Introduction

Gene editing has transitioned from theoretical exploration to a transformative discipline reshaping the landscape of science and medicine. At the heart of this transformation lies Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), a revolutionary tool derived from bacterial defense systems. Introduced in 2012, the CRISPR-Cas9 system enables precise genetic modifications by using RNA-guided molecular scissors to target specific DNA sequences. This breakthrough has driven remarkable advancements in precision medicine, immunology, and regenerative therapies, reshaping the possibilities of modern science.

Recent innovations, such as base editing and prime editing, have expanded CRISPR’s capabilities, allowing for single-nucleotide changes and precise DNA alterations without creating double-stranded breaks. Additionally, enzymes like Cas12 and Cas13, which target RNA rather than DNA, open new frontiers in viral diagnostics and antiviral therapies. This article explores these advancements and highlights their transformative potential in areas such as CAR T-cell therapy, immune function enhancement, HIV eradication and organ transplantation.

Innovations in CRISPR Technology

CRISPR’s evolution has addressed limitations of earlier gene-editing techniques, offering unparalleled precision and efficiency. Base editing permits single-nucleotide alterations, a key advancement in correcting point mutations responsible for many genetic disorders. Similarly, prime editing broadens CRISPR’s scope, enabling the insertion or deletion of genetic sequences without double-stranded breaks (Anzalone et al., 2019).

The introduction of Cas12 and Cas13 enzymes has further diversified CRISPR’s applications. Cas12 targets DNA with enhanced precision, while Cas13 focuses on RNA, allowing real-time diagnostics and the ability to combat RNA-based pathogens such as SARS-CoV-2 (Freije & Sabeti, 2021). Together, these innovations have positioned CRISPR as a cornerstone of molecular biology, driving advancements across diverse scientific domains.

Advances in Treating Sickle Cell Disease

One of CRISPR’s most celebrated successes is its application in treating sickle cell disease (SCD) and beta-thalassemia, debilitating genetic disorders caused by mutations in the hemoglobin gene. In 2019, Victoria Gray became the first patient to receive CRISPR therapy for SCD. By editing her hematopoietic stem cells, scientists induced the production of fetal hemoglobin, which bypasses the defective adult hemoglobin gene.

Gray’s treatment was transformative: it eliminated her severe pain crises and significantly reduced her need for blood transfusions. This pioneering case demonstrated CRISPR’s potential to cure inherited diseases, and subsequent trials have replicated similar successes (Frangoul et al., 2020). In 2023, exa-cel became the first approved CRISPR-based therapy for SCD, marking a milestone in genome-editing medicine.

In 2023, exa-cel became the first approved genome editing medicine (Sickle cell disease)

The first patient to be treated for sickle cell disease using CRISPR,

Victoria Gray reflected on her journey:

“At one point in my life, I stopped planning for the future because I felt I didn’t have one. Now I can dream again, without limitation.” – Victoria Gray,

CAR T-Cell Therapy and Cancer Treatment

Chimeric Antigen Receptor (CAR) T-cell therapy has been redefined by CRISPR, particularly in cancer immunotherapy. By editing T cells, CRISPR enhances their ability to recognize and destroy cancer cells. Advances like multiplexed CRISPR systems enable simultaneous editing of multiple genes, improving T-cell efficacy and reducing immune exhaustion. For instance, CRISPR has been used to knock out PD-1 receptors, boosting T-cell effectiveness against solid tumors (Rupp et al., 2017).

Moreover, CRISPR has facilitated the development of universal CAR T cells, creating “off-the-shelf” treatments that are cost-effective and accessible.

Immune Function Enhancement

CRISPR’s ability to enhance immune function has been a game-changer for tackling infectious diseases and autoimmune disorders. For example, by editing hematopoietic stem cells (HSCs) to remove the CCR5 receptor, which HIV uses to infect cells, researchers have created immune cells resistant to the virus, offering a promising avenue for long-term remission (Xu et al., 2019).

In autoimmune diseases, CRISPR has been employed to edit genes such as FoxP3 in regulatory T cells, restoring immune homeostasis. This approach holds potential for treating conditions like type 1 diabetes and lupus, where immune dysregulation plays a central role.

