Genomic Immunology and Engineering Immunity

In his talk, Dr. Marson presented work from his team which aims to understand gene programs controlling the behavior and properties of immune cells, particularly T cells. His lab leverages genetic engineering strategies to better understand immune cell functions and instruct T cell modification for future cell therapies for a broad range of human disease states.

His team has been developing CRISPR/Cas9 editing tools, specifically non-viral approaches to gene editing, to enable the precise and efficient modification of immune cells. They found that electroporating the Cas9 ribonucleoprotein complex alone or combined with DNA payloads into T cells proved to be an efficient strategy to knockout or knockin gene sequences of interest. For example, by enabling replacing the TCR alpha and beta sequence, ultimately re-writing T cell specificity.

To improve non-viral gene knockin efficiency, Dr. Marson’s team engineered modifications to the DNA payloads and Cas9 protein to promote co-localization and delivery or “shuttle” to the nucleus. However, realizing the toxicity associated with high levels of double-stranded DNA payloads, his team has adapted the “shuttle” strategy to single-stranded DNA donor templates. Currently, they are leveraging this approach to developing various T cell therapeutics.

To meet manufacturing or “GMP” standards enabling developing T cell therapeutics through non-viral approaches, Marson’s team is partnering with GenScript to synthesize long single-stranded DNA (e.g., CAR construct). His team has not only found a source for GMP grade long single-stranded DNA but is delighted with the improved knockin efficiency achieved by using GenScript’s synthesized payloads.

In the second part of his talk, Dr. Marson shared progress on genome-wide target discovery in primary T cells to enable the development of better cell therapies. Their studies leveraged a hybrid approach to gene editing by relying first on lentiviral delivery of a library of guide RNAs followed by Cas9 delivery into primary T cells. This approach supported identifying genes critical for improved T cell therapeutic properties (e.g., T cell proliferation and cancer cell killing).