HLA-DRB1 risk alleles. Benham et al. report a first-in-human phase 1 trial of a single injection of autologous dendritic cells modified with an NF-κB inhibitor that have been exposed to four citrullinated peptide antigens. They find that HLA risk genotype–positive RA patients had reduced numbers of effector T cells and decreased production of proinflammatory cytokines compared with untreated RA patient controls. The therapy was safe and did not induce disease flares. These data support larger studies of antigen-specific immunotherapy for RA. In animals, immunomodulatory dendritic cells (DCs) exposed to autoantigen can suppress experimental arthritis in an antigen-specific manner. In rheumatoid arthritis (RA), disease-specific anti–citrullinated peptide autoantibodies (ACPA or anti-CCP) are found in the serum of about 70% of RA patients and are strongly associated with HLA-DRB1 risk alleles. This study aimed to explore the safety and biological and clinical effects of autologous DCs modified with a nuclear factor κB (NF-κB) inhibitor exposed to four citrullinated peptide antigens, designated “Rheumavax,” in a single-center, open-labeled, first-in-human phase 1 trial. Rheumavax was administered once intradermally at two progressive dose levels to 18 human leukocyte antigen (HLA) risk genotype–positive RA patients with citrullinated peptide–specific autoimmunity. Sixteen RA patients served as controls. Rheumavax was well tolerated: adverse events were grade 1 (of 4) severity. At 1 month after treatment, we observed a reduction in effector T cells and an increased ratio of regulatory to effector T cells; a reduction in serum interleukin-15 (IL-15), IL-29, CX3CL1, and CXCL11; and reduced T cell IL-6 responses to vimentin447–455–Cit450 relative to controls. Rheumavax did not induce disease flares in patients recruited with minimal disease activity, and DAS28 decreased within 1 month in Rheumavax-treated patients with active disease. This exploratory study demonstrates safety and biological activity of a single intradermal injection of autologous modified DCs exposed to citrullinated peptides, and provides rationale for further studies to assess clinical efficacy and antigen-specific effects of autoantigen immunomodulatory therapy in RA.

Adoptive T-cell Transfer and Chemotherapy in the First-line Treatment of Metastatic and/or Locally Recurrent Nasopharyngeal Carcinoma

The outcomes for patients with metastatic or locally recurrent Epstein–Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) remain poor. Adoptive immunotherapy with EBV-specific cytotoxic T lymphocytes (EBV-CTLs) has proven clinical efficacy, but it has never been evaluated in the first-line treatment setting in combination with chemotherapy. To evaluate the safety and efficacy of a chemotherapy in combination with adoptive EBV-CTL transfer, we conducted a phase 2 clinical trial consisting of four cycles of gemcitabine and carboplatin (GC) followed by up to six doses of EBV-CTL. Thirty-eight patients were enrolled, and 35 received GC and EBV-CTL. GC-CTL therapy resulted in a response rate of 71.4% with 3 complete responses and 22 partial responses. With a median follow up of 29.9 months, the 2-year and 3-year overall survival (OS) rate was 62.9 and 37.1%, respectively. Five patients did not require further chemotherapy for more than 34 months since initiation of CTL. Infusion of CTL products containing T cells specific for LMP2 positively correlated with OS (hazard ratio: 0.35; 95% confidence interval: 0.14–0.84; P = 0.014). Our study achieved one of the best survival outcomes in patients with advanced NPC, setting the stage for a future randomized study of chemotherapy with and without EBV-CTL.

Allergic airway diseases in a tropical urban environment are driven by dominant mono‐specific sensitization against house dust mites

Southeast Asian populations are increasingly affected by allergic airway diseases. Etiology and specific causes, however, are still unknown. The aim of this study is therefore to identify allergens and risk factors for the high prevalence of allergic airway disease in the tropical urban environment.

