1. DNA CLONING IN CANCER TREATMENT : GENE INFUSION (CAR-T Therapy)
Meet Parikh, Vaibhav Waste & Christian Bach
Abstract
Generation of third-party CAR T immunotherapies
CAR-T cells with a particular focus on efficacy, reproducibility, manufacturing costs and release testing. By undertaking a systematic analysis of the manufacture of CAR T cells from reported clinical trial data to date, we have been able to quantify recent trends and track the uptake of new process technology. Delivering new processing options will be key to the success of the CAR-T cells ensuring that excessive manufacturing costs do not disrupt the delivery of exciting new therapies to the wide possible patient cohort.
To date, although the large number of clinical trials have utilized autologous T cells as the primary source for CAR T cells generation, this strategy bears substantial manufacturing challenges and, for some patients, may not be feasible owning to being in advanced disease condition or trouble with manufacturing proper numbers of CAR T cells.
On the other hand, allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is one of the therapeutic modalities in some patients with high risk B-cell leukemia/lymphoma however relapse might be occur and most often leads to patient death. Some patients with B-cell malignancies that had progressed after alloHSCT they received autologous CAR T cells have been genetically modified to express a tumor-specific CAR, thus directing immunoreactivity toward the tumor in a MHC-independent manner .
However, the endogenous ab T cell receptor (TCR) on infused CAR T cells may recognize major and minor histocompatibility antigens on the allogeneic hematopoietic stem cell leading to graft-versus-host-disease (GVHD). The knockdown of endogenous TCRs will confer a higher level of expression and more efficient antigen recognition of exogenous TCRs. Even more, the knockout of endogenous TCRs will reduce the probability of TCR gene transfer induced GVHD disease. In some studies a number of patients have been treated with CD19-specific CAR T cells following alloHSCT1.
Although in these studies GVHD was not reported, however, this possibility cannot be ruled out entirely. It seems that the generation of third-party CAR T cells is rational solution and, in contrast to the generation of patient/allo-HSCT donor derived CAR T.
DNA
Cloning
CAR-T
Cancer Treatment
Immunotherapy
Figure 1: Interrelate the therapy with major factors.
Mechanism
Figure 2:- CAR T cell mechanism in leukemia
Figure 3:- Therapy cycle with CAR T implementations
RESULTS
CAR-modified T-cells or CAR T-cells are a form of cellular therapy using either autologous or allogeneic T-cells as a platform for modification. Autologous donor cells are advantageous as they prevent the potential complication of GVHD and are generally easily accessible. Retroviral and lentiviral vector systems and DNA transposons have been used in order to express CARs in T-cells. This, unfortunately, can lead to variable expression based on the location of integration. Although efficient, the possibility of insertional mutagenesis and all associated untoward effects exists. Although insertional mutagenesis has not been observed in CAR-modified T-cell therapies, alternative delivery strategies are actively being developed .
CONCLUSION
The field of gene editing technology is currently making targeted gene editing a provocative prospect for the development of customized adoptive T cell immunotherapies, bringing hope for treatment of tumors. However, several potential drawbacks in gene- edited T cell therapies must be assessed in preclinical studies and their clinical application is still facing some of concerns. One of the primary concerns is the safety of genetically-engineered T cells. Although several studies have aimed to improve the specificity of gene editing and minimize off-target effects, it remains to be defined how much accuracy is needed for each specific clinical application.
REFERENCES
1. Center for Cellular Immunotherapies, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; 2Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
2. Friedman, A.A. et al. (2015) Precision medicine for cancer with next-generation functional diagnostics. Nat. Rev. Cancer 15, 747–756