Expression of T-cell phenotypic markers as a function of cell division during allogeneic versus homeostatic proliferation.

CFSE-labeled T cells from hCD4 transgenic B6 mice were transferred into semiallogeneic (B6/D2) or syngeneic (B6) lethally irradiated mice. CD4⁺ and CD8⁺ donor (hCD4⁺ gated) T cells recovered from spleens of recipient mice were analyzed for expression levels of (A) indicated T-cell activation markers, (B) mCD4 and mCD8 molecule, as well as the hCD4 marker for both cell types, and (C) intracellular IFN-γ production. The figure compares results obtained 40 hours after allogeneic transfer versus 88 hours after syngeneic transfer. For IFN-γ staining experiments (C), cells were collected from allogeneic or syngeneic recipients 8 days after transplantation. The control group was constituted by nonirradiated mice receiving syngeneic T cells in which no T-cell divisions were observed. In these mice, the level of expression for the different markers examined was comparable to the one observed on T cells freshly isolated from donor mice (not shown). Similar results were obtained in 3 allogeneic and 3 syngeneic recipient mice, at each time point.