Selective Susceptibility of Human Skin Antigen Presenting Cells to Productive Dengue Virus Infection

Dengue is a growing global concern with 390 million people infected each year. Dengue virus (DENV) is transmitted by mosquitoes, thus host cells in the skin are the first point of contact with the virus. Human skin contains several populations of antigen-presenting cells which could drive the immune response to DENV in vivo: epidermal Langerhans cells (LCs), three populations of dermal dendritic cells (DCs), and macrophages. Using samples of normal human skin we detected productive infection of CD14+ and CD1c+ DCs, LCs and dermal macrophages, which was independent of DC-SIGN expression. LCs produced the highest viral titers and were less sensitive to IFN-β. Nanostring gene expression data showed significant up-regulation of IFN-β, STAT-1 and CCL5 upon viral exposure in susceptible DC populations. In mice infected intra-dermally with DENV we detected parallel populations of infected DCs originating from the dermis and migrating to the skin-draining lymph nodes. Therefore dermal DCs may simultaneously facilitate systemic spread of DENV and initiate the adaptive anti-viral immune response.

CD103+ Dendritic Cells Control Th17 Cell Function in the Lung

Th17 cells express diverse functional programs while retaining their Th17 identity, in some cases exhibiting a stem-cell-like phenotype. Whereas the importance of Th17 cell regulation in autoimmune and infectious diseases is firmly established, the signaling pathways controlling their plasticity are undefined. Using a mouse model of invasive pulmonary aspergillosis, we found that lung CD103(+) dendritic cells (DCs) would produce IL-2, dependent on NFAT signaling, leading to an optimally protective Th17 response. The absence of IL-2 in DCs caused unrestrained production of IL-23 and fatal hyperinflammation, which was characterized by strong Th17 polarization and the emergence of a Th17 stem-cell-like population. Although several cell types may be affected by deficient IL-2 production in DCs, our findings identify the balance between IL-2 and IL-23 productions by lung DCs as an important regulator of the local inflammatory response to infection.

Warburg metabolism in tumor-conditioned macrophages promotes metastasis in human pancreatic ductal adenocarcinoma

ABSTRACT Patients with pancreatic ductal adenocarcinoma (PDAC) face a clinically intractable disease with poor survival rates, attributed to exceptionally high levels of metastasis. Epithelial-to-mesenchymal transition (EMT) is pronounced at inflammatory foci within the tumor; however, the immunological mechanisms promoting tumor dissemination remain unclear. It is well established that tumors exhibit the Warburg effect, a preferential use of glycolysis for energy production, even in the presence of oxygen, to support rapid growth. We hypothesized that the metabolic pathways utilized by tumor-infiltrating macrophages are altered in PDAC, conferring a pro-metastatic phenotype. We generated tumor-conditioned macrophages in vitro, in which human peripheral blood monocytes were cultured with conditioned media generated from normal pancreatic or PDAC cell lines to obtain steady-state and tumor-associated macrophages (TAMs), respectively. Compared with steady-state macrophages, TAMs promoted vascular network formation, augmented extravasation of tumor cells out of blood vessels, and induced higher levels of EMT. TAMs exhibited a pronounced glycolytic signature in a metabolic flux assay, corresponding with elevated glycolytic gene transcript levels. Inhibiting glycolysis in TAMs with a competitive inhibitor to Hexokinase II (HK2), 2-deoxyglucose (2DG), was sufficient to disrupt this pro-metastatic phenotype, reversing the observed increases in TAM-supported angiogenesis, extravasation, and EMT. Our results indicate a key role for metabolic reprogramming of tumor-infiltrating macrophages in PDAC metastasis, and highlight the therapeutic potential of using pharmacologics to modulate these metabolic pathways.

A Systematic Meta-analysis of Immune Signatures in Patients With Acute Chikungunya Virus Infection

Background. Individuals infected with chikungunya virus (CHIKV) normally exhibit a variety of clinical manifestations during the acute phase of infection. However, studies in different patient cohorts have revealed that disease manifestations vary in frequency. Methods. Disease profiles between patients with acute CHIKV-infection and febrile patients without CHIKV were compared and examined to determine whether any clinical presentations were associated with the clinical outcome of CHIKV infection. Circulatory immune mediators profiles were then characterized and compared with data from 14 independent patient cohort studies. The particular immune mediator signature that defines acute CHIKV infection was determined. Results. Our findings revealed a specific pattern of clinical presentations of joint-specific arthralgia from this CHIKV cohort. More importantly, we identified an immune mediator signature dominated by proinflammatory cytokines, which include interferon α and γ and interleukin 2, 2R, 6, 7, 12, 15, 17, and 18, across different patient cohorts of CHIKV load associated with arthralgia. Conclusions. To our knowledge, this is the first study that associated levels of CHIKV load with arthralgia as an indicator of acute CHIKV infection. Importantly, our findings also revealed specific immune mediator signatures that can be used to better define CHIKV infection.

