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.