The Emergence of T-Bodies/CAR T Cells

Abstract

The nickname "T-body" is used to denote a T cell expressing an antigen-specific or antibody-based chimeric receptor that combines antibody specificity with T-cell effector or regulatory function. Initially, we designed and constructed chimeric antibody-based receptors and expressed them in T cells to study the role of major histocompatibility complex in triggering T-cell activation. To this end, we replaced both variable domains (Vα and Vβ of the native T-cell receptor chains) with antibody-derived VH and VL sequences. After transfection into T cells, the 2 chimeric chains paired, associated with the CD3 complex, and endowed transfectants with non-major histocompatibility complex-restricted antibody type specificity. In subsequent studies, we developed next generation of chimeric antibody-based receptors by fusing an antibody single-chain variable fragment to T-cell activation motifs. This modular configuration simplified gene transfer, avoided mixed pairing with endogenous T-cell receptor chains, and enabled simultaneous insertion of various domains as costimulatory moieties to generate T-bodies with efficient antitumor reactivity.

Adoptive T-Cell Therapy for Cancer

“…On cloning T-cell receptors (TCR) which recognized defined tumor-associated antigens, these TCR were genetically engineered into the PBL of HLA-appropriate patients and the expanded cells given in adoptive transfer protocols (Morgan et al, 2006). Another approach used a novel chimeric antigen receptor (CAR) where the ligand-binding domain was derived from the single chain variable fragment of a monoclonal antibody which bound a cell surface molecule on tumors (Eshhar, Waks, & Gross, 2014; Eshhar, Waks, Gross, & Schindler, 1993). This was covalently linked in tandem via a transmembrane domain to the CD3-zeta activating moiety from T-cells to trigger activation on ligation of the CAR in an MHC-independent fashion (often with interposed costimulatory domains to enhance activation or cell survival) (Brentjens et al, 2007).…”

Bioelectrochemical Switches for the Quantitative Detection of Antibodies Directly in Whole Blood

“…As initial validation of the antibody-activated switch architecture we used the well-characterized hapten 2,4-dinitrophenol (DNP) 28 , thus targeting anti-DNP antibodies (DNP-Ab). To do so we designed a tetra-modified DNA stem loop that contains two DNP moieties attached in the middle of the 5 base-pair double-stranded stem and a 18-base poly-thymine loop (~10 nm).…”

An optimized single chain TCR scaffold relying on the assembly with the native CD3-complex prevents residual mispairing with endogenous TCRs in human T-cells

“…Transport to the cell membrane and provision of T-cell signaling upon antigen encounter is accomplished by fusion to the CD3ζ-chain as pioneered by Z. Eshhar for chimeric antigen receptor (CAR)-engineered T-cells [14]. The chimeric immunoreceptor construct assembles to homodimers and operates outside the TCR/CD3-complex which is believed to make mispairing with endogenous TCRs highly unlikely [15, 16].…”