HIV Eradication Efforts

CRISPR has shown groundbreaking promise in combating HIV. Studies have demonstrated its ability to excise HIV-1 DNA integrated into the host genome, effectively eliminating latent reservoirs of the virus. When combined with antiretroviral therapies (ARTs), CRISPR offers a potential cure by addressing aspects of the infection that ART cannot (Ebina et al., 2013).

In addition, CRISPR is being used to engineer cells resistant to HIV, providing a prophylactic solution for high-risk populations. These advancements signal a shift from managing HIV as a chronic condition to pursuing a functional cure.

Organ Transplantation and Regenerative Medicine

Gene editing is revolutionizing xenotransplantation, the use of animal organs for human transplants. By editing pig genomes to remove genes responsible for immune rejection and zoonotic diseases, researchers have created genetically modified pig organs suitable for transplantation (Yang et al., 2021).

CRISPR is also advancing the field of regenerative medicine by enabling the engineering of immunologically compatible human tissues. By editing pluripotent stem cells, scientists aim to create bioengineered organs tailored to individual patients, reducing their dependency on immunosuppressive therapies.

Challenges and Ethical Considerations

Despite its potential, CRISPR raises significant ethical and technical challenges. Concerns over off-target effects, germline editing, and equitable access must be addressed through stringent oversight and ethical frameworks. The debate surrounding “designer babies” underscores the importance of ensuring that gene-editing technologies are used responsibly and inclusively.

Conclusion

The advancements in CRISPR technology represent a paradigm shift in medicine, agriculture, and biotechnology. By enabling precise genetic modifications, CRISPR is addressing challenges previously deemed insurmountable, from curing genetic diseases to enhancing food security. While challenges remain, the transformative potential of these tools continues to reshape the future of science, offering innovative solutions to humanity’s most pressing issues.

References

• Frangoul, H., Altshuler, D., Cappellini, M. D., Chen, Y. S., Domm, J., Eustace, B. K., … & Grupp, S. A. (2020). CRISPR-Cas9 gene editing for sickle cell disease and β-thalassemia. New England Journal of Medicine, 384(3), 252–260. https://doi.org/10.1056/NEJMoa2031054
• Anzalone, A. V., Randolph, P. B., Davis, J. R., Sousa, A. A., Koblan, L. W., Levy, J. M., & Liu, D. R. (2019). Search-and-replace genome editing without double-strand breaks or donor DNA. Nature, 576(7785), 149–157. https://doi.org/10.1038/s41586-019-1711-4
• Freije, C. A., & Sabeti, P. C. (2021). Detecting and responding to the next pandemic using CRISPR-based diagnostics. Nature Biotechnology, 39(8), 845–850. https://doi.org/10.1038/s41587-021-00901-0
• Rupp, L. J., Schumann, K., Roybal, K. T., Gate, R. E., Hamilton, J. R., & Lim, W. A. (2017). CRISPR-Cas9 and targeted CAR T cells: Combating solid tumor challenges. Cell, 169(4), 729–737. https://doi.org/10.1016/j.cell.2017.04.035
• Xu, L., Yang, H., Gao, Y., Chen, Z., Xie, L., & Liu, Y. (2019). CRISPR-edited stem cells in HIV therapy. Cell Research, 29(8), 566–578. https://doi.org/10.1038/s41422-019-0193-y
• Yang, L., Güell, M., Niu, D., & Church, G. M. (2021). Genome editing in xenotransplantation: Paving the way for pig-to-human organ transplantation. Annual Review of Genomics and Human Genetics, 22, 1–28. https://doi.org/10.1146/annurev-genom-112820-091506
• Ebina, H., Misawa, N., Kanemura, Y., & Koyanagi, Y. (2013). Harnessing CRISPR-Cas9 for excising latent HIV-1 provirus. Scientific Reports, 3(1), 2510. https://doi.org/10.1038/srep02510

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By

Nadeeka Ranadeva [MSc (Molecular Pathology, UOC, Masters in Medical Statistics (reading, UOK), BSc Sp. in Human Biology (FOM, USJP), Special training in CRISPR (HKU)]

Senior Lecturer

KIU