Plasmacytoid dendritic cells prime IL-10-producing T regulatory cells by inducible costimulator ligand.

Although there is evidence for distinct roles of myeloid dendritic cells (DCs [mDCs]) and plasmacytoid pre-DCs (pDCs) in regulating T cell-mediated adaptive immunity, the concept of functional DC subsets has been questioned because of the lack of a molecular mechanism to explain these differences. In this study, we provide direct evidence that maturing mDCs and pDCs express different sets of molecules for T cell priming. Although both maturing mDCs and pDCs upregulate the expression of CD80 and CD86, only pDCs upregulate the expression of inducible costimulator ligand (ICOS-L) and maintain high expression levels upon differentiation into mature DCs. High ICOS-L expression endows maturing pDCs with the ability to induce the differentiation of naive CD4 T cells to produce interleukin-10 (IL-10) but not the T helper (Th)2 cytokines IL-4, -5, and -13. These IL-10-producing T cells are T regulatory cells, and their generation by ICOS-L is independent of pDC-driven Th1 and Th2 differentiation, although, in the later condition, some contribution from endogenous IL-4 cannot be completely ruled out. Thus, in contrast to mDCs, pDCs are poised to express ICOS-L upon maturation, which leads to the generation of IL-10-producing T regulatory cells. Our findings demonstrate that mDC and pDCs are intrinsically different in the expression of costimulatory molecules that drive distinct types of T cell responses.

Barriers to COVID-19 Prevention Measures Among People Experiencing Homelessness with Substance Use Disorder or Serious Mental Illness.

People experiencing homelessness (PEH) are at disproportionate risk of becoming infected and having severe illness from coronavirus disease 2019 (COVID-19), especially when residing in congregate settings like homeless shelters. Behavioral health problems related to substance use disorder (SUD) and severe mental illness (SMI) may have created additional challenges for PEH to practice prevention measures like mask wearing, physical distancing, handwashing, and quarantine and isolation. The study objective was to understand the perceived barriers PEH face regarding COVID-19 non-pharmaceutical prevention strategies and identify recommendations for overcoming barriers. From August-October 2020, qualitative phone interviews with 50 purposively selected behavioral health professionals across the United States serving PEH with SUD or SMI were conducted. Professionals described that PEH faced barriers to prevention that were structural (e.g., access to necessary resources), behavioral (related to SUD or SMI), or related to the priority of other needs. Recommendations to overcome these barriers included providing free prevention resources (e.g., masks and hand sanitizer), providing education about importance of prevention strategies, and prioritizing access to stable housing. Interviews took place before COVID-19 vaccines were available, so barriers to vaccination are not included in this paper. Findings can help support tailored approaches during COVID-19 and future public health threats.

Multivalent smallpox DNA vaccine delivered by intradermal electroporation drives protective immunity in nonhuman primates against lethal monkeypox challenge.

The threat of a smallpox-based bioterrorist event or a human monkeypox outbreak has heightened the importance of new, safe vaccine approaches for these pathogens to complement older poxviral vaccine platforms. As poxviruses are large, complex viruses, they present technological challenges for simple recombinant vaccine development where a multicomponent mixtures of vaccine antigens are likely important in protection. We report that a synthetic, multivalent, highly concentrated, DNA vaccine delivered by a minimally invasive, novel skin electroporation microarray can drive polyvalent immunity in macaques, and offers protection from a highly pathogenic monkeypox challenge. Such a diverse, high-titer antibody response produced against 8 different DNA-encoded antigens delivered simultaneously in microvolumes has not been previously described. These studies represent a significant improvement in the efficiency of the DNA vaccine platform, resulting in immune responses that mimic live viral infections, and would likely have relevance for vaccine design against complex human and animal pathogens.

Behavioral Health Providers' Experience with Changes in Services for People Experiencing Homelessness During COVID-19, USA, August-October 2020.

