High Throughput Characterization of Novel Costimulatory Domains for Chimeric Antigen Receptors

We have developed a unique approach for characterizing and phenotyping novel CAR signaling domains using synthetic DNA libraries. This strategy identifies clinically relevant domains optimized for use in next generation T cell immunotherapies.

Chimeric Antigen Receptors (CARs) are the first successful synthetic immune receptors for adoptive T cell therapy. Although CD28 and 41BB costimulatory domains have shown clinical success in 2nd-generation CARs, using different costimulatory domains of the CAR can elicit distinct T cell functions including cytokine secretion, cytotoxicity, and overall persistence in the patient. Determining the most effective intracellular signals will extend CAR therapeutic success, including its application to solid tumors and treatment opportunities beyond cancer.

Here, we have developed a high-throughput approach for phenotyping novel CAR signaling domains using synthetic DNA libraries. To enable rapid characterization of specific T cell functions across this library, we employed a pooled screen in primary human T cells, which combines FACS sorting and deep sequencing of DNA-barcoded CAR variants. We used this approach to characterize over 40 CAR intracellular signaling domains, some of which alter cytokine secretion, improve proliferative capacity, and confer resistance to exhaustion, relative to the standard CD28 and 41BB CARs. Finally, we performed further in-depth phenotyping (both in vitro and in vivo) on a small number of domains, confirming their improved short-term killing dynamics, increased long-term cytotoxic potential, and reduced exhaustion compared to the state-of-the-art CAR architectures. This integrated strategy to identify optimized CAR signaling domains will both improve T cell immunotherapy and expand our general understanding of T cell receptor signaling.

Selected Publications

Pooled screening of CAR T cells identifies diverse immune signaling domains for next-generation immunotherapies
Sci Transl Med. 2022 11 09; 14(670):eabm1463. Goodman DB, Azimi CS, Kearns K, Talbot A, Garakani K, Garcia J, Patel N, Hwang B, Lee D, Park E, Vykunta VS, Shy BR, Ye CJ, Eyquem J, Marson A, Bluestone JA, Roybal KT. PMID: 36350984.

Research Team

Maria Jose Duran

Junior Specialist

Daniel B. Goodman, Ph.D.

Postdoctoral Fellow

Camillia Azimi

PhD Student

ClarityChua copy
Clarity Chua

Junior Specialist


Media highlights of Kole and the lab’s research.
'Smart' immune cells kill tumours and stop them regrowing in mice
Attacking glioblastoma and other solid tumors with CAR-Ts that target multiple antigens
Tweaking Mother Nature, biologists aim for better cancer-fighting cells
'Cell Bots' Chase Down Cancer, Deliver Drugs Directly to Tumors
Synthetic Notch receptors were featured in Notable Advances 2016
Kole Roybal receives the inaugural Sartorius & Science Magazine Prize in Regenerative Medicine and Cell Therapy 2018
Boosting the immune system to fight cancer
Cell Design Labs, Little Partner Of Kite Pharma, Pushes T-Cell Engineering Frontier