Newsletter - January 2014
The History of Co-Transplantation of UC-MSC and CB-HSC into Human Patients
Recently, two exciting studies in China were published that highlight the co-transplantation of human umbilical cord mesenchymal stem cells (UC-MSC) and human umbilical cord blood hematopoietic stem cells (CB-HSC) into human patients. These papers provide some of the first human data to support a scientific hypothesis that was first suggested at the 7th International Cord Blood Society (ICBS) Congress in 2004 (1).
In the late 1990's and early 2000's my son, Kyle Cetrulo, and I founded and ran the ICBS, a pioneering educational foundation that held annual symposia about cord blood research. The 7th ICBS Congress was held at Tufts New England Medical Center in October 2004. As we were planning the 2004 ICBS Congress, Drs. Kathy Mitchell and Mark Weiss from Kansas State University published papers that identified Wharton's Jelly from the umbilical cord as a source of MSCs (2,3,4). Wanting to learn more, we invited them to give a presentation.
At the time, I was a Professor of OB/GYN at Tufts University School of Medicine. I became interested in mesenchymal stem cells (MSC) as a more powerful cell type for regenerative medicine applications, especially when compared to the hematopoietic stem cells found in umbilical cord blood (CB-HSC). HSC are great at forming other blood cells such as red blood cells, white blood cells and platelets; but are not the best cell for regenerative medicine therapies that look to form new neurons, muscle, bone, cartilage and other tissue types to treat non-blood based diseases.
Coincidently, in the fall of 2004, Dr. Hans Klingemann was hired as the new Director of Bone Marrow Transplantation at Tufts New England Medical Center in Boston, and I made sure that he also attended the 7th ICBS Congress. I had big plans to involve Dr. Klingemann in our research on Wharton's Jelly stem cells - soon after the ICBS meeting, I began to deliver consented donations of placentas, umbilical cords and cord blood collected during my OB/GYN shifts to Dr. Klingemannís laboratory. As the tissue specimens began to pile up, they generated the response I was looking for, and we began to collaborate.
Dr. Klingemann, with his oncology background where researchers were already using bone marrow derived MSC to enhance HSC transplantation (5,6,7), postulated that MSC from the Wharton's Jelly could be co-transplanted with the cord blood HSC in order to enhance the engraftment of the cord blood unit. Dr. Robb Friedman, Monica Betancur, and Dr. Laurent Boissel, who were working in Dr. Klingemann's laboratory, decided to focus on this research hypothesis. The results of this study demonstrated that human UC-MSC can support human CB-HSC in a NOD/SCID mouse transplant model. These results were published in a paper titled "Umbilical cord mesenchymal stem cells: adjuvants for human cell transplantation" (8).
In 2008, together with Dr. Rouzbeh R. Taghizadeh, we formed AuxoCell Laboratories, Inc., the world's first company to focus exclusively on developing the clinical potential of stem cells from Wharton's Jelly (aka Cord Tissue). Our approach is to focus on native, primary MSC from the cord tissue rather than expanded MSC. We find that minimally manipulated native MSC from the cord tissue are even more potent than culture expanded cord tissue MSC, when compared in a NOD/SCID mouse transplant model (9,10).
Nevertheless, I was excited to see two papers with human data come out of China, where culture expanded human UC-MSC are being used for clinical trials. The first paper, published in Transplantation in 2012 (11), is a pilot study that compared five patients who were co-transplanted with culture expanded UC-MSC and CB-HSC versus nine patients who were transplanted with CB-HSC alone. Of great significance, the co-transplanted group had significantly faster recovery of their immune system, reaching engraftment in a similar time frame as a bone marrow transplant. This is very important because cord blood transplants usually take 10 days longer than bone marrow to engraft.
The second study was published in Cell Transplantation in 2013 (12). In this article, UC-MSC and CB-HSC were co-transplanted first in animals and then in humans. Twenty human patients with high-risk leukemia were randomized to a co-transplant group versus a CB-HSC transplant group. Again, there were no serious adverse events and the engraftment time was significantly shorter in the eight patients receiving the co-transplantation regimen.
These two studies both show that co-transplantation of ex vivo expanded banked UC-MSC together with CB-HSC are safe in human patients and have the exciting potential of speeding engraftment to the gold standard set by bone marrow transplants. Hopefully, this data further encourages more robust studies using the powerful combination of UC-MSC and CB-HSC. We look forward to the day when human co-transplantation studies are authorized by the FDA in the United States.
