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T helper (Th) 17 cells have recently been implicated in psoriasis pathogenesis, but mechanisms of how these cells traffic into inflamed skin are unknown. By immunostaining for interleukin (IL)-17A and IL-22, we show numerous cells present in psoriasis lesions that produce these cytokines. We next found that Th17 cytokines (IL-17A, IL-22, and tumor necrosis factor (TNF)-α) markedly increased the expression of CC chemokine ligand (CCL) 20, a CC chemokine receptor (CCR)6 ligand, in human keratinocyte monolayer and raft cultures in a dose- and time-dependent manner. Lastly, we showed in mice that subcutaneous injection with recombinant IL-17A, IL-22, or TNF-α led to the upregulation of both CCL20 and CCR6 expression in skin as well as cutaneous T-cell infiltration. Taken together, these data show that Th17 cytokines stimulate CCL20 production in vitro and in vivo, and thus provide a potential explanation of how CCR6-positive Th17 cells maintain their continual presence in psoriasis through a positive chemotactic feedback loop.

Interleukin-1 receptor-associated kinase 1 (IRAK1), an essential mediator of innate immunity and inflammatory responses, is constitutively active in multiple cancers. We evaluated the role of IRAK1 in acute myeloid leukemia (AML) and assessed the inhibitory activity of multikinase inhibitor pacritinib on IRAK1 in AML. We demonstrated that IRAK1 is overexpressed in AML and provides a survival signal to AML cells. Genetic knockdown of IRAK1 in primary AML samples and xenograft model showed a significant reduction in leukemia burden. Kinase profiling indicated pacritinib has potent inhibitory activity against IRAK1. Computational modeling combined with site-directed mutagenesis demonstrated high-affinity binding of pacritinib to the IRAK1 kinase domain. Pacritinib exposure reduced IRAK1 phosphorylation in AML cells. A higher percentage of primary AML samples showed robust sensitivity to pacritinib, which inhibits FLT3, JAK2, and IRAK1, relative to FLT3 inhibitor quizartinib or JAK1/2 inhibitor ruxolitinib, demonstrating the importance of IRAK1 inhibition. Pacritinib inhibited the growth of AML cells harboring a variety of genetic abnormalities not limited to FLT3 and JAK2. Pacritinib treatment reduced AML progenitors in vitro and the leukemia burden in AML xenograft model. Overall, IRAK1 contributes to the survival of leukemic cells, and the suppression of IRAK1 may be beneficial among heterogeneous AML subtypes.

Antibiotics are widely used by all specialties in the hospital setting. We evaluated previously defined high-risk antibiotic use in relation to Clostridioides difficile infections (CDIs). We analyzed 2016-2017 data from 171 hospitals. High-risk antibiotics included second-, third-, and fourth-generation cephalosporins, fluoroquinolones, carbapenems, and lincosamides. A CDI case was a positive stool C. difficile toxin or molecular assay result from a patient without a positive result in the previous 8 weeks. Hospital-associated (HA) CDI cases included specimens collected >3 calendar days after admission or ≤3 calendar days from a patient with a prior same-hospital discharge within 28 days. We used the multivariable Poisson regression model to estimate the relative risk (RR) of high-risk antibiotic use on HA CDI, controlling for confounders. The median days of therapy for high-risk antibiotic use was 241.2 (interquartile range [IQR], 192.6-295.2) per 1,000 days present; the overall HA CDI rate was 33 (IQR, 24-43) per 10,000 admissions. The overall correlation of high-risk antibiotic use and HA CDI was 0.22 (P = .003), and higher correlation was observed in teaching hospitals (0.38; P = .002). For every 100-day (per 1,000 days present) increase in high-risk antibiotic therapy, there was a 12% increase in HA CDI (RR, 1.12; 95% CI, 1.04-1.21; P = .002) after adjusting for confounders. High-risk antibiotic use is an independent predictor of HA CDI. This assessment of poststewardship implementation in the United States highlights the importance of tracking trends of antimicrobial use over time as it relates to CDI.

