Mesenchymal stromal cells (MSC) possess several fairly unique properties that, combined, make them ideally suited for cellular-based immunotherapy and as vehicles for gene and drug delivery for a wide range of diseases/disorders.

Key among these are:

1) their relative ease of isolation from a variety of tissues;

2) the ability to be expanded in culture without a loss of functionality, a property that varies to some degree with tissue source;

3) they are relatively immune-inert, perhaps obviating the need for precise donor/recipient matching;

4) they possess potent immunomodulatory functions that can be tailored by so-called licensing in vitro and in vivo ;

5) the efficiency with which they can be modified with viral-based vectors; and

6) their almost uncanny ability to selectively home to damaged tissues, tumors, and metastases following systemic administration.

In this review, it’s summarized the latest research in the immunological properties of MSC, their use as immunomodulatory/anti-inflammatory agents, methods for licensing MSC to customize their immunological profile, and their use as vehicles for transferring both therapeutic genes in genetic disease and drugs/genes designed to destroy tumor cells.