title: Single CD28 stimulation induces stable and polyclonal expansion of human regulatory T cells.
abstract: CD4+FOXP3+ Treg are essential for immune tolerance. Phase-1 clinical trials of Treg-therapy to treat graft-versus-host-disease reported safety and potential therapeutic efficacy. Treg-based trials have started in organ-transplant patients. However, efficient ex vivo expansion of a stable Treg population remains a challenge and exploring novel ways for Treg expansion is a pre-requisite for successful immunotherapy. Based on the recent finding that CD28-signaling is crucial for survival and proliferation of mouse Treg, we studied single-CD28 stimulation of human Treg, without T cell receptor stimulation. Single-CD28 stimulation of human Treg in the presence of recombinant human IL-2(rhIL-2), as compared to CD3/CD28/rhIL-2 stimulation, led to higher expression levels of FOXP3. Although the single-CD28 expanded Treg population was equally suppressive to CD3/CD28 expanded Treg, pro-inflammatory cytokine (IL-17A/IFNγ) production was strongly inhibited, indicating that single-CD28 stimulation promotes Treg stability. As single-CD28 stimulation led to limited expansion rates, we examined a CD28-superagonist antibody and demonstrate a significant increased Treg expansion that was more efficient than standard anti-CD3/CD28-bead stimulation. CD28-superagonist stimulation drove both naïve and memory Treg proliferation. CD28-superagonist induction of stable Treg appeared both PI3K and mTOR dependent. Regarding efficient and stable expansion of Treg for adoptive Treg-based immunotherapy, application of CD28-superagonist stimulation is of interest.
authors.affiliation: Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud university medical center, Nijmegen, The Netherlands.|College of Computer Science, Qinghai Normal University, Xining, Qinghai, China.
authors.forename: Xuehui
authors.initials: X
authors.lastname: He
authors.affiliation: Laboratory of Clinical Chemistry, Department of Laboratory Medicine, Radboud university medical center, Nijmegen, The Netherlands.
authors.forename: Ruben L
authors.initials: RL
authors.lastname: Smeets
authors.affiliation: Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud university medical center, Nijmegen, The Netherlands.
authors.forename: Esther
authors.initials: E
authors.lastname: van Rijssen
authors.affiliation: Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Annemieke M H
authors.initials: AM
authors.lastname: Boots
authors.affiliation: Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud university medical center, Nijmegen, The Netherlands.
authors.forename: Irma
authors.initials: I
authors.lastname: Joosten
authors.affiliation: Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud university medical center, Nijmegen, The Netherlands.
authors.forename: Hans J P M
authors.initials: HJ
authors.lastname: Koenen
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D018106:CD28 Antigens / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D019175:DNA Methylation; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D020381:Interleukin-17 / Q000378:metabolism; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D020123:Sirolimus / Q000494:pharmacology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D000911:Antibodies, Monoclonal; D018106:CD28 Antigens; D017252:CD3 Complex; D051858:Forkhead Transcription Factors; D007371:Interferon-gamma; D020381:Interleukin-17; D007376:Interleukin-2; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011994:Recombinant Proteins; D020123:Sirolimus; D058570:TOR Serine-Threonine Kinases; D000077191:Wortmannin; C418974:FOXP3 protein, human; C546842:MTOR protein, human