Tacrolimus treatment of plasmacytoid dendritic cells inhibits dinucleotide (CpG-)-induced tumour necrosis factor-alpha secretion

Coencapsulation of Immunosuppressive Drug with Anti-Inflammatory Molecule in Pickering Emulsions as an Innovative Therapeutic Approach for Inflammatory Dermatoses

Psoriasis is an inflammatory skin disease characterized by epidermal and immune dysfunctions. Although efficient, current topical treatments display adverse effects, including skin atrophy and burning sensation, leading to poor patient adherence. To overcome these downsides, pickering emulsions were formulated in which the calcitriol-containing dispersed phase was stabilized with either cyclosporin A- or tacrolimus-loaded poly(lactic-co-glycolic) acid nanoparticles. This study aimed to investigate their biological effects on lymphocytes and epidermal cells and their effectiveness in an imiquimod-induced psoriasis-like mouse model. Results showed that both emulsions significantly inhibited nuclear factor of activated T cell translocation in T lymphocytes as well as their IL-2 production, cell activation, and proliferation. In keratinocytes, inhibition of nuclear factor of activated T cell translocation decreased the production of IL-8 and TNF-α. Topical application of emulsions over skin biopsies ex vivo showed accumulation of rhodamin B-coupled poly(lactic-co-glycolic) acid nanoparticles throughout the epidermis by immunofluorescence and significantly decreased the antigen-presenting capacity of Langerhans cells in relation to a reduced expression of activation markers CD40, CD86, and HLA-DR. Using an imiquimod-induced psoriasis model in vivo, pickering emulsions significantly alleviated psoriasiform lesions potentially attributed to the decreased cutaneous expression of T-cell markers, proinflammatory cytokines, chemokines, and specific epidermal cell genes. Altogether, pickering emulsion might be a very efficient formulation for treating inflammatory dermatoses.

Therapeutic Potentials of Low-Dose Tacrolimus for Aberrant Endometrial Features in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a major anovulatory infertility affecting a great proportion of women of childbearing age and is associated with obesity, insulin resistance and chronic inflammation. Poor endometrial receptivity and recurrent implantation failure are major hurdles to the establishment of pregnancy in women with PCOS. The accumulating body of evidence obtained from experimental and clinical studies suggests a link between inherent adaptive and innate immune irregularities and aberrant endometrial features in PCOS. The use of conventional therapeutic interventions such as lifestyle modification, metformin and ovarian stimulation has achieved limited clinical success in restoring ovulation and endometrial receptivity in women with PCOS. Unlike other immunosuppressive drugs prescribed in the clinical management of autoimmune and inflammatory disorders that may have deleterious effects on fertility and fetal development, preclinical studies in mice and in women without PCOS but with repeated implantation failure revealed potential therapeutic benefits for the use of low-dose tacrolimus in treating female infertility. Improved systemic and ovarian immune functions, endometrial progesterone receptor and coreceptor expressions and uterine vascular adaptation to pregnancy were among features of enhanced progesterone-receptor sensitivity in the low-dose tacrolimus-treated mouse model of the disease. In this review, we have compiled available experimental and clinical data in literature on endometrial progesterone resistance and current therapeutic options, as well as mechanisms of actions and reported outcomes relevant to the potential therapeutic benefits for the use of low-dose tacrolimus in treating PCOS-associated female infertility.

Low-Dose Tacrolimus Prevents Dysregulated Peri-Conceptional Ovarian and Systemic Immune Cellular Homeostasis in Subjects with PCOS

Polycystic ovary syndrome (PCOS) is characterized by failure of ovulation and is associated with obesity and chronic inflammation. Recent evidence suggests that anomalous activation of ovarian macrophages and numerical and functional deficits in the Th17 (CD4+IL17A+) and the CD4+CD25+CD127^low Tregs plays crucial role in PCOS. We have shown that the pre-pregnancy use of tacrolimus prevents adverse reproductive outcomes in a mouse model of PCOS. Here we used the HFD-NONcNZO mice to test a hypothesized beneficial use of tacrolimus relative to metformin in favorably influencing the ovarian and systemic immune milieux conducive to gestational success in subjects with PCOS. Compared to normative controls, our data revealed an aberrant peri-conceptional suppression of the CD4⁺CD25⁺CD127^low Tregs together with an overexpression of the Th17 T cells and lack of coordinated activation of ovarian macrophages in untreated HFD-dNONcNZO mice. Significant variances in treatment outcomes favoured the use of tacrolimus over metformin in treated mice. Consistent with the human fertility studies, this investigation reveals a beneficial systemic use of tacrolimus (0.1 mg/kg) in promoting early pregnancy in individuals with PCOS and suggests the need for further research into the selective inhibition of IL17A as a plausibly alternative immunotherapeutic approach in the clinical management of infertile individuals with PCOS.

