Browsing by Subject "T-solu"

Adoptive cell therapy utilizes the patient's own immunological system in the treatment of cancer. T cells expressing the chimeric antigen receptor (CAR) are produced from the patient's own T-cells. The CAR gene is introduced into the T cells by a gene transfer vector, which results in the T cells expressing the CAR molecule that recognizes the antigen on the surface of the cancer cell. When CAR-T cells are returned to the body, they recognize the cancer cell with the CAR molecule and destroy it. CAR-T cell therapy has shown promising results in the treatment of malignant hematological cancers. The white blood cells used as starting material for CAR-T cells are collected from the patient using a specially designed leukapheresis device. The collected leukapheresis product is transported to the CAR-T cell manufacturing site as soon as possible, either fresh or frozen. The aim of this stability study of leukapheresis products was to determine the effect of storage time and temperature on the quality of fresh cell products regarding cell number, viability and composition. In addition, the goal was to determine the optimal storage temperature and the shelf life of leukapheresis product to ensure high quality cell starting material for CAR-T cell production. The study was performed by dividing the leukapheresis products into two cell bags immediately after collection, one stored at +15–25 °C and the other at +2–8 °C for five days. The leukapheresis products were examined at five different time points (0, 25, 49, 73 and 121 h) for white blood cell count, viability, apoptosis and white blood cell composition. The microbiological purity of the cell products was examined after leukapheresis. The leukocyte composition was stable, viability and cell yield over 80 % for at least 72 hours at +2–8 °C storage temperature. Although small proportions of cells were apoptotic after the 48 hours of storage +2–8 °C, the leukapheresis products contained more than 80 % viable leukocytes after 72 hours and over 70 % after 120 hours. Leukapheresis products remained stable for 48 hours at +15–25 °C, after which their leukocyte composition changed, leukocyte viabilities and yields decreased. The viabilities of the leucocytes were above 90 % for 48 hours at +15–25 °C, but at the 73 h time point, only half of the cells were viable. The optimum storage temperature for leukapheresis products was +2–8 °C, at which white blood cells remained in good quality for 72 hours. These results can be used to set quality requirements for the cell source material of CAR-T cell product and to plan the transport from the collection site of the leukapheresis to the CAR-T cell production site.

Somatic mutations contribute to tumorigenesis. Although these mutations occur in all proliferating cells, their accumulation under non-malignant conditions, such as in autoimmune disorders, has not been investigated. Here, we show that patients with newly diagnosed rheumatoid arthritis have expanded CD8+ T-cell clones; in 20% (5/25) of patients CD8+ T cells, but not CD4+ T cells, harbour somatic mutations. In healthy controls (n=20), only one mutation is identified in the CD8+ T-cell pool. Mutations exist exclusively in the expanded CD8+ effector-memory subset, persist during follow-up, and are predicted to change protein functions. Some of the mutated genes (SLAMF6, IRF1) have previously been associated with autoimmunity. RNA sequencing of mutation-harbouring cells shows signatures corresponding to cell proliferation. Our data provide evidence of accumulation of somatic mutations in expanded CD8+ T cells, which may have pathogenic significance for RA and other autoimmune diseases.