title: Ex vivo expansion of human CD8+ T cells using autologous CD4+ T cell help.
abstract: BACKGROUND
  Using in vivo mouse models, the mechanisms of CD4+ T cell help have been intensively investigated. However, a mechanistic analysis of human CD4+ T cell help is largely lacking. Our goal was to elucidate the mechanisms of human CD4+ T cell help of CD8+ T cell proliferation using a novel in vitro model.
  
  
  RESULTS
  We developed a genetically engineered novel human cell-based artificial APC, aAPC/mOKT3, which expresses a membranous form of the anti-CD3 monoclonal antibody OKT3 as well as other immune accessory molecules. Without requiring the addition of allogeneic feeder cells, aAPC/mOKT3 enabled the expansion of both peripheral and tumor-infiltrating T cells, regardless of HLA-restriction. Stimulation with aAPC/mOKT3 did not expand Foxp3+ regulatory T cells, and expanded tumor infiltrating lymphocytes predominantly secreted Th1-type cytokines, interferon-γ and IL-2. In this aAPC-based system, the presence of autologous CD4+ T cells was associated with significantly improved CD8+ T cell expansion in vitro. The CD4+ T cell derived cytokines IL-2 and IL-21 were necessary but not sufficient for this effect. However, CD4+ T cell help of CD8+ T cell proliferation was partially recapitulated by both adding IL-2/IL-21 and by upregulation of IL-21 receptor on CD8+ T cells.
  
  
  CONCLUSIONS
  We have developed an in vitro model that advances our understanding of the immunobiology of human CD4+ T cell help of CD8+ T cells. Our data suggests that human CD4+ T cell help can be leveraged to expand CD8+ T cells in vitro.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Massachusetts, United States of America.
authors.forename: Marcus O
authors.initials: MO
authors.lastname: Butler
authors.forename: Osamu
authors.initials: O
authors.lastname: Imataki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Makito
authors.initials: M
authors.lastname: Tanaka
authors.forename: Sascha
authors.initials: S
authors.lastname: Ansén
authors.forename: Alla
authors.initials: A
authors.lastname: Berezovskaya
authors.forename: Genita
authors.initials: G
authors.lastname: Metzler
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Milstein
authors.forename: Mary M
authors.initials: MM
authors.lastname: Mooney
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Murray
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mano
authors.forename: Lee M
authors.initials: LM
authors.lastname: Nadler
authors.forename: Naoto
authors.initials: N
authors.lastname: Hirano
mesh_terms: D017252:CD3 Complex / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D007378:Interleukins / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D020014:K562 Cells; D016246:Lymphocytes, Tumor-Infiltrating / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D016853:Muromonab-CD3 / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D053655:Receptors, Interleukin-21 / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D000098546:Interleukin-21
chemical_list: D017252:CD3 Complex; D016207:Cytokines; D007376:Interleukin-2; D007378:Interleukins; D016853:Muromonab-CD3; D053655:Receptors, Interleukin-21; D007371:Interferon-gamma; D000098546:Interleukin-21