T helper (Th) 17 cells, a novel T-cell subset, have been implicated in the pathogenesis of psoriasis and other autoimmune inflammatory diseases. Interleukin (IL)-23 stimulates survival and proliferation of Th17 cells, and thus serves as a key master cytokine regulator for these diseases. In psoriasis, IL-23 is overproduced by dendritic cells and keratinocytes, and this cytokine stimulates Th17 cells within dermis to make IL-17A and IL-22. IL-22, in particular, drives keratinocyte hyperproliferation in psoriasis. Future targeting of these key cytokines is likely to lead to dramatic clinical improvement in patients with psoriasis. This review focuses on the numerous recent studies on the roles of IL-23 and Th17 cells in the pathogenesis of psoriasis.

SignificanceMononuclear cells obtained from freshly isolated patient samples with various hematologic malignancies were evaluated for sensitivities to combinations of drugs that target specific cell-signaling pathways. The diagnostic, genetic/cytogenetic, and cellular features of the patient samples were correlated with effective drug combinations. For myeloid-derived tumors, such as acute myeloid leukemia, several combinations of targeted agents that include a kinase inhibitor and venetoclax, a selective inhibitor of BCL2, are effective. Translating the genetic and epigenetic heterogeneity underlying human cancers into therapeutic strategies is an ongoing challenge. Large-scale sequencing efforts have uncovered a spectrum of mutations in many hematologic malignancies, including acute myeloid leukemia (AML), suggesting that combinations of agents will be required to treat these diseases effectively. Combinatorial approaches will also be critical for combating the emergence of genetically heterogeneous subclones, rescue signals in the microenvironment, and tumor-intrinsic feedback pathways that all contribute to disease relapse. To identify novel and effective drug combinations, we performed ex vivo sensitivity profiling of 122 primary patient samples from a variety of hematologic malignancies against a panel of 48 drug combinations. The combinations were designed as drug pairs that target nonoverlapping biological pathways and comprise drugs from different classes, preferably with Food and Drug Administration approval. A combination ratio (CR) was derived for each drug pair, and CRs were evaluated with respect to diagnostic categories as well as against genetic, cytogenetic, and cellular phenotypes of specimens from the two largest disease categories: AML and chronic lymphocytic leukemia (CLL). Nearly all tested combinations involving a BCL2 inhibitor showed additional benefit in patients with myeloid malignancies, whereas select combinations involving PI3K, CSF1R, or bromodomain inhibitors showed preferential benefit in lymphoid malignancies. Expanded analyses of patients with AML and CLL revealed specific patterns of ex vivo drug combination efficacy that were associated with select genetic, cytogenetic, and phenotypic disease subsets, warranting further evaluation. These findings highlight the heuristic value of an integrated functional genomic approach to the identification of novel treatment strategies for hematologic malignancies.

Background Multisite practical clinical trials evaluate treatments in real-world practice. A multisite randomized Veterans Health Administration (VHA) cooperative study (CSP#555) published in 2011 compared the first long-acting injectable (LAI) second-generation antipsychotic (SGA), Risperidone Consta®, in veterans with a diagnosis of schizophrenia or schizoaffective disorder, to oral antipsychotics, with unexpected null results for effectiveness and cost-effectiveness. Whether null results of this type could change VHA practice has not been studied. Methods A longitudinal observational analysis was used to evaluate the impact of the trial findings on VHA clinical practices. National administrative data compared new starts on LAI risperidone during the 4 years before the publication of CSP#555 in 2011 to new starts on LAI risperidone during the 4 years after. Results Among 119,565 Veterans with the indicated diagnoses treated with antipsychotics from 2007 to 2015, the number and proportion of new starts on LAI risperidone declined significantly following the study publication, as did the total number of annual users and drug expenditures. However, data from 2007 to 2010 showed the decline in new starts actually preceded the publication of CSP#555. This change was likely explained by the increase in new starts, total use, and expenditures on a newer medicine, LAI paliperidone, a 4-week LAI treatment, in the 2 years prior to the publication of CSP#555. Conclusions The declining use of LAI risperidone likely primarily reflects the substitution of a longer-acting LAI SGA, paliperidone, that came to market 2 years before the study publication, a substitution that may have been reinforced by null CSP#555 study results for LAI risperidone.