- Cetrulo, et al., Wharton's Jelly Stem Cells: Isolation, Extraction and Prelminary Characterization, Biology of Blood and Marrow Transplantation, Kluge Carden Jennings Publishing, Charlottesville, VA, US 11(11):938 (2005)
- Mitchell KE, Weiss ML, Mitchell BM, Martin P, Davis D, Morales L, Helwig B, Beerenstrauch M, Abou-Easa K, Hildreth T, Troyer D, Medicetty S. Matrix cells from Wharton's jelly form neurons and glia. Stem Cells. 2003;21(1):50-60. Erratum in: Stem Cells. 2003;21(2):247. PubMed PMID: 12529551.
- Weiss ML, Mitchell KE, Hix JE, Medicetty S, El-Zarkouny SZ, Grieger D, Troyer DL. Transplantation of porcine umbilical cord matrix cells into the rat brain. Exp Neurol. 2003 Aug;182(2):288-99. PubMed PMID: 12895440.
- Medicetty S, Bledsoe AR, Fahrenholtz CB, Troyer D, Weiss ML. Transplantation of pig stem cells into rat brain: proliferation during the first 8 weeks. Exp Neurol. 2004 Nov;190(1):32-41. PubMed PMID: 15473978.
- Noort WA, Kruisselbrink AB, in't Anker PS, Kruger M, van Bezooijen RL, de Paus RA, Heemskerk MH, Löwik CW, Falkenburg JH, Willemze R, Fibbe WE. Mesenchymal stem cells promote engraftment of human umbilical cord blood-derived CD34(+) cells in NOD/SCID mice. Exp Hematol. 2002 Aug;30(8):870-8. PubMed PMID: 12160838.
- Wang HS, Hung SC, Peng ST, Huang CC, Wei HM, Guo YJ, Fu YS, Lai MC, Chen CC. Mesenchymal stem cells in the Wharton's jelly of the human umbilical cord. Stem Cells. 2004;22(7):1330-7. PubMed PMID: 15579650.
- Lazarus HM, Koc ON, Devine SM, Curtin P, Maziarz RT, Holland HK, Shpall EJ, McCarthy P, Atkinson K, Cooper BW, Gerson SL, Laughlin MJ, Loberiza FR Jr, Moseley AB, Bacigalupo A. Cotransplantation of HLA-identical sibling culture-expanded mesenchymal stem cells and hematopoietic stem cells in hematologic malignancy patients. Biol Blood Marrow Transplant. 2005 May;11(5):389-98. PubMed PMID: 15846293.
- Friedman R, Betancur M, Boissel L, Tuncer H, Cetrulo C, Klingemann H. Umbilical cord mesenchymal stem cells: adjuvants for human cell transplantation. Biol Blood Marrow Transplant. 2007 Dec;13(12):1477-86. PubMed PMID: 18022578.
- Taghizadeh RR, Cetrulo KJ, Cetrulo CL. Wharton's Jelly stem cells: future clinical applications. Placenta. 2011 Oct;32 Suppl 4:S311-5. doi: 10.1016/j.placenta.2011.06.010. Epub 2011 Jul 6. Review. PubMed PMID: 21733573.
- Taghizadeh, R.R., Perinatal Mesenchymal Stem Cell Banking for Umbilical Cord Blood Transplantations and Regenerative Medicine, Perinatal Stem Cells, Volume 2, Wiley-Blackwell Publishing, 53-69, 2013.
- Wu KH, Sheu JN, Wu HP, Tsai C, Sieber M, Peng CT, Chao YH. Cotransplantation of umbilical cord-derived mesenchymal stem cells promote hematopoietic engraftment in cord blood transplantation: a pilot study. Transplantation. 2013 Mar 15;95(5):773-7. doi: 10.1097/TP.0b013e31827a93dd. PubMed PMID: 23274973.
- Wu KH, Tsai C, Wu HP, Sieber M, Peng CT, Chao YH. Human Application of Ex-Vivo Expanded Umbilical Cord-Derived Mesenchymal Stem Cells: Enhance Hematopoiesis after Cord Blood Transplantation. Cell Transplant. 2013 Feb 26. doi: 10.3727/096368913X663523. [Epub ahead of print] PubMed PMID: 23452720.
The use of umbilical cord stem cells in China is booming
Most scientists think of mesenchymal stromal cells (MSC, or mesenchymal stem cells) as being associated with bone marrow or adipose tissue. However, new explorations of MSC derived from umbilical cord tissue (UC-MSC) promises abundance and great therapeutic value of these cells.
The obvious advantage of UC-MSC is the easy availability and abundance of inexpensive raw material (the umbilical cord), which could be utilized by cord blood banks and processing facilities for making of-the-shelf cellular products. Once you start to search for any type of data related to UC-MSC, you will be amazed how much has been done in China. I'd even say more - this is predominantly a "Chinese phenomenon".
A search a query in ClinicalTrials.gov database for "umbilical cord mesenchymal stem" yields the above map of trial locations. If you read through the clinical trials and sort out some "noise", you will get about 70% (39 out of 56) of all worldwide UC-MSC trials attributed to China!
