Personalized dendritic cell vaccine facilitates the preparation of neoantigen-reactive T cells for adoptive transfer (scTCR-Seq)

Adoptive cell transfer (ACT) using neoantigen-specific T cells is an effective immunotherapeutic strategy. However, the difficulty in identifying and screening neoantigen-specific T cells limits its widespread application. Here, we prepared neoantigen-reactive T cells (NRTs) after immunization with a tumor lysate-loaded dendritic cell (DC) vaccine (OCDC) for ACT. Our results demonstrated that the OCDC vaccine could induce a neoantigen-specific immune response, and it was feasible to prepare NRTs by loading immunogenic neoantigens onto DCs and coculturing them with spleen lymphocytes from mice immunized with the OCDC vaccine. We then transferred these NRTs back to the LL/2 tumor-bearing mice after OCDC vaccine immunization and found that OCDC vaccine and NRTs adoptive transfer combination treatment could induce a stronger antitumor response. Furthermore, we found that infused NRTs could migrate into the tumor microenvironment to exert antitumor effects. Our research provides a new and convenient method of preparing NRTs for ACT. The clinical translation of this approach has the potential to increase ACT efficacy. We sequenced five groups of mice treated differently through scRNA-seq and scTCR-seq.The sequencing was performed by the 10x Genomics single-cell 5′ V(D)J library platform. The cell suspension was loaded into Chromium microfluidic chips with V3 chemistry and barcoded with a 10× Chromium Controller (10X Genomics). Single-cell gene expression and TCR libraries were generated according to the manufacturer’s instructions. RNA from the barcoded cells was subsequently reverse-transcribed, and sequencing libraries were constructed with reagents from a Chromium Single Cell 30 v3 reagent kit (10X Genomics) according to the manufacturer’s instructions. Sequencing was performed with Illumina according to the manufacturer’s instructions (Illumina).