Mycobacterial cell wall lipids bind the conserved CD1 family of antigen-presenting molecules and activate T cells via their T cell receptors (TCRs). Sulfoglycolipids (SGLs) are uniquely synthesized by Mycobacterium tuberculosis, but tools to study SGL-specific T cells in humans are lacking. We designed a novel hybrid synthesis of a naturally occurring SGL, generated CD1b tetramers loaded with natural or synthetic SGL analogs, and studied the molecular requirements for TCR binding and T cell activation. Two T cell lines derived using natural SGLs are activated by synthetic analogs independently of lipid chain length and hydroxylation, but differentially by saturation status. By contrast, two T cell lines derived using an unsaturated SGL synthetic analog were not activated by the natural antigen. Our data provide a bioequivalence hierarchy of synthetic SGL analogs and SGL-loaded CD1b tetramers. These reagents can now be applied to large-scale translational studies investigating the diagnostic potential of SGL-specific T cell responses or SGL-based vaccines.

This study demonstrated that cyclomethyline (2) and the corresponding enantiomers (R)-(−)-2 and (S)-(+)-2, displaying α 2C -adrenoreceptor (AR) agonism/α 2A -AR antagonism, similarly to allyphenyline (1) and its enantiomers, significantly decreased the naloxone-precipitated withdrawal symptoms in mice at very low doses. It also highlighted that such positive effects on morphine dependence can even be improved by additional serotoninergic 5-HT 1A receptor (5-HT 1A -R) activation. Indeed, 1 or the single (S)-(+)-1, 2, or both its enantiomers, all behaving as α 2C -AR agonists/α 2A -AR antagonists/5-HT 1A -R agonists, alone and at the same low dose, improved morphine withdrawal syndrome and exerted a potent antidepressant-like effect. Therefore, considering the elevated comorbidity between opiate abuse and depressed mood and the benefit of these multifunctional compounds to both disorders, it is possible that they prove more efficacious and less toxic than a cocktail of drugs in managing opioid addiction. KEYWORDS: α 2 -adrenergic ligands, 5-HT 1A -R agonists, morphine withdrawal symptoms reduction, antidepressant-like effect M orphine use is the classical approach in the treatment of chronic or cancer-related pain. Nevertheless, even when legally allowed and closely monitored, long-term opioid administration alters central pain-related systems, inducing tolerance and dependence. Opioid addiction, termed a "chronic relapsing disease", is associated with a myriad of health and social problems; hence, its management is an extremely important area of research. 1 α 2 -Adrenoreceptors (α 2 -ARs), which have been demonstrated to be extremely sensitive to opioid exposure and to play a key role in opiate withdrawal symptoms, 2 belong to the superfamily of G-protein-coupled receptors. The three α 2A -, α 2B -, and α 2C -AR subtypes are widely distributed in the central nervous system (CNS) and peripheral tissues. 3 Studies with genetically engineered mice have demonstrated that the α 2A subtype mediates hypotension, sedation, and analgesia, as well as inhibition of monoamine release and metabolism in the brain. The α 2B subtype mediates vasoconstriction, while the α 2C subtype appears to be involved in many CNS processes, such as the startle reflex, stress responses, and control of locomotion as well as feedback inhibition of adrenal cathecolamine release. Moreover, in the brain, α 2A -and α 2C -ARs, as "heteroreceptors", inhibit dopamine and serotonin release. Finally, the α 2C subtype can contribute to adrenergic-opioid synergy and spinal α 2 -agonist-mediated analgesia. 3−5 In detoxification, α 2 -AR agonists such as clonidine and lofexidine are often clinically used alone or in combination with traditional treatments to reduce the intensity of withdrawal symptoms, thus increasing treatment duration. However, the α 2A -AR activation triggered by these compounds is responsible for side effects such as sedation and hypotension.

In an attempt to find new antibiotics, novel ways of interfering with important biological functions should be explored, especially with those which are necessary or even irreplaceable for bacterial survival, growth, and virulence. The purpose of this review is to highlight B-type vitamin transporters from the energy-coupling factor (ECF) family, which are not present in humans, as potential antimicrobial targets. In addition, a druggability analysis of an ECF transporter for folic acid and sequence-conservation studies in seven prominent pathogens revealed new druggable pockets. Evaluation of the presence of de novo biosynthetic routes for the vitamins in question in the seven pathogens confirmed that this target class holds promise for the discovery of antimicrobial drugs with a new mechanism of action, possibly on a broad-spectrum level.

