AUTHOR=Boucher Alexander , Anderson Courtney , Hinman Rochelle , Kindschuh Molly , Fung Jeremy , Wang Tiansu , Klooster Isabella , Kim Elise , Roth Caroline , Vander Oever Michael , Khan Bakhmala , Zelikson Natalie , Vagima Yaron , Saribasak Huseyin , Santry Lisa , Klapper Leah Natasha , Hess Shmuel , Mooney Jill , Bublik Débora Rosa , Laken Haley , Barzel Adi , Borden Philip , Plewa Cherylene , Chadbourne Ana Maria , Bridgen Devin , Nahmad Alessio D. TITLE=Engineered human B cells targeting tumor-associated antigens exhibit antigen presentation and antibody-mediated functions JOURNAL=Frontiers in Immunology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2025.1621222 DOI=10.3389/fimmu.2025.1621222 ISSN=1664-3224 ABSTRACT=B cell engineering represents a promising therapeutic strategy that recapitulates adaptive immune functions, such as memory retention, antibody secretion and affinity maturation in murine models of viral infection. These mechanisms may be equally beneficial in oncology. Recent studies have linked endogenous anti-tumor B cell immunity to favorable prognosis across multiple malignancies. Here, we present functional validation of human B cells engineered to target tumor-associated membrane and intracellular antigens. We demonstrate that engineered B cells express therapeutically relevant membrane B cell receptors that are secreted as antibodies upon differentiation. Additionally, engineered B cells take up tumor-associated antigens and demonstrate potent antigen presentation capabilities, while their secreted antibodies activate T cell responses via immune complexes and induce tumor-directed cytotoxic responses. B cell engineering to target tumor-associated antigens may thus have utility as a novel modality for solid tumor therapy.