Are therapeutic human mesenchymal stromal cells compatible with human blood?

Multipotent mesenchymal stromal cells (MSCs) are tested in numerous clinical trials. Questions have been raised concerning fate and function of these therapeutic cells after systemic infusion. We therefore asked whether culture-expanded human MSCs elicit an innate immune attack, termed instant blood-mediated inflammatory reaction (IBMIR), which has previously been shown to compromise the survival and function of systemically infused islet cells and hepatocytes.

Mesenchymal stromal cells engage complement and complement receptor bearing innate effector cells to modulate immune responses.

Infusion of human third-party mesenchymal stromal cells (MSCs) appears to be a promising therapy for acute graft-versus-host disease (aGvHD). To date, little is known about how MSCs interact with the body's innate immune system after clinical infusion. This study shows, that exposure of MSCs to blood type ABO-matched human blood activates the complement system, which triggers complement-mediated lymphoid and myeloid effector cell activation in blood.

Preparatory studies of composite mesenchymal stem cell islets for application in intraportal islet transplantation.

Background: Low engraftment and adverse immune reactions hamper the success rate of clinical islet transplantation. In this study, we investigated the capacity of human mesenchymal stem cells (MSCs) to adhere to human islets of Langerhans and their effects in immune modulation and during blood interactions in vitro.

Methods: Composite MSC-islets were formed by suspension co-culture, and the phenotype was evaluated by confocal microscopy.

Fetal and adult multipotent mesenchymal stromal cells are killed by different pathways.

Background Aims: Multipotent mesenchymal stromal cells, also known as mesenchymal stem cells (MSC), can be isolated from adult and fetal tissues. Recently, there has been considerable interest in MSC because they have features favorable for transplantation, namely their multipotency and non-immunogenic properties.

Methods: We analyzed how human MSC derived from first-trimester fetal liver and adult bone marrow interact with naive and activated innate natural killer (NK) cells.