Bone marrow stromal cells are essential for maintaining a favourable microenvironment for cell regeneration and differentiation. Extensive studies are exploring how these cells influence the gene regulation of haematopoietic stem cells and other bone marrow cells. The molecular mechanisms underlying their immunomodulatory effects are the subject of intensive research, including the study of interactions with immune cells and the signalling pathways involved.
Cellular Interactions
Interactions between stromal cells and other bone marrow cells, including haematopoietic stem cells, are a critical area of research. This includes investigations into:
- Cell adhesions
- Paracrine signalling
- Specific molecular interactions
Immunomodulatory Properties
Bone marrow stromal cells, also known as mesenchymal stem/stromal cells (MSCs), possess potent immunomodulatory functions. They regulate a wide variety of immune cells, both innate and adaptive, by:
- Inhibiting proinflammatory T-cell subsets such as Th1 and Th17
- Promoting regulatory T cells (Tregs) and B cells that suppress inflammation
- Acting through direct cell-cell contact and secretion of soluble factors including interleukins (IL-10, IL-6, IL-8), prostaglandin E2 (PGE2), and indoleamine 2,3-dioxygenase (IDO)
This modulation helps prevent excessive immune reactions and supports tissue repair.
Therapeutic Potential
MSCs-mediated immunoregulation holds significant therapeutic promise for conditions such as:
- Autoimmune diseases
- Graft-versus-host disease
- Inflammatory disorders
Clinical trials and animal models demonstrate their ability to reduce inflammation, promote tissue healing, and restore immune balance in various diseases.
Dynamic Immunoregulation
The complex crosstalk between stromal cells and immune cells is highly influenced by the inflammatory microenvironment. MSCs can switch between immunostimulatory and immunosuppressive phenotypes depending on environmental cues. Deciphering these mechanisms opens avenues for innovative therapies targeting the bone marrow niche and immune-related diseases.