Cryopreserved hMSCs maintain comparable in vitro functional activity compared to fresh hMSCs

INTRODUCTION:

Human mesenchymal stem cells (hMSC) are currently in use in over 400 clinical trials and are critical components of tomorrow’s cell-based products and devices (1, 2, 3). Secretion of biomolecules by hMSC influences many biological processes and is thought to be central to the mechanism of action. Since widespread clinical use of hMSC and cell-based therapies with positive economic outcomes will be facilitated by frozen storage, cryopreserved hMSC must maintain high levels of biological function upon thaw.  Additionally, while hMSC have an excellent clinical track record in terms of safety, efficacy data has been difficult to come by, suggesting that more standardized cell formats are needed.  This too could be addressed by effective means of cryopreservation, allowing off-the-shelf hMSC products to be widely used in Regenerative Medicine, Tissue Engineering and for 3D BioPrinting of cells and tissues.

To date, there have been conflicting results on the impact of cryopreservation on hMSC function.  The Galipeau lab showed that cryopreserved MSC have impaired immunosuppressive function in response to the pro-inflammatory cytokine, IFN-γ (lower IDO response, and decreased T-cell suppression) relative to proliferating cells (5, 6). The LeBlanc group similarly found that cryopreserved hMSC have reduced responsiveness to IFN-γ, decreased production of anti-inflammatory mediators, and impaired blood regulatory properties (7). In contrast, other studies support the use of cryopreserved hMSC.  The Mueller lab showed that cryopreservation of hMSC did not change the cells’ immunomodulatory activity, viability, or differentiation (8). The Weiss group also performed in vivo tests of thawed hMSC and found that “in an immunocompetent mouse model of allergic airways inflammation … thawed MSCs are as effective as fresh MSCs.” (9)  The difference in results is likely due to differences in the cryopreservation formulations, controlled rate freezing protocols, and how the cells are thawed and handled prior to implantation.

To address the critical issue of cryopreservation in our hMSC systems, we compared the biological activity of RoosterBio hMSCs from 2 donors either (a) with cells straight out of cryopreservation (THAW) or (b) with cells that had been in culture for at least 5 days (FRESH), while controlling for PDL.  Based on the literature, we established a conservative  hypothesis for this study that cryopreserved hBM-MSC would exhibit diminished immunosuppression and altered angiogenic cytokine secretion compared to proliferating hBM-MSC in response to challenge by inflammatory cytokines. We tested this hypothesis with RoosterBio’s hBM-MSC, produced with GMP-compatible and scalable manufacturing processes, by comparing the immunomodulatory activity and angiogenic cytokine secretion of proliferating (FRESH) to cryopreserved and thawed (THAW) hBM-MSC.  By presenting the results of this study, we hope to provide additional data points for the industry on the use of cryopreserved, off-the-shelf hMSCs for Regenerative Medicine, Tissue Engineering and 3D BioPrinting.

METHODS AND EXPERIMENTAL DESIGN:

See you at MSC 2015?

MSC 2015 is quickly approaching next month and we at RoosterBio are getting ready.  This conference is arguably the single most important conference related to MSCs, and Cleveland is the considered by many to be the birthplace of the current paradigm of MSCs used in therapeutic contexts.  We will be sending most of our company, and we do look forward to seeing everyone there. Not only is this conference full of great sessions and talks, but the networking at this bi-yearly MSC conference is always top notch and yet another reason to attend.

The faculty and sessions at MSC 2015 are hyper-relevant to today’s more important topics, and the sessions are organized by several key themes.  Day 1 of the conference will be kicked off with a Keynote from Arnold Caplan , the godfather of MSCs (and yes, if you Google “MSC Godfather” you get Arnold Caplan), who is always entertaining and insightful to where MSC technology is going. The sessions look to be focused on Clinical Trial updates by the likes of Athersys, Katerina LeBlanc, Dan Weiss and Jacques Galipeau, among others. 

Day 2 of the conference gets kicked off with a keynote from Frank Barry from The National University of Ireland at Galway, and he will be speaking on MSC Translation.  My favorite topic, MSC BioManufacturing, will be covered that morning, and we all know that MSC technology cannot be translated into humans without consistent, robust and cost effective manufacturing processes that are capable of maintaining the quality parameters and functions of these critical cells.  Sessions on MSCs in applications like cardiology and organ transplantation will follow, and the day will end with the session I am most excited about – Next Generation MSCs.  Jan Nolta and Mike West will highlight this “not to miss” session.

The final day of the conference will have a keynote from Stanton Gerson, followed by many new and impactful applications including MSCs in Cancer and Sepsis.  The last two sessions are on potentially the most impactful translational areas of MSCs (as it pertains with shear numbers of patients treated), which are the use in Sports Medicine and Veterinary Sciences.  I will bet that Bob Harman at Vet Stem has treated more patients with MSCs than any other clinic or company in the World – and I plan on asking him what that number is at the conference, so look for it in our Twitter feed.

It does look like the dedicated organizing team at Case has done a great job at organizing yet another stellar event, and we look forward to seeing you there.  Be sure to stop by our Booth and posters and say hello!