The COVID-19 pandemic caused disruptions in behavioral health services (BHS), essential for people experiencing homelessness (PEH). BHS changes created barriers to care and opportunities for innovative strategies for reaching PEH. The authors conducted 50 qualitative interviews with behavioral health providers in the USA during August-October 2020 to explore their observations of BHS changes for PEH. Interviews were transcribed and entered into MAXQDA for analysis and to identify salient themes. The largest impact from COVID-19 was the closure or limited hours for BHS and homeless shelters due to mandated "stay-at-home" orders or staff working remotely leading to a disconnection in services and housing linkages. Most providers initiated telehealth services for clients, yielding positive outcomes. Implications for BHS are the need for long-term strategies, such as advances in communication technology to support BHS and homeless services and to ensure the needs of underserved populations are met during public health emergencies.

Impact of Social Isolation during the COVID-19 Pandemic on Mental Health, Substance Use, and Homelessness: Qualitative Interviews with Behavioral Health Providers.

The United States is experiencing a syndemic of homelessness, substance use disorder, and mental health conditions, which has been further exacerbated by the COVID-19 pandemic. Although it is expected that mitigation strategies will curb community transmission of COVID-19, the unintended consequences of social isolation on mental health and substance use are a growing public health concern. Awareness of changing mental health and substance use treatment needs due to the pandemic is critical to understanding what additional services and support are needed during and post-pandemic, particularly among people experiencing homelessness who have pre-existing serious mental illness or substance use disorder. To evaluate these effects and support our understanding of mental health and substance use outcomes of the COVID-19 pandemic, we conducted a qualitative study where behavioral health providers serving people experiencing homelessness described the impact of COVID-19 among their clients throughout the United States. Behavioral health providers shared that experiencing social isolation worsened mental health conditions and caused some people to return to substance use and fatally overdose. However, some changes initiated during the pandemic resulted in positive outcomes, such as increased client willingness to discuss mental health topics. Our findings provide additional evidence that the social isolation experienced during the pandemic has been detrimental to mental health and substance use outcomes, especially for people experiencing homelessness.

Simulation Tools for Inclusive Design Solutions.

Disability has been redefined by the World Health Organization as a function of a person's interaction with the environment and not merely an innate part of a person. This redefinition highlights the need for inclusiveness in design solutions. To aid this, we apply and test the potential of different tools that restrict designers' physical abilities at deriving inclusive design perspectives among designers. Various tools and simulated conditions are often adopted in user-centered design to sup-port need-finding by eliciting rich data on users' needs and guide designers to empathize with users. Simulation tools that restrict designers' physical abilities have been applied to understand certain perspectives of people with physical challenges, yet these tools lack the ability to evoke an inclusive design perspective among designers. Through a co-creation workshop, participants were exposed to two forms of simulations: direct and situational physical impairments. This was achieved using different tools that simulate the same physical restriction. In this study, a noise- canceller and earphones were used to simulate a reduced hearing attention. Participants were asked to generate user needs and design functions by applying both the simulation tools. The study results comprise the outcomes of 33 participants who volunteered to participate in a co-design workshop that provided a venue for them to interact and work alongside users with physical challenges. This paper analyses the inclusiveness attained through different types of simulated conditions. With a growing need to create tools and technologies that delight the user, it is necessary to equip designers with the tools that would help them with the process. The study demonstrates the application and impact of one such tool.

Immunogenicity of a DNA vaccine candidate for COVID-19.

The coronavirus family member, SARS-CoV-2 has been identified as the causal agent for the pandemic viral pneumonia disease, COVID-19. At this time, no vaccine is available to control further dissemination of the disease. We have previously engineered a synthetic DNA vaccine targeting the MERS coronavirus Spike (S) protein, the major surface antigen of coronaviruses, which is currently in clinical study. Here we build on this prior experience to generate a synthetic DNA-based vaccine candidate targeting SARS-CoV-2 S protein. The engineered construct, INO-4800, results in robust expression of the S protein in vitro. Following immunization of mice and guinea pigs with INO-4800 we measure antigen-specific T cell responses, functional antibodies which neutralize the SARS-CoV-2 infection and block Spike protein binding to the ACE2 receptor, and biodistribution of SARS-CoV-2 targeting antibodies to the lungs. This preliminary dataset identifies INO-4800 as a potential COVID-19 vaccine candidate, supporting further translational study.

