Journal: Science (New York, N.Y.)
Article Title: Engineering synthetic suppressor T cells that execute locally targeted immunoprotective programs
doi: 10.1126/science.adl4793
Figure Lengend Snippet: ( A ) Synthetic suppressor T cells that act as a source for inhibitory cytokines and a sink for inflammatory cytokines drove stronger suppression of CAR T cells in vitro. Synthetic suppressor T cells that induced a combination of TGFβ1 and CD25 were more potent at suppressing CD8 + CAR T cell activity compared with each individual payload alone. Cell counts are normalized to the 0 hour time point ( n = 3 replicates, error bars = standard error, filled markers indicate two-tailed t test, P < 0.05, comparison to no-suppressor cell control). ( B ) Synthetic suppressor T cells depleted IL-2 produced by activated CD4 + T cells in vitro. Human CD4 + T cells activated by anti-CD3/CD28 beads for 24 hours were cocultured with synthetic suppressor T cells activated with synNotch activating beads (anti-Myc beads). The IL-2 levels in the supernatant were measured by ELISA ( t = 48 hours, n = 3 replicates, error bars = standard error, two-tailed t test comparing TGFβ1 and CD25 to each payload alone, * P < 0.05). ( C ) Synthetic suppressor T cells required both TGFβ1 and CD25 to be produced by the same cell for effective suppression in vitro. Separation of TGFβ1 and CD25 into two separate cells led to weaker suppression of CD8 + CAR T cell killing (reduced target-cell proliferation) than a one-cell system where both payloads are produced by the same suppressor T cell in vitro ( n = 3 replicates, error bars = standard error, filled markers indicate two-tailed t test, P < 0.05, comparison to no-suppressor cell control). ( D ) CD25 drives increased TGFβ1 production by synthetic suppressor T cells in vitro. Suppressor cells that induced a combination of TGFβ1 and CD25 led to more TGFβ1 accumulation than suppressor cells inducing TGFβ1 alone. Suppressor cells were activated in vitro with synNotch activation beads (anti-Myc beads). TGFβ1 levels were measured by ELISA of supernatant ( t = 72 hours, n = 3 replicates, error bars = standard error, two-tailed t test between TGF β1 circuit with and without CD25, * P < 0.05). ( E ) CD25 can enhance suppressor cell activity by two mechanisms. CD25 depletes IL-2 from the local microenvironment and drives preferential proliferation of suppressor cells. An increase in suppressor cell number can yield higher TGFβ1 accumulation.
Article Snippet: Human polyclonal T reg cells were isolated by sorting CD4 + (BioLegend, SK3 clone), high CD25 + (Thermo Fisher, 4E3 clone), and CD127 − (BD Biosciences, HIL-7R-M21 clone) immediately after isolation of primary human CD4 + T cells from leukapheresis packs.
Techniques: In Vitro, Activity Assay, Two Tailed Test, Comparison, Control, Produced, Enzyme-linked Immunosorbent Assay, Activation Assay