Evaluation of gene delivery strategies to efficiently overexpress functional HLA-G on human bone marrow stromal cells

Abstract

Mesenchymal stromal cells (MSC) constitutively express low levels of human leukocyte antigen-G (HLA-G), which has been shown to contribute to their immunomodulatory and anti-inflammatory properties. Here, we hypothesized that overexpression of HLA-G on bone marrow-derived MSC would improve their immunomodulatory function, thus increasing their therapeutic potential. Therefore, we investigated which gene transfer system is best suited for delivering this molecule while maintaining its immuno-modulatory effects. We performed a side-by-side comparison between three nonviral plasmid-based platforms (pmax-HLA-G1; MC-HLA-G1; pEP-HLA-G1) and a viral system (Lv-HLA-G1) using gene transfer parameters that yielded similar levels of HLA-G1-expressing MSC. Natural killer (NK) cell-mediated lysis assays and T cell proliferation assays showed that MSC modified with the HLA-G1 expressing viral vector had significantly lower susceptibility to NK-lysis and significantly reduced T cell proliferation when compared to nonmodified cells or MSC modified with plasmid. We also show that, in plasmid-modified MSC, an increase in Toll-like receptor (TLR)9 expression is the mechanism responsible for the abrogation of HLA-G1’s immunomodulatory effect. Although MSC can be efficiently modified to overexpress HLA-G1 using viral and nonviral strategies, only viral-based delivery of HLA-G1 is suitable for improvement of MSC’s immunomodulatory properties.

Uterine Natural Killer Cell and Human Leukocyte Antigen-G1 and Human Leukocyte Antigen-G5 Expression in Vaginal Discharge of Threatened-Abortion Women: A Case-Control Study

“…Furthermore, it is possible that the low expression of HLA-G1 contributed to allogenic NK cell proliferative response in semiallogenic fetus. On the other hand, HLA-G1 and HLA-G5 have an important role in the upregulation of T regulatory cells in the pregnant women [ 16 ]. Also, our results showed that the high expression of HLA-G resulted in an excess of IL-10 in the vaginal discharge.…”

Cartilage Tissue Engineering: Recent Advances and Perspectives from Gene Regulation/Therapy

“…The vectors for gene delivery can be divided into two classes: viral and nonviral. Despite progresses in the development of nonviral gene delivery vector and transfection methods (e.g., in vivo electroporation, microporation, nanoparticles) to enhance the delivery efficiency, nonviral gene delivery is still generally considered less effective than viral vectors such as retrovirus/lentivirus, adenovirus, adeno‐associated virus (AAV) and baculovirus . In particular, transfection of adult MSCs is very inefficient …”

An update on potentials and promises of T cell co‐signaling molecules in transplantation

“…Boura et al () demonstrated that human bone marrow‐derived mesenchymal stem cells lentivirally engineered to overexpress HLA‐G1 decrease the proliferation of allogeneic T cells and their resistance against NK cell‐mediated lysis. In a similar study, pluripotent stem cells overexpressing HLA‐E were less detected by NK cells and allogeneic T cells (Gornalusse et al, ).…”

“…Especially, in xenotransplantation, where NK cells are critically important in foreign tissue rejection, HLA-G and HLA-E accompany with fair success. Also, the effect of soluble forms of these molecules on the tolerance in allotransplantation remains to be clarified in upcoming studies Boura et al (2014). demonstrated that human bone marrowderived mesenchymal stem cells lentivirally engineered to overexpress HLA-G1 decrease the proliferation of allogeneic T cells and their resistance against NK cell-mediated lysis.…”