Fig 6.

Reduced survival of allogeneic mesenchymal stem cells (MSCs) in vivo. LEW rats were injected with 3.5 × 10⁶ syngeneic or allogeneic MSCs or allogeneic T cells (three animals per group). After 2 weeks, all groups received 2.5 × 10⁶ CFSE-stained LEW MSCs and Far Red-stained DA MSCs (ratio 1:1). Lungs were harvested 24 hr after injection. Mononuclear cells were enriched using a Ficoll gradient and stained with anti-rat CD90-PE. (A) Gating strategy: Not P1 → MSC gate → CD90⁺ (top row). Bottom row: Shown are representative dot plots of CD90⁺ cells recovered from lungs of non-injected controls, LEW MSC pre-treated and DA MSC pre-treated rats (left to right). The percentages given are percentage of events ± S.D. in the MSC gate that are CD90⁺ CFSE⁺ (LEW MSCs) or CD90⁺ Far Red⁺ double positive (DA MSCs), respectively. (B) Ratio of allogeneic MSCs (CD90⁺ Far Red⁺) to syngeneic MSCs (CD90⁺ CFSE⁺) in LEW rats pre-treated with DA MSCs or LEW MSCs. Rats pre-treated with DA T cells were used as positive controls. Each black diamond represents an individual animal (n = 3/group), the grey lines show the mean (*P < 0.05; non-parametric Mann–Whitney test).