Analysis of the peripheral blood (PB) of thy/liv implanted NSG mice demonstrates long-term reconstitution with human T cells. A) Flow cytometric analysis of the PB of NOD/SCID-hu (N/S-hu) (black circles) and NSG thy/liv (gray triangles) mice demonstrates systemic reconstitution of implanted NSG mice with human cells (CD45+; solid line) and human T cells (CD3+; dashed line). Gating strategy: live cells→human CD45→human CD3. B) Flow cytometric analysis of cells from PB of a representative NSG-hu thy/liv mouse (29 weeks post-implant) demonstrates these mice are exclusively reconstituted with human T cells with greater than 99% of cells expressing human CD3. There is a lack of B cells (CD19+), natural killer cells (CD56+), and myeloid cells (CD33+) in the PB of TOM. PB CD3 expressing cells were then analyzed for CD4 and CD8 expression levels. The majority of CD3+ cells in PB expressed CD4 (87%).