Infusion of dendritic cells carrying donor lymphocytes treated with 8-methoxypsoralen and ultraviolet A light induces CD19+ IL-10+ regulatory B cells and promotes skin allograft survival

Mesenchymal stem cells transfected with sFgl2 inhibit the acute rejection of heart transplantation in mice by regulating macrophage activation

Background

Mesenchymal stem cells (MSCs) have become a promising candidate for cell-based immune therapy for acute rejection (AR) after heart transplantation due to possessing immunomodulatory properties. In this study, we evaluated the efficacy of soluble fibronectin-like protein 2 (sFgl2) overexpressing mesenchymal stem cells (sFgl2-MSCs) in inhibiting AR of heart transplantation in mice by regulating immune tolerance through inducing M2 phenotype macrophage polarization.

Methods and results

The sFgl2, a novel immunomodulatory factor secreted by regulatory T cells, was transfected into MSCs to enhance their immunosuppressive functions. After being co-cultured for 72 h, the sFgl2-MSCs inhibited M1 polarization whereas promoted M2 of polarization macrophages through STAT1 and NF-κB pathways in vitro. Besides, the sFgl2-MSCs significantly enhanced the migration and phagocytosis ability of macrophages stimulated with interferon-γ (IFN-γ) and lipopolysaccharide (LPS). Further, the application potential of sFgl2-MSCs in AR treatment was demonstrated by heterotopic cardiac transplantation in mice. The tissue damage and macrophage infiltration were evaluated by H&E and immunohistochemistry staining, and the secretion of inflammatory cytokines was analyzed by ELISA. The results showed that sFgl2-MSCs injected intravenously were able to locate in the graft, promote the M2 polarization of macrophages in vivo, regulate the local and systemic immune response, significantly protect tissues from damaging, and finally prolonged the survival time of mice heart grafts.

Conclusion

sFgl2-MSCs ameliorate AR of heart transplantation by regulating macrophages, which provides a new idea for the development of anti-AR treatment methods after heart transplantation.

Antitumoral and Immunomodulatory Effect of Mahonia aquifolium Extracts

The prodrug potential of Mahonia aquifolium, a plant used for centuries in traditional medicine, recently gained visibility in the literature, and the activity of several active compounds isolated from its extracts was studied on biologic systems in vitro and in vivo. Whereas the antioxidative and antitumor activities of M. aquifolium-derived compounds were studied at some extent, there are very few data about their outcome on the immune system and tumor cells. To elucidate the M. aquifolium potential immunomodulatory and antiproliferative effects, the bark, leaf, flower, green fruit, and ripe fruit extracts from the plant were tested on peripheral blood mononuclear cells and tumor cells. The extracts exert fine-tuned control on the immune response, by modulating the CD25 lymphocyte activation pathway, the interleukin-10 signaling, and the tumor necrosis-alpha secretion in four distinct human peripheral blood mononuclear cell (PBMC) subpopulations. M. aquifolium extracts exhibit a moderate cytotoxicity and changes in the signaling pathways linked to cell adhesion, proliferation, migration, and apoptosis of the tumor cells. These results open perspectives to further investigation of the M. aquifolium extract prodrug potential.

New Application of Psoralen and Angelicin on Periodontitis With Anti-bacterial, Anti-inflammatory, and Osteogenesis Effects

Psoralen and angelicin are two effective compounds isolated from psoraleae, a traditional Chinese medicine. They have a wide range of applications for bone disease treatment and immune modulation. In this study, we explored their new applications for the treatment of periodontal diseases. This study aimed to investigate the effects of psoralen and angelicin on Porphyromonas gingivalis growth and P. gingivalis-derived lipopolysaccharide (Pg-LPS)-induced inflammation, and further to evaluate their effects on osteogenesis. Finally, the effects of angelicin on a mouse model of periodontitis were also investigated. The results showed that psoralen and angelicin had beneficial dose-dependent effects regarding the inhibition of planktonic P. gingivalis and biofilms of P. gingivalis. There were no significant differences in the viability of monocyte-like THP-1 cells and human periodontal ligament cells (hPDLCs) treated with either psoralen or angelicin compared to the untreated control cells. Psoralen and angelicin also markedly decreased the mRNA expression and release of inflammatory cytokines (interleukin [IL]-1β and IL-8) by THP-1 cells in a dose-dependent manner. They significantly enhanced the alkaline phosphatase (ALP) activity of hPDLCs and up-regulated the expression of osteogenic proteins (runt-related transcription factor 2 [RUNX2], distal-less homeobox 5 [DLX5], and osteopontin [OPN]). Angelicin significantly attenuated alveolar bone loss and inflammation response in the mice with periodontitis. In conclusion, our data demonstrated that psoralen and angelicin could inhibit the growth of planktonic P. gingivalis and P. gingivalis biofilm. It is also the first report on the anti-inflammatory effect of psoralen and angelicin against Pg-LPS. They also had an osteogenesis-potentiating effect on hPDLCs. The in vivo study also indicated the effect of angelicin regarding protection against periodontitis. Our study highlighted the potential ability of psoralen and angelicin to act as novel natural agents to prevent and treat periodontitis.

