Umbilical cord blood (CB) is used increasingly to restore hematopoiesis in transplant patients lacking sibling, or unrelated donors. A major disadvantage of CB transplantation (CBT) is the low cell dose with resultant delays in neutrophil and platelet engraftment, as well as a high rate of engraftment failure. A major hypothesis of this grant is that ex vivo-expanded CB progenitors will provide more rapid hematopoietic reconstitution and less engraftment failure than unmanipulated CB. In the two clinical CB expansion trials conducted during the last RO1 funding period, CD133+ progenitors were isolated and cultured ex vivo in a liquid culture system targeting committed, or more primitive hematopoietic progenitors. In those sequential trials, trends in faster time to engraftment were seen, but significant losses of CD34+ progenitors occurred. To avoid the need for positive selection, which results in a substantial loss of CD34+ cells, we have developed an alternative approach that involves the ex vivo co-culture of CB mononuclear cells (MNC) with bone marrow-derived mesenchymal stem cells (MSC). We hypothesize that MSC, by functioning as a surrogate hematopoietic 'niche', will provide a more suitable microenvironment for the expansion of lineage-committed CB hematopoietic progenitors than afforded by current liquid suspension culture systems. As accrual to the current CB expansion trials nears completion, this competitive renewal application will focus on the clinical evaluation of CB expansion in MSC co-cultures, with the long-term goal of improving neutrophil and platelet engraftment in CBT patients. Although a low cell dose is clearly the chief limitation of CBT, a number of investigators have also reported a deficit in the homing of CB cells to the marrow. Thus, it is conceivable that even with optimal ex vivo expansion, inadequate homing may limit the rapidity of engraftment which is the goal of this proposal. The homing defect has been attributed to low levels of fucosylation of cell surface molecules responsible for binding to P- and/or E-selectins expressed by the marrow microvasculature. This interaction is a key component of the recruitment of hematopoietic progenitors to the marrow. We hypothesize that increasing the level of CB cell surface fucosylation will improve interactions with selectins, thereby improving homing and engraftment.
Aim 3 will evaluate the modification of unmanipulated and expanded CB progenitor cells with a fucosyltransferase, as a means to facilitate their recruitment to the marrow.
Umbilical cord blood is being used increasingly for many patients with high-risk hematological malignancies and genetic disorders who do not have a bone marrow donor, but is associated with a longer time to engraftment compared to marrow. The expansion of cord blood in the laboratory prior to infusion appears to shorten time to engraftment;additionally the treatment of the cord blood with a sugar molecule prior to infusion appears to improve its ability to home to the bone marrow quickly. Both these strategies will be explored in the grant thereby making the transplant safer for patients in terms of infectious and bleeding complications and will thus improve survival.
|Kellner, Joshua; Li, Sufang; Zweidler-McKay, Patrick A et al. (2015) Phenotypic and functional comparison of mobilized peripheral blood versus umbilical cord blood megakaryocyte populations. Cytotherapy 17:418-27|
|Mehta, Rohtesh S; Di Stasi, Antonio; Andersson, Borje S et al. (2014) The development of a myeloablative, reduced-toxicity, conditioning regimen for cord blood transplantation. Clin Lymphoma Myeloma Leuk 14:e1-5|
|Bear, Adham S; Hanley, Patrick J; Bosque, Doyle M et al. (2014) Low rate of infusional toxicity after expanded cord blood transplantation. Cytotherapy 16:1153-7|
|Robinson, Simon N; Thomas, Michael W; Simmons, Paul J et al. (2014) Fucosylation with fucosyltransferase VI or fucosyltransferase VII improves cord blood engraftment. Cytotherapy 16:84-9|
|Parmar, S; de Lima, M; Worth, L et al. (2014) Is there an expiration date for a cord blood unit in storage? Bone Marrow Transplant 49:1109-12|
|Robinson, Simon N; Simmons, Paul J; Thomas, Michael W et al. (2012) Ex vivo fucosylation improves human cord blood engraftment in NOD-SCID IL-2R?(null) mice. Exp Hematol 40:445-56|
|Robinson, Simon N; Simmons, Paul J; Yang, Hong et al. (2011) Mesenchymal stem cells in ex vivo cord blood expansion. Best Pract Res Clin Haematol 24:83-92|
|Yang, H; Robinson, S N; Lu, J et al. (2010) CD3(+) and/or CD14(+) depletion from cord blood mononuclear cells before ex vivo expansion culture improves total nucleated cell and CD34(+) cell yields. Bone Marrow Transplant 45:1000-7|
|Xing, Dongxia; Ramsay, Alan G; Gribben, John G et al. (2010) Cord blood natural killer cells exhibit impaired lytic immunological synapse formation that is reversed with IL-2 exvivo expansion. J Immunother 33:684-96|
|Safdar, Amar; Decker, William K; Li, Sufang et al. (2009) De novo T-lymphocyte responses against baculovirus-derived recombinant influenzavirus hemagglutinin generated by a naive umbilical cord blood model of dendritic cell vaccination. Vaccine 27:1479-84|
Showing the most recent 10 out of 29 publications