What is more exciting though, is that Chinese researchers are not only conducting the trials, but also publishing their results! In 2013 I was able to identify 8 clinical trials (not necessarily registered), whose results were published and indexed in the PubMed database. The clinical studies published by Chinese researchers assess UC-MSC for the conditions: autism, spinal cord injury, traumatic brain injury, type 1 diabetes, lupus, rheumatoid arthritis, aplastic anemia, primary biliary cirrhosis; as well as case reports for cerebral palsy and multiple sclerosis. The results of these studies are positive - meaning safety and feasibility were accomplished in Phase 1. Most of these reports finished with the phrase: "a larger, randomized controlled cohort study is warranted to confirm the clinical efficacy". However, such trials as rheumatoid arthritis (172 patients), autism (37 patients) and traumatic brain injury (40 patients) were designed to test efficacy and included control groups. According to their results, UC-MSC provided significant therapeutic benefit.
Yet another puzzle of the "Chinese phenomenon" is the lack of reporting in the Western mass media. None of those 8 published trials were picked up by media outlets and discussed publicly. This trend is opposite to the Western world, where any trial's report is highly discussed in mass media and among professionals. One of the possible (and probably the major) reasons for this is a common negative perception of the validity of Chinese science and clinical research among Westerners.
China is known to have a lack of enforcement of regulatory compliance; despite a government ban, clinics offering unproven stem cell "therapies" are rampant. Less stringent regulation of clinical trials in China could be a big reason for Western distrust of Chinese trial results. I'd argue, however, that professionals should read all published reports and rigorously analyze them, in order to judge the accuracy and validity of the "Chinese phenomenon". By discussing these Chinese results with peers, we can, at least, learn a lot from from their experience.
Immunomodulatory Properties of Wharton's Jelly MSCs: Myth, Reality, and Hidden Potential
When someone thinks to the potential of regenerative medicine, the main idea is that of immature cells which may transdifferentiate towards a mature cell type, which may be used to repopulate a target organ cells, and thereby treat human diseases. This concept drives a lot of research undertaken worldwide.
Wharton's jelly mesenchymal stem cells (WJ-MSC) are not an exception to this rule: They are derived from the tissue constituting the bulk of the umbilical cord (1). Applications of these cells, often supported by data from several in vivo models, range from the nervous system to the liver, pancreas, heart and other organs in the body (2-4).
Usually when stem cells from a donor (allogeneic) are transplanted - or differentiated cells derived from donor stem cells - they are subjected to the same immune restrictions which regulate organ transplantation: often the use of mmune suppressants is mandatory, and then part of the real advantages of stem cell therapy over whole organ transplantation are lost.
However, MSCs feature unusual properties when they interact with immune system cells. Several literature reports have highlighted that MSCs are able to modulate the activity of immune cells, and in particular lymphocytes, by means of several mechanisms, e.g. by secreting molecules which find receptors on lymphocytes, or by direct cell-cell interactions (5). These abilities are promising for cell therapy for a number of reasons. Moreover, they are not limited to bone marrow-derived MSC, which constitute the prototype of all other MSCs, but are particularly prominent in perinatal stem cells, i.e. those cells which are derived by perinatal tissues such as placenta, umbilical cord, and umbilical cord blood (6,7).
The main reason these perinatal MSC have an advantage is the environment in which perinatal tissues develop. In fact, the human fetus represents a semi-allogeneic entity for the mother, which her immune system naturally tends to fight. To overcome this natural rejection, and let the pregnancy get to term, placental cells are able to express several molecules, both secreted or located in the plasma membrane, that have immunomodulatory properties. The activity of these molecules create an environment of peripheral tolerance towards the fetal tissues.
In our experience with WJ-MSC, we strongly believe that these cells maintain a sort of "positional memory" even when grown ex vivo (8). This allows them to continue expressing molecules with immune-modulating activity after they are extracted from their tissue of origin, namely the umbilical cord, and expanded under tissue culture conditions. Even more exciting, they seem to be able to pass on this ability: Very recent reports on MSC from both Wharton's jelly and from amniotic membrane suggest that expression of immunomodulatory molecules is not limited to the undifferentiated parent stem cells, but is also featured in their differentiated progeny.