Preclinical evaluation of the immunomodulatory properties of cardiac adipose tissue progenitor cells using umbilical cord blood mesenchymal stem cells: a direct comparative study

Cell-based strategies to regenerate injured myocardial tissue have emerged over the past decade, but the optimum cell type is still under scrutiny. In this context, human adult epicardial fat surrounding the heart has been characterized as a reservoir of mesenchymal-like progenitor cells (cardiac ATDPCs) with potential clinical benefits. However, additional data on the possibility that these cells could trigger a deleterious immune response following implantation are needed. Thus, in the presented study, we took advantage of the well-established low immunogenicity of umbilical cord blood-derived mesenchymal stem cells (UCBMSCs) to comparatively assess the immunomodulatory properties of cardiac ATDPCs in an in vitro allostimulatory assay using allogeneic mature monocyte-derived dendritic cells (MDDCs). Similar to UCBMSCs, increasing amounts of seeded cardiac ATDPCs suppressed the alloproliferation of T cells in a dose-dependent manner. Secretion of proinflammatory cytokines (IL6, TNFα, and IFNγ) was also specifically modulated by the different numbers of cardiac ATDPCs cocultured. In summary, we show that cardiac ATDPCs abrogate T cell alloproliferation upon stimulation with allogeneic mature MDDCs, suggesting that they could further regulate a possible harmful immune response in vivo. Additionally, UCBMSCs can be considered as valuable tools to preclinically predict the immunogenicity of prospective regenerative cells.

Anti-interferon alpha treatment in SLE

Several studies in the last decade have highlighted the role of the type I interferon (IFN-I) pathway, and particularly interferon alpha (IFNα) in SLE pathogenesis. As a result, a multitude of potential treatments targeting IFNα have emerged in the last few years, a few of which have already completed phase II clinical trials. Some of the treatment strategies have focused on blocking IFNα or its receptor and others the plasmacytoid dendritic cell (pDC), which is the principal IFNα producing cell. In this review, we will discuss the evidence supporting a pathogenic role of IFNα and pDC in SLE, provide an update on the current status of these therapeutic strategies, and discuss the potential advantages and disadvantages of each therapeutic approach.

Tacrolimus on Kimura's disease: a case report

OBJECTIVE

We report preliminary results of an ongoing study that assesses the efficacy of tacrolimus on Kimura's disease (KD).

STUDY DESIGN

A patient with refractory KD after surgery and treatment with prednisone was treated with tacrolimus. Tacrolimus (FK-506) was administered at an initial dosage of 1 mg every 12 hours, and FK-506 concentration in the blood was monitored monthly. FK-506 blood concentration was controlled within 5 to 15 μg/L. After 6 months, the dosage of tacrolimus was reduced to 0.5 mg daily for another 2 months and then treatment was stopped.

RESULTS

Swelling of the bilateral salivary glands disappeared within the first week. No serious side effects were noted and the disease has not recurred in the 2 years of follow-up.

CONCLUSIONS

Tacrolimus may be an effective treatment for patients with KD, but more research is needed to determine its long-term efficacy and safety as well as its mechanism of action.

Relevance of cytotoxic alloreactivity under different immunosuppressive regimens in clinical islet cell transplantation

Islet or beta cell transplantation provides a promising cure for type 1 diabetes patients, but insulin-independency decreases frequently over time. Immunosuppressive regimens are implemented attempting to cope with both auto- and alloimmunity after transplantation. We analysed the influence of different immunotherapies on autoreactive and alloreactive T cell patterns and transplant outcome. Patients receiving three different immunosuppressive regimens were analysed. All patients received anti-thymocyte globulin induction therapy. Twenty-one patients received tacrolimus-mycophenolate mofetil maintenance immunosuppression, whereas the other patients received tacrolimus-sirolimus (SIR, n = 5) or SIR only (n = 5). Cellular autoreactivity and alloreactivity (CTL precursor frequency) were measured ex vivo. Clinical outcome in the first 6 months after transplantation was correlated with immunological parameters. C-peptide levels were significantly different between the three groups studied (P = 0.01). We confirm that C-peptide production was correlated negatively with pretransplant cellular autoreactivity and low graft size (P = 0.001, P = 0.007 respectively). Combining all three therapies, cellular autoimmunity after transplantation was not associated with delayed insulin-independence or C-peptide production. In combined tacrolimus-SIR and SIR-treated patients, CTL alloreactivity was associated with less insulin independence and C-peptide production (P = 0.03). The percentage of donors to whom high CTLp frequencies were measured was lower in insulin-independent recipients (P = 0.03). In this cohort of islet cell graft recipients, clinical outcome in the first 6 months after transplantation correlates with the applied immunosuppressive regimen. An association exists between insulin-independence and lower incidence of CTL alloreactivity towards donor human leucocyte antigen. This observational study demonstrates the usefulness of monitoring T cell reactivity against islet allografts to correlate immune function with graft survival.

Expression and function of the IL-2 receptor in activated human plasmacytoid dendritic cells

Human and mouse plasmacytoid dendritic cells (PDC) express IL-2 mRNA specifically upon TLR stimulation, but not under CD40L stimulation. Even though the expression of the IL-2R by PDC has been described, the functional implications of this expression remain unknown. Here, we investigated the expression and function of the IL-2R in activated human PDC. The IL-2Ralpha chain, CD25, is expressed in both CpG- and CD40L-activated PDC. CD25 expression is a relatively rapid event, as the receptor was detected 6 h after the initial activation signal. Exogenous IL-2 added to CD40L-activated PDC increased the expression of CD25, enhanced the secretion of pro-inflammatory cytokines and promotes PDC survival. CpG-activated PDC cultured in the presence of IL-2R-blocking monoclonal antibodies showed a reduced expression of pro-inflammatory cytokines, especially TNF-alpha. This reduction was dose and time dependent, suggesting a regulatory role of IL-2 in TNF secretion that might occur at the post-transcriptional level. These results indicate that the expression of the IL-2R is relevant to human PDC activation, and that IL-2 may be an important auto- and/or paracrine factor modulating the activation and survival of PDC. Finally, CD25 expression may be considered as a useful early activation marker for human PDC.