A biomimetic five-module chimeric antigen receptor (CAR) designed to target and eliminate antigen-specific T cells.

Reference
Kobayashi S, Thelin MA, Parrish HL, Deshpande NR, Lee MS, Karimzadeh A, Niewczas MA, Serwold T, Kuhns MS. 2020. A biomimetic five-module chimeric antigen receptor (CAR) designed to target and eliminate antigen-specific T cells. Proc Natl Acad Sci U S A. 117:28950–28959. doi:10.1073/pnas.2012495117.
Abstract

T cells express clonotypic T cell receptors (TCRs) that recognize peptide antigens in the context of class I or II MHC molecules (pMHCI/II). These receptor modules associate with three signaling modules (CD3γε, δε, and ζζ) and work in concert with a coreceptor module (either CD8 or CD4) to drive T cell activation in response to pMHCI/II. Here, we describe a first-generation biomimetic five-module chimeric antigen receptor (CAR). We show that 1) chimeric receptor modules built with the ectodomains of pMHCII assemble with CD3 signaling modules into complexes that redirect cytotoxic T lymphocyte (CTL) specificity and function in response to the clonotypic TCRs of pMHCII-specific CD4 T cells, and 2) surrogate coreceptor modules enhance the function of these complexes. Furthermore, we demonstrate that adoptively transferred CAR-CTLs can mitigate type I diabetes by targeting autoimmune CD4 T cells in NOD mice. This work provides a framework for the construction of biomimetic CARs that can be used as tools to study the impact of particular antigen-specific T cells in immune responses, and may hold potential for ameliorating diseases mediated by pathogenic T cells.