T‐cell surface generation of dual bivalent, bispecific T‐cell engaging, RNA duplex cross‐linked antibodies (dbBiTERs) for re‐directed tumor cell lysis

Abstract

Background: Genetic engineered Bispecific T-cell engagers (BiTEs) generate potent cytotoxic effects. Methods: Alternately, click chemistry engineered, dual specific bivalent Bispecific Tcell engaging antibodies (dbBiTEs) on T-cell surfaces can be generated from parent monoclonal antibodies. Results: We show the formation of dbBiTEs on the surface of T-cells along with the introduction of complementary 2′-OMe RNA 32-mer oligonucleotides allowing duplex formation between antibodies, designated as dbBiTERs. dbBiTERs generated in solution from anti-CEA and anti-CD3 OKT3 antibodies retained specific binding to CEA positive versus CEA negative cancer cells and to CD3 positive T-cells comparable to dbBiTEs. When T-cells were precoated with dbBiTEs or dbBiTERs and mixed with CEA positive versus CEA negative cancer cells, similar dose dependent and specific cytotoxicity were observed in redirected cell lysis assays. On-cell generated dbBiTERs exerted potent cytotoxic responses against CEA positive targets and were localized at the cell surface by immuno-gold EM. In addition, we demonstrate that target and T-cells, each coated separately with complementary 2′OMe-RNA-linked antibodies can be crosslinked by RNA duplex formation in vitro to generate redirected cell lysis. Conclusion: The facile generation of dbBiTERs with specific cytolytic activity from intact antibodies and their generation on-cell offers a new avenue for antigen specific T-cell therapy.

Current challenges and therapeutic advances of CAR-T cell therapy for solid tumors

“…CEA, a cell surface binding glycoprotein that is expressed in normal tissues at low levels while in a variety of solid tumor tissues at high levels, is another promising target antigen [ 203 ]. Steven et al conducted a Phase 1b clinical trial (NCT02416466) [ 204 ].…”

Clinical Applications of Combined Immunotherapy Approaches in Gastrointestinal Cancer: A Case-Based Review

“…Favorable outcomes achieved with CIK cell therapy led to increased efforts to improve the efficacy of combined approaches. There exists strong preclinical evidence on the synergistic efficacy of pro-inflammatory cytokines such as interleukins [101][102][103][104] and interferon [105] as well as cytotoxic agents [106], novel small molecule inhibitors [107][108][109], immune checkpoint inhibitors [110][111][112], monoclonal antibodies [113,114] and dendritic cell [115][116][117] or viral-based vaccines [118][119][120] combined with adoptive cell therapy. Several stromal or intracellular mechanisms implicated in synergistic activity have been identified.…”

Clinical Applications of Combined İmmunotherapy Approaches in Gastrointestinal Cancer: A Case-Based Review

“…Favorable outcomes achieved with CIK cell therapy led to increased efforts to improve efficacy with combined approaches. There exists strong preclinical evidence on the synergistic efficacy of proinflammatory cytokines such as interleukins (101)(102)(103)(104) and interferon (105) as well as cytotoxic agents (106), novel small molecule inhibitors (107)(108)(109), immune checkpoint inhibitors (110)(111)(112), monoclonal antibodies (113,114) and dendritic cell (115)(116)(117) or viral-based vaccines (118-120) combined with adoptive cell therapy. Several stromal or intracellular mechanisms implicated in the synergistic activity have been identified.…”