Prior to the recent boom of studies on immune modulation by MSCs (in the last 6-7 years), the only immune-related markers which were (sometimes) evaluated following differentiation were type I and type II MHC, namely HLA-ABC and HLA-DR. In fact, undifferentiated MSCs express low to medium levels of human leukocyte antigen (HLA) Class I and low levels of HLA Class II to avoid recognition by the immune system (5). In our opinion, the most relevant studies on this topic came out in the last year: The Australia-based group of Manuelpillai explored the maintenance of immune modulation of human amniotic membrane cells when they differentiated towards hepatocytes (9). Our group in Italy investigated the maintenance of various immunomodulatory molecules in WJ-MSCs when they differentiated towards osteoblasts, chondrocytes and adipocytes (10). The molecules we looked at were non-classical type I MHCs (such as HLA-E) and CD276, which we were the first to describe in WJ-MSCs (10).
But why is the maintenance of the immunomodulatory features such a crucial advantage of MSC from perinatal tissues? It is important because it enables the infused donor cells, whether differentiated or not, to engraft into the diseased target organ and positively modify its microenvironment to promote repopulation. Some diseases for which cell therapy has been proposed, such as liver fibrosis or type I diabetes, derive from previous conditions where one or more immune-related processes have caused damage in the organ (chronic inflammation in the liver, pancreatitis in the pancreas) (11). These processes may have exhausted the local population of progenitor stem cells that would normally ensure the regeneration of the functional cells of the organ (12). Therefore, the infusion of immunomodulatory MSC provide a significant advantage by better overcoming host responses, providing the needed functional bridging action, and modifying the underlying pathological conditions at the basis of disease.
In the case of diabetes, our group is exploring co-transplantation of both pancreatic islets and WJ-MSCs in animal models. Our goal is to achieve, in vivo, both the expression of differentiated functions (e.g. insulin production) and immunomodulatory activities (e.g., molecules that suppress inflammation or protect newly generated endocrine cells from immune system attacks).
We hope that our studies and others will let us better understand the hidden potentials of WJ-MSCs, which hold a lot of promise for the regenerative medicine field. A greater understanding of the bioactive components secreted by undifferentiated and differentiated stem cells will enable a more informed use of these cells and their therapeutic derivatives to target specific diseases.
- Corrao S, et al. Umbilical cord revisited: from Wharton's jelly myofibroblasts to mesenchymal stem cells. Histol Histopathol. 2013; 28(10):1235-44 PubMed PMID: 23595555.
- Anzalone R, et al. New emerging potentials for human Wharton's jelly mesenchymal stem cells: immunological features and hepatocyte-like differentiative capacity. Stem Cells Dev. 2010; 19(4):423-38. PubMed PMID: 19958166.
- Vawda R, Fehlings MG.Mesenchymal cells in the treatment of spinal cord injury: current & future perspectives. Curr Stem Cell Res Ther. 2013; 8(1):25-38. PubMed PMID: 23270635.
- López Y, et al. Wharton's jelly or bone marrow mesenchymal stromal cells improve cardiac function following myocardial infarction for more than 32 weeks in a rat model: a preliminary report. Curr Stem Cell Res Ther. 2013; 8(1):46-59. PubMed PMID: 23270633.
- Murphy MB, et al. Mesenchymal stem cells: environmentally responsive therapeutics for regenerative medicine. Exp Mol Med. 2013; 45:e54. PubMed PMID: 24232253.
- Taghizadeh RR, et al. Wharton's Jelly stem cells: future clinical applications. Placenta. 2011;32 Suppl 4:S311-5. PubMed PMID: 21733573.
- La Rocca G, Anzalone R. Perinatal stem cells revisited: directions and indications at the crossroads between tissue regeneration and repair. Curr Stem Cell Res Ther. 2013; 8(1):2-5. PubMed PMID: 23452028.
- La Rocca G, et al. Novel immunomodulatory markers expressed by WJMSC: an updated review in regenerative and reparative medicine. Open Tissue Eng Regen Med J 2012; 5:50-8.
- Tee JY, et al. Immunogenicity and immunomodulatory properties of hepatocyte-like cells derived from human amniotic epithelial cells. Curr Stem Cell Res Ther. 2013; 8(1):91-9. PubMed PMID: 23270634.
- La Rocca G, et al. Human Wharton's jelly mesenchymal stem cells maintain the expression of key immunomodulatory molecules when subjected to osteogenic, adipogenic and chondrogenic differentiation in vitro: new perspectives for cellular therapy. Curr Stem Cell Res Ther. 2013; 8(1):100-13. PubMed PMID: 23317435.
- Anzalone R, et al. Wharton's jelly mesenchymal stem cells as candidates for beta cells regeneration: extending the differentiative and immunomodulatory benefits of adult mesenchymal stem cells for the treatment of type 1 diabetes. Stem Cell Rev. 2011; 7(2):342-63. PubMed PMID: 20972649.
- Mansilla E, et al. Could metabolic syndrome, lipodystrophy, and aging be mesenchymal stem cell exhaustion syndromes? Stem Cells Int. 2011;2011:943216 PubMed PMID: 21716667.