bioRxiv Science⌕ Search

Biology subjects

Acevedo, L. A.

Publications and source records attributed to Acevedo, L. A..

3 recordsLinked to original sources

Development of a Fully Non-Viral 1XX-enhanced BCMA CAR-T Cell Therapy for Multiple Myeloma

Multiple myeloma (MM) is a clonal plasma cell malignancy characterized by bone marrow infiltration, monoclonal immunoglobulin production, and microenvironmental dysregulation that leads to systemic organ damage. The advent of B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T-cell therapy has induced unprecedented responses and durability for patients with relapsed/refractory MM. These outcomes are rarely observed with prior salvage strategies, although relapse remains the predominant long-term challenge for most patients. The two currently approved BCMA CAR-T cell products use viral vectors to semi-randomly insert the CAR gene, which results in heterogeneous genomic composition and variability in efficacy, safety, and product consistency. To address these challenges, we integrated targeted CRISPR genome engineering with precise CAR transgene insertion at the T-cell receptor alpha constant (TRAC) locus, 1XX CAR signaling architecture to enhance potency and durability, and non-viral manufacturing with a single-stranded DNA repair template to improve efficiency and yield. This approach confers physiological CAR expression, reduces insertional mutagenesis, and improves persistence by mitigating tonic signaling and exhaustion. Our GMP manufacturing process consistently achieved high CAR integration (37.7-72.7%) and yields across all full-scale runs and met predefined release criteria for identity, purity, safety, and quality. In NSG mouse models of MM, the UCCT-BCMA-1 product exhibited exceptionally potent tumor control, CAR-T cell expansion 100-1000-fold greater than that of lentiviral constructs, and durable clearance of myeloma cells after multiple rechallenges. These findings establish a CRISPR-edited, fully non-viral manufacturing platform for next-generation 1XX-BCMA CAR-T therapies with enhanced persistence, safety, and efficacy. One Sentence SummaryCRISPR-engineered, TRAC-targeted 1XX-BCMA CAR-T therapy with improved safety, potency, and persistence in relapsed and refractory multiple myeloma.

cancer biology↗

Development of a robotic cluster for automated and scalable cell therapy manufacturing

The production of commercial autologous cell therapies such as chimeric antigen receptor T cells requires complex manual manufacturing processes. Skilled labor costs and challenges in manufacturing scale-out have contributed to high prices for these products. Here, we present a robotic system that uses industry-standard cell therapy manufacturing equipment to automate the steps involved in cell therapy manufacturing. The robotic cluster consists of a robotic arm and customized modules, allowing the robot to manipulate a variety of standard cell therapy instruments and materials such as incubators, bioreactors, and reagent bags. This system enables existing manual manufacturing processes to be rapidly adapted to robotic manufacturing, without having to adopt a completely new technology platform. Proof-of-concept for the robotic clusters expansion module was demonstrated by activating and expanding human CD8+ T cells. The robotic cultures showed comparable cell yields, viability, and identity to those manually performed. Such modular robotic solutions may support scale-up and scale-out of cell therapies that are developed using classical manual methods in academic laboratories and biotechnology companies.

bioengineering↗

Identification and Characterization of a B-Raf Kinase Alpha Helix Critical for the Activity of MEK Kinase in MAPK Signaling

In the MAPK pathway, an oncogenic V600E mutation in B-Raf kinase causes the enzyme to be constitutively active, leading to aberrantly high phosphorylation levels of its downstream effectors, MEK and ERK kinases. The V600E mutation in B-Raf accounts for more than half of all melanomas and [~]3% of all cancers and many drugs target the ATP-binding site of the enzyme for its inhibition. Since B-Raf can develop resistance against these drugs and such drugs can induce paradoxical activation, drugs that target allosteric sites are needed. To identify other potential drug targets, we generated and kinetically characterized an active form of B-RafV600E expressed using a bacterial expression system. In doing so, we identified an alpha helix on B-Raf, found at the B-Raf-MEK interface, that is critical for their interaction and the oncogenic activity of B-RafV600E. We performed binding experiments between B-Raf mutants and MEK using pull downs and biolayer interferometry, and assessed phosphorylation levels of MEK in vitro and in cells as well as its downstream target ERK to show that mutating certain residues on this alpha helix is detrimental to binding and downstream activity. Our results suggest that this B-Raf alpha helix binding site on MEK could be a site to target for drug development to treat B-RafV600E-induced melanomas.

biochemistry↗