Alloantigen-specific type 1 regulatory T cells suppress through CTLA-4 and PD-1 pathways and persist long-term in patients.

Type 1 regulatory T (Tr1) cells are inducible, interleukin (IL)-10FOXP3 regulatory T cells that can suppress graft-versus-host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We have optimized an in vitro protocol to generate a Tr1-enriched cell product called T-allo10, which is undergoing clinical evaluation in patients with hematological malignancies receiving a human leukocyte antigen (HLA)–mismatched allo-HSCT. Donor-derived T-allo10 cells are specific for host alloantigens, are anergic, and mediate alloantigen-specific suppression.

The Importance of Solvent Effects on the Mechanism of the Pfeiffer Effect.

The Pfeiffer effect is observed when an optically active compound such as an amino acid is introduced to a solution containing a labile racemic metal complex, and an equilibrium shift is obtained. The "perturbation" results in an excess of one enantiomer over the other. The shift is a result of a preferential outer sphere interaction between the introduced chiral species and one enantiomeric form (Λ or Δ) of a labile metal complex.