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mRNA-based vaccines effectively induce protective neutralizing antibodies against SARS-CoV-2, the etiological agent of COVID-19. Yet, the kinetics and compositional patterns of vaccine-induced antibody responses to the original strain and emerging variants of concern remain largely unknown. Here we characterized serum antibody classes and subclasses targeting the spike receptor-binding domain of SARS-CoV-2 wild type and α, β, γ and δ variants in a longitudinal cohort of SARS-CoV-2 naïve and COVID-19 recovered individuals receiving the mRNA-1273 vaccine. We found that mRNA-1273 vaccine recipients developed a SARS-CoV-2-specific antibody response with a subclass profile comparable to that induced by natural infection. Importantly, these antibody responses targeted both wild type SARS-CoV-2 as well as its α, β, γ and δ variants. Following primary vaccination, individuals with pre-existing immunity showed higher induction of all antibodies but IgG3 compared to SARS-CoV-2-naïve subjects. Unlike naïve individuals, COVID-19 recovered subjects did not mount a recall antibody response upon the second vaccine dose. In these individuals, secondary immunization resulted in a slight reduction of IgG1 against the receptor-binding domain of β and γ variants. Despite the lack of recall humoral response, vaccinees with pre-existing immunity still showed higher titers of IgG1 and IgA to all variants analyzed compared to fully vaccinated naïve individuals. Our findings indicate that mRNA-1273 vaccine triggered cross-variant antibody responses with distinct profiles in vaccinees with or without pre-existing immunity and suggest that individuals with prior history of SARS-CoV-2 infection may not benefit from the second mRNA vaccine dose with the current standard regimen.

Abstract Background Although effective in reducing relapse rate and delaying progression, current therapies for multiple sclerosis (MS) do not completely halt disease progression. T cell autoimmunity to myelin antigens is considered one of the main mechanisms driving MS. It is characterized by autoreactivity to disease-initiating myelin antigen epitope(s), followed by a cascade of epitope spreading, which are both strongly patient-dependent. Targeting a variety of MS-associated antigens by myelin antigen-presenting tolerogenic dendritic cells (tolDC) is a promising treatment strategy to re-establish tolerance in MS. Electroporation with mRNA encoding myelin proteins is an innovative technique to load tolDC with the full spectrum of naturally processed myelin-derived epitopes. Methods In this study, we generated murine tolDC presenting myelin oligodendrocyte glycoprotein (MOG) using mRNA electroporation and we assessed the efficacy of MOG mRNA-electroporated tolDC to dampen pathogenic T cell responses in experimental autoimmune encephalomyelitis (EAE). For this, MOG35–55-immunized C57BL/6 mice were injected intravenously at days 13, 17, and 21 post-disease induction with 1α,25-dihydroxyvitamin D3-treated tolDC electroporated with MOG-encoding mRNA. Mice were scored daily for signs of paralysis. At day 25, myelin reactivity was evaluated following restimulation of splenocytes with myelin-derived epitopes. Ex vivo magnetic resonance imaging (MRI) was performed to assess spinal cord inflammatory lesion load. Results Treatment of MOG35–55-immunized C57BL/6 mice with MOG mRNA-electroporated or MOG35–55-pulsed tolDC led to a stabilization of the EAE clinical score from the first administration onwards, whereas it worsened in mice treated with non-antigen-loaded tolDC or with vehicle only. In addition, MOG35–55-specific pro-inflammatory pathogenic T cell responses and myelin antigen epitope spreading were inhibited in the peripheral immune system of tolDC-treated mice. Finally, magnetic resonance imaging analysis of hyperintense spots along the spinal cord was in line with the clinical score. Conclusions Electroporation with mRNA is an efficient and versatile tool to generate myelin-presenting tolDC that are capable to stabilize the clinical score in EAE. These results pave the way for further research into mRNA-electroporated tolDC treatment as a patient-tailored therapy for MS.

