Detection of extrathymically derived T lymphocytes in the cord blood of FOXN1^−/− human fetus.

<p>(A) Flow cytometry analysis of CBMCs from WT (left dot plots) or FOXN1^−/− (right dot plots) fetuses (16 weeks of gestation). CD7 and CD2 together with the CD8α and CD8β expression patterns for the gated CD45⁺CD3⁻ cells are shown. CD8α and CD4 expression is shown for the gated CD45⁺CD3⁺ cells. Numbers indicate the frequency of the cells within the gate. Experiment was repeated two times. Data were obtained by gating first on viable cells and later on CD45⁺ cells. (B) RT-PCR analysis of CD3ε expression in CBMCs. The expression of CD3ε transcript in human skin fibroblasts (negative control), human thymus (positive control), CBMCs from WT or FOXN1^−/− fetuses is shown. Blanck, no cDNA. β-actin was used as loading control. Representative results from three independent experiments are shown. (C) Quantitative real-time PCR showing the expression of mRNAs encoding CD3ε (relative to β-actin) in skin fibroblasts (negative control), thymus (positive control) and CBMCs from WT or FOXN1^−/− fetuses (16 weeks of gestation). Representative results from two independent experiments are shown.