Dissecting the dynamic transcriptional landscape of early T helper cell differentiation into Th1, Th2, and Th1/2 hybrid cells

Selective differentiation of CD4+ T helper (Th) cells into specialized subsets such as Th1 and Th2 cells is a key element of the adaptive immune system driving appropriate immune responses. Besides those canonical Th-cell lineages, hybrid phenotypes such as Th1/2 cells arise in vivo, and their generation could be reproduced in vitro. While master-regulator transcription factors like T-bet for Th1 and GATA-3 for Th2 cells drive and maintain differentiation into the canonical lineages, the transcriptional architecture of hybrid phenotypes is less well understood. In particular, it has remained unclear whether a hybrid phenotype implies a mixture of the effects of several canonical lineages for each gene, or rather a bimodal behavior across genes. Th-cell differentiation is a dynamic process in which the regulatory factors are modulated over time, but longitudinal studies of Th-cell differentiation are sparse. Here, we present a dynamic transcriptome analysis following Th-cell differentiation into Th1, Th2, and Th1/2 hybrid cells at 3-h time intervals in the first hours after stimulation. We identified an early bifurcation point in gene expression programs, and we found that only a minority of ~20% of Th cell-specific genes showed mixed effects from both Th1 and Th2 cells on Th1/2 hybrid cells. While most genes followed either Th1- or Th2-cell gene expression, another fraction of ~20% of genes followed a Th1 and Th2 cell-independent transcriptional program associated with the transcription factors STAT1 and STAT4. Overall, our results emphasize the key role of high-resolution longitudinal data for the characterization of cellular phenotypes.Peer Reviewe

Acetalated dextran encapsulated AR-12 as a host-directed therapy to control Salmonella infection

AR-12 has been evaluated in clinical trials as an anti-cancer agent but also has demonstrated host-directed, broad-spectrum clearance of bacteria. We have previously shown that AR-12 has activity in vitro against Salmonella enterica serovar Typhimurium and Francisella species by inducing autophagy and other host immune pathways. AR-12 treatment of S. Typhimurium-infected mice resulted in a 10-fold reduction in bacterial load in the liver and spleen and an increased survival time. However, AR-12 treatment did not protect mice from death, likely due poor formulation. In the current study, AR-12 was encapsulated in a microparticulate carrier formulated from the novel degradable biopolymer acetalated dextran (Ace-DEX) and subsequently evaluated for its activity in human monocyte-derived macrophages (hMDMs). Our results show that hMDMs efficiently internalized Ace-DEX microparticles (MPs), and that encapsulation significantly reduced host cell cytotoxicity compared to unencapsulated AR-12. Efficient macrophage internalization of AR-12 loaded MPs (AR-12/MPs) was further demonstrated by autophagosome formation that was comparable to free AR-12 and resulted in enhanced clearance of intracellular Salmonella. Taken together, these studies provide support that Ace-DEX encapsulated AR-12 may be a promising new therapeutic agent to control intracellular bacterial pathogens of macrophages by targeting delivery and reducing drug toxicity

PRMT5-Selective Inhibitors Suppress Inflammatory T Cell Responses and Experimental Autoimmune Encephalomyelitis

In the autoimmune disease multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), expansion of pathogenic, myelin-specific Th1 cell populations drives active disease; selectively targeting this process may be the basis for a new therapeutic approach. Previous studies have hinted at a role for protein arginine methylation in immune responses, including T cell–mediated autoimmunity and EAE. However, a conclusive role for the protein arginine methyltransferase (PRMT) enzymes that catalyze these reactions has been lacking. PRMT5 is the main PRMT responsible for symmetric dimethylation of arginine residues of histones and other proteins. PRMT5 drives embryonic development and cancer, but its role in T cells, if any, has not been investigated. In this article, we show that PRMT5 is an important modulator of CD4+ T cell expansion. PRMT5 was transiently upregulated during maximal proliferation of mouse and human memory Th cells. PRMT5 expression was regulated upstream by the NF-κB pathway, and it promoted IL-2 production and proliferation. Blocking PRMT5 with novel, highly selective small molecule PRMT5 inhibitors severely blunted memory Th expansion, with preferential suppression of Th1 cells over Th2 cells. In vivo, PRMT5 blockade efficiently suppressed recall T cell responses and reduced inflammation in delayed-type hypersensitivity and clinical disease in EAE mouse models. These data implicate PRMT5 in the regulation of adaptive memory Th cell responses and suggest that PRMT5 inhibitors may be a novel therapeutic approach for T cell–mediated inflammatory disease

A strategic action framework for multipurpose prevention technologies combining contraceptive hormones and antiretroviral drugs to prevent pregnancy and HIV.

ObjectiveMultipurpose prevention technologies (MPTs) are an innovative class of products that deliver varied combinations of human immunodeficiency virus (HIV) prevention, other sexually transmitted infection (STI) prevention, and contraception. Combining separate strategies for different indications into singular prevention products can reduce the stigma around HIV and STI prevention, improve acceptability of and adherence to more convenient products, and be more cost-effective by addressing overlapping risks.MethodsThis article outlines a strategic action framework developed as an outcome of a series of expert meetings held between 2014 and 2016. The meetings focused on identifying opportunities and challenges for MPTs that combine hormonal contraception (HC) with antiretroviral drugs into single products. The framework aims to present an actionable strategy, by addressing key research gaps and outlining the key areas for progress, to guide current and future HC MPT development.ResultsWe identified eight primary action areas for the development of impactful HC MPTs, and includes aspects from epidemiology, pharmacology, clinical trial design, regulatory requirements, manufacturing and commercialisation, behavioural science, and investment needs for research and development.ConclusionOverall, the challenges involved with reconciling the critical social-behavioural context that will drive MPT product use and uptake with the complexities of research and development and regulatory approval are of paramount importance. To realise the potential of MPTs given their complexity and finite resources, researchers in the MPT field must be strategic about the way forward; increased support among policy-makers, advocates, funders and the pharmaceutical industry is critical

A strategic action framework for multipurpose prevention technologies combining contraceptive hormones and antiretroviral drugs to prevent pregnancy and HIV.