The use of autologous tolerogenic dendritic cells (tolDC) has become a promising alternative for the treatment of autoimmune diseases. Among the different strategies available, the use of vitamin D3 for the generation of tolDC (vitD3-tolDC) constitutes one of the most robust approaches due to their immune regulatory properties, which are currently being tested in clinical trials. However, the mechanisms that vitD3-tolDC trigger for the induction of tolerance remain elusive. For this reason, we performed a full phenotypical, functional, and transcriptomic characterization of T cells upon their interaction with autologous, antigen-specific vitD3-tolDC. We observed a strong antigen-specific reduction of T cell proliferation, combined with a decrease in the relative prevalence of TH1 subpopulations and IFN-γ production. The analysis of the transcriptomic profile of T CD4+ cells evidenced a significant down-modulation of genes involved in cell cycle and cell response to mainly pro-inflammatory immune-related stimuli, highlighting the role of JUNB gene as a potential biomarker of these processes. Consequently, our results show the induction of a strong antigen-specific hyporesponsiveness combined with a reduction on the TH1 immune profile of T cells upon their interaction with vitD3-tolDC, which manifests the regulatory properties of these cells and, therefore, their therapeutic potential in the clinic.

Autologous antigen-specific therapies based on tolerogenic dendritic cells (tolDC) offer the possibility to treat autoimmune diseases by restoring homeostasis and targeting specifically autoreactive responses. Here, we explore the hypothesis that systemic inflammation occurring in autoimmune diseases, such as multiple sclerosis (MS), can generate a disease-specific environment able to alter the functionality of tolDC. In this context in fact, a combined therapy of tolDC with an immunomodulatory treatment could potentiate the beneficial effect of this antigen-specific cell therapy. For this purpose, we analyzed the efficacy of a combined therapy based on the use of vitamin D3 (VitD3)-tolDC plus interferon beta (IFN-beta) in MS. VitD3-tolDC were generated from healthy donors and MS patients and co-cultured with allogeneic peripheral blood mononuclear cells, in the presence or absence of IFN-beta. In vitro, VitD3-tolDC treatment reduced the percentage of activated T cells and allogeneic proliferation, whereas VitD3-tolDC+IFN-beta treatment enhanced the suppressive ability of VitD3-tolDC and, additionally, induced a shift towards a Th2 profile. To determine the clinical benefit of the combined therapy, C57BL/6-experimental autoimmune encephalomyelitis (EAE)-induced mice were treated with antigen-specific VitD3-tolDC and/or IFN-beta. Treatment of EAE mice with combined therapy ameliorated the disease course compared to each monotherapy. These results suggest that a combined therapy based on antigen-specific VitD3-tolDC and IFN-beta may represent a promising strategy for MS patients.

The administration of autologous tolerogenic dendritic cells (tolDC) has become a promising alternative for the treatment of autoimmune diseases, such as multiple sclerosis (MS). Specifically, the use of vitamin D3 for the generation of tolDC (vitD3-tolDC) constitutes one of the most widely studied approaches, as it has evidenced significant immune regulatory properties, both in vitro and in vivo. In this article, we generated human vitD3-tolDC from monocytes from healthy donors and MS patients, characterized in both cases by a semi-mature phenotype, secretion of IL-10 and inhibition of allogeneic lymphocyte proliferation. Additionally, we studied their transcriptomic profile and selected a number of differentially expressed genes compared to control mature and immature dendritic cells for their analysis. Among them, qPCR results validated CYP24A1, MAP7 and MUCL1 genes as biomarkers of vitD3-tolDC in both healthy donors and MS patients. Furthermore, we constructed a network of protein interactions based on the literature, which manifested that MAP7 and MUCL1 genes are both closely connected between them and involved in immune-related functions. In conclusion, this study evidences that MAP7 and MUCL1 constitute robust and potentially functional biomarkers of the generation of vitD3-tolDC, opening the window for their use as quality controls in clinical trials for MS.

