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The Wharton's jelly of the umbilical cord is believed to be a source of mesenchymal stem cells (MSCs) which can be therapeutically applied in degenerative diseases.In this study, we investigated the immunomodulatory effect of umbilical cord derived-mesenchymal stem cells (UC-MSCs) and bone marrow-derived-mesenchymal stem cells (BM-MSCs) on differentiation, maturation, and endocytosis of monocyte-derived dendritic cells in a transwell culture system under laboratory conditions. Monocytes were differentiated into immature dendritic cells (iDCs) in the presence of GM-CSF and IL-4 for 6 days and then differentiated into mature dendritic cells (mDCs) in the presence of TNF-α for 2 days. In every stage of differentiation, immature and mature dendritic cells were separately co-cultured with UC-MSCs and BM-MSCs. The findings showed that UC-MSCs and BM-MSCs inhibited strongly differentiation and maturation of dendritic cells at higher dilution ratios (1:1). The BM-MSCs and UC-MSCs showed more inhibitory effect on CD1a, CD83, CD86 expression, and dendritic cell endocytic activity, respectively. On the other hand, these cells severely up-regulated CD14 marker expression. We concluded that UC-MSCs and BM-MSCs could inhibit differentiation, maturation and endocytosis in monocyte-derived DCs through the secreted factors and free of any cell-cell contacts under laboratory conditions. As DCs are believed to be the main antigen presenting cells for naïve T cells in triggering immune responses, it would be logical that their inhibitory effect on differentiation, maturation and function can decrease or modulate immune and inflammatory responses.

Multiple Sclerosis (MS) is an inflammatory demyelinating and neurodegenerative disorder of the central nervous system (CNS), which mainly affects young adults. Activated T lymphocytes promote the neuro-inflammatory cascade of MS by secreting pro-inflammatory cytokines and play a significant role in its pathogenesis. T lymphocytes may trigger the inflammation, which in turn leads to axonal loss and neurodegeneration observed in the course of MS. Currently, there is no cure for MS, however, one of the most promising neuroprotective research tools consists of the use of bone marrow derived mesenchymal stem cells (MSC). This method promotes immune system regulation and possibly induces neurological repair and re-myelination of the damaged axons. Recent studies have shown that MSC exert an immune regulatory function and induce T regulatory-cell proliferation, therefore, it may serve as a potentially useful treatment for immune-mediated diseases such as MS. In this pilot study a group of MS patients underwent MSC therapy and we assayed the expression of an X-linked transcription factor, FoxP3, as a specific marker of T Regulatory cells in peripheral blood, prior to and after the treatment. Using q RT-PCR for measurement of expression of FoxP3 by peripheral blood mononuclear cells, we found that in all subjects, except for one, the expression of FoxP3 at 6 months after intrathecal injection of MSC was significantly higher than the levels prior to treatment. Such significant enhanced expression of FoxP3 associated with clinical stability. Findings from this pilot study further support the potential of bone marrow derived MSC for treatment of MS patients.

The human leukocyte antigen-B27 is one of the class I molecules of the major histocompatibility complex which is strongly associated with ankylosing spondylitis (AS). The strength of the disease association with B27 varies markedly among racial and ethnic populations. It is an allele family, which constitutes about 31 subtypes, with a considerable geographic and ethnic difference in distribution. It is important to know whether certain subtypes show any preferential association with AS. Because there is no report regarding HLA-B27 subtypes in Iranian patients with AS, the main purpose of the present study was to assess the frequency of subtypes of human leukocyte antigen (HLA)-B27 in patients with ankylosing spondylitis in Iranian populationOne hundred and nineteen AS patients (82 HLA-B27 positive and 37 HLA-B27 negative) were selected for this study. HLA-B27 positive patients were screened by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) for B*27 subtyping.The results of present study revealed that only two subtypes were detected in Iranian patients, including B*2705 (52 patients, 63.4%) and B*2702 (30 patients, 36.6%). Our results showed a restricted number of HLA-B27 subtypes associated with AS in Iran and an elevated frequency of the B*2705 allele in these patients similar to other Euro-Caucasoid (Aryan) groups in the world.