CD4⁺ RTEs are capable of responding to TCR stimulation.

<p>Busulfan chimeras were established as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163604#pone.0163604.g002" target="_blank">Fig 2</a>. Spleens and livers were taken on day 28 post BMT (d21 p.i.) and CD4⁺ cells were collected by MACS. CD4⁺ cells were stimulated with anti-CD3 and anti-CD28 for 12 hours and stained for CD3, CD4, CD45.1, IFNγ and TNFα. Graphs represent the distribution of IFNγ and TNFα expression from recipient CD4⁺ T cells or donor-derived CD4⁺ RTEs in both the liver (<b>A</b>) and the spleen (<b>C</b>). Distributions were calculated by converting the frequency of cytokine expression into a proportion (x%) of all cytokine expressing recipient/donor-derived CD4⁺ T cells (100%), with regards to the relative cytokine axis. Graph represents the mean for 5 animals per group from 1 experiment. Flow plots represent gates used to determine IFNγ⁺ and TNFα⁺ expression by CD4⁺ T cells in both the liver (<b>B</b>) and the spleen (<b>D</b>).