Currently, cancer, leishmaniasis and bacterial infections represent a serious public health burden worldwide. Six cinnamyl and benzodioxyl derivatives incorporating selenium (Se) as selenocyanate, diselenide, or selenide were designed and synthesized through a nucleophilic substitution and/or a reduction using hydrides. Ferrocene was also incorporated by a Friedel–Crafts acylation. All the compounds were screened in vitro for their antiproliferative, antileishmanial, and antibacterial properties. Their capacity to scavenge free radicals was also assessed as a first approach to test their antioxidant activity. Benzodioxyl derivatives 2a–b showed cytotoxicity against colon (HT-29) and lung (H1299) cancer cell lines, with IC₅₀ values below 12 µM, and were also fairly selective when tested in nonmalignant cells. Selenocyanate compounds 1–2a displayed potent antileishmanial activity in L. major and L. infantum, with IC₅₀ values below 5 µM. They also exhibited antibacterial activity in six bacterial strains, notably in S. epidermidis with MIC and MBC values of 12.5 µg/mL. Ferrocene-containing selenide 2c was also identified as a potent antileishmanial agent with radical scavenging activity. Remarkably, derivative 2a with a selenocyanate moiety was found to act as a multitarget compound with antiproliferative, leishmanicidal, and antibacterial activities. Thus, the current work showed that 2a could be an appealing scaffold to design potential therapeutic drugs for multiple pathologies.

A high-affinity antibody response to both infection and vaccination critically relies on the ability of B cells to capture and process antigen for presentation to CD4+ T cells. The cellular processes from antigen recognition to full B cell activation require a finely orchestrated series of events, involving signalling and intracellular trafficking mechanisms. Here, we describe a novel regulator of B cell receptor (BCR) endocytosis and intracellular trafficking. Multidomain trafficking protein sorting-related receptor with A-type repeats (SorLA) associates with the BCR and regulates uptake of both soluble and substrate-bound antigens. SorLA deletion results in altered BCR–antigen intracellular trafficking to degradative compartments, modulating eventual antigen presentation. Crucially, this change in antigen trafficking results in a significant reduction in plasma cells and humoral responses in vivo. Given the critical importance of antigen presentation in immunity, as well as autoimmune disease and malignancy, these results identify a new cellular pathway in B cell biology with potential implications for immune regulation.