Large-scale depletion of CD25+ regulatory T cells from patient leukapheresis samples.
The ability to selectively enrich or deplete T lymphocytes of specific phenotype and function holds significant promise for application in adoptive immunotherapy protocols. Although CD4+ T cells can have an impact on CD8+ T-cell effector function, memory, and maintenance, a subset of CD4+ T cells, CD25+ regulatory T cells (Treg), can regulate peripheral self tolerance and possess the ability to suppress antitumor responses. The authors report the ability to selectively deplete CD25+ Treg cells from patient leukapheresis samples using a clinical-grade, large-scale immunomagnetic system. Using leukapheresis samples containing up to 1.3 x 10(10) white blood cells, efficient depletion of Treg cells was measured by flow cytometric analysis of CD25 expression and FOXP3 expression on post-depletion products. Remnant CD25+ cells could not be detected in CD25-depleted products after short-term culture in IL-2 or enriched following secondary immunomagnetic selection for CD25+ cells, confirming that efficient depletion had occurred. In parallel to efficient enrichment of CD25- cells, immunomagnetic selection resulted in the recovery of Treg cells, since CD25+ lymphocytes removed during depletion were primarily composed of CD4+ T cells that expressed high levels of FOXP3 and possessed suppressive activity against autologous TCR-stimulated CD4+ CD25- T cells in vitro. These results show that selective separation of functional CD25+ Treg cells from large-scale samples can be performed in large scale under clinical-grade conditions with sufficient selection, recovery, viability, ability to expand, and function for potential use in adoptive immunotherapy.
Powell
Daniel J
DJ
Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-1201, USA.
Parker
Linda L
LL
Rosenberg
Steven A
SA
D015703:Antigens, CD / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D002452:Cell Count; D018920:Coculture Techniques; D004268:DNA-Binding Proteins / Q000235:genetics; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007108:Immune Tolerance / Q000187:drug effects / Q000276:immunology; D018189:Immunomagnetic Separation / Q000379:methods*; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000494:pharmacology; D007937:Leukapheresis; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D008212:Lymphocyte Depletion / Q000379:methods*; D016853:Muromonab-CD3 / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000276:immunology* / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015854:Up-Regulation / Q000276:immunology
D015703:Antigens, CD; D004268:DNA-Binding Proteins; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D007376:Interleukin-2; D016853:Muromonab-CD3; D015375:Receptors, Interleukin-2