Transfection of FcγRIIIa (CD16) Alone Can Be Sufficient To Enable Human αβTCR T Lymphocytes To Mediate Antibody-Dependent Cellular Cytotoxicity.

To combine the immune potential of T cells and Ab therapy, we and others have previously shown that T cells transduction with a fusion receptor that binds the Fc portion of human Ig enable them to mediate Ab-dependent cellular cytotoxicity (ADCC). The fusion receptors previously described included the FcγRIIIa (CD16) receptor coupled to different chains intended to translate the signal. In this work, we questioned whether the transfection of CD16 alone into T human lymphocytes and NK cells could be sufficient for CD16 expression and function, or whether the cotransfection of a transducing chain was mandatory. Our results demonstrated that: 1) transfection of CD16 alone into a human NK cell line and primary T cells can be sufficient for CD16 expression and function; 2) cotransfection of CD3ζ or FcεRIγ increased CD16 expression; 3) yet this increased CD16 expression increased the ADCC score only for trastuzumab, not for rituximab or cetuximab; and 4) compared with that of peripheral NK cells, ADCC scores by autologous CD16-transfected T cells ranked differently according to the opsonized target cell. Together, these results showed that neither the use of a fusion receptor nor the cotransfection of a transducing chain is mandatory to transfer the ADCC function to human lymphocytes. Thus, depending on the effector/Ab/target combination considered, transfection of CD16 alone can be sufficient to enable T cells to mediate ADCC. In the context of immunotherapy, such a strategy is by nature safer than the use of a chimeric receptor, and is freely available.