For decades, gene-editing science has been limited to making small, precise edits to human DNA, akin to correcting typos in the genetic code. Arc Institute researchers are changing that paradigm with a universal gene editing system that allows for cutting and pasting of entire genomic paragraphs, rearranging whole chapters, and even restructuring entire passages of the genomic manuscript.

CAR T cells are patient-derived, genetically engineered immune cells. They are “living drugs” and constitute a milestone in modern medicine. Equipping T cells, a key cell type of the immune system, with a “chimeric antigen receptor” (CAR) enables them to specifically recognize and attack cancer cells.

CAR T cell therapy has demonstrated its potential by curing patients with otherwise untreatable blood cancers. But it still fails for most patients, often due to T cell intrinsic dysfunction. To address their current limitations and to make CAR T cells intrinsically stronger, scientists at the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences and the Medical University of Vienna have developed a new method for systematic discovery of genetic boosters of CAR T cell function.

The new study, published in Nature, introduces CELLFIE, a CAR T cell engineering and high-content CRISPR screening platform, enabling researchers to systematically modify CAR T cells and evaluate their therapeutic potential.

Oligonucleotide therapies — engineered strands of DNA or RNA — are transforming modern medicine. These cutting-edge treatments bring a new level of precision in combating disease by targeting specific genes to be silenced, activated or edited. “Nucleotide therapeutics allow us to design predictable outcomes by modifying sequences to address almost any condition,” says Peter Guterstam, product manager at biotechnology company Cytiva.

Due to an influx of research in recent years, many nucleotide-based drug candidates, including genetic therapies and vaccines for cancer and viral infections, are now in advanced clinical trial stages. “The development timeline is much quicker than we are used to,” notes Guterstam.

Significant challenges arise during development of RNA and DNA based therapies. From mRNA vaccines to gene editing, scientists are refining delivery methods, optimizing synthesis, and tackling scaling hurdles.

T cells can be reprogrammed with transgenic antigen recognition receptors, including chimeric antigen receptors and T cell receptors, to selectively recognize and kill cancer cells. Such adoptive T cell therapies are effective in patients with certain haematological cancers but challenges persist, including primary and secondary resistance, a lack of efficacy in patients with solid tumours, a narrow range of targetable antigens, and time-consuming and complex manufacturing processes. CRISPR-based genome editing is a potent strategy to enhance cellular immunotherapies. Conventional CRISPR–Cas9 systems are useful for gene editing, transgene knock-in or gene knockout but can result in undesired editing outcomes, including translocations and chromosomal truncations. Base editing and prime editing technologies constitute a new generation of CRISPR platforms and enable highly precise and programmable installation of defined nucleotide variants in primary T cells. Owing to their high precision and versatility, base editing and prime editing systems, hereafter collectively referred to as CRISPR 2.0, are advancing to become the new standard for precision-engineering of cellular immunotherapies. CRISPR 2.0 can be used to augment immune cell function, broaden the spectrum of targetable antigens and facilitate streamlined production of T cell therapies. Notably, CRISPR 2.0 is reaching clinical maturity, with multiple clinical trials of CRISPR 2.0-modified cellular therapies currently ongoing. In this Review, we discuss emerging CRISPR 2.0 technologies and their progress towards clinical translation, highlighting challenges and opportunities, and describe strategies for the use of CRISPR 2.0 to advance cellular immunotherapy for haematological malignancies and solid tumours in the future.

#CRISPR9

Several persistent challenges limit the efficacy and applicability of adoptive T cell therapies for cancer, including suboptimal function and/or persistence in vivo, a narrow range of targetable antigens and complex manufacturing processes. This Review discusses the potential of ‘CRISPR 2.0’ precision gene-editing platforms, such as base editing and prime editing to address all of these challenges, and describes the progress made towards clinical translation of these technologies.