Identification of Potential Plasma microRNA Stratification Biomarkers for Response to Allogeneic Adipose-Derived Mesenchymal Stem Cells in Rheumatoid Arthritis.

The ability to identify and stratify patients that will respond to specific therapies has been transformational in a number of disease areas, particularly oncology. It is anticipated that this will also be the case for cell-based therapies, particularly in complex and heterogeneous diseases such as rheumatoid arthritis (RA). Recently, clinical results with expanded allogenic adipose-derived mesenchymal stem cells (eASCs) have indicated clinical efficacy in highly refractory RA patients. In this study, we set out to determine if circulating microRNAs (miRNAs) could be identified as potential biomarkers associated with response to eASCs in these RA patients. The miRNA expression profiles of pre-treatment plasma samples from responder and nonresponder patients were determined using microarrays. Ten miRNAs were identified that were differentially expressed in the responder group as compared to the nonresponder group. To confirm the differential expression of these 10 miRNA biomarkers, they were further assayed by quantitative reverse-transcriptase polymerase chain reaction (QRT-PCR). From this analysis, three miRNAs, miR-26b-5p, miR-487b-3p and miR-495-3p, were confirmed as being statistically significantly upregulated in the responder group as compared with the nonresponder group. Receiver operating characteristic analysis confirmed their diagnostic potential. These miRNAs could represent novel candidate stratification biomarkers associated with RA patient response to eASCs and are worthy of further clinical validation. Stem Cells Translational Medicine 2017;6:1202-1206.

Differential utilization of CD134 as a functional receptor by diverse strains of feline immunodeficiency virus.

The feline homologue of CD134 (fCD134) is the primary binding receptor for feline immunodeficiency virus (FIV), targeting the virus preferentially to activated CD4+ helper T cells. However, with disease progression, the cell tropism of FIV broadens such that B cells and monocytes/macrophages become significant reservoirs of proviral DNA, suggesting that receptor utilization may alter with disease progression. We examined the receptor utilization of diverse strains of FIV and found that all strains tested utilized CD134 as the primary receptor. Using chimeric feline x human CD134 receptors, the primary determinant of receptor function was mapped to the first cysteine-rich domain (CRD1) of fCD134. For the PPR and B2542 strains, the replacement of CDR1 of fCD134 (amino acids 1 to 64) with human CD134 (hCD134) alone was sufficient to confer nearly optimal receptor function. However, evidence of differential utilization of CD134 was revealed, since strains GL8, CPGammer (CPG41), TM2, 0827, and NCSU1 required determinants in the region spanning amino acids 65 to 85, indicating that these strains may require a more stringent interaction for infection to proceed.