Characteristics of Pooled Wharton's Jelly Mesenchymal Stromal Cells (WJ-MSCs) and their Potential Role in Rheumatoid Arthritis Treatment.

Introduction: Mesenchymal stromal cells (MSC) from Wharton's jelly of umbilical cord is primitive and serve as an inexhaustible source of stem cells with greater potential in clinics. The existence of heterogeneity among the donor MSCs makes it difficult to predict the properties and clinical outcome of WJ-MSCs. We developed a strategy to minimize the donor to donor heterogeneity and produce consistency in biological properties by pooling three individual donors WJ-MSCs. Further, evaluated the effectiveness of the pooled MSCs in regulating the disease severity of Rheumatoid arthritis (RA) in animal models.

Methods: WJ-MSCs were isolated from umbilical cord obtained from different donors, characterised and pooled based on the gender of baby. The biological properties of the pooled WJ-MSCs were compared to the individual WJ-MSCs. Further, the pooled WJ-MSCs were analysed for their safety profile in both in vitro and in vivo settings. The efficiency of pooled WJ-MSCs in regulating RA pathogenesis was also analysed in mice models of Collagen induced arthritis (CIA).

Results: We identified differences in proliferation capacity, pro inflammatory gene expression levels among individual WJ-MSCs isolated from different donors and the variation is also attributed to gender difference. WJ-MSCs pooled and cultured from different donor's exhibit all the MSC characteristics and exhibited superior immunosuppressive capabilities. In the in vivo toxicity study, pooled MSCs are found to be safe, and further in the RA preclinical studies, they were found to decrease the disease severity in these animals.

Conclusions: Pooled WJ-MSCs reduces heterogeneity of individual donors and have superior immunosuppressive property. It is also effective in reducing the disease severity in the experimental animal models of RA.