Fig 2. γδ T cells possess an inhibitory effect on the Foxp3 response.

A). Addition of γδ T cells to TCR-δ^-/- responder T cells inhibited the Foxp3 T cell response. CD3⁺ T cells (1 x 10⁶/well) prepared from immunized TCR-δ^-/- mice were cultured in the presence or absence of isolated γδ T cells (5 x 10⁴/well) from immunized B6. After culture in medium containing 1ng/ml IL-2 for 5 days, the percentage of Foxp3⁺ T cells among CD3⁺ T cells was determined by FACS analysis. B). Addition of a minimum of 1% γδ T cells to TCR-δ^-/- responder T cells effectively inhibited the Foxp3 T cell response. TCR-δ^-/- responder T cells were cultured in medium containing 1 ng/ml recombinant IL-2 in the presence or absence of different numbers of isolated γδ T cells from immunized B6 mice. The percentage of Foxp3⁺ cells among the responder T cells were assessed at the end of five day cultures. C). Administration to TCR-δ^-/- mice with 1 x 10⁶/mouse of γδ T cells inhibited the Foxp3 T cell response. TCR-δ^-/- mice were injected with 1 x 10⁶/mouse γδ T cells, isolated from immunized B6 mice, before they were immunized. Thirteen days after immunization, Foxp3⁺ T cells were evaluated. Data are from one single experiment and are representative of multiple (>5) independent experiments.