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bioRxiv · 10.1101/2020.08.10.241869

Antigen-Specific T Cell Recall Assay To Screen Drugs For Off-Target Effects

Kleiman, E.·Sierra, G.·Magcase, D.·George, M. V.·Daftarian, P. M.
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Abstract

Extracellular adenosine suppresses T cell immunity in the tumor microenvironment. We have developed an in vitro recall assay utilizing a sequential adenosine dosing regimen guide for testing drug off-target effects on memory T cell expansion/function. As a proof of principle, we show low dose adenosine analog GS-5734, a monophosphoramidate prodrug of an adenosine analog, does not alter memory T cell recall whereas toxicity observed at high dose favors antigen-specific memory T cell survival/proliferation over non-specific CD8+ T cells. Parent drug GS-445124 at high dosage interferes with antigen-specific T cell recall without cellular toxicity. Despite similar chemical structure, these drugs displayed opposing effects on memory T cell expansion. This assay platform has broad utility in screening memory T cell off-target effects.

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Kleiman, E., Sierra, G., Magcase, D., George, M. V., Daftarian, P. M.. 2020-08-10. Antigen-Specific T Cell Recall Assay To Screen Drugs For Off-Target Effects. https://doi.org/10.1101/2020.08.10.241869

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