The IgG4 hinge with CD28 transmembrane domain improves VHH-based CAR T cells targeting a membrane-distal epitope of GPC1 in pancreatic cancer.

Heterogeneous antigen expression is a key barrier influencing the activity of chimeric antigen receptor (CAR) T cells in solid tumors. Here, we develop CAR T cells targeting glypican-1 (GPC1), an oncofetal antigen expressed in pancreatic cancer. We report the generation of dromedary camel VHH nanobody (D4)-based CAR T cells targeting GPC1 and the optimization of the hinge (H) and transmembrane domain (TM) to improve activity. We find that a structurally rigid IgG4H and CD28TM domain brings the two D4 fragments in proximity, driving CAR dimerization and leading to enhanced T-cell signaling and tumor regression in pancreatic cancer models with low antigen density in female mice. Furthermore, single-cell-based proteomic and transcriptomic analysis of D4-IgG4H-CD28TM CAR T cells reveals specific genes (e.g., HMGB1) associated with high T-cell polyfunctionality. This study demonstrates the potential of VHH-based CAR T for pancreatic cancer therapy and provides an engineering strategy for developing potent CAR T cells targeting membrane-distal epitopes.

Chemogenetic manipulation of the bed nucleus of the stria terminalis counteracts social behavioral deficits induced by early life stress in C57BL/6J mice.

Trauma during critical periods of development can induce long-lasting adverse effects. To study neural aberrations resulting from early life stress (ELS), many studies utilize rodent maternal separation, whereby pups are intermittently deprived of maternal care necessary for proper development. This can produce adulthood behavioral deficits related to anxiety, reward, and social behavior. The bed nucleus of the stria terminalis (BNST) encodes aspects of anxiety-like and social behaviors, and also undergoes developmental maturation during the early postnatal period, rendering it vulnerable to effects of ELS. Mice underwent maternal separation (separation 4 hr/day during postnatal day (PD)2-5 and 8 hr/day on PD6-16) with early weaning on PD17, which induced behavioral deficits in adulthood performance on two-part social interaction task designed to test social motivation (choice between a same-sex novel conspecific or an empty cup) and social novelty preference (choice between the original-novel conspecific vs. a new-novel conspecific). We used chemogenetics to non-selectively silence or activate neurons in the BNST to examine its role in social motivation and social novelty preference, in mice with or without the history of ELS. Manipulation of BNST produced differing social behavior effects in non-stressed versus ELS mice; social motivation was decreased in non-stressed mice following BNST activation, but unchanged following BNST silencing, while ELS mice showed no change in social behavior after BNST activation, but exhibited enhancement of social motivation-for which they were deficient prior-following BNST silencing. Findings emphasize the BNST as a potential therapeutic target for social anxiety disorders instigated by childhood trauma.

A Virtual Reality Intervention for the Treatment of Phantom Limb Pain: Development and Feasibility Results.

OBJECTIVE: To describe the development of a virtual reality (VR) treatment for phantom limb pain (PLP) and phantom sensations and provide feasibility data from testing the treatment in a population of veterans. DESIGN & SUBJECTS: Fourteen participants completed a baseline visit evaluating their amputation, PLP, and phantom sensations. Subsequently, participants completed a VR treatment modeled after mirror therapy for PLP, navigating in a VR environment with a bicycle pedaler and motion sensor to pair their cadence to a VR avatar. The VR avatar enabled visualization of the participant's intact phantom limb in motion, a hypothesized mechanism of mirror therapy. SETTING: Laboratory. METHODS: Participants completed pre- and post-treatment measures to evaluate changes in PLP, phantom sensations, and rate helpfulness, realism, immersion, adverse experiences, and treatment satisfaction. RESULTS: Eight of 14 participants (57.1%) reported PLP pre-VR treatment, and 93% (13/14) reported one or more unpleasant phantom sensations. After treatment, 28.6% (4/14) continued to report PLP symptoms (t[13] = 2.7, P = 0.02, d = 0.53) and 28.6% (4/14) reported phantom sensations (t[13] = 4.4, P = 0.001, d = 1.7). Ratings of helpfulness, realism, immersion, and satisfaction were uniformly high to very high. There were no adverse experiences. Four participants completed multiple VR treatments, showing stable improvements in PLP intensity and phantom sensations and high user ratings. CONCLUSIONS: This feasibility study of a novel VR intervention for PLP was practical and was associated with significant reductions in PLP intensity and phantom sensations. Our findings support continued research in VR-based treatments in PLP, with a need for direct comparisons between VR and more established PLP treatments.