Design and synthesis of potent inhibitors of cholesteryl ester transfer protein (CETP) exploiting a 1,2,3,4-tetrahydroquinoline platform.

Tetrahydroquinoline A is a potent inhibitor of the cholesterol ester transfer protein (CETP), a target for the treatment of low HDL-C and atherosclerosis. Low HDL-C has been identified as a key risk factor for cardiovascular disease in addition to high LDL-C, the target of the statin drugs. Tetrahydroquinoline A inhibits partially purified CETP with an IC(50) of 39nM. The preparation of a series of potent inhibitors of CETP designed around a 1,2,3,4-tetrahydroquinoline platform will be discussed.

Synthesis and structure-activity relationships of thiadiazole-derivatives as potent and orally active peroxisome proliferator-activated receptors alpha/delta dual agonists.

Replacement of the methyl-thiazole moiety of GW501516 (a PPARdelta selective agonist) with [1,2,4]thiadiazole gave compound 21 which unexpectedly displayed submicromolar potency as a partial agonist at PPARalpha in addition to the high potency at PPARdelta. A structure-activity relationships study of 21 resulted in the identification of 40 as a potent and selective PPARalpha/delta dual agonist. Compound 40 and its close analogs represent a new series of PPARalpha/delta dual agonists. The high potency, high selectivity, significant gene induction, excellent PK profiles, low P450 inhibition or induction, and good in vivo efficacy in four animal models support 40 being selected as a pre-clinical study candidate, and may render 40 as a valuable pharmacological tool in elucidating the complex roles of PPARalpha/delta dual agonists, and the potential usage for the treatment of metabolic syndrome.

Synthesis and identification of [1,2,4]thiadiazole derivatives as a new series of potent and orally active dual agonists of peroxisome proliferator-activated receptors alpha and delta.

Cardiovascular disease is the most common cause of morbidity and mortality in developed nations. To effectively target dyslipidemia to reduce the risk of cardiovascular disease, it may be beneficial to activate the peroxisome proliferator-activated receptors (PPARs) PPARalpha and PPARdelta simultaneously through a single molecule. Replacement of the methylthiazole of 5 (the PPARdelta selective agonist) with [1,2,4]thiadiazole gave compound 13, which unexpectedly displayed submicromolar potency as a partial agonist at PPARalpha in addition to the high potency at PPARdelta. Optimization of 13 led to the identification of 24 as a potent and selective PPARalpha/delta dual agonist. Compound 24 and its close analogs represent a new series of PPARalpha/delta dual agonists. The high potency, significant gene induction, excellent PK profiles, and good in vivo efficacies in three animal models may render compound 24 as a valuable pharmacological tool in elucidating the complex roles of PPARalpha/delta dual agonists and as a potential treatment of the metabolic syndrome.

Design and synthesis of indane-ureido-thioisobutyric acids: A novel class of PPARalpha agonists.

A series of aminoindane derivatives were synthesized and shown to be potent PPARalpha agonists. The compounds were obtained as racemates in 12 steps, and tested for PPARalpha activation and PPARalpha mediated induction of the HD gene. SAR was developed by variation to the core structure as shown within. Oral bioavailability was demonstrated in a Sprague-Dawley rat, while efficacy to reduce plasma triglycerides and plasma glucose was demonstrated in db/db mice.

Stress-related mediators stimulate vascular endothelial growth factor secretion by two ovarian cancer cell lines.

