COVER An Arabidopsis seedling with weakened cell adhesion is treated with an inhibitor of the growth hormone brassinosteroid. Brassinosteroid inhibition slows epidermal growth, which constrains growth of internal tissue, causing mechanical stresses and opening cracks as epidermal cells are pulled apart. Similar stresses produce internal contortions of carnivorous plant, Utricularia gibba, illustrating how mechanical connectivity between cells coordinates growth between cell layers. See page 1275.

Credit: Rob Kessler and Robert Kelly-Bellow

ONLINE COVER Two bottlenose dolphins (Tursiops truncates) jump near a ship in the Strait of Gibraltar. Vessel noise during oceanic transportation is known to disrupt natural marine life processes such as foraging, social interactions, and migration behaviors. Findlay et al. identify multiple strategies to reduce the area and severity of ships’ impact on marine life. Their models show disruptions can be eliminated by moderate slowdowns in ship speeds, design changes to hulls and propellers, and avoiding known habitats to increase distance between vessels and animals. These strategies could immediately reduce the effects of the most prominent human noise source in oceans.

ONLINE COVER Unraveling Tumor TRM Signatures. The phenotype of resident memory T cells (TRM) differs between tissues, but how cancer affects the residence program of tumor-infiltrating T cells is unclear. Gavil et al. analyzed T cells from murine mammary fat pads and breast carcinoma tissue to identify defining characteristics of tumor TRM. Rather than adopting typical features of residence, breast tumor TRM acquired a signature distinct from healthy tissue including chronic antigen-driven exhaustion. This month’s cover shows an immunofluorescence image of T cells (cyan) expressing the TRM marker CD103 (magenta) within murine mammary ductal epithelium (green) after priming with vesicular stomatitis virus.

ONLINE COVER Soft Robot Fabrication. Fabricating fully functional soft robots that do not require assembly of the component parts can be achieved by monolithic three-dimensional printing. Zhai et al. have developed a 3D-printing process that can produce airtight soft robots integrated with pneumatic valves, control switches, and fluidic circuits that are fabricated within the grippers during the printing process. The electronics-free soft grippers were reliant on the integrated contact and gravity switches to control the capture and release of objects. This month’s cover is an image of a soft robot gripper, developed by the monolithic 3D-printing process, grasping a tennis ball.

ONLINE COVER This week, Weiß et al. report that the Ca²⁺ microdomains that form in response to adhesion to specific extracellular matrix proteins facilitate the activation of mouse T cells, in part, by enabling the nuclear translocation of the transcription factor NFAT1. The image shows NFAT1 (green) in mouse T cells adhering to BSA in the left column or collagen IV in the right column before being stimulated at the top and after being stimulated in the middle and at the bottom with beads coated with CD3 and CD28 antibodies. Nuclei are stained with DAPI (blue).

ONLINE COVER A Viral Vaccine for Bacterial Infection. Shown is a scanning electron micrograph (SEM) of Neisseria meningitidis, a leading cause of childhood meningitis. Protein-based capsular group B meningococcus (MenB) vaccines have been approved, but the durability of immune responses elicited by such vaccines is limited. Dold et al. developed an adenoviral-vectored meningococcal vaccine that expresses the MenB antigen, factor H binding protein. A single dose of the adenoviral-vectored MenB vaccine elicited robust bactericidal antibody responses that persisted for up to 60 weeks in mice, showing superior durability over a protein vaccine comparator. An optimized version of the vaccine using the ChAdOx1 backbone is now being evaluated in a phase 1 clinical trial.