Adaptive Tolerance Can Be Induced Independently of Regulatory Activity

Abstract

<div><p>(A) Intracellular staining with antibodies to <i>foxp3</i> (left panels) or an isotype-matched control (right panels) on naive 5C.C7 T cells (middle two panels) or antigen-adapted T cells (bottom two panels). Positive control staining in a polyclonal population of B10.A T cells marks approximately 19% of the CD4⁺ T cells (top two panels).</p> <p>(B) A new cohort of naive 5C.C7 T cells expands similarly in B10.A, PCC^+/+, CD3ε^−/− hosts (open squares) even if they already harbor expanded 5C.C7 T cells (solid squares). Newly transferred 5C.C7 T cells were distinguished from the previous population using congenic markers (Ly5.1).</p> <p>(C) Congenically marked Ly5.1^+/+,5C.C7 T cells that expanded in a naive B10.A, PCC^+/+, CD3ε^−/− host (open squares) or a PCC^+/+, CD3ε^−/− host that had been injected with Ly5.2 ^+/+,5C.C7 T cells 28 d in advance (solid squares) were purified by FACS sorting (Ly5.1+, CD4+) and restimulated in vitro to measure IFNγ secretion.</p></div