Desired response to phototherapy vs photoaggravation in psoriasis: what makes the difference?

Psoriasis commonly responds beneficially to UV radiation from natural sunlight or artificial sources. Therapeutic mechanisms include the proapoptotic and immunomodulating effects of UV, affecting many cells and involving a variety of pro- and anti-inflammatory cytokines, downregulating the Th17/IL-23 response with simultaneous induction of regulatory immune cells. However, exposure to UV radiation in a subset of psoriasis patients leads to exacerbation of the disease. We herein shed light on the predisposing factors of photosensitive psoriasis, including genetics (such as HLA-Cw*0602 or CARD14), gender and coexisting photodermatoses such as polymorphic light eruption (PLE) in the context of potential molecular mechanisms behind therapeutic photoresponsiveness or photoaggravation. UV-induced damage/pathogen-associated molecular patterns, damage to self-coding RNA (signalling through Toll-like receptors), certain antimicrobial peptides and/or inflammasome activation may induce innate immunity, leading to psoriasis at the site of UV exposure when there is concomitant, predisposing resistance against UV-induced suppression of the adaptive immune response (like in PLE) that otherwise would act to reduce psoriasis.

Percentage and function of CD4+CD25+ regulatory T cells in patients with hyperthyroidism

The current study observed the percentage of peripheral blood (PB) CD4⁺CD25⁺ regulatory T cells (Tregs) and the influence of CD4⁺CD25⁺ Tregs on the proliferation of naïve CD4 T cells in patients with hyperthyroidism. Furthermore, preliminary discussions are presented on the action mechanism of CD4⁺CD25⁺ Tregs on hyperthyroidism attacks. The present study identified that compared with the percentage of PB CD4⁺CD25⁺ Tregs in healthy control subjects, no significant changes were observed in the percentage of PB CD4⁺CD25⁺ Tregs in patients with hyperthyroidism (P>0.05). For patients with hyperthyroidism, CD4⁺CD25⁺ Tregs exhibited significantly reduced inhibition of the proliferation of naïve CD4 T cells and decreased secretion capacity on the cytokines of CD4 T cells, compared with those of healthy control subjects (P<0.05). In addition, it was demonstrated that thyroid function of patients with hyperthyroidism was significantly improved (P<0.05) subsequent to receiving medication. Compared with the percentage of PB CD4⁺CD25⁺ Tregs in patients with hyperthyroidism before treatment, no significant changes were observed in the percentage of PB CD4⁺CD25⁺ Tregs in hyperthyroidism patients following treatment (P>0.05). In the patients with hyperthyroidism, following treatment, CD4⁺CD25⁺ Tregs exhibited significantly increased inhibition of the proliferation of naïve CD4 T cells and increased secretion capacity of CD4 T cell cytokines, compared with those of the patients with hyperthyroidism prior to treatment (P<0.05). PB CD4⁺CD25⁺ Tregs function was decreased in patients with hyperthyroidism, and its non-proportional decrease may be closely associated with the occurrence and progression of hyperthyroidism.

Assay of Peripheral Regulatory Vδ1 T Cells in Ankylosing Spondylitis and its Significance

BACKGROUND Ankylosing spondylitis (AS) involves inflammation at the sacroiliac joint and spine attachment site. This study aimed to observe the ratio and function of peripheral regulatory Vδ1 T cells in AS patients to investigate their roles in AS pathogenesis. MATERIAL AND METHODS Peripheral blood mononuclear cells (PBMC) were separated by density-gradient centrifugation from AS patients and healthy controls. Flow cytometry was used to determine the ratio between Vδ1 and CD4 T cells of PBMC in AS patients and controls. Flow cytometry sorting (FCS) was used to obtain Vδ1 and naïve CD4 T cells with purity higher than 90%. CFSE staining method was used to detect the effect of Vδ1 T cells on proliferation of naïve CD4 T cells. The effect of Vδ1 T cells on secretion of IFN-γ from naïve CD4 T cells and the ability to secrete IL-10 from Vδ1 T cells were determined by flow cytometry. RESULTS AS patients had significantly lower Vδ1 T cell ratio in PBMC compared to controls (p<0.05), but their CD4 T cell ratio was significantly elevated (p<0.05). Functional assay showed suppression of naïve CD4 T cell proliferation and IFN-γ secretion by peripheral Vδ1 T cells in AS patients (p<0.01). AS patients also had lower IL-10 secreting level from peripheral derived Vδ1 T cells (p<0.01). CONCLUSIONS The immune suppression of peripheral Vδ1 T cell in AS patient increases the ratio of peripheral CD4 T cells and IFN-γ level, leading to AS pathogenesis. This immune suppression is mainly due to suppressed IL-10 secretion.

