Characterization of natural killer and natural killer-like T cells derived from ex vivo expanded and activated cord blood mononuclear cells: implications for adoptive cellular immunotherapy.
ABSTRACT Cord blood (CB) is limited by the absence of available donor effector cells for post-unrelated CB transplantation adoptive cellular immunotherapy. We reported the ability to ex vivo expand (EvE) CB mononuclear cells (MNC) after short-term incubation with anti-CD3, interleukin (IL)-2, IL-7, and IL-12 (antibody/cytokine [AB/CY]) into subpopulations of CD3(-)/56(+) natural killer (NK) cells with enhanced in vitro and in vivo tumor cytotoxicity.
We compared 2- vs 7-day EvE of rethawed CB MNCs in AB/CY and activation of NK and NK-like T (NKT) cell (CD3(+)/56(+)) subsets expressing specific NK-cell receptors along with IL-15, IL-18, and interferon-gamma production.
Nonadherent total cell number were significantly increased at day 7 (p<0.001) along with NK-cell number (20-fold) and an enrichment in NKT-like subsets (36-fold). There was no change in the NK(dim) subset; yet the NKT(bright) and NKT KIR3DL1(dim) subsets were significantly increased (p<0.05). NK cells expressing the inhibitory natural cytoxicity receptor CD94/NKG2A were decreased (p<0.001), while those expressing activating natural cytoxicity receptor CD94/NKG2D receptor and activating NK and NKT KIR2DS4 subsets were significantly increased (p<0.001). IL-18 and interferon-gamma protein production was also significantly increased (p<0.001 and p<0.05, respectively). Lysosomal-associated membrane protein-1 and granzyme B expression were increased (p<0.001 and p>0.01, respectively), which correlated with the significant increase in NK, LAK, and tumor cytotoxicity of the EvE cells.
This study demonstrates that previously cryopreserved and rethawed CB MNCs can be EvE up to 7 days to yield viable and activated NK and NKT-like subsets that appear to be cytolytic based on the cell repertoire and could be utilized in the future as adoptive cellular immunotherapy post-unrelated CB transplantation.
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ABSTRACT: Umbilical cord blood (UCB) is an abundant source of haematopoietic stem cells (HSC) for allogeneic HSC transplant. Since the first UCB transplant in 1988, many scientific data have been collected. Many umbilical cord blood banks have been established worldwide for the collection and cryopreservation as well as for the international exchange with more than 400,000 UCB units available. There is probably a twofold figure of UCB units collected for the private UCB banks. More than 20,000 UCB units have been used for treating malignant and non-malignant diseases both in adults and children. Unrelated UCB HSCs became an alternative to bone-marrow derived HSCs based on their advantages, including a prompt availability, decrease of graftversus- host disease (GVHD) and better longterm immune recovery, resulting in a similar long-term survival. UCB stem cells can be transplanted to an allogeneic patient in spite of the high degree of HLA mismatches, which is highly important for the patients who cannot find a HLA-identical allogeneic donor. Since the low number of cells in the UCB units still represents the main cause of failure of engraftment, new strategies, such as double-unit UCB transplantation, intra-bone injection of UCB cells, simultaneous transplantation of accessory cells and the reduced intensity conditioning regimen, were developed to increase the success of UCB transplantation. Several clinical studies using UCB stem cells that have been previously expanded in vitro are underway. These procedures and the future development of regenerative medicine will further broaden possible indications for the use of UCB derived stem cells in adults.Zdrav Vestn. 04/2012;