Generation of Tumor-Specific Cytotoxic T Cells From Blood via In Vitro Expansion Using Autologous Dendritic Cells Pulsed With Neoantigen-Coupled Microbeads.

For the past decade, adoptive cell therapy including tumor-infiltrating lymphocytes, genetically modified cytotoxic lymphocytes expressing a chimeric antigen receptor, or a novel T-cell receptor has revolutionized the treatment of many cancers. Progress within exome sequencing and neoantigen prediction technologies provides opportunities for further development of personalized immunotherapies. In this study, we present a novel strategy to deliver in silico predicted neoantigens to autologous dendritic cells (DCs) using paramagnetic beads (EpiTCer beads). DCs pulsed with EpiTCer beads are superior in enriching for healthy donor and patient blood-derived tumor-specific CD8+ T cells compared to DC loaded with whole-tumor lysate or 9mer neoantigen peptides. A dose-dependent effect was observed, with higher EpiTCer bead per DC being favorable. We concluded that CD8+ T cells enriched by DC loaded with EpiTCer beads are tumor specific with limited tumor cross-reactivity and low recognition of autologous non-activated monocytes or CD8+ T cells. Furthermore, tumor specificity and recognition were improved and preserved after additional expansion using our Good Manufacturing Process (GMP)-compatible rapid expansion protocol. Phenotypic analysis of patient-derived EpiTCer DC expanded CD8+ T cells revealed efficient maturation, with high frequencies of central memory and effector memory T cells, similar to those observed in autologous expanded tumor-infiltrating lymphocytes. These results indicate that DC pulsed with EpiTCer beads enrich for a T-cell population with high capacity of tumor recognition and elimination, which are features needed for a T-cell product to be used for personalized adoptive cell therapy.

Fluorescence microscopy data for quantitative mobility and interaction analysis of proteins in living cells.

The data provided with this paper are image series of slowly diffusing GlyRa3 molecules, linked to either eGFP or mCherry fluorescent proteins, at the membrane of HEK cells, acquired on a Zeiss LSM880 confocal laser scanning microscope. Raster spectral image cross-correlation spectroscopy (RSICS) is applied to the data, a technique that exploits intensity fluctuations in confocal image series recorded using a spectral detector to study the diffusion and concentration of molecules, and interactions between them. First, spectral filters are created from reference image series containing GlyRa3 labeled with a single fluorophore. Once experimental data containing GlyRa3 labeled with both fluorophores is acquired, single images are either autocorrelated, or the cross-correlation is calculated between two images, each one containing the data for eGFP or mCherry labeled GyRa 3. Data is then fit with a one-component model assuming a two-dimensional Gaussian point spread function to obtain the diffusion coefficient, D, and average number of molecules in the focus, N. The software package PAM is used to analyze all the acquired data. The data can be used as a reference for artifact-free two-color ccRICS that contains slowly diffusing interacting molecules. Additionally, the analysis workflow described in this paper helps researchers avoid common errors during a RICS experiment.