N-acylphosphatidylethanolamine phospholipase D (NAPE-PLD) is a membrane-associated zinc enzyme that catalyzes the hydrolysis of N-acylphosphatidylethanolamines (NAPEs) into fatty acid ethanolamides (FAEs). Here, we describe the identification of the first small-molecule NAPE-PLD inhibitor, the quinazoline sulfonamide derivative 2,4-dioxo-N-[4-(4-pyridyl)phenyl]-1H-quinazoline-6-sulfonamide, ARN19874.

The energy-coupling factor (ECF) transporters are a family of transmembrane proteins involved in the uptake of vitamins in a wide range of bacteria. Inhibition of the activity of these proteins could reduce the viability of pathogens that depend on vitamin uptake. Their central role in the metabolism of bacteria and absence in humans make the ECF transporters a potential antibacterial target, which can be further investigated making use of a selective chemical probe. Here, we report on the virtual screening, design, synthesis, structure–activity relationships (SARs) and coarse-grained molecular dynamics simulations of the first class of inhibitors of the ECF transporters. We investigated the mechanism of action of this chemical class and profiled the best hit compounds regarding their pharmaceutical properties. The optimized hit has a minimum inhibitory concentration (MIC) value of 2 µg/mL against Streptococcus pneumoniae, which opens up the possibility to use this chemical class to investigate the role of the ECF transporters in health and disease.

In this review, we analyze the enzyme DXS, the first and rate-limiting protein in the methylerythritol 4-phosphate pathway. This pathway was discovered in 1996 and is one of two known metabolic pathways for the biosynthesis of the universal building blocks for isoprenoids. It promises to offer new targets for the development of anti-infectives against the human pathogens, malaria or tuberculosis. We mapped the sequence conservation of 1-deoxy-xylulose-5-phosphate synthase on the protein structure and analyzed it in comparison with previously identified druggable pockets. We provide a recent overview of known inhibitors of the enzyme. Taken together, this sets the stage for future structure-based drug design.

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Opioid addiction is often characterized as a chronic relapsing condition due to the severe somatic and behavioral signs, associated with depressive disorders, triggered by opiate withdrawal. Since prolonged abstinence remains a major challenge, our interest has been addressed to such objective. Exploring multitarget interactions, the present investigation suggests that 3 or its (S)-enantiomer and 4, endowed with effective α 2C -AR agonism/α 2A -AR antagonism/5-HT 1A -R agonism, or 7 and 9−11 producing efficacious α 2C -AR agonism/α 2A -AR antagonism/I 2 −IBS interaction might represent novel multifunctional tools potentially useful for reducing withdrawal syndrome and associated depression. Such agents, lacking in sedative side effects due to their α 2A -AR antagonism, might afford an improvement over current therapies with clonidine-like drugs.KEYWORDS: α 2 -Adrenergic ligands, 5-HT 1A agonists, I 2 −IBS ligands, morphine withdrawal symptoms reduction, antidepressant-like effect O pioid exposure is known to induce potent analgesic effect as well as relaxation and euphoria. The repeated use of opiate drugs, both for the relief of chronic or cancer-related pain and for recreational drug-taking behavior, can lead to the development of dependence. Addiction to opioids is a complex syndrome involving tolerance, drug-seeking, and physical dependence with withdrawal avoidance behaviors. It is often characterized as a chronic relapsing condition and is a major health and social issue in most societies. 1 Detoxification, a necessary step for many forms of long-term abstinence-based treatments, makes use of two approaches: tapering using methadone or buprenorphine, or abrupt termination of opioid use, potentially precipitated by an opioid antagonist (i.e., naltrexone) with administration of α 2 -adrenoreceptor (α 2 -AR) agonists to reduce withdrawal symptoms. 1 α 2 -ARs have been demonstrated to be extremely sensitive to opioid exposure. 2 Subdivided into α 2A -, α 2B -, and α 2C -subtypes, α 2 -ARs belong to the superfamily of G-protein-coupled receptors and are widely distributed in the central nervous system (CNS) and in peripheral tissues. 3 The α 2A subtype mediates hypotension, sedation and analgesia, as well as inhibition of monoamine release and metabolism in the brain. The α 2B -subtype mediates vasoconstriction. The α 2C -subtype appears to be involved in feedback inhibition of adrenal cathecolamine release and can contribute to adrenergic-opioid synergy. In the brain, α 2A -and α 2C -ARs, as "heteroreceptors", inhibit dopamine and serotonin release. 3−5 The nonsubtype selective α 2 -AR agonist clonidine has been clinically used alone or in combination with traditional treatments for relief of withdrawal symptoms during detoxification, thus increasing treatment duration. Nevertheless, clonidine, due to its α 2A -AR subtype activation, is responsible for side effects of sedation and hypotension, 1 that limit the use of high doses. Strong association between protracted abstinence and depressive disorder...