Cell Specific eQTL Analysis without Sorting Cells

The functional consequences of trait associated SNPs are often investigated using expression quantitative trait locus (eQTL) mapping. While trait-associated variants may operate in a cell-type specific manner, eQTL datasets for such cell-types may not always be available. We performed a genome-environment interaction (GxE) meta-analysis on data from 5,683 samples to infer the cell type specificity of whole blood cis-eQTLs. We demonstrate that this method is able to predict neutrophil and lymphocyte specific cis-eQTLs and replicate these predictions in independent cell-type specific datasets. Finally, we show that SNPs associated with Crohn’s disease preferentially affect gene expression within neutrophils, including the archetypal NOD2 locus.

Induced-Pluripotent-Stem-Cell-Derived Primitive Macrophages Provide a Platform for Modeling Tissue-Resident Macrophage Differentiation and Function

Summary Tissue macrophages arise during embryogenesis from yolk‐sac (YS) progenitors that give rise to primitive YS macrophages. Until recently, it has been impossible to isolate or derive sufficient numbers of YS‐derived macrophages for further study, but data now suggest that induced pluripotent stem cells (iPSCs) can be driven to undergo a process reminiscent of YS‐hematopoiesis in vitro. We asked whether iPSC‐derived primitive macrophages (iMacs) can terminally differentiate into specialized macrophages with the help of growth factors and organ‐specific cues. Co‐culturing human or murine iMacs with iPSC‐derived neurons promoted differentiation into microglia‐like cells in vitro. Furthermore, murine iMacs differentiated in vivo into microglia after injection into the brain and into functional alveolar macrophages after engraftment in the lung. Finally, iPSCs from a patient with familial Mediterranean fever differentiated into iMacs with pro‐inflammatory characteristics, mimicking the disease phenotype. Altogether, iMacs constitute a source of tissue‐resident macrophage precursors that can be used for biological, pathophysiological, and therapeutic studies. Graphical Abstract Figure. No Caption available. HighlightsHuman and mouse iPSCs can recapitulate YS hematopoiesisHuman and mouse iPSCs can differentiate into YS macrophage‐like cells (iMacs)iMacs can further differentiate to tissue macrophage‐like cells with organ‐specific cuesiMacs derived from an FMF patient’s iPSCs exhibit disease‐specific characteristics &NA; Yolk‐sac (YS) embryonic macrophages contribute to tissue‐resident macrophages but remain difficult to study because of their stage‐dependent limited availability. Takata et al. demonstrate that iPSCs can generate YS macrophage‐like cells (iMacs) that differentiate into functional tissue‐resident macrophage‐like cells upon receiving organ‐specific cues, thus providing a platform for modeling tissue‐resident macrophages.

Zika Virus Infects Human Fetal Brain Microglia and Induces Inflammation

Background The unprecedented reemergence of Zika virus (ZIKV) has startled the world with reports of increased microcephaly in Brazil. ZIKV can infect human neural progenitors and impair brain growth. However, direct evidence of ZIKV infection in human fetal brain tissues remains elusive. Methods Investigations were performed with brain cell preparations obtained from 9 donors. Virus infectivity was assessed by detection of virus antigen by flow cytometry together with various hematopoietic cell surface markers. Virus replication was determined by viral RNA quantification. Cytokine levels in supernatant obtained from virus-infected fetal brain cells were measured simultaneously in microbead-based immunoassays. Results We also show that ZIKV infection was particularly evident in hematopoietic cells with microglia, the brain-resident macrophage population being one of the main targets. Infection induces high levels of proinflammatory immune mediators such as interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), interleukin 1β (IL-1β), and monocyte chemotactic protein 1 (MCP-1). Conclusions Our results highlight an important role for microglia and neuroinflammation during congenital ZIKV pathogenesis.