Fig. 1.

The adoptive transfer of antigen specific, foxp3⁺ Tregs induces multiple amino acid enzyme depleting transcripts within skin grafts. (A) In vitro-generated Tregs (1 × 10⁷ DBYT cells) were adoptively transferred to CBA.RAG1^−/− recipient female mice 1 day before grafting with CBA.RAG1^−/− male tail skin (n = 8; black bars). Control RAG1^−/− recipients received similar grafts, but no DBYT cells (n = 4; white bars). After 6 days, grafts were harvested and analyzed for the expression of gene transcripts by low-density TaqMan RT-PCR array. Grafted samples were compared with normal tail skin from CBA.RAG1^−/− (n = 4; gray bars). Data are shown as mean ± SD of log₁₀(RQ) values, where n indicates the number of recipient skin graft samples tested in independent experiments. Transcripts significantly (P < 0.05) up-regulated either by syngeneic grafting alone or Tregs in male grafts are indicated. Note that FoxP3 detection within grafts showed a wide variation, because it was close to the limit of detection, but was negative in all mice not given DBYT cells. (B) Tregs (1 × 10⁷ DBYT cells) were adoptively transferred to A1.RAG1^−/− female recipient mice given a male CBA.RAG1^−/− skin graft 1 day later. One group of grafted mice received only Tregs (white bars), and other groups also received 2 mg of either a neutralizing anti-TGF-β (gray bars) or an isotype-matched control (black bars) mAb. Another group received no Tregs as a control for ongoing graft rejection (to which all data were normalized: indicated by the horizontal line at RQ = 0). All grafts were harvested and analyzed 6 days later for the expression of gene transcripts by low-density TaqMan RT-PCR array. Data are shown as mean ± SD of log₁₀(RQ) values for independent biological replicate samples from 6 individually grafted mice per group. Transcripts significantly (P < 0.05) up-regulated by Tregs in male grafts are indicated by *, and those significantly dependent on TGF-β are indicated by #.