Umbilical Cord Blood T Cells Respond against the Melan-A/MART-1 Tumor Antigen and Exhibit Reduced Alloreactivity as Compared with Adult Blood-Derived T Cells

Abstract

Material

CD8+ T-cell reconstitution in recipients of umbilical cord blood transplantation and characteristics associated with leukemic relapse

“…As reported previously, 15 A2/Melan-A ϩ T cells in the graft inoculum were polyclonal (median Ds ϭ 0.90; Figure 2A-B; supplemental Figure 2). Diversity declined significantly at 2 and 3 months after UCBT (P Ͻ .05) to increase again at 6 months, albeit to a level significantly lower than that observed in the graft (P Ͻ .05).…”

“…A2/Melan-A-specific T cells represent one of the only preimmune T-cell repertoires that can be studied in humans. 15,17,18 Here, we provide evidence that some UCB-derived CD8 ϩ T lymphocytes persisted in pediatric recipients in the first 6 months after UCBT. Their clonal diversity reached a nadir at 3 months after UCBT.…”

“…In addition, they produced significantly less IFN-␥ but were more likely to achieve terminal differentiation and less likely to exhibit bifunctional properties (IFN-␥ production and cytolytic activity) than T lymphocytes derived from adult blood. 15 In theory, these properties are compatible with a low incidence of GVHD and a high incidence of OI; however, little is known regarding the fate of CD8 ϩ T cells once they are transplanted into UCBT recipients.…”

Development of an IFN-γ ELISpot Assay to Assess Varicella-Zoster Virus-specific Cell-mediated Immunity Following Umbilical Cord Blood Transplantation

“…>300 spots), we recommend using no more than 2 x 10 5 PBMC per well. When faced with low frequencies of antigen specific T cells, assay sensitivity can be enhanced by prestimulating cells in vitro with cognate antigen or expand them with polyclonal activators such as phytohemagglutinin (PHA) for a defined period of time (typically 3-7 days) 38 . However, the final optimized procedure for the VZV ELISpot assay presented herein does not include in vitro prestimulation and/or expansion steps.…”

“…The sensitivity of ICS compares to that of ELISpot, but it requires larger numbers of cells 36,37 . Methods that make use of fluorescent class I or class II peptide-major histocompatibility complex (pMHC) oligomers (pMHC tetramers) [38][39][40] are precise and enable multiparametric characterization of lymphocyte subsets based on expression of cell surface markers.…”