Dendritic cells (DC) are professional antigen presenting cells that have a key role in shaping the immune response. Tolerogenic DC (tolDC) have immuno-regulatory properties and they are a promising prospective therapy for multiple sclerosis and other autoimmune diseases. Ethyl pyruvate (EP) is a redox analog of dimethyl fumarate (Tecfidera), a drug for multiple sclerosis treatment. We have recently shown that EP ameliorates experimental autoimmune encephalomyelitis, a multiple sclerosis murine model. Here, we expanded our study to its tolerogenic effects on DC. Phenotypic analysis has shown that DC obtained from mice or humans reduce expression of molecules required for T cell activation such as CD86, CD83, and HLA-DR under the influence of EP, while CD11c expression and viability of DC are not affected. Furthermore, EP-treated DC restrain proliferation and modulate cytokine production of allogeneic lymphocytes. These results demonstrate that EP has the ability to direct DC toward tolDC.

Peripheral blood biomarkers able to predict disease activity in multiple sclerosis (MS) patients have not been identified yet. Here, we analyzed the immune phenotype of T lymphocyte subpopulations in peripheral blood samples from 66 RRMS patients under DMF (n=22) or fingolimod (n=44) treatment, by flow cytometry. A correlation study between the percentage and absolute cell number of each lymphocyte subpopulation with the presence of relapses or new MRI lesions during 12-month follow-up was performed. Patients who had undergone relapses showed at baseline higher percentage of Th1CM cells (relapsed: 11.60±4.17%vs. nonrelapsed: 9.25±3.17%, p11.48% had a 50% relapse-free survival compared to patients with Th1Th17CMcells

The last years have witnessed a breakthrough in the development of cell-based tolerance-inducing cell therapies for the treatment of autoimmune diseases and solid-organ transplantation. Indeed, the use of tolerogenic dendritic cells (tolDC) and regulatory macrophages (Mreg) is currently being tested in Phase I and Phase II clinical trials worldwide, with the aim of finding an effective therapy able to abrogate the inflammatory processes causing these pathologies without compromising the protective immunity of the patients. However, there exists a wide variety of different protocols to generate human tolDC and Mreg and, consequently, the characteristics of each product are heterogeneous. For this reason, the identification of biomarkers able to define their functionality (tolerogenicity) is of great relevance, on the one hand, to guarantee the safety of tolDC and Mreg before administration and, on the other hand, to compare the results between different cell products and laboratories. In this article, we perform an exhaustive review of protocols generating human tolDC and Mreg in the literature, aiming to elucidate if there are any common transcriptomic signature or potential biomarkers of tolerogenicity among the different approaches. However, and although several effectors seem to be induced in common in some of the most reported protocols to generate both tolDC or Mreg, the transcriptomic profile of these cellular products strongly varies depending on the approach used to generate them.

mRNA-based vaccines effectively induce protective neutralizing antibodies against SARS-CoV-2, the etiological agent of COVID-19. Yet, the kinetics and compositional patterns of vaccine-induced antibody responses to the original strain and emerging variants of concern remain largely unknown. Here we characterized serum antibody classes and subclasses targeting the spike receptor-binding domain of SARS-CoV-2 wild type and α, β, γ and δ variants in a longitudinal cohort of SARS-CoV-2 naïve and COVID-19 recovered individuals receiving the mRNA-1273 vaccine. We found that mRNA-1273 vaccine recipients developed a SARS-CoV-2-specific antibody response with a subclass profile comparable to that induced by natural infection. Importantly, these antibody responses targeted both wild type SARS-CoV-2 as well as its α, β, γ and δ variants. Following primary vaccination, individuals with pre-existing immunity showed higher induction of all antibodies but IgG3 compared to SARS-CoV-2-naïve subjects. Unlike naïve individuals, COVID-19 recovered subjects did not mount a recall antibody response upon the second vaccine dose. In these individuals, secondary immunization resulted in a slight reduction of IgG1 against the receptor-binding domain of β and γ variants. Despite the lack of recall humoral response, vaccinees with pre-existing immunity still showed higher titers of IgG1 and IgA to all variants analyzed compared to fully vaccinated naïve individuals. Our findings indicate that mRNA-1273 vaccine triggered cross-variant antibody responses with distinct profiles in vaccinees with or without pre-existing immunity and suggest that individuals with prior history of SARS-CoV-2 infection may not benefit from the second mRNA vaccine dose with the current standard regimen. [ABSTRACT FROM AUTHOR]

