Baradaran, B. | Search bioRxiv

bioRxiv2026

Scaling up polarization-sensitive optical coherence tomography to image the whole macaque brain

Polarization-sensitive optical coherence tomography (PS-OCT) is a label-free imaging technique that exploits birefringence to visualize myelinated axons at micrometer resolution. However, serial PS-OCT imaging has been limited to small volumes, including tissue blocks from larger species, owing to constraints in acquisition speed, system stability, and data processing. These limitations have prevented its application to whole-brain mapping in large mammals. Here we present a scalable PS-OCT acquisition system and computational pipeline for whole-brain imaging in the rhesus macaque. The framework integrates high-throughput serial imaging with automated reconstruction and processing, enabling volumetric imaging at micrometer-scale resolution across decimeter-scale brain volumes. Using this approach, we acquired two complete macaque brains at a voxel size of 5.5 x 5.5 x 3.4 m and an effective resolution of approximately 10 x 10 x 5.5 m, generating multi-terabyte datasets consisting of multiple contrasts including fiber orientation information. The datasets and associated processing tools are made publicly available. This platform establishes a method for large-scale, high-resolution mapping of white matter architecture in primate brains. The resulting datasets provide a reference for validating MRI models and support the development of neurotechnological applications, including deep brain stimulation, where accurate characterization of axonal organization is required.

neuroscience↗

bioRxiv2023

Characterization of CAR T Cells Manufactured using Genetically Engineered Artificial Antigen Presenting Cells

ObjectiveChimeric antigen receptor (CAR) T cell therapy has recently emerged as a promising approach for the treatment of different types of cancer. Improving CAR T cell manufacturing in terms of costs and product quality is an important concern for expanding the accessibility of this therapy. One proposed strategy for improving T cell expansion is to use genetically engineered artificial antigen presenting cells (aAPC) expressing a membrane-bound anti-CD3 for T cell activation. In this study, we characterized CAR T cells generated with this approach in terms of expansion efficiency, immunophenotype, and cytotoxicity. Materials and MethodsIn this experimental study, we generated an aAPC line by engineering K562 cells to express a membrane-bound anti-CD3 (mOKT3). T cell activation was performed by culturing PBMCs with either mitomycin C-treated aAPCs or surface-immobilized anti-CD3 and anti-CD28 antibodies. Untransduced and CD19-CAR-transduced T cells were characterized in terms of expansion, activation markers, IFN-{gamma} secretion, CD4/CD8 ratio, memory phenotype, and exhaustion markers. Cytotoxicity of CD19-CAR T cells generated by aAPCs and antibodies was also investigated using a bioluminescence-based co-culture assay. ResultsOur findings showed that the engineered aAPC line has the potential to expand CAR T cells similar to that of the antibody-based method. Although activation with aAPCs leads to a higher ratio of CD8+ and effector memory T cells in the final product, we did not observe a significant difference in IFN-{gamma} secretion cytotoxic activity or exhaustion between CAR T cells generated with aAPC or antibodies. ConclusionOur results show that despite the differences in the immunophenotypes of aAPC and antibody-based CAR T cells, both methods can be used to manufacture potent CAR T cells. These findings can be instrumental for the improvement of the T cell manufacturing process and future applications of aAPC-derived CAR T cells.

immunology↗