AUTHOR=Thakur Archana , Scholler John , Kubicka Ewa , Bliemeister Edwin T. , Schalk Dana L. , June Carl H. , Lum Lawrence G. 

TITLE=Bispecific Antibody Armed Metabolically Enhanced Headless CAR T Cells

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.690437

DOI=10.3389/fimmu.2021.690437

ISSN=1664-3224

ABSTRACT=<p>Adoptive T cell therapies for solid tumors is challenging. We generated metabolically enhanced co-activated-T cells by transducing intracellular co-stimulatory (41BB, ICOS or ICOS-27) and CD3ζ T cell receptor signaling domains followed by arming with bispecific antibodies (BiAbs) to produce armed “Headless CAR T cells” (hCART). Various hCART armed with BiAb directed at CD3ϵ and various tumor associated antigens were tested for: 1) specific cytotoxicity against solid tumors targets; 2) repeated and dual sequential cytotoxicity; 3) survival and cytotoxicity under <italic>in vitro</italic> hypoxic condition; and 4) cytokine secretion. The 41BBζ  transduced hCART (hCART<sub>41BBζ</sub>) armed with HER2 BiAb (HER2 hCART<sub>41BBζ</sub>)  or armed with EGFR BiAb (EGFR hCART<sub>41BBζ</sub>) killed multiple tumor lines significantly better than control T cells and secreted Th<sub>1</sub> cytokines/chemokines upon tumor engagement at effector to target ratio (E:T) of 2:1 or 1:1. HER2 hCART serially killed tumor targets up to 14 days. Sequential targeting of EGFR or HER2 positive tumors with HER2 hCART<sub>41BBζ</sub> followed by EGFR hCART<sub>41BBζ</sub> showed significantly increased cytotoxicity compared single antigen targeting and continue to kill under <italic>in vitro</italic> hypoxic conditions. In summary, metabolically enhanced headless CAR T cells are effective serial killers of tumor targets, secrete cytokines and chemokines, and continue to kill under <italic>in vitro</italic> hypoxic condition.</p>