Delayed-rectifier K؉ currents (I DR ) in pancreatic ␤-cells are thought to contribute to action potential repolarization and thereby modulate insulin secretion. The voltagegated K ؉ channel, K V 2.1, is expressed in ␤-cells, and the biophysical characteristics of heterologously expressed channels are similar to those of I DR in rodent ␤-cells. A novel peptidyl inhibitor of K V 2.1/K V 2.2 channels, guangxitoxin (GxTX)-1 (half-maximal concentration ϳ1 nmol/l), has been purified, characterized, and used to probe the contribution of these channels to ␤-cell physiology. In mouse ␤-cells, GxTX-1 inhibits 90% of I DR and, as for K V 2.1, shifts the voltage dependence of channel activation to more depolarized potentials, a characteristic of gating-modifier peptides. GxTX-1 broadens the ␤-cell action potential, enhances glucose-stimulated intracellular calcium oscillations, and enhances insulin secretion from mouse pancreatic islets in a glucose-dependent manner. These data point to a mechanism for specific enhancement of glucose-dependent insulin secretion by applying blockers of the ␤-cell I DR , which may provide advantages over currently used therapies for the treatment of type 2 diabetes.

The 'Nanopatch' (NP) comprises arrays of densely packed projections with a defined geometry and distribution designed to physically target vaccines directly to thousands of epidermal and dermal antigen presenting cells (APCs). These miniaturized arrays are two orders of magnitude smaller than standard needles-which deliver most vaccines-and are also much smaller than current microneedle arrays. The NP is dry-coated with antigen, adjuvant, and/or DNA payloads. After the NP was pressed onto mouse skin, a protein payload co-localized with 91.4 + or - 4.1 APC mm(-2) (or 2925 in total) representing 52% of the delivery sites within the NP contact area, agreeing well with a probability-based model used to guide the device design; it then substantially increases as the antigen diffuses in the skin to many more cells. APC co-localizing with protein payloads rapidly disappears from the application area, suggesting APC migration. The NP also delivers DNA payloads leading to cutaneous expression of encoded proteins within 24 h. The efficiency of NP immunization is demonstrated using an inactivated whole chikungunya virus vaccine and a DNA-delivered attenuated West Nile virus vaccine. The NP thus offers a needle-free, versatile, highly effective vaccine delivery system that is potentially inexpensive and simple to use.

BACKGROUND: Human embryonic kidney-293 (HEK-293) cells are commonly used as a transient expression host but their application in stable therapeutic protein production is limited. This is presumably due to the absence of a suitable amplifiable expression system and hence limited protein output compared with other mammalian cells such as Chinese hamster ovary cells. This paper describes a rapid clonal selection method for isolating HEK293 cell lines with high specific productivity, for a non-amplifiable expression system, to achieve high-level, scalable expression of recombinant antibodies.

The cover image shows the Nanopatch, a densely packed microneedle array, and individual microneedles. The microneedles are shown alone, after dry‐coating with vaccine (red) and following the delivery of vaccine into the skin. The Nanopatch delivers dry‐coated vaccines directly to antigen‐presenting cells (green) by puncturing the dry outer layers of skin (gray). The vaccine coating dissolves and is released into the viable epidermis and dermis, which are both rich with antigen‐presenting cells. These antigen‐presenting cells are stimulated by Nanopatch application and the delivered vaccine. Immunization with inactivated whole Chikungunya virus vaccine and a DNA‐delivered attenuated West Nile virus vaccine resulted in sustained and protective immune response. These data show that the Nanopatch is a robust and versatile vaccine delivery system for fighting diseases. For more information, please read the Full Paper “Nanopatch‐Targeted Skin Vaccination against West Nile Virus and Chikungunya Virus in Mice” by M. A. F. Kendall and co‐workers, beginning .