Percentage of Peripheral CD19+CD24hiCD38hi Regulatory B Cells in Neonatal Sepsis Patients and Its Functional Implication

BACKGROUND As a major cause of mortality in neonates, neonatal sepsis is often accompanied by immune dysfunctions, which are frequently caused by dysregulated T cell sub-populations. The role of regulatory B cells in neonatal sepsis, however, remains unknown. Therefore, this study investigated the percentage and functional variation of CD19+CD24hiCD38hi regulatory B cells in peripheral blood of neonatal sepsis patients in an attempt to elucidate the role of these regulatory B cells in pathogenesis of sepsis. MATERIAL AND METHODS Flow cytometry was used to quantify the percentage of CD19+CD24hiCD38hi regulatory B cells from peripheral blood samples. The correlation between B cell percentage and C reactive protein (CRP) level was analyzed. Secretion level of interleukin-10 (IL-10) and effects on the proliferation of naïve CD4+ T cells were further analyzed. RESULTS The percentage of CD19+CD24hiCD38hi regulatory B cells in neonatal sepsis patients was significantly higher compared to healthy controls (p<0.05), and was positively correlated with serum CRP level. The percentage of IL-10+ CD19+CD24hiCD38hi regulatory B cells was also higher in sepsis patients, and also had more potent inhibition on naïve CD4+ T cells (p<0.01). CONCLUSIONS The elevation of CD19+CD24hiCD38hi regulatory B cells in neonatal sepsis can inhibit body immune function and thus may participate in the pathogenesis of sepsis.

Premise and promise of mesenchymal stem cell-based therapies in clinical vascularized composite allotransplantation

PURPOSE OF REVIEW

Over the past decade, clinical vascularized composite allotransplantation (VCA) has enabled functional and quality of life restoration in a wide range of indications secondary to devastating tissue loss. However, the spectre of toxicity and long-term complications of chronic immunosuppression has curtailed the momentum of VCA. This study summarizes the literature evidence behind successful mesenchymal stem cell (MSC)-based cell therapies highlighting their multipronged immunomodulatory, restorative and regenerative characteristics with special emphasis towards VCA applications.

RECENT FINDINGS

Experimental and clinical studies in solid organs and VCA have confirmed that MSCs facilitate immunosuppression-free allograft survival or tolerance, stimulate peripheral nerve regeneration, attenuate ischaemia-reperfusion injury, and improve tissue healing after surgery. It has been hypothesized that MSC-induced long-term operational tolerance in experimental VCA is mediated by induction of mixed donor-specific chimerism and regulatory T-cell mechanisms. All these characteristics of MSCs could thus help expand the scope and clinical feasibility of VCA.

SUMMARY

Cellular therapies, especially those focusing on MSCs, are emerging in solid organ transplantation including VCA. Although some clinical trials have begun to assess the effects of MSCs in solid organ transplantation, much scientific domain remains uncharted, especially for VCA.

Diversity of gut microflora is required for the generation of B cell with regulatory properties in a skin graft model

B cells have been reported to promote graft rejection through alloantibody production. However, there is growing evidence that B cells can contribute to the maintenance of tolerance. Here, we used a mouse model of MHC-class I mismatched skin transplantation to investigate the contribution of B cells to graft survival. We demonstrate that adoptive transfer of B cells prolongs skin graft survival but only when the B cells were isolated from mice housed in low sterility "conventional" (CV) facilities and not from mice housed in pathogen free facilities (SPF). However, prolongation of skin graft survival was lost when B cells were isolated from IL-10 deficient mice housed in CV facilities. The suppressive function of B cells isolated from mice housed in CV facilities correlated with an anti-inflammatory environment and with the presence of a different gut microflora compared to mice maintained in SPF facilities. Treatment of mice in the CV facility with antibiotics abrogated the regulatory capacity of B cells. Finally, we identified transitional B cells isolated from CV facilities as possessing the regulatory function. These findings demonstrate that B cells, and in particular transitional B cells, can promote prolongation of graft survival, a function dependent on licensing by gut microflora.