PURPOSE: Stress has long been believed to influence carcinogenesis, but little is known about physiological mechanisms that may underlie these effects. We have recently observed lower levels of vascular endothelial growth factor (VEGF) in ovarian cancer patients with greater social support, whereas higher VEGF was found in patients with greater distress. The goal of this study was to examine possible mechanisms underlying these relationships. EXPERIMENTAL DESIGN: The effects of stress-related mediators including norepinephrine (NE), epinephrine, isoproterenol (a nonspecific beta-adrenergic agonist), and cortisol on the production of VEGF by the ovarian cell lines SKOV3 and EG were investigated. RESULTS: NE and isoproterenol significantly enhanced VEGF production by SKOV3 cells, and all three of the adrenergic agonists enhanced VEGF production by EG cells. These effects were blocked by the beta antagonist propranolol, supporting a role for beta-adrenergic receptors in these effects. Reverse transcriptase-PCR studies indicated constitutive expression of beta-1 and beta-2 adrenergic receptors on both cell lines. Effects of cortisol on VEGF production varied according to the specific cell line and dose, with stimulating effects on SKOV3 at pharmacologic doses (1000 nM) and on EG at physiological stress level doses (10 nM), and inhibitory effects on EG at pharmacologic doses. Although priming with cortisol blunted NE-induced VEGF production from both cell lines at 3 h, significant increases in VEGF were still seen. Priming with cortisol enhanced isoproterenol-induced VEGF production from SKOV3. CONCLUSION: These findings provide the first experimental evidence of a pathway by which biobehavioral stress mediators could directly contribute to the progression of ovarian tumors.

Benzoxazinones as PPARgamma agonists. 2. SAR of the amide substituent and in vivo results in a type 2 diabetes model.

A series of benzoxazinones has been synthesized and tested for PPARgamma agonist activity. Synthetic approaches were developed to provide either racemic or chiral compounds. In vitro functional potency could be measured through induction of the aP2 gene, a target of PPARgamma. These studies revealed that compounds with large aliphatic chains at the nitrogen of the benzoxazinone were the most potent. Substitution of the chain was tolerated and in many cases enhanced the in vitro potency of the compound. Select compounds were further tested for metabolic stability, oral bioavailability in rats, and efficacy in db/db mice after 11 days of dosing. In vivo analysis with 13 and 57 demonstrated that the series has potential for the treatment of type 2 diabetes.

Age-environment and gene-environment interactions in the pathogenesis of Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disease characterized by dopaminergic cell death and deposition of Lewy bodies within the substantia nigra of the midbrain. Although the major risk factors for PD are aging and environmental factors, there is an important genetic component. An age-related change in xenobiotic metabolism alters the metabolism of and net exposure to, environmental neurotoxins. Genetic variability in xenobiotic metabolism may similarly increase the susceptibility to PD by altering the metabolism of neurotoxins. Genetic studies of rare familial cases of PD indicate a central mechanistic role for the aggregation of alpha-synuclein, a protein found in Lewy bodies. Environmental factors like pesticides and heavy metals can also influence alpha-synuclein aggregation. Common final pathways for aging, environmental, and genetic mechanisms can thus exist, involving both direct neurotoxicity and alpha-synuclein aggregation.

Optimization of electroporation-enhanced intradermal delivery of DNA vaccine using a minimally invasive surface device.

In vivo electroporation (EP) is an efficient nonviral method for enhancing DNA vaccine delivery and immunogenicity in animals and humans. Intradermal delivery of DNA vaccines is an attractive strategy because of the immunocompetence of skin tissue. We have previously reported a minimally invasive surface intradermal EP (SEP) device for delivery of prophylactic DNA vaccines. Robust antibody responses were induced after vaccine delivery via surface EP in several tested animal models. Here we further investigated the optimal EP parameters for efficient delivery of DNA vaccines, with a specific emphasis on eliciting cellular immunity in addition to robust humoral responses. In a mouse model, using applied voltages of 10-100 V, transgene expression of green fluorescent protein and luciferase reporter genes increased significantly when voltages as low as 10 V were used as compared with DNA injection only. Tissue damage to skin was undetectable when voltages of 20 V and less were applied. However, inflammation and bruising became apparent at voltages above 40 V. Delivery of DNA vaccines encoding influenza virus H5 hemagglutinin (H5HA) and nucleoprotein (NP) of influenza H1N1 at applied voltages of 10-100 V elicited robust and sustained antibody responses. In addition, low-voltage (less than 20 V) EP elicited higher and more sustained cellular immune responses when compared with the higher voltage (above 20 V) EP groups after two immunizations. The data confirm that low-voltage EP, using the SEP device, is capable of efficient delivery of DNA vaccines into the skin, and establishes that these parameters are sufficient to elicit both robust and sustainable humoral as well as cellular immune responses without tissue damage. The SEP device, functioning within these parameters, may have important clinical applications for delivery of prophylactic DNA vaccines against diseases such as HIV infection, malaria, and tuberculosis that require both cellular and humoral immune responses for protection.

