Co-stimulatory bispecific antibodies induce enhanced T cell activation and tumor cell killing in breast cancer models
Although T cell-recruiting CD3-binding bispecific antibodies (BiMAb) have been proven to be clinically effective for hematologic malignancies, the success of BiMAb targeting solid tumor-associated antigens (TAA) in carcinomas so far remains poor. We reasoned that provision of co-stimulatory BiMAb in...
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| Main Authors: | , , , , , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
16 August 2021
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| In: |
Frontiers in immunology
Year: 2021, Volume: 12, Pages: 1-22 |
| ISSN: | 1664-3224 |
| DOI: | 10.3389/fimmu.2021.719116 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.3389/fimmu.2021.719116 Verlag, lizenzpflichtig, Volltext: https://www.frontiersin.org/article/10.3389/fimmu.2021.719116 
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| Author Notes: | Karsten M. Warwas, Marten Meyer, Márcia Gonçalves, Gerhard Moldenhauer, Nadja Bulbuc, Susanne Knabe, Claudia Luckner-Minden, Claudia Ziegelmeier, Claus Peter Heussel, Inka Zörnig, Dirk Jägera and Frank Momburg |
| Summary: | Although T cell-recruiting CD3-binding bispecific antibodies (BiMAb) have been proven to be clinically effective for hematologic malignancies, the success of BiMAb targeting solid tumor-associated antigens (TAA) in carcinomas so far remains poor. We reasoned that provision of co-stimulatory BiMAb in combination with αTAA-αCD3 BiMAb would boost T cell activation and proliferative capacity, and thereby facilitate the targeting of weakly or heterogeneously expressed tumor antigens. Various αTAA-αCD3 and αTAA-αCD28 BiMAb in a tetravalent IgG1-Fc based format have been analyzed, targeting multiple breast cancer antigens including HER2, EGFR, CEA, and EpCAM. Moreover, bifunctional fusion proteins of αTAA-tumor necrosis factor ligand (TNFL) superfamily members including 4-1BBL, OX40L, CD70 and TL1A have been tested. The functional activity of BiMAb was assessed using co-cultures of tumor cell lines and purified T cells in monolayer and tumor spheroid models. Only in the presence of tumor cells, αTAA-αCD3 BiMAb activated T cells and induced cytotoxicity in vitro, indicating a strict dependence on cross-linking. Combination treatment of αTAA-αCD3 BiMAb and co-stimulatory αTAA-αCD28 or αTAA-TNFL fusion proteins drastically enhanced T cell activation in terms of proliferation, activation marker expression, cytokine secretion and tumor cytotoxicity. Furthermore, BiMAb providing co-stimulation were shown to reduce the minimally required dose to achieve T cell activation by at least tenfold. Immuno-suppressive effects of TGF-β and IL-10 on T cell activation and memory cell formation could be overcome by co-stimulation. BiMAb-mediated co-stimulation was further augmented by immune checkpoint-inhibiting antibodies. Effective co-stimulation could be achieved by targeting a second breast cancer antigen, or by targeting fibroblast activation protein (FAP) expressed on another target cell. In tumor spheroids derived from pleural effusions of breast cancer patients, co-stimulatory BiMAb were essential for the activation tumor-infiltrating lymphocytes and cytotoxic anti-tumor responses against breast cancer cells. Taken together we showed that co-stimulation significantly potentiated the tumoricidal activity of T cell-activating BiMAb while preserving the dependence on TAA recognition. This approach could provide for a more localized activation of the immune system with higher efficacy and reduced peripheral toxicities. |
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| Item Description: | Gesehen am 12.11.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1664-3224 |
| DOI: | 10.3389/fimmu.2021.719116 |