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β-Thalassemia is a genetic anemia caused by partial or complete loss of β-globin synthesis, leading to ineffective erythropoiesis and RBCs with a short life span. Currently, there is no efficacious oral medication modifying anemia for patients with β-thalassemia. The inappropriately low levels of the iron regulatory hormone hepcidin enable excessive iron absorption by ferroportin, the unique cellular iron exporter in mammals, leading to organ iron overload and associated morbidities. Correction of unbalanced iron absorption and recycling by induction of hepcidin synthesis or treatment with hepcidin mimetics ameliorates β-thalassemia. However, hepcidin modulation or replacement strategies currently in clinical development all require parenteral drug administration. We identified oral ferroportin inhibitors by screening a library of small molecular weight compounds for modulators of ferroportin internalization. Restricting iron availability by VIT-2763, the first clinical stage oral ferroportin inhibitor, ameliorated anemia and the dysregulated iron homeostasis in the Hbb(th3/+) mouse model of β-thalassemia intermedia. VIT-2763 not only improved erythropoiesis but also corrected the proportions of myeloid precursors in spleens of Hbb(th3/+) mice. VIT-2763 is currently being developed as an oral drug targeting ferroportin for the treatment of β-thalassemia.

Since the discovery of the first VLP derived from Hepatitis B virus in 19801, the field has expanded substantially. Besides successful use of VLPs as safe autologous virus-targeting vaccines, the powerful immunogenicity of VLPs has been also harnessed to generate immune response against heterologous and even self antigens2–4. Linking adjuvants to VLPs displaying heterologous antigen ensures simultaneous delivery of all vaccine components to the same antigen presenting cells. As a consequence, antigen presenting cells, such as dendritic cells (DCs) will process and present the antigen displayed on VLPs while receiving co-stimulatory signals by the VLP-incorporated adjuvant. Similarly, antigen-specific B cells recognizing the antigen linked to the VLP are simultaneously exposed to the adjuvant. Here we demonstrate in mice that physical association of antigen, carrier (VLPs) and adjuvant is more critical for B than T cell responses. As a model system, we used the E7 protein from human papilloma virus (HPV), which spontaneously forms oligomers with molecular weight ranging from 158 kDa to 10 MDa at an average size of 50 nm. E7 oligomers were either chemically linked or simply mixed with virus-like particles (VLPs) loaded with DNA rich in non-methylated CG motifs (CpGs), a ligand for toll-like receptor 9. E7-specific IgG responses were strongly enhanced if the antigen was linked to the VLPs. In contrast, both CD4+ and CD8+ T cell responses as well as T cell-mediated protection against tumor growth was comparable for linked and mixed antigen formulations. Therefore, our data show that B cell but not T cell responses require antigen-linkage to the carrier and adjuvant for optimal vaccination outcome.

Fibroblast contamination can make establishing primary melanoma cell cultures from native biopsies a major challenge, due to fibroblasts overgrowing the melanoma cells. Standard protocols therefore enrich for highly proliferative melanoma cells that grow well in vitro but may not represent the full range of in vivo tumor heterogeneity. Here we apply conditional methods that more effectively retrieve melanoma cells by differential trypsinization or by inducing fibroblast senescence through contact inhibition, serum starvation or deprivation of adhesion. Simple mixing experiments of melanoma and fibroblast cells demonstrated the efficacy of the new protocols in retrieving slow-growing melanoma cells. Applying our protocols to 20 cultures that had failed to grow by conventional methods, we could retrieve 12 (60%) validated melanoma cell cultures. Further application of the protocols in the live-cell biobank of 124 early passage cultures significantly improved recovery rates from 13% using standard protocols to 70% overall for the new workflow.

The cover shows a colour series of mouse footpads injected with small fluorescent nanoparticles. The image depicts the afferent lymphatic vessels connecting the injection site with the draining popliteal lymph node and the more distal sciatic lymph node. Lymphatic vessels (in green in the left row) run together with the veins (darker curves) and carry free draining antigen to the lymph nodes. This image was provided by the authors of Manolova (pp. 1404–1413) , in which it is demonstrated that particle size critically influences the mode of antigen transport to the draining lymph nodes; DC are strictly required for transport of large (500–2000 nm) particles, whereas smaller particles (20–200 nm), such as virus-like particles (30 nm), drain freely.