Quantifying T cell Mediated Killing for Melanoma Immunotherapy
Adoptive cell therapy (ACT), based on the adoptive transfer of tumor-infiltrating lymphocytes (TILs) has well-recognized advantages such as (1) high specificity for target cells; (2) the ability to target even micrometastases; (3) the potential to proliferate in vivo within the host thus increasing both surveillance and destruction capabilities, and (4) the feasibility to treat late stage tumors refractory to all other treatment methods with clinical response rates of ~50%. Despite numerous improvements in the last decade, ACT treatments still result in a wide range of outcomes. Functional heterogeneity, at the single-cell level, of cells infused for ACT has not been routinely characterized and consequently their efficacy and persistence in vivo following ACT are unpredictable. By using a high-throughput single-cell methodology, we demonstrate here that our assay has been able to quantify and indentify sub-populations within a TILs sample based on their individual killing potentials when matched with different number of targets.