Impact of Adipose-Derived Mesenchymal Stem Cells (ASCs) of Rheumatic Disease Patients on T Helper Cell Differentiation

Adipose-Derived Mesenchymal Stem Cells from Arthritis Patients: Differential Modulation of CD4⁺ T Cell Activation and Cytokine Production

BACKGROUND Adipose-derived stem cells (ASCs) from intra-articular adipose tissue of osteoarthritis (OA) and rheumatoid arthritis (RA) patients similarly regulate the proliferation of activated CD4⁺ T lymphocytes and exhibit comparable differentiation potential. This study aimed to assess the impact of ASCs from RA patients on CD4⁺ T cell activation and differentiation into Th17 and T regulatory (Treg) cells. MATERIAL AND METHODS Intra-articular adipose tissue samples were obtained from patients with RA and OA, who underwent knee replacement surgery. ASCs were isolated and cultured either with isolated CD4⁺ cells or with peripheral blood mononuclear cells. After culture, CD4⁺ T cell phenotype was evaluated by flow cytometry, and cytokine concentrations in culture supernatants were analyzed via ELISA. Blocking experiments were conducted to identify the soluble agents responsible for the immunomodulatory effects of ASCs. RESULTS RA- and OA-derived ASCs effectively modulated CD25 and CD69 expression on CD4⁺ cells. RA-derived ASCs failed to induce Tregs, decreased HLA-DR expression, and increased IL-35 production. RA- and OA-derived ASCs reduced TNF and IFN-γ production but increased IL-17 production. The immunomodulatory activities of ASCs were linked to the kynurenine pathway and prostaglandin E2. CONCLUSIONS This study indicates that ASCs modulate the phenotype of CD4⁺ T cells and influence the production of both pro-inflammatory and anti-inflammatory cytokines. However, ASCs from RA patients appear to have impaired immunomodulatory abilities, raising concerns about their therapeutic potential. Further research is needed to enhance our understanding of ASCs biology and their therapeutic utility.

Mesenchymal stem cells in autoimmune disease: A systematic review and meta-analysis of pre-clinical studies

Mesenchymal Stem Cells (MSCs) are of interest in the clinic because of their immunomodulation capabilities, capacity to act upstream of inflammation, and ability to sense metabolic environments. In standard physiologic conditions, they play a role in maintaining the homeostasis of tissues and organs; however, there is evidence that they can contribute to some autoimmune diseases. Gaining a deeper understanding of the factors that transition MSCs from their physiological function to a pathological role in their native environment, and elucidating mechanisms that reduce their therapeutic relevance in regenerative medicine, is essential. We conducted a Systematic Review and Meta-Analysis of human MSCs in preclinical studies of autoimmune disease, evaluating 60 studies that included 845 patient samples and 571 control samples. MSCs from any tissue source were included, and the study was limited to four autoimmune diseases: multiple sclerosis, rheumatoid arthritis, systemic sclerosis, and lupus. We developed a novel Risk of Bias tool to determine study quality for in vitro studies. Using the International Society for Cell & Gene Therapy's criteria to define an MSC, most studies reported no difference in morphology, adhesion, cell surface markers, or differentiation into bone, fat, or cartilage when comparing control and autoimmune MSCs. However, there were reported differences in proliferation. Additionally, 308 biomolecules were differentially expressed, and the abilities to migrate, invade, and form capillaries were decreased. The findings from this study could help to explain the pathogenic mechanisms of autoimmune disease and potentially lead to improved MSC-based therapeutic applications.

Adipose-derived stem cells in immune-related skin disease: a review of current research and underlying mechanisms

Adipose-derived stem cells (ASCs) are a critical adult stem cell subpopulation and are widely utilized in the fields of regenerative medicine and stem cell research due to their abundance, ease of harvest, and low immunogenicity. ASCs, which are homologous with skin by nature, can treat immune-related skin diseases by promoting skin regeneration and conferring immunosuppressive effects, with the latter being the most important therapeutic mechanism. ASCs regulate the immune response by direct cell-cell communication with immune cells, such as T cells, macrophages, and B cells. In addition to cell-cell interactions, ASCs modulate the immune response indirectly by secreting cytokines, interleukins, growth factors, and extracellular vesicles. The immunomodulatory effects of ASCs have been exploited to treat many immune-related skin diseases with good therapeutic outcomes. This article reviews the mechanisms underlying the immunomodulatory effects of ASCs, as well as progress in research on immune-related skin diseases.

Factors Defining Human Adipose Stem/Stromal Cell Immunomodulation in Vitro

Human adipose tissue-derived stem/stromal cells (hASCs) are adult multipotent mesenchymal stem/stromal cells with immunomodulatory capacities. Here, we present up-to-date knowledge on the impact of different experimental and donor-related factors on hASC immunoregulatory functions in vitro. The experimental determinants include the immunological status of hASCs relative to target immune cells, contact vs. contactless interaction, and oxygen tension. Factors such as the ratio of hASCs to immune cells, the cellular context, the immune cell activation status, and coculture duration are also discussed. Conditioning of hASCs with different approaches before interaction with immune cells, hASC culture in xenogenic or xenofree culture medium, hASC culture in two-dimension vs. three-dimension with biomaterials, and the hASC passage number are among the experimental parameters that greatly may impact the hASC immunosuppressive potential in vitro, thus, they are also considered. Moreover, the influence of donor-related characteristics such as age, sex, and health status on hASC immunomodulation in vitro is reviewed. By analysis of the literature studies, most of the indicated determinants have been investigated in broad non-standardized ranges, so the results are not univocal. Clear conclusions cannot be drawn for the fine-tuned scenarios of many important factors to set a standard hASC immunopotency assay. Such variability needs to be carefully considered in further standardized research. Importantly, field experts' opinions may help to make it clearer.