Migration of resident dendritic cells (DC) from the skin to local lymph nodes (LN) triggers T cell-mediated immune responses during cutaneous infection, autoimmune disease and vaccination. Here we investigated whether the development and migration of skin resident DC were regulated by interferon regulatory factor 4 (IRF4), a transcription factor that is required for the development of CD11b+ splenic DC. We found that the skin of naïve IRF4−/− mice contained normal numbers of epidermal Langerhans cells (eLC) and increased numbers of CD11b+ and CD103+ dermal DC populations, indicating that tissue DC development and skin residency is not disrupted by IRF4 deficiency. In contrast, numbers of migratory eLC and CD11b+ dermal DC were significantly reduced in the cutaneous LN of IRF4−/− mice, suggesting a defect in constitutive migration from the dermis during homeostasis. Upon induction of skin inflammation, CD11b+ dermal DC in IRF4−/− mice did not express the chemokine receptor CCR7, and failed to migrate to cutaneous LN, while the migration of eLC was only mildly impaired. Thus, while dispensable for their development, IRF4 is crucial for the CCR7-mediated migration of CD11b+ dermal DC, a predominant population in murine and human skin that plays a vital role in normal and pathogenic cutaneous immunity.

Dendritic cells (DCs) initiate immune responses in barrier tissues including lung and skin. Conventional DC subsets, CD11b− (cDC1s) or CD11b+ (cDC2s), arise via distinct networks of transcription factors involving IRF4 and IRF8 and are specialized for unique functional responses. Using mice in which a conditional Irf4 or Irf8 allele is deleted in CD11c+ cells, we determined if IRF4 or IRF8 deficiency beginning in CD11c+ cDC precursors (pre-cDCs) changed the homeostasis of mature DCs or pre-DCs in the lung, dermis and spleen. CD11c-cre-Irf4−/− mice selectively lacked a lung-resident CD11chiCD11b+SIRPα+CD24+ DC subset, but not other lung CD11b+ DCs or alveolar macrophages. Numbers of CD11b+CD4+ splenic DCs, but not CD11b+ dermal DCs, were reduced, indicating cDC2s in the lung and dermis develop via different pathways. Irf4 deficiency did not alter numbers of cDC1s. CD11c-cre-Irf8−/− mice lacked lung-resident CD103+ DCs and splenic CD8α+ DCs, yet harbored increased IRF4-dependent DCs. This correlated with a reduced number of Irf8−/− pre-cDCs, which contained elevated IRF4, suggesting that Irf8 deficiency diverts pre-cDC fate. Analyses of Irf4 and Irf8 haploinsufficient mice showed that while one Irf4 allele was sufficient for lung cDC2 development, two functional Irf8 alleles were required for differentiation of lung cDC1s. Thus, IRF8 and IRF4 act in pre-cDCs to direct the terminal differentiation of cDC1 and cDC2 subsets in the lung and spleen. These data suggest that variation in IRF4 or IRF8 levels resulting from genetic polymorphisms or environmental cues will govern tissue DC numbers and therefore regulate the magnitude of DC functional responses.

Analyses of frequency profiles of markers on disease or drug-response related genes in diverse populations are important for the dissection of common diseases. We report the results of analyses of data on 405 SNPs from 75 such genes and a 5.2 Mb chromosome, 22 genomic region in 1871 individuals from diverse 55 endogamous Indian populations. These include 32 large (>10 million individuals) and 23 isolated populations, representing a large fraction of the people of India. We observe high levels of genetic divergence between groups of populations that cluster largely on the basis of ethnicity and language. Indian populations not only overlap with the diversity of HapMap populations, but also contain population groups that are genetically distinct. These data and results are useful for addressing stratification and study design issues in complex traits especially for heterogeneous populations.

Treatment of pain with morphine and its congeners in sickle cell anemia is suboptimal, warranting the need for analgesics devoid of side effects, addiction and tolerance liability. Small-molecule nociceptin opioid receptor ligands show analgesic efficacy in acute and chronic pain models. We show that AT-200, a high affinity nociceptin opioid receptor agonist with low efficacy at the mu opioid receptor, ameliorated chronic and hypoxia/reoxygenation-induced mechanical, thermal and deep tissue/musculoskeletal hyperalgesia in HbSS-BERK sickle mice. The antinociceptive effect of AT-200 was antagonized by SB-612111, a nociceptin opioid receptor antagonist, but not naloxone, a nonselective mu opioid receptor antagonist. Daily 7-day treatment with AT-200 did not develop tolerance and showed a sustained anti-nociceptive effect, which improved over time and led to reduced plasma serum amyloid protein, neuropeptides, inflammatory cytokines and mast cell activation in the periphery. These data suggest that AT-200 ameliorates pain in sickle mice via the nociceptin opioid receptor by reducing inflammation and mast cell activation without causing tolerance. Thus, nociceptin opioid receptor agonists are promising drugs for treating pain in sickle cell anemia.

