Meditation and Compassion Therapy in Psychiatric Disorders: A Pilot Study.

Introduction Our study aimed to compare meditation and compassion-based group therapy with the standard of care in patients with eating disorders, drug addiction, alcohol addiction, and depression, concerning acceptance, mindfulness awareness, self-compassion, and psychological distress. Methods A controlled designed study was performed, comparing meditation and compassion-focused group therapy added to the standard of care with the standard of care alone, on patients with eating disorders, drug addiction, alcohol addiction, and mood disorders. Four validated questionnaires were administered: the Acceptance and Action Questionnaire-II (AAQ-II), which assesses the ability to be fully in touch with the present moment; the Mindful Attention Awareness Scale (MAAS), which assesses the ability to experience consciously what is happening in the present moment; the Self-Compassion Scale (SCS), which assesses self-compassion characteristics, including loving-kindness; and the Symptom Checklist-90 (SCL-90), which measures psychological distress (anxiety, depression, psychotic behavior, etc.). Results There was a total of 75 subjects, out of which 48 represented the experimental group, and 27 represented the control group. The overall mean age of the subjects was 44.8 ± 13.2 years. There were statistically significant increases in the experimental group (baseline vs. end of study) for the AAQ-II, MAAS, and SCS scores, and a statistically significant decrease in the SCL-90 score. In the control group, there was a statistically significant decrease in the SCL-90 score, but no significant differences for other measurements. The comparisons between the two groups at the end of the study were as follows: AAQ-II: 0.7 (-5.74 to 7.15), p = 0.827; MAAS: 4.78 (-3.19 to 12.75), p = 0.233; SCS: 5.89 (-3.18 to 14.96), p = 0.199; SCL-90: -0.26 (-0.62 to 0.1), p = 0.157. Conclusion Within the experimental group, all scales improved statistically significantly. There were no statistically significant differences at the end of the study concerning the four scales between the groups. The comparison between groups was limited by data availability.

Extracellular vesicles at the crossroad between cancer progression and immunotherapy: focus on dendritic cells.

Extracellular vesicles (EVs) are nanosized heat-stable vesicles released by virtually all cells in the body, including tumor cells and tumor-infiltrating dendritic cells (DCs). By carrying molecules from originating cells, EVs work as cell-to-cell communicators in both homeostasis and cancer but may also represent valuable therapeutic and diagnostic tools. This review focuses on the role of tumor-derived EVs (TEVs) in the modulation of DC functions and on the therapeutic potential of both tumor- and DC-derived EVs in the context of immunotherapy and DC-based vaccine design. TEVs were originally characterized for their capability to transfer tumor antigens to DCs but are currently regarded as mainly immunosuppressive because of the expression of DC-inhibiting molecules such as PD-L1, HLA-G, PGE2 and others. However, TEVs may still represent a privileged system to deliver antigenic material to DCs upon appropriate engineering to reduce their immunosuppressive cargo or increase immunogenicity. DC-derived EVs are more promising than tumor-derived EVs since they expose antigen-loaded MHC, costimulatory molecules and NK cell-activating ligands in the absence of an immunosuppressive cargo. Moreover, DC-derived EVs possess several advantages as compared to cell-based drugs such as a higher antigen/MHC concentration and ease of manipulation and a lower sensitivity to immunosuppressive microenvironments. Preclinical models showed that DC-derived EVs efficiently activate tumor-specific NK and T cell responses either directly or indirectly by transferring antigens to tumor-infiltrating DCs. By contrast, however, phase I and II trials showed a limited clinical efficacy of EV-based anticancer vaccines. We discuss that the future of EV-based therapy depends on our capability to overcome major challenges such as a still incomplete understanding of their biology and pharmacokinetic and the lack of standardized methods for high-throughput isolation and purification. Despite this, EVs remain in the limelight as candidates for cancer immunotherapy which may outmatch cell-based strategies in the fullness of their time.

Extracellular microRNAs induce dendritic cell-dependent joint inflammation and potentiate osteoclast differentiation via TLR7/8 engagement.

OBJECTIVES: Monocyte-derived dendritic cells (DCs) are key players in the induction of inflammation, autoreactive T cell activation and loss of tolerance in rheumatoid arthritