As a cell-based method that needs to be applied in the clinic, CAR-T-related projects need to pass rigorous mycoplasma release testing. This is clearly stipulated in the pharmacopoeia of various countries. Among them, the culture method and the indicator cell method are widely recognized as classical methods, but both methods have unavoidable defects, so the nucleic acid method has been popularized and promoted. However, it should be noted that the nucleic acid method for the detection of mycoplasma requires corresponding methodological validation according to the requirements in the pharmacopoeia. The German Mycoplasma mb qPCR detection system has passed the methodological validation of the Japanese Pharmacopoeia and the European Pharmacopoeia, and has met the requirements of the Pharmacopoeia in terms of sensitivity, accuracy and specificity.
The CAR-T method (Chimeric Antigen Receptor T-cell Therapy) is an immune method that can be used in the course of certain types of leukemia and lymphoma, especially B-cell-derived hematologic malignancies.
Poor functional durability limits the effectiveness of CAR-T. CD28-based chimeric antigen receptors (CARS) have potent effector functions against T cells, but have a limited lifespan.
Recently, an article published in Cancer Discovery titled: "Disruption of SUV39H1-Mediated H3K9 Methylation Sustains Car T Cell Function" showed that genetic disruption of SUV39H1, which encodes histone-3, lysine-9 methyltransferase, enhances human CAR - Early expansion, long-term persistence, and overall anti-tumor efficacy of T cells.
CAR-T cells with sustained SUV39H1 editing exhibit better expansion and tumor rejection under multiple rechallenges. Transcriptional and genomic accessibility analysis of repeat challenge CAR-T cells revealed improved expression and accessibility of memory transcription factors in SUV39H1-edited CAR-T cells. SUV39H1 editing also reduces the expression of inhibitory receptors and limits the exhaustion of CAR-T cells that undergo multiple rechallenges.
Thus, the results of this study demonstrate the potential of epigenetic programming of CAR-T cells to balance their function and persistence, thereby improving the CAR-T approach.