Greenberg, E. | bioRxiv Science

bioRxiv2025

A membrane-driven biochemical oscillator tunable by the volume to surface area ratio

Oscillations are ubiquitous features of biological organisms, playing crucial roles in processes from circadian rhythms to developmental patterning. Protein-based biochemical oscillators have particular applications in synthetic biology because they can access fast and slow timescales that are independent from the transcription-translation machinery required of genetic oscillators. Here, we introduce and model such a mass-conserving biochemical oscillator using mass-action reaction kinetics that exploits dynamic changes to membrane phospholipid concentrations to drive proteins on and off the membrane in robust, tunable rhythms. Importantly, the oscillations rely on amplification of reactions on the membrane via dimensional reduction, and they are therefore tunable by variations in the volume-to-surface area ratio (V/A) of the system. With components inspired by the endocytic machinery, we show that a wide range of physiologically relevant biochemical rates can produce oscillations in part due to this independent geometric control. A broad computational screen of the high-dimensional parameter space reveals that oscillations require relatively strict enzyme kinetic design rules for low V/A but much more permissive kinetics for larger V/A. We validate that oscillations persist with more realistic reaction-diffusion simulations that captures explicit diffusion and stochastic, integer valued copy numbers, in overall good agreement with the period and amplitude of the deterministic oscillators. Because the oscillations rely on time-dependent changes to the surface properties and not post-translational modifications to the protein subunits, we demonstrate that it can be coupled to a self-assembling trimer, driving not only changes in localization but trimer yield. Our analysis establishes this membrane-localization oscillator as a new, geometry tunable and programmable timing module and suggests a potential for geometry sensing in engineered or cell-free systems.

biophysics↗

bioRxiv2024

Novel immunotherapy for multiple solid cancers using an Anti-HVEM blocking monoclonal antibody

INTRODUCTIONImmune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, yet their efficacy remains limited. Therefore, there is a clear need for new anti-tumor agents. HVEM (Herpes Virus Entry Mediator) plays a regulatory role in immunity, making it a promising cancer therapeutic target. EXPERIMENTAL DESIGNWe have developed Anti-4CB1, a fully human HVEM-BTLA and HVEM-CD160 blocking mAb and tested its anti-tumor activity in various in-vitro, ex-vivo and in-vivo models, alone or in combination with Anti-PD1. Finally, we analyzed HVEM expression in serum samples and melanoma tumor tissues and its correlation with HVEM and PD1 blockade treatment response. RESULTSIn-vitro assays demonstrated enhanced melanoma cell killing by autologous TILs in the presence of Anti-4CB1. In addition, Anti-4CB1 significantly increased cytotoxicity by up to 233% in a variety of ex-vivo cancer tissue samples of different indications. Notably, Anti-4CB1 demonstrated effectiveness in samples where Anti-PD1 was ineffective. In addition, significant anti-tumor activity at 10 mg/kg in combination with Anti-PD1 (TGI 95% p=0.0001) or at 25 mg/kg as monotherapy (TGI 50% p=0.0096) was demonstrated in a colon carcinoma transgenic mice model. Moreover, significant anti-tumor activity was observed in a mouse ImmunoGraft model (TGI 53% p=0.0102 as monotherapy). Finally, we demonstrated that HVEM expression correlated with response to Anti-HVEM and Anti-PD1 treatments. DISCUSSIONWe describe the development of Anti-4CB1, a fully human anti-HVEM mAb, blocking HVEM-BTLA and HVEM-CD160 human interactions and enhancing lymphocytes cytotoxicity against various cancer cells ex-vivo. In-vivo, Anti-4CB1 showed promising anti-tumor effects, particularly in combination with Anti-PD1, suggesting its therapeutic potential. Finally, HVEM expression may serve as a predictive marker for Anti-HVEM and Anti-PD1 treatments response, offering potential diagnostic utility in patient selection for these immunotherapies. These results support Anti-4CB1 potential as an anti-cancer therapeutic agent. Translational RelevanceThe discovery of immune checkpoint inhibitors (ICIs), marks a significant breakthrough in cancer therapy. However, despite the remarkable success of current ICIs targeting CTLA4 and PD1/PD-L1 pathways, a significant proportion of patients fail to respond or develop resistance. Therefore, the search for novel ICIs is crucial for advancing cancer immunotherapy. Anti-HVEM emerged as a promising candidate, as we demonstrate in ex-vivo and in-vivo models, its ability to block the HVEM-BTLA interaction, resulting in enhanced antitumor immune responses in solid tumors, alone or in combination with existing ICIs, to improve treatment outcomes. Moreover, the correlation between HVEM expression and treatment responses highlight its potential as an attractive target for biomarker-driven therapies. Investigating HVEM as an ICI offers a promising path to expand therapeutic options, personalize treatment approaches, address the evolving challenges in cancer immunotherapy and improve patient outcomes.

cancer biology↗