Normally, the immune system recognizes cells and molecules of the host body to spare those while staying vigilant against foreign antigens. However, in certain pathological conditions, the immune system starts acting against these host cells, resulting in autoimmune disease. These diseases are marked by immune responses directed against self-antigens. More than fifty types of autoimmune diseases have been identified, which are categorized into organ-specific and systemic disorders. Conventional therapies for autoimmune diseases can be highly effective, but long-term treatments often leave the patient susceptible to life-threatening conditions. In addition, the benefits of many of these drugs are outweighed by related toxicities. Therefore, there is a strong need for the development of more specific strategies that lower the risk of systemic immune suppression while improving tolerability.

Stem cell therapy is emerging as one of the most promising tools for promoting tissue repair and protecting from damage caused by immune attacks. Stem cells mediate immune suppression through several mechanisms, including immune modulation and suppression of inflammation. Stem cells promote the induction of regulatory T (Treg) cells and inhibit the proliferation of dendritic cells (DC), T and B cells, leading to increased immune tolerance. The immunosuppressive properties of stem cells are due to various secreted biomolecules, including interleukin-10 (IL-10), transforming growth factor-β (TGF-β), nitric oxide (NO), indoleamine 2,3-dioxygenase (IDO), and prostaglandin E2 (PGE2). Overall, these features make stem cells an ideal therapeutic agent for providing long-term, sustained protection from autoimmunity. The immunomodulating characters of stem cells have prompted their use, and although the recorded success rate has shown inconsistent clinical outcomes, this could in part be attributed to a number of factors such as lack of proper randomized controlled studies, and incomplete information on dosage or routes of administration. Furthermore, the longevity of the therapeutic benefits has varied. These confusions can only be resolved by conducting extensive randomized studies with larger cohorts.

The aim of this Special Issue is to invite the submission of research articles from researchers and clinicians carrying out preclinical studies on stem cells or their clinical importance in the treatment of autoimmune diseases. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Immunomodulatory properties of stem cells
• Anti-inflammatory properties of stem cells
• Preclinical on the effects of stem cells in autoimmune disorders
• Therapeutic potential of stem cells in autoimmune disorders
• Clinical trials using stem cells in autoimmune disorders