Takacsi-Nagy et al. generated a library of synthetic T cell Transcription Factors (sTFs) through combinatorial assembly of AP-1 family TF subdomains. Expressed in CAR-T cells, certain sTFs improved CAR-T persistence/proliferation over natural TFs in a chronic stimulation assay. sTFs induced unique transcriptional and epigenetic T cell states from natural TFs, although their DNA binding sites were conserved. One combination (JUN-FOS-BATF) especially improved cytotoxicity and in vivo persistence. The most impactful subdomains did not correlate with natural expression levels. Recombination of ETS and FOX family TF domains was also effective.

Contributed by Alex Najibi

ABSTRACT: Human protein-coding genes evolved via rearrangement of domains from ancestral genes. We develop a scalable, evolutionarily guided method to assemble novel genes from constituent domains within a protein family, termed DESynR (domain engineered via synthesis and recombination) genes. In primary human T cells, DESynR activator protein-1 (AP-1) transcription factors (TFs) significantly outperform natural AP-1 TFs across in vitro and in vivo antitumor assays. DESynR AP-1 TFs induce broad transcriptional and epigenetic reprogramming and establish non-natural T cell states that optimize features of exhaustion, effector and cytotoxic function, and persistence-sometimes co-opting gene modules from disparate cell types. Reprogramming is primarily driven by differential regulation of established AP-1-bound regulatory elements rather than unique binding. Finally, we screen DESynR erythroblast transformation-specific (ETS) and forkhead box (FOX) TFs to support generalizability across protein families. Overall, we demonstrate that reconfiguring existing protein domains may uncover non-evolved genes that program therapeutically relevant cell states.

Author Info: (1) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford Univer sity, Stanford, CA, USA. (2) Center for Immunotherapy Design, Stanford University, Stanford, CA, USA; Division of Allergy, Immunology, and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA. (3) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA; Department of Genetics, Stanford University, Stanford, CA, USA. (4) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA. (5) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA. (6) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA; Department of Bioengineering, Stanford University, Stanford, CA, USA. (7) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA. (8) Program in Immunology, Stanford University, Stanford, CA, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA. (9) Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA; Department of Medicine, University of California, San Francisco, San Francisco, CA, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA. (10) Department of Pathology, Stanford University, Stanford, CA, USA. (11) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA. (12) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA. (13) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA. (14) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford University, Stanford, CA, USA. (15) Department of Pathology, Stanford University, Stanford, CA, USA. (16) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA. (17) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford University, Stanford, CA, USA. (18) Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA. (19) Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA; Weill Cancer Hub West, Stanford, CA, USA. (20) Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA; Department of Medicine, University of California, San Francisco, San Francisco, CA, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA; Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA; Weill Cancer Hub West, Stanford, CA, USA. (21) Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA; Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA; Ludwig Center for Cancer Stem Cell Research and Medicine, Stanford University School of Medicine, Stanford, CA, USA; Weill Cancer Hub West, Stanford, CA, USA. (22) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA; Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA; Weill Cancer Hub West, Stanford, CA, USA. Electronic address: troth@stanford.edu. (23) Department of Pathology, Stanford University, Stanford, CA, USA; Center for Immunotherapy Design, Stanford University, Stanford, CA, USA; Program in Immunology, Stanford University, Stanford, CA, USA; Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA; Weill Cancer Hub West, Stanford, CA, USA. Electronic address: satpathy@stanford.edu.