Surface programmable activation receptor (SPAR) cell platform for the rapid detection of melanoma-specific biomarkers

• Published in: Journal of clinical oncology Vol. 37; no. 15_suppl; p. e14263
• Main Authors: Lwande, Joel, Kittle, Joseph D, Williams, M. Russell, Liang, Shengwen, McQuaid, Kyle, Frenchmeyer, Melissa, Tang, Yuanyuan, Neese, Allison, Hua, Jiangzhou, McBrairty, Charles
• Format: Journal Article
• Language: English
• Published: 20.05.2019
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2019.37.15_suppl.e14263

Abstract only e14263 Background: We have previously demonstrated that SPAR modified T cells effectively detect bacterial and viral pathogens. SPAR cells are engineered to express a modified T cell receptor (TCR) capable of antibody-directed signal transduction and respond with a Ca 2+ -mediated production of luminescent signal upon target detection. Here we describe the ability of SPAR cells to rapidly detect the cell surface expression of melanoma biomarkers without a requirement for extensive sample preparation. Methods: SPAR cells expressing both an engineered T cell receptor and the luminescent reporter protein aequorin were developed via the transfection of Jurkat cells with the aequorin expression vector pEF1-Aeq and an engineered TCR complex composed of mouse FcγRI fused to the CD3ζ subunit. The mFcγRI-CD3ζ receptor binds to the Fc region of full-length mouse IgG2 antibodies: SPAR cells are programmed for target detection via the addition of target-specific antibody. The ability of programmed SPAR cells to accurately detect melanoma-specific cell surface biomarkers was evaluated using whole cells from cultured mouse (B16-F10) and human (SK-Mel-28) melanoma cell lines. SPAR cells were programmed by incubation with murine antibodies directed toward the melanoma biomarkers CD133 or TRP1, then mixed with melanoma cells or K562 control cells and evaluated for signal generation. Results: SPAR cells programmed with anti-CD133 or anti-TRP1 antibody produced luminescent signal within minutes when combined with human SK-Mel-28 cells or mouse B16-F10 cells, respectively, known to abundantly express the appropriate biomarker. No signal was generated when programmed SPAR cells were incubated with K562 cells. Further studies also document cytokine production following receptor engagement. Conclusions: SPAR cells can be programmed for the rapid and specific detection of known cell surface cancer biomarkers. The Ca 2+ -dependent production of luminescent signal and cytokine release in response to TCR engagement suggests SPAR cell activation. Thus, in addition to biomarker detection the SPAR system may ultimately provide predictive insights into the potency of antibody-directed cell therapy.