Improvement of dyslipidemia, insulin sensitivity, and energy balance by a peroxisome proliferator-activated receptor alpha agonist.

Peroxisome proliferator-activated receptor alpha (PPARalpha) is a member of the nuclear receptor family of ligand-activated transcription factors. It plays an important role in the regulation of genes involved in lipid metabolism and transport. Compound A is a potent and orally active PPARalpha agonist that activated both human and rat PPARalpha receptors. The compound induced the expression of genes involved in fatty acid metabolism in a rodent hepatoma cell line and in the liver of db/db mouse. The ability of compound A to stimulate fatty acid beta-oxidation was demonstrated in human hepatocytes and human skeletal muscle cells, which confirmed a functional activation of PPARalpha-mediated activities. Compound A was shown to be a more potent and efficacious antidyslipidemic agent in atherogenic rat and db/db mouse models as compared with fenofibrate. The increase in high-density lipoprotein cholesterol levels by compound A was at least partially due to an increase in serum apolipoprotein A-I protein concentrations in human PPARalpha transgenic mouse. The triglyceride-lowering effect was further confirmed in a higher species, obese dog models. In addition, compound A dose-dependently ameliorated hyperglycemia and hyperinsulinemia, and improved glucose tolerance in db/db mice. In a diet-induced obesity mouse model, compound A decreased body weight mainly by increasing energy expenditure and reducing fat deposition. In conclusion, the novel and potent PPARalpha agonist improves lipid profile, insulin sensitivity, and energy balance in animal models.

Dihydro-[1H]-quinolin-2-ones as retinoid X receptor (RXR) agonists for potential treatment of dyslipidemia.

A number of RXR modulators with novel structural features were synthesized and screened in the functional assays. The synthesis and the structure-activity relationship within the series of compounds will be presented. Some in vivo data generated in the models for dyslipidemia and diabetes will also be presented.

RXR-LXR heterodimer modulators for the potential treatment of dyslipidemia.

A number of RXR agonists were synthesized and screened in functional assays. The synthesis and the structure-activity relationship (SAR) within the series of compounds will be presented. Some in vivo data in rodent models for dyslipidemia and diabetes will also be presented.

Age-related alteration in hepatic disposition of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and pesticides.

Idiopathic Parkinson's disease may be caused by environmental neurotoxins such as pesticides, however the major risk factor is old age. We postulated that the high incidence of Parkinson's disease in older people is secondary to age-related impairment of the hepatic detoxification of xenobiotics. Previously, we have shown that there are significant differences between the hepatic disposition of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and pesticides. Here, we investigated whether there are age-related differences in the hepatic disposition of MPTP and pesticides, putatively associated with the pathogenesis of Parkinson's disease. We measured the hepatic disposition of paraquat, dichlorodiphenyltrichloroethane (DDT), malathion and MPTP using the multiple indicator dilution technique in the perfused livers of Fischer F344 rats aged 3 and 18 months. The recoveries of MPTP, DDT and malathion were increased from the livers of the older rats (by 258%, 253% and 134% compared with young rats, respectively). The hepatic transport of DDT and malathion into hepatocytes was reduced with age suggesting that part of the impaired uptake of neurotoxins may be secondary to an age-related barrier to influx. Ageing may increase risk of Parkinson's disease by altering hepatic detoxification and increasing systemic bioavailability of neurotoxins.

Discovery of a dihydropyrimidine series of molecules that selectively mimic the biological actions of calcitonin.

The use of a multiplex mimetic assay led us to identify 1,4-dihydropyrimidines with potent and selective calcitonin receptor mimetic activity. Subsequent modification of the dihydropyrimidine scaffold led to a series of molecules that were efficacious in a neonatal mouse calvaria in vitro model. Dihydropyrimidine 5h, in particular, was identified as a calcitonin mimetic (EC(50)=6 microM), active in-vivo in the Weanling rat model when administered subcutaneously.