Purpose: A phase 1/2 study evaluating the safety and activity of memory-enriched CD19-directed chimeric antigen receptor (CD19-CAR) T cells in adults with relapsed/refractory B-cell acute lymphoblastic leukemia (ALL). Experimental Design: In phase 1, we tested sequentially two cell populations for CAR transduction: 1) central memory (Tcm) or 2) naïve, stem and central memory (Tn/mem) T cells. The study employed an activity constrained for toxicity design to determine the recommended phase 2 dose (RP2D), which was tested in phase 2. Results: The Tcm cohort was closed early due to lack of activity. The 200x10 6 Tn/mem-derived CD19-CAR T cell dose was found to be safe, active, and was declared the RP2D. At RP2D, 58 participants underwent leukapheresis and 46 received CD19-CAR T cells. Median age for treated participants was 38 years (22-72). Twenty-nine (63%) participants had relapsed post-allogeneic hematopoietic cell transplantation (alloHCT), 18 (39%) had Philadelphia-like genotype and 16 (35%) had extramedullary disease (EMD) at lymphodepletion. Three (7%) participants had grade 3 cytokine release syndrome (CRS), and none had grade ≥4 CRS. Eight (17%) participants had grade ≥3 neurotoxicity, including one fatal cerebral edema. Forty (87%) patients achieved complete remission (CR)/CR with incomplete hematologic recovery, 2 (4%) progressed, and 4 (9%) were unevaluable for response. Among 42 response-evaluable participants, 16/17 with Philadelphia-like ALL and 13/15 with EMD at LD responded. Twenty-one (53%) responders underwent alloHCT consolidation, which was associated with improved relapse-free survival (aHR=0.16, 95%CI:0.05-0.48; P =0.001). Conclusion: Tn/mem-derived CD19-CAR T cells were safe and active, including in Philadelphia-like ALL and EMD.

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Background: Human mitochondrial DNA (mtDNA) variations have been implicated in a broad spectrum of diseases. With over 3000 mtDNA variations reported across databases, establishing pathogenicity of variations in mtDNA is a major challenge. We have designed and developed a comprehensive weighted scoring system (MtSNPscore) for identification of mtDNA variations that can impact pathogenicity and would likely be associated with disease. The criteria for pathogenicity include information available in the literature, predictions made by various in silico tools and frequency of variation in normal and patient datasets. The scoring scheme also assigns scores to patients and normal individuals to estimate the cumulative impact of variations. The method has been implemented in an automated pipeline and has been tested on Indian ataxia dataset (92 individuals), sequenced in this study, and other publicly available mtSNP dataset comprising of 576 mitochondrial genomes of Japanese individuals from six different groups, namely, patients with Parkinson's disease, patients with Alzheimer's disease, young obese males, young non-obese males, and type-2 diabetes patients with or without severe vascular involvement. MtSNPscore, for analysis can extract information from variation data or from mitochondrial DNA sequences. It has a webinterface http://bioinformatics.ccmb.res.in/cgi-bin/snpscore/Mtsnpscore.pl that provides flexibility to update/modify the parameters for estimating pathogenicity.

Dimorphic transitions between yeast-like and filamentous forms occur in many fungi and are often associated with pathogenesis. One of the cues for such a dimorphic switch is the availability of nutrients. Under conditions of nitrogen limitation, fungal cells (such as those of Saccharomyces cerevisiae and Ustilago maydis) switch from budding to pseudohyphal or filamentous growth. Ammonium transporters (AMTs) are responsible for uptake and, in some cases, for sensing the availability of ammonium, a preferred nitrogen source. Homodimer and/or heterodimer formation may be required for regulating the activity of the AMTs. To investigate the potential interactions of Ump1 and Ump2, the AMTs of the maize pathogen U. maydis, we first used the split-ubiquitin system, followed by a modified split-YFP (yellow fluorescent protein) system, to validate the interactions in vivo. This analysis showed the formation of homo- and hetero-oligomers by Ump1 and Ump2. We also demonstrated the interaction of the high-affinity ammonium transporter, Ump2, with the Rho1 GTPase, a central protein in signaling, with roles in controlling polarized growth. This is the first demonstration in eukaryotes of the physical interaction in vivo of an ammonium transporter with the signaling protein Rho1. Moreover, the Ump proteins interact with Rho1 during the growth of cells in low ammonium concentrations, a condition required for the expression of the Umps. Based on these results and the genetic evidence for the interaction of Ump2 with both Rho1 and Rac1, another small GTPase, we propose a model for the role of these interactions in controlling filamentation, a fundamental aspect of development and pathogenesis in U. maydis.