Aberrant B-cell receptor (BCR) signaling is a key driver in lymphoid malignancies. Bruton tyrosine kinase (BTK) inhibitors that disrupt BCR signaling have received regulatory approvals in therapy of mantle cell lymphoma (MCL). However, responses are incomplete and patients who experience BTK inhibitor therapy failure have dire outcomes. CG-806 (luxeptinib) is a dual BTK/SYK inhibitor in clinical development in hematologic malignancies. Here we investigated the pre-clinical activity of CG-806 in MCL. In vitro treatment with CG-806 thwarted survival of MCL cell lines and patient-derived MCL cells in a dose-dependent manner. CG-806 blocked BTK and SYK activation and abrogated BCR signaling. Contrary to ibrutinib, CG-806 downmodulated the anti-apoptotic proteins Mcl-1 and Bcl-xL, abrogated survival of ibrutinib-resistant MCL cell lines, and partially reversed the pro-survival effects of stromal microenvironment-mimicking conditions in primary MCL cells. Dual BTK/SYK inhibition led to mitochondrial membrane depolarization accompanied by mitophagy and metabolic reprogramming toward glycolysis. In vivo studies of CG-806 demonstrated improved survival in one of the two tested aggressive MCL PDX models. While suppression of the anti-apoptotic Bcl-2 family proteins and NFκB signaling correlated with in vivo drug sensitivity, OxPhos and MYC transcriptional programs were upregulated in the resistant model following treatment with CG-806. BAX and NFKBIA were implicated in susceptibility to CG-806 in a whole-genome CRISPR-Cas9 library screen (in a diffuse large B-cell lymphoma cell line). A high-throughput in vitro functional drug screen demonstrated synergy between CG-806 and Bcl-2 inhibitors. In sum, dual BTK/SYK inhibitor CG-806 disrupts BCR signaling and induces metabolic reprogramming and apoptosis in MCL. The Bcl-2 network is a key mediator of sensitivity to CG-806 and combined targeting of Bcl-2 demonstrates synergy with CG-806 warranting continued exploration in lymphoid malignancies.

Acute myeloid leukemia (AML) is characterized by a complex interplay between genomic alterations, aberrant hematopoiesis, and immune evasion. The aryl hydrocarbon receptor (AHR) pathway is a critical player in this phenomenon determining the fate of stem cell differentiation as well as dictating immune cell development and function. Despite this critical connection, little is known about how AHR regulates the immune microenvironment in AML. We performed a retrospective study examining the pre-treatment effect of immune cell numbers (T and NK cells) in the bone marrow and their impact on overall survival in AML patients undergoing 7+3 induction chemotherapy. Utilizing flow cytometry and both bulk and single-cell RNA sequencing of AML patient samples, we characterized the immune signature of blast cells and the influence of AHR on the immune microenvironment. Lastly, we performed functional studies to determine impact of pharmacological and genomic AHR inhibition on NK cell function. Higher bone marrow NK cell percentage in ND-AML correlated with poorer OS and expression of HLA-E on leukemic blasts. AHR upregulation was associated with HLA-E expression on blasts and an innate immune resistant signature defined by upregulation of key cytokine pathways, interferon gamma (IFN-g) pathway, and MHC class I/II as well as impaired NK cell profiles. High AHR expression in AML was associated with monocytic maturation and discrepant MHC class I/II profiles. Pre-treatment of blasts with an AHR inhibitor (AHRi) prior to NK cell killing assay downregulated key checkpoint molecules, including HLA-E, and key IFN-g signaling transcription factors (STAT1, IRF1) and led to enhanced NK cell killing among multiple FAB subsets in AML. The data support targeting the AHR pathway as a dual tumor intrinsic and immune targeting therapeutic strategy for AML, particularly in combination with NK cellular therapy.

Acute myeloid leukemia (AML) results from the enhanced proliferation and impaired differentiation of hematopoietic stem and progenitor cells. Using an ex vivo functional screening assay, we identified that the combination of the BTK inhibitor ibrutinib and BCL2 inhibitor venetoclax (IBR + VEN), currently in clinical trials for chronic lymphocytic leukemia (CLL), demonstrated enhanced efficacy on primary AML patient specimens, AML cell lines, and in a mouse xenograft model of AML. Expanded analyses among a large cohort of hematologic malignancies (n = 651 patients) revealed that IBR + VEN sensitivity associated with selected genetic and phenotypic features in both CLL and AML specimens. Among AML samples, 11q23 MLL rearrangements were highly sensitive to IBR + VEN. Analysis of differentially expressed genes with respect to IBR + VEN sensitivity indicated pathways preferentially enriched in patient samples with reduced ex vivo sensitivity, including IL-10 signaling. These findings suggest that IBR + VEN may represent an effective therapeutic option for patients with AML.