title: Ex vivo expansion and Th1/Tc1 maturation of umbilical cord blood T cells by CD3/CD28 costimulation.
abstract: One major limitation of UCBT is the lack of donor cells available for posttransplantation donor leukocyte infusions (DLI) to boost immunity or induce graft-versus-leukemia (GVL) activity. Starting from a approximately 5% fraction of a UCB graft, we report the feasibility and biological characteristics of ex vivo expansion of frozen/thawed CB T cells by anti-CD3 and anti-CD28 antibody-coated Dynal beads in the presence of interleukin (IL)-2. We postulated that while undergoing expansion, UCB T cells may mature toward a Th1/Tc1 phenotype and acquire the potential for cytotoxicity. Whereas an almost 2-log expansion also led to the acquisition of IL-12Ralpha and an increase in Th1 characteristics, postexpansion lymphocytes produced less interferon-gamma, tumor necrosis factor-alpha, and granzyme B; stored almost no perforin; and lacked cytotoxicity against allogeneic targets. Collectively, these suggest relative safety from acute/hyperacute graft-versus-host disease. CD8(+) T cells expanded preferentially, whereas a higher rate of apoptosis in CD4(+) T cells also promoted an inverted CD4/CD8 ratio. Most expanded T cells retained expression of CD27, CD28, and L-selectin but down-regulated CCR-7. In summary, UCB T cell proliferation sustained by CD3/CD28 co-stimulatory beads and IL-2 can lead to clinically relevant doses of DLI from a very small fraction of the UCB graft, although future strategies to reduce apoptosis may enhance their clinical potential.
authors.affiliation: Department of Pediatrics, Pediatric Blood and Marrow Transplantation, Durham, North Carolina.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Mazur
authors.affiliation: Department of Pediatrics, Pediatric Blood and Marrow Transplantation, Durham, North Carolina.
authors.forename: Craig C
authors.initials: CC
authors.lastname: Davis
authors.affiliation: Department of Pediatrics, Pediatric Blood and Marrow Transplantation, Durham, North Carolina; Department of Immunology, Duke University Medical Center, Durham, North Carolina. Electronic address: szabo001@mc.duke.edu.
authors.forename: Paul
authors.initials: P
authors.lastname: Szabolcs
mesh_terms: D018106:CD28 Antigens; D017252:CD3 Complex; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D005240:Feasibility Studies; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D008213:Lymphocyte Activation; D016176:T-Lymphocyte Subsets / Q000166:cytology*; D013601:T-Lymphocytes / Q000166:cytology*; D018417:Th1 Cells / Q000166:cytology*
chemical_list: D018106:CD28 Antigens; D017252:CD3 Complex