751 Neo-X-Prime bispecific antibodies targeting CD40 and tumor antigens promote cross-presentation of tumor exosome-derived neoantigen and induce superior anti-tumor responses compared to CD40 mAb
| Autor: | Barnabas Nyesiga, Mia Thagesson, Anna Rosén, Karin Hägerbrand, Mattias Levin, Karin Barchan, Laura Varas, Anette Sundstedt, Anna Säll, Doreen Werchau, Peter Ellmark, Lill Ljung, Laura Von Schantz, Eva Lindqvist, Adnan Deronic |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Pharmacology
Cancer Research CD40 biology Chemistry medicine.drug_class T cell Immunology Priming (immunology) Cross-presentation Neoplasms. Tumors. Oncology. Including cancer and carcinogens Monoclonal antibody Exosome medicine.anatomical_structure Oncology Antigen biology.protein medicine Cancer research Molecular Medicine Immunology and Allergy Antigen-presenting cell RC254-282 |
| Zdroj: | Journal for ImmunoTherapy of Cancer, Vol 9, Iss Suppl 2 (2021) |
| ISSN: | 2051-1426 |
| Popis: | BackgroundAlligator's Neo-X-Prime platform aims to enable antigen presenting cells to efficiently enhance priming of tumor neoantigen-specific T cells with the goal of overcoming PD-1 resistance in certain tumor types. We hypothesize that binding of a CD40 x TAA bispecific antibody (bsAb) to CD40 on dendritic cells (DCs) and a tumor-associated antigen (TAA) on tumor exosomes or tumor debris leads to (i) activation of the DC, (ii) uptake of the tumor material, (iii) cross-presentation of tumor-derived neoantigen (present in exosomes or debris) and, iv) priming of tumor neoantigen-specific T cells, resulting in an increased quantity and/or quality of the tumor-targeting T cell pool.MethodsFunctionality was evaluated in vitro using CD40 reporter cells and monocyte-derived DCs, co-cultured with cells expressing TAA. Further, co-localization of TAA-expressing cellular debris with a CD40-expressing human B cell line in the presence of bsAbs was assessed using live cell imaging. In vivo, anti-tumor efficacy and immunological memory were assessed in human CD40 transgenic (hCD40tg) mice bearing MB49 bladder carcinoma tumors transfected with human TAA or controls. T cells isolated from OVA-specific TCR-transgenic mice were used to evaluate the effect of Neo-X-Prime bsAbs on antigen-specific T cell expansion in the presence of hCD40tg DCs and exosomes from MB49 tumors transfected with both human TAA and OVA using flow cytometry.ResultsUsing CEA as a highly expressed TAA, we have developed lead Neo-X-Prime CD40-CEA bsAbs engineered to achieve an optimal profile. Further, using Neo-X-Prime concept molecules targeting EpCAM, we have demonstrated the ability to mediate co-localization of tumor debris and CD40 expressing antigen presenting cells that is dependent on the receptor density of the TAA. We have further shown that addition of Neo-X-Prime bsAbs to a co-culture of murine DCs, T cells and tumor-derived exosomes induces increased expansion of model neoantigen-specific T cells. In vivo, Neo-X-Prime bsAbs display a potent, TAA-dependent anti-tumor effect that is superior to CD40 mAbs. Cured mice develop a broad immunological memory that is not dependent on expression of the TAA. The tumor-localizing property of Neo-X-Prime bsAbs also shows potential for improved safety compared to CD40 monospecific antibodies.ConclusionsNeo-X-Prime bsAbs have the potential to tumor-selectively target CD40-expressing antigen-presenting cells to mediate an expansion of the tumor-specific T cell repertoire, resulting in increased T cell infiltration and potent anti-tumor effects.Ethics ApprovalAll experiments were performed after approval from the Malmö/Lund Animal Ethics Committee. |
| Databáze: | OpenAIRE |
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