CellRaft Array for Screening and Isolation of Highly Effective Cytotoxic T Cells

Project SummaryAdoptive cell therapyACTis an emerging immunotherapy which shows significant promise in treating both leukemia and solid tumorsas well as certain infectious diseasesACT comprises the isolation and ex vivo expansion of cytotoxic T lymphocytesCTLsrecognizing epitopes of a mutated or aberrantly expressed protein present almost exclusively on the surface of a patient s tumor cellsTo meet the need for personalized enrichment of the most effective CTLsthis Phase II STTR will employ Cell Microsystemsproprietary CellRaft technology to develop a high throughputautomated platformthe CLEAR AIRSystemto efficiently screen for and isolate highly activetumor directed CTLs on a single cell basisThe CellRafttechnology is based on a unique microwell array recently developed by the Allbritton Lab at the University of North Carolina at Chapel HillCell Microsystems has an exclusive license to the CellRafttechnologycurrently marketing both the consumable CellRaft Arrays as well as microscope accessories enabling imagingisolation and retrieval of single cells from the arrayIn Phase I we used the CellRaft technology to assay the cytotoxic activity and kinetics of CTLsT cells were pre treated with peptide epitopes known to be expressed on influenza infected cellsEpitope treated and untreated CTL populations were then co incubated with cells expressing the influenza epitopes and monitored for cytotoxic activityBy performing these assays at the single cell levela unique population ofsuper killerswere identified as those exhibiting cytotoxicity at leaststandard deviations above mean cytotoxicity levelsThese super killers were enriched by approximatelyfold in epitope treated CTLs compared to untreated CTLsThese data indicate that the CellRaft technology is amenable to performing CTL cytotoxicity assays and retrieval of CTLs for downstream propagation and analysisIn Phase II we will build on these data bydesigning and testing awell CellRaft Array containingsmall arrays within a single consumable to test multiple conditions and immunoreactive epitopes in the cytotoxicity assayusing this newwell CellRaft array to assay sequence dependent cytotoxicity of tumor cell expressed epitopesenabling rapid imaging and long term culture on the automated CLEAR AIRSystem for longitudinal studies such as these andperforming external validation studies at both UNC Chapel Hill and MD Anderson Cancer Center for novel CTL recognition proteinsThis workflow will allow analysis of the T cell receptor without requiring the best killing cells to be propagation capablean issue observed in Phase I with the best killing cellsCommerciallywe view the CellRaft Systemas both a research tool enabling correlation of killing efficiency with the molecular characteristics of the T cell receptorTCRand eventually as a clinical tool for identifying efficacious TCR sequences as well as other time course based phenotypic screens