ObjectiveMultipurpose prevention technologies (MPTs) are an innovative class of products that deliver varied combinations of human immunodeficiency virus (HIV) prevention, other sexually transmitted infection (STI) prevention, and contraception. Combining separate strategies for different indications into singular prevention products can reduce the stigma around HIV and STI prevention, improve acceptability of and adherence to more convenient products, and be more cost-effective by addressing overlapping risks.MethodsThis article outlines a strategic action framework developed as an outcome of a series of expert meetings held between 2014 and 2016. The meetings focused on identifying opportunities and challenges for MPTs that combine hormonal contraception (HC) with antiretroviral drugs into single products. The framework aims to present an actionable strategy, by addressing key research gaps and outlining the key areas for progress, to guide current and future HC MPT development.ResultsWe identified eight primary action areas for the development of impactful HC MPTs, and includes aspects from epidemiology, pharmacology, clinical trial design, regulatory requirements, manufacturing and commercialisation, behavioural science, and investment needs for research and development.ConclusionOverall, the challenges involved with reconciling the critical social-behavioural context that will drive MPT product use and uptake with the complexities of research and development and regulatory approval are of paramount importance. To realise the potential of MPTs given their complexity and finite resources, researchers in the MPT field must be strategic about the way forward; increased support among policy-makers, advocates, funders and the pharmaceutical industry is critical

A strategic action framework for multipurpose prevention technologies combining contraceptive hormones and antiretroviral drugs to prevent pregnancy and HIV.

OBJECTIVE:Multipurpose prevention technologies (MPTs) are an innovative class of products that deliver varied combinations of human immunodeficiency virus (HIV) prevention, other sexually transmitted infection (STI) prevention, and contraception. Combining separate strategies for different indications into singular prevention products can reduce the stigma around HIV and STI prevention, improve acceptability of and adherence to more convenient products, and be more cost-effective by addressing overlapping risks. METHODS:This article outlines a strategic action framework developed as an outcome of a series of expert meetings held between 2014 and 2016. The meetings focused on identifying opportunities and challenges for MPTs that combine hormonal contraception (HC) with antiretroviral drugs into single products. The framework aims to present an actionable strategy, by addressing key research gaps and outlining the key areas for progress, to guide current and future HC MPT development. RESULTS:We identified eight primary action areas for the development of impactful HC MPTs, and includes aspects from epidemiology, pharmacology, clinical trial design, regulatory requirements, manufacturing and commercialisation, behavioural science, and investment needs for research and development. CONCLUSION:Overall, the challenges involved with reconciling the critical social-behavioural context that will drive MPT product use and uptake with the complexities of research and development and regulatory approval are of paramount importance. To realise the potential of MPTs given their complexity and finite resources, researchers in the MPT field must be strategic about the way forward; increased support among policy-makers, advocates, funders and the pharmaceutical industry is critical

Turning the promise of multipurpose prevention technologies into a market reality: a commentary

The promise of multipurpose prevention technologies (MPTs) for the prevention of HIV and unintended pregnancy are on the horizon. While many are still in clinical development, others are closer to becoming a realistic, accessible option for users, like the dual prevention pill (DPP). Researchers, governments, donors, and implementers will have to collaboratively address systemic challenges to successfully introduce and scale-up MPTs. To ensure the rollout of MPTs is successful, the global community should address user and country-specific needs, coordinate with advocates and policymakers, and set a realistic plan for product introduction and scale-up that considers the needs of both family planning (FP) and HIV programs, while laying the groundwork for future new product introduction. To achieve these aims, global and regional stakeholder coordination should emphasize country-led, person-centered decision-making while addressing: (1) procurement and supply chain barriers; (2) the potential burden on health systems; and (3) the impact on current programs

Efficient Delivery of the Toll-like Receptor Agonists Polyinosinic:Polycytidylic Acid and CpG to Macrophages by Acetalated Dextran Microparticles

To enhance the immune activity of vaccine adjuvants polyinosinic:polycytidylic acid (poly I:C) and CpG acetalated dextran (Ac-DEX) microparticles can be used. Ac-DEX is a biodegradable and water-insoluble polymer that degrades significantly faster at pH 5.0 (phagosomal pH) than at pH 7.4 and has tunable degradation rates that can range from hours to months. This is an ideal characteristic for delivery of an antigen and adjuvant within the lysosomal compartment of a phagocytic cell. We evaluated poly I:C and CpG encapsulated in Ac-DEX microparticles using RAW macrophages as a model antigen-presenting cell. These cells were cultured with poly I:C or CpG in their free form, encapsulated in a fast degrading Ac-DEX, in slow degrading Ac-DEX, or in the Food and Drug Administration-approved polymer poly­(lactic-<i>co</i>-glycolic acid) (PLGA). Ac-DEX had higher encapsulation efficiencies for both poly I:C and CpG than PLGA. Furthermore, poly I:C or CpG encapsulated in Ac-DEX also showed, in general, a significantly stronger immunostimulatory response than PLGA and unencapsulated CpG or poly I:C, which was indicated by a higher rate of nitric oxide release and increased levels of cytokines such as TNF-α, IL-6, IL-10, and IFN-γ. Overall, we have illustrated a method for enhancing the delivery of these vaccine adjuvants to further enhance the development of Ac-DEX vaccine formulations