The use of autologous tolerogenic dendritic cells (tolDC) has become a promising alternative for the treatment of autoimmune diseases. Among the different strategies available, the use of vitamin D3 for the generation of tolDC (vitD3-tolDC) constitutes one of the most robust approaches due to their immune regulatory properties, which are currently being tested in clinical trials. However, the mechanisms that vitD3-tolDC trigger for the induction of tolerance remain elusive. For this reason, we performed a full phenotypical, functional, and transcriptomic characterization of T cells upon their interaction with autologous, antigen-specific vitD3-tolDC. We observed a strong antigen-specific reduction of T cell proliferation, combined with a decrease in the relative prevalence of TH1 subpopulations and IFN- γ production. The analysis of the transcriptomic profile of T CD4+ cells evidenced a significant down-modulation of genes involved in cell cycle and cell response to mainly pro-inflammatory immune-related stimuli, highlighting the role of JUNB gene as a potential biomarker of these processes. Consequently, our results show the induction of a strong antigen-specific hyporesponsiveness combined with a reduction on the TH1 immune profile of T cells upon their interaction with vitD3-tolDC, which manifests the regulatory properties of these cells and, therefore, their therapeutic potential in the clinic. [ABSTRACT FROM AUTHOR]

Aim: Dimethyl fumarate (DMF) is one of the most promising therapies for relapsing‐remitting multiple sclerosis (RRMS) patients since it has shown immunomodulatory and neuroprotective effects. However, a percentage of RRMS patients do not exhibit an optimal response to DMF. The objective of this study was to identify early biomarkers of treatment response by analyzing changes in peripheral leukocyte subpopulations directly in whole blood samples. Methods: A longitudinal and prospective study analyzing peripheral blood leukocyte subpopulations in 22 RRMS patients before initiating DMF treatment (baseline) and at 1, 3, 6, and 12 months of follow‐up was performed. Differences between no evidence of disease activity (NEDA) and ongoing disease activity (ODA) patients were analyzed. Results: The beneficial effect of DMF was associated with a specific depletion of memory CD4+ and CD8+ T lymphocytes and B cells. Importantly, only NEDA patients showed (a) a shift from a pro‐ to an antiinflammatory profile, with an increase of Th2 cells and a decrease of Th1‐like Th17 lymphocytes; and (b) an increase of regulatory CD56bright NK cells. Conclusion: The optimal response to DMF is mediated by a shift to antiinflammatory and immunoregulatory profile, which puts forward Th1‐like Th17 lymphocytes as a potential early biomarker of treatment response. [ABSTRACT FROM AUTHOR]

Peripheral blood biomarkers able to predict disease activity in multiple sclerosis (MS) patients have not been identified yet. Here, we analyzed the immune phenotype of T lymphocyte subpopulations in peripheral blood samples from 66 RRMS patients under DMF (n=22) or fingolimod (n=44) treatment, by flow cytometry. A correlation study between the percentage and absolute cell number of each lymphocyte subpopulation with the presence of relapses or new MRI lesions during 12-month follow-up was performed. Patients who had undergone relapses showed at baseline higher percentage of Th1CM cells (relapsed: 11.60±4.17%vs. nonrelapsed: 9.25±3.17%, p<0.05) and Th1Th17CM cells (relapsed: 15.65±6.15%vs. nonrelapsed: 10.14±4.05%, p<0.01) before initiating DMF or fingolimod treatment. Kaplan-Meier analysis revealed that patients with Th1Th17CM (CD4+CCR7+CD45RA-CCR6+CXCR3+) cells>11.48% had a 50% relapse-free survival compared to patients with Th1Th17CMcells<11.48% whose relapse-free survival was 88% (p=0.013, log-rank test). Additionally, a high percentage of Th1Th17CM cells was also found in patients with MRI activity (MRI activity: 14.02±5.87%vs. no MRI activity: 9.82±4.06%, p<0.01). Our results suggest that the percentage of Th1Th17CM lymphocytes at baseline is a predictive biomarker of activity during the first 12 months of treatment, regardless of the treatment. [ABSTRACT FROM AUTHOR]

The administration of autologous tolerogenic dendritic cells (tolDC) has become a promising alternative for the treatment of autoimmune diseases, such as multiple sclerosis (MS). Specifically, the use of vitamin D3 for the generation of tolDC (vitD3-tolDC) constitutes one of the most widely studied approaches, as it has evidenced significant immune regulatory properties, both in vitro and in vivo. In this article, we generated human vitD3-tolDC from monocytes from healthy donors and MS patients, characterized in both cases by a semi-mature phenotype, secretion of IL-10 and inhibition of allogeneic lymphocyte proliferation. Additionally, we studied their transcriptomic profile and selected a number of differentially expressed genes compared to control mature and immature dendritic cells for their analysis. Among them, qPCR results validated CYP24A1, MAP7 and MUCL1 genes as biomarkers of vitD3-tolDC in both healthy donors and MS patients. Furthermore, we constructed a network of protein interactions based on the literature, which manifested that MAP7 and MUCL1 genes are both closely connected between them and involved in immune-related functions. In conclusion, this study evidences that MAP7 and MUCL1 constitute robust and potentially functional biomarkers of the generation of vitD3-tolDC, opening the window for their use as quality controls in clinical trials for MS. [ABSTRACT FROM AUTHOR]

Clinical studies with cellular therapies using tolerance-inducing cells, such as tolerogenic antigen-presenting cells (tolAPC) and regulatory T cells (Treg) for the prevention of transplant rejection and the treatment of autoimmune diseases have been expanding the last decade. In this perspective, we will summarize the current perspectives of the clinical application of both tolAPC and Treg, and will address future directions and the importance of immunomonitoring in clinical studies that will result in progress in the field. [ABSTRACT FROM AUTHOR]

Dendritic cells (DC) are professional antigen presenting cells that have a key role in shaping the immune response. Tolerogenic DC (tolDC) have immuno-regulatory properties and they are a promising prospective therapy for multiple sclerosis and other autoimmune diseases. Ethyl pyruvate (EP) is a redox analog of dimethyl fumarate (Tecfidera), a drug for multiple sclerosis treatment. We have recently shown that EP ameliorates experimental autoimmune encephalomyelitis, a multiple sclerosis murine model. Here, we expanded our study to its tolerogenic effects on DC. Phenotypic analysis has shown that DC obtained from mice or humans reduce expression of molecules required for T cell activation such as CD86, CD83, and HLA-DR under the influence of EP, while CD11c expression and viability of DC are not affected. Furthermore, EP-treated DC restrain proliferation and modulate cytokine production of allogeneic lymphocytes. These results demonstrate that EP has the ability to direct DC toward tolDC. [ABSTRACT FROM AUTHOR]

Summary: Aims: Fingolimod, an orally active immunomodulatory drug for relapsing‐remitting multiple sclerosis (RRMS), sequesters T cells in lymph nodes through functional antagonism of the sphingosine‐1‐phosphate receptor, reducing the number of potential autoreactive cells that migrate to the central nervous system. However, not all RRMS patients respond to this therapy. Our aim was to test the hypothesis that by immune‐monitoring RRMS patient's leukocyte subpopulations it is possible to find biomarkers associated with clinical response to fingolimod. Methods: Prospective study. Analysis of peripheral blood mononuclear cell subpopulations by multiparametric flow cytometry, at baseline and +1, +3, +6, +12 months of follow‐up in 40 RRMS patients starting fingolimod therapy. Results: Fingolimod treatment induced a severe lymphopenia affecting mainly T and B cells. A relative increase in Treg (memory Treg: 3.8 ± 1.0% baseline vs 8.8 ± 4.4% month +1; activated Treg: 1.5 ± 0.7% baseline vs 3.7 ± 2.1% month +1, P < 0.001) as well as transitional B cells (10.5 ± 12.3% baseline vs 18.7 ± 14.6% month +1, P < 0.001) was observed. Interestingly, lymphocyte subpopulations were already at baseline significantly different in responder patients. The percentage of recent thymic emigrants (RTE) used to stratify fingolimod responder, and no responder patients was the best biomarker (4.0 ± 1.4% vs 7.4 ± 1.9%, respectively [P < 0.001]). Conclusion: The results support that immune‐monitoring of lymphocyte subpopulations in peripheral blood is a promising tool to select RRMS candidate for fingolimod treatment. [ABSTRACT FROM AUTHOR]

Background Treatment with tolerogenic dendritic cells (Tol DC) is a promising, cell-based strategy to regulate autoimmune diseases such as multiple sclerosis ( MS) in an antigen-specific way. This technique involves the use of Tol DC from MS patients cultured in the presence of vitamin D3 (VitD3) and pulsed with myelin peptides to induce a stable hyporesponsiveness in myelin-specific autologous T cells. Aim The purpose of this study was to analyze the in vivo effect of VitD3-Tol DC treatment on experimental autoimmune encephalomyelitis, an animal model of MS. Methods Bone marrow-derived Tol DC cultured in the presence of VitD3 and pulsed with peptide 40-55 of the myelin oligodendrocyte glycoprotein ( MOG40-55) were administrated preventively, preclinically, and therapeutically to EAE-induced mice. Results We found that VitD3-Tol DC- MOG treatment showed a beneficial effect, not only decreasing the incidence of the disease but also reducing the severity of the clinical signs mediated by induction of regulatory T cells (Treg), as well as IL-10 production and reduction of Ag-specific lymphoproliferation. Our results support VitD3-Tol DC-peptide(s) treatment as a potential strategy to restore tolerance in autoimmune diseases such as MS. [ABSTRACT FROM AUTHOR]

Autologous antigen-specific therapies based on tolerogenic dendritic cells (tolDC) offer the possibility to treat autoimmune diseases by restoring homeostasis and targeting specifically autoreactive responses. Here, we explore the hypothesis that systemic inflammation occurring in autoimmune diseases, such as multiple sclerosis (MS), can generate a disease-specific environment able to alter the functionality of tolDC. In this context in fact, a combined therapy of tolDC with an immunomodulatory treatment could potentiate the beneficial effect of this antigen-specific cell therapy. For this purpose, we analyzed the efficacy of a combined therapy based on the use of vitamin D3 (VitD3)-tolDC plus interferon beta (IFN-beta) in MS. VitD3-tolDC were generated from healthy donors and MS patients and co-cultured with allogeneic peripheral blood mononuclear cells, in the presence or absence of IFN-beta. In vitro, VitD3-tolDC treatment reduced the percentage of activated T cells and allogeneic proliferation, whereas VitD3-tolDC+IFN-beta treatment enhanced the suppressive ability of VitD3-tolDC and, additionally, induced a shift towards a Th2 profile. To determine the clinical benefit of the combined therapy, C57BL/6-experimental autoimmune encephalomyelitis (EAE)-induced mice were treated with antigen-specific VitD3-tolDC and/or IFN-beta. Treatment of EAE mice with combined therapy ameliorated the disease course compared to each monotherapy. These results suggest that a combined therapy based on antigen-specific VitD3-tolDC and IFN-beta may represent a promising strategy for MS patients. [ABSTRACT FROM AUTHOR]

Background: Although effective in reducing relapse rate and delaying progression, current therapies for multiple sclerosis (MS) do not completely halt disease progression. T cell autoimmunity to myelin antigens is considered one of the main mechanisms driving MS. It is characterized by autoreactivity to disease-initiating myelin antigen epitope(s), followed by a cascade of epitope spreading, which are both strongly patient-dependent. Targeting a variety of MS-associated antigens by myelin antigen-presenting tolerogenic dendritic cells (tolDC) is a promising treatment strategy to re-establish tolerance in MS. Electroporation with mRNA encoding myelin proteins is an innovative technique to load tolDC with the full spectrum of naturally processed myelin-derived epitopes.Methods: In this study, we generated murine tolDC presenting myelin oligodendrocyte glycoprotein (MOG) using mRNA electroporation and we assessed the efficacy of MOG mRNA-electroporated tolDC to dampen pathogenic T cell responses in experimental autoimmune encephalomyelitis (EAE). For this, MOG35-55-immunized C57BL/6 mice were injected intravenously at days 13, 17, and 21 post-disease induction with 1α,25-dihydroxyvitamin D3-treated tolDC electroporated with MOG-encoding mRNA. Mice were scored daily for signs of paralysis. At day 25, myelin reactivity was evaluated following restimulation of splenocytes with myelin-derived epitopes. Ex vivo magnetic resonance imaging (MRI) was performed to assess spinal cord inflammatory lesion load.Results: Treatment of MOG35-55-immunized C57BL/6 mice with MOG mRNA-electroporated or MOG35-55-pulsed tolDC led to a stabilization of the EAE clinical score from the first administration onwards, whereas it worsened in mice treated with non-antigen-loaded tolDC or with vehicle only. In addition, MOG35-55-specific pro-inflammatory pathogenic T cell responses and myelin antigen epitope spreading were inhibited in the peripheral immune system of tolDC-treated mice. Finally, magnetic resonance imaging analysis of hyperintense spots along the spinal cord was in line with the clinical score.Conclusions: Electroporation with mRNA is an efficient and versatile tool to generate myelin-presenting tolDC that are capable to stabilize the clinical score in EAE. These results pave the way for further research into mRNA-electroporated tolDC treatment as a patient-tailored therapy for MS. [ABSTRACT FROM AUTHOR]

Tolerogenic dendritic cell (tolDC)-based therapies have become a promising approach for the treatment of autoimmune diseases by their potential ability to restore immune tolerance in an antigen-specific manner. However, the broad variety of protocols used to generate tolDC in vitro and their functional and phenotypical heterogeneity are evidencing the need to find robust biomarkers as a key point towards their translation into the clinic, as well as better understanding the mechanisms involved in the induction of immune tolerance. With that aim, in this study we have compared the transcriptomic profile of tolDC induced with either vitamin D3 (vitD3-tolDC), dexamethasone (dexa-tolDC) or rapamycin (rapa-tolDC) through a microarray analysis in 5 healthy donors. The results evidenced that common differentially expressed genes could not be found for the three different tolDC protocols. However, individually, CYP24A1, MUCL1 and MAP7 for vitD3-tolDC; CD163, CCL18, C1QB and C1QC for dexa-tolDC; and CNGA1 and CYP7B1 for rapa-tolDC, constituted good candidate biomarkers for each respective cellular product. In addition, a further gene set enrichment analysis of the data revealed that dexa-tolDC and vitD3-tolDC share several immune regulatory and anti-inflammatory pathways, while rapa-tolDC seem to be playing a totally different role towards tolerance induction through a strong immunosuppression of their cellular processes. [ABSTRACT FROM AUTHOR]