Structural, biochemical, and functional properties of the Rap1-Interacting Adaptor Molecule (RIAM)

An antibody targeting an immune checkpoint molecule BTN2A2 enhances anti-tumor immunity

Tumors exploit immune checkpoints to evade immune responses. Therefore, targeting these checkpoints has become a key strategy in cancer immunotherapy. In this study, we have developed a novel immune checkpoint inhibitor (ICI) targeting the B7 family-related molecule BTN2A2. The human BTN2A2 protein, which was highly expressed in some tumor tissues and activated antigen-presenting cells (APCs), can inhibit T cell activation and proliferation. The anti-BTN2A2 monoclonal antibody (mAb) can neutralize the inhibitory effect of BTN2A2 on T cells. In mouse models of pancreatic cancer and glioma, compared to the control group, the anti-BTN2A2 treatment group exhibited tumor shrinkage of 35.8 % (P < 0.05) and 51.2 % (P < 0.01), respectively, along with increased CD8+ tumor-infiltrating lymphocytes (TILs) by 1.7-fold (P < 0.001) and 2.2-fold (P < 0.001), respectively. In addition, anti-BTN2A2 mAb also increased the infiltration of B cells, M1 macrophages, and the expression of inflammatory cytokines in T cells, while reducing the infiltration of M2 macrophages, myeloid-derived suppressor cells (MDSCs), and regulatory T cells (Tregs). Thus, anti-hBTN2A2 mAb normalizes the immunodeficient tumor microenvironment (TME) and inhibits tumor growth. Our results suggest that targeting the BTN2A2 immune checkpoint may represent a novel strategy for cancer treatment, especially in immunosuppressive 'cold' tumors.

Targeting integrin pathways: mechanisms and advances in therapy

Integrins are considered the main cell-adhesion transmembrane receptors that play multifaceted roles as extracellular matrix (ECM)-cytoskeletal linkers and transducers in biochemical and mechanical signals between cells and their environment in a wide range of states in health and diseases. Integrin functions are dependable on a delicate balance between active and inactive status via multiple mechanisms, including protein-protein interactions, conformational changes, and trafficking. Due to their exposure on the cell surface and sensitivity to the molecular blockade, integrins have been investigated as pharmacological targets for nearly 40 years, but given the complexity of integrins and sometimes opposite characteristics, targeting integrin therapeutics has been a challenge. To date, only seven drugs targeting integrins have been successfully marketed, including abciximab, eptifibatide, tirofiban, natalizumab, vedolizumab, lifitegrast, and carotegrast. Currently, there are approximately 90 kinds of integrin-based therapeutic drugs or imaging agents in clinical studies, including small molecules, antibodies, synthetic mimic peptides, antibody-drug conjugates (ADCs), chimeric antigen receptor (CAR) T-cell therapy, imaging agents, etc. A serious lesson from past integrin drug discovery and research efforts is that successes rely on both a deep understanding of integrin-regulatory mechanisms and unmet clinical needs. Herein, we provide a systematic and complete review of all integrin family members and integrin-mediated downstream signal transduction to highlight ongoing efforts to develop new therapies/diagnoses from bench to clinic. In addition, we further discuss the trend of drug development, how to improve the success rate of clinical trials targeting integrin therapies, and the key points for clinical research, basic research, and translational research.

What makes tics tick? Insights into Tourette syndrome

This issue of Biomedical Journal provides the reader with articles concerning the latest understanding of Tourette syndrome (TS), the relation to genetic predisposition, defects in the dopaminergic system, and related comorbidities which further complications like sleep disruption. Treatment approaches for TS, attention deficit hyperactivity disorder and developmental coordination disorder are discussed. The second section of this issue offers insights into inside out integrin activation and its link to T cell activation, demonstrates how polarity in immune cells allows adoption to specialized functions, and describes the endosomal signaling of internalized T cell receptors (TCRs). The link between mutations in TCR signaling and immunodeficiencies is elucidated, as well as the interactions of thymocyte-expressed molecule involved in selection in T cell development. Additionally, we learn about a potential biomarker for colorectal cancer, screening tools for determining frailty in older adults, surgical approaches in spinal metastases, the influence of autophagy on mating behavior, and the effect of nitrite administration on SNARE proteins associated with insulin secretion. Finally, parameters for surgery in breast cancer are discussed, as well as gender and age dependent pain perception in a lysosomal storage disease, and the use of laser meridian massage in opioid use disorder. Three letters complement this issue, one concerning neuroimaging in pediatric COVID-19 patients, and two discussing the role of cancer antigen-125 and renal impairment in ovarian cancer patients.

The ins and outs of T cell signaling

This special edition summarizes major advances in our understanding of signaling by T lymphocytes. T cell interactions with antigen-presenting cells (APCs) and other immune cells are characterized by changes in T cell adhesion and major rearrangements of the actin cytoskeleton. This issue describes some of the mediators of these changes both within the T cells and on the T cell surface. The five articles focus on “inside-out integrin signaling” in T cells, components of the immunological synapse between lymphocyte and APCs, an unexpected role for T cell receptor (TCR) signaling from endosomes, transfer of membrane constituents from APCs to T cells via trogocytosis, immune deficiencies in these T cell signaling pathways, and the role of thymocyte-expressed molecule involved in selection (THEMIS) in thymocyte development and peripheral T cell function.