High-affinity CD16-polymorphism and Fc-engineered antibodies enable activity of CD16-chimeric antigen receptor-modified T cells for cancer therapy

Abstract

BACKGROUNDCD16-chimeric antigen receptors (CAR) T cells recognise the Fc-portion of therapeutic antibodies, which can enable the selective targeting of different antigens. Limited evidence exists as to which CD16-CAR design and antibody partner might be most effective. We have hypothesised that the use of high-affinity CD16 variants, with increased Fc-terminus antibody affinity, combined with Fc-engineered antibodies, would provide superior CD16-CAR T cell efficacy.METHODSCD16-CAR T (wild-type or variants) cells were co-cultured with Panc-1 pancreatic cancer, Raji lymphoma or A375 melanoma cells in the presence or absence of anti-CD20, anti-MCSP, wild-type or the glycoengineered antibody variants. The endpoints were proliferation, activation, and cytotoxicity in vitro.RESULTSThe CD16 158 V variant of CD16-CAR T cells showed increased cytotoxic activity against all the tested cancer cells in the presence of the wild-type antibody directed against MCSP or CD20. Glycoengineered antibodies enhanced CD16-CAR T cell activity irrespective of CD16 polymorphisms as compared with the wild-type antibody. The combination of the glycoengineered antibodies with the CD16-CAR 158 V variant synergised as seen by the increase in all endpoints.CONCLUSIONThese results indicate that CD16-CAR with the high-affinity CD16 variant 158 V, combined with Fc-engineered antibodies, have high anti-tumour efficacy.

CD16‐158‐valine chimeric receptor T cells overcome the resistance of KRAS‐mutated colorectal carcinoma cells to cetuximab

“…The presence of valine instead of phenylalanine at position 158 of CD16 (CD16 158V ) and the presence of histidine instead of arginine at position 131 of CD32 (CD32 131H ) enhance the IgG binding affinity of these receptors . Notably, CD16 158V has preferentially been utilized for in vitro and in vivo studies …”

“…24,27 Notably, CD16 158V has preferentially been utilized for in vitro and in vivo studies. [13][14][15]28 To evaluate Fcγ-CR T cell antibody-binding capacity, polymorphic CD32-CR and CD16-CR T cells were incubated with cetuximab or panitumumab, for 30 min, at 4 C. CD32 131R -CR T cells efficiently bound both cetuximab and panitumumab, whereas CD32 131H -CR T cells only displayed a minimal binding for panitumumab ( Fig. 1d, lower panel).…”

CAR T Cell Therapy for Solid Tumors: Bright Future or Dark Reality?

“…Examples include (1) avidin-CARs/biotin-labeled scFvs, (2) CD16-CAR/mAbs, (3) anti-fluorescein isothiocyanate (FITC)-CARs/FITC-labeled scFvs, (4) coiledcoil CARs (SUPRA CARs), (5) anti-PNE-CARs/PNE-scFvs, and (6) NKG2D-CARs/ULBP2-mAbs. [153][154][155][156][157][158][159] Lastly, bispecific T cell engagers (BiTEs) have been expressed in T cells, 160,161 and more recently adapted to CAR T cells, opening up the opportunity to target multiple antigens and redirecting bystander T cells to tumor cells. 162 In addition to designing CAR T cells to target multiple antigens, strategies are being pursued to engineer T cells to activate bystander T cells to recognize tumor cells (aka induce antigen/epitope spreading).…”

CD16-158-Valine Chimeric Receptor T Cells Overcome the Resistance of KRAS-mutated Colorectal Carcinoma Cells to Cetuximab

“…CD16-CR has also been produced in other laboratories while, to the best of our knowledge, CD32-CR has not. CD16 158V has preferentially been utilized for in vitro and in vivo studies [9][10][11]23 . However, Kudo et al…”