Identification and Evaluation of New Immunoregulatory Genes in Mesenchymal Stromal Cells of Different Origins: Comparison of Normal and Inflammatory Conditions

Abstract

BACKGROUND Mesenchymal stromal cells (MSCs) possess potent immunomodulatory properties that increase their value as a cell-based therapeutic tool for managing various immune-based disorders. Over the past years, accumulated results from trials using MSCs-based therapy have shown substantial contradictions. Although the reasons underlying these discrepancies are still not completely understood, it is well known that the immunomodulatory activities mediated by distinct MSCs differ in a manner dependent on their tissue origin and adequate response to inflammation priming. Thus, characterization of new molecular pathway(s) through which distinct MSC populations can exert their immunomodulatory effects, particularly during inflammation, will undoubtedly enhance their therapeutic potential. MATERIAL AND METHODS After confirming their compliance with ISCT criteria, quantitative real time-PCR (qRT-PCR) was used to screen new immunoregulatory genes in MSCs, derived from adipose tissue, foreskin, Wharton's jelly or the bone-marrow, after being cultivated under normal and inflammatory conditions. RESULTS FGL2, GAL, SEMA4D, SEMA7A, and IDO1 genes appeared to be differentially transcribed in the different MSC populations. Moreover, these genes were not similarly modulated following MSCs-exposure to inflammatory signals. CONCLUSIONS Our observations suggest that these identified immunoregulatory genes may be considered as potential candidates to be targeted in order to enhance the immunomodulatory properties of MSCs towards more efficient clinical use.

Figure 1

Characterization of FGL2, GAL, SEMA4D, SEMA7A and IDO1 transcription levels in MSCs cultivated under basic or inflammatory conditions. Total RNA was prepared from BM-, WJ-, AT- and FSK-MSCs cultivated in the absence or presence of inflammatory cocktail. GAPDH-normalized FGL2 (A), GAL (B), SEMA4D (C), SEMA7A (D) and IDO1 (E) mRNA levels were determined using qRT-PCR. When cultivated under inflammatory conditions, cells were indicated as BMⁱ, WJⁱ, ATⁱ and FSKⁱ. Values reported represent the averages of three independent experiments ±SEM. The statistical significance was determined using Mann-Whitney U- test (* p<0.05; ** p<0.01 versus untreated control cells).