Functional characterization of alloreactive T cells identifies CD25 and CD71 as optimal targets for a clinically applicable allodepletion strategy.
Immunotherapy with allodepleted donor T cells (ADTs) improves immunity after T cell-depleted stem cell transplantation, but infection/relapse remain problematic. To refine this approach, we characterized the expression of surface markers/cytokines on proliferating alloreactive T cells (ATs). CD25 was expressed on 83% of carboxyfluorescein diacetate succinimidyl ester(dim) ATs, confirming this as an excellent target for allodepletion. Seventy percent of CD25(-) ATs expressed CD71 (transferrin receptor), identifying this as a novel marker to target ATs persisting after CD25 depletion. Comparison of residual alloreactivity after combined CD25/71 versus CD25 immunomagnetic depletion showed enhanced depletion of alloreactivity to host with CD25/71 depletion in both secondary (2 degrees) mixed lymphocyte reactions (P < .01) and interferon-gamma enzyme-linked immunospot assays (P < .05) with no effect on third-party responses. In pentamer/interferon-gamma enzyme-linked immunospot assays, antiviral responses to cytomegalovirus, Epstein-Barr virus, and adenovirus were preserved after CD25/71 allodepletion. CD25/71 ADTs can be redirected to recognize leukemic targets through lentiviral transfer of a chimeric anti-CD19zeta T-cell receptor. Finally, we have established conditions for clinically applicable CD25/71 allodepletion under European Union Good Manufacturing Practice conditions, resulting in highly effective, reproducible, and selective depletion of ATs (median residual alloreactivity to host in 2 degrees mixed lymphocyte reaction of 0.39% vs third-party response of 62%, n = 5). This strategy enables further clinical studies of adoptive immunotherapy with larger doses of ADTs to enhance immune reconstitution after T cell-depleted stem cell transplantation.
Samarasinghe
Sujith
S
Department of Molecular Immunology, Institute of Child Health, London, United Kingdom.
Mancao
Christoph
C
Pule
Martin
M
Nawroly
Niga
N
Karlsson
Helen
H
Brewin
Jennifer
J
Openshaw
Peter
P
Gaspar
H Bobby
HB
Veys
Paul
P
Amrolia
Persis J
PJ
D015703:Antigens, CD / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D008212:Lymphocyte Depletion; D011990:Receptors, Transferrin / Q000276:immunology*; D033581:Stem Cell Transplantation; D013601:T-Lymphocytes / Q000276:immunology*; D014184:Transplantation, Homologous
D015703:Antigens, CD; C068126:CD71 antigen; C508017:IL2RA protein, human; D053645:Interleukin-2 Receptor alpha Subunit; D011990:Receptors, Transferrin