Inactivated Platelet Lysate Supports the Proliferation and Immunomodulant Characteristics of Mesenchymal Stromal Cells in GMP Culture Conditions.

Katia Mareschi,Massimiliano Bergallo,Sara Castiglia,Ivana Ferrero,Alessia Giovanna Santa Banche Niclot,Elena Marini,Aloe Adamini,Deborah Rustichelli,Luciana Labanca,Franca Fagioli

doi:10.3390/biomedicines8070220

Abstract

Mesenchymal stromal cells (MSCs) isolated from bone marrow (BM-MSCs) are considered advanced therapy medicinal products (ATMPs) and need to be produced according to good manufacturing practice (GMP) in their clinical use. Human platelet lysate (HPL) is a good GMP-compliant alternative to animal serum, and we have demonstrated that after pathogen inactivation with psoralen, it was safer and more efficient to use psoralen in the production of MSCs following GMP guidelines. In this study, the MSCs cultivated in fetal bovine serum (FBS-MSC) or inactivated HPL (iHPL-MSC) were compared for their immunomodulatory properties. We studied the effects of MSCs on (1) the proliferation of total lymphocytes (Ly) and on naïve T Ly subsets induced to differentiate in Th1 versus Th2 Ly; (2) the immunophenotype of different T-cell subsets; (3) and the cytokine release to verify Th1, Th2, and Th17 polarization. These were analyzed by using an in vitro co-culture system. We observed that iHPL-MSCs showed the same immunomodulatory properties observed in the FBS-MSC co-cultures. Furthermore, a more efficient effect on the increase of naïve T- cells and in the Th1 cytokine release from iHPL was observed. This study confirms that iHPL, used as a medium supplement, may be considered a good alternative to FBS for a GMP-compliant MSC expansion, and also to preserve their immunomodulatory proprieties.

Highlights

We demonstrated that human platelet lysate (HPL) subject to pathogen inactivation (inactivated HPL was more advantageous in Mesenchymal stromal cells (MSCs) isolated from bone marrow (BM-MSCs) in terms of their cellular growth and stemness
The use of inactivated human platelet lysate (iHPL) as an alternative to fetal bovine serum (FBS) to isolate and expand MSCs confirmed that it is possible to obtain a large number of MSCs for clinical doses, which keep all of their characteristics intact, including their immunomodulatory properties
It was found that the pathogen inactivation treatment did not modify the characteristics of HPL, and made it safer and more suitable for MSC isolation and expansion for clinical use, and could be a requirement for good manufacturing practice (GMP) MSC expansion

Summary

Introduction

Mesenchymal stromal cells (MSCs) are multipotent cells that can be isolated from a variety of tissues, capable of producing significant factors including multiple cytokines and growth factors.In recent years, their peculiar immunomodulatory characteristics, mediated by the release of a plethora of trophic factors in their secretome, have been considered as having more than their multilineageBiomedicines 2020, 8, 220; doi:10.3390/biomedicines8070220 www.mdpi.com/journal/biomedicinesBiomedicines 2020, 8, 220 differentiation potential for their clinical use in severe disease clinical trials, namely: autoimmune, chronic inflammatory, and degenerative conditions [1,2].MSCs isolated from bone marrow (BM-MSCs) are considered advanced therapy medicinal products (ATMPs) and need to be produced according to good manufacturing practice (GMP) [3,4] in their clinical use. Mesenchymal stromal cells (MSCs) are multipotent cells that can be isolated from a variety of tissues, capable of producing significant factors including multiple cytokines and growth factors In recent years, their peculiar immunomodulatory characteristics, mediated by the release of a plethora of trophic factors in their secretome, have been considered as having more than their multilineage. As the use of xenogeneic protein-free GMP-compliant growth media is a prerequisite for clinical MSC isolation and expansion, human platelet lysate (HPL) has efficiently substituted fetal bovine serum (FBS) in MSC clinical manufacturing. For these reasons, it represents a good. PI technology was used for the first time in 1991 [9] to treat fresh-frozen plasma, and later for platelets and red cells (RBCs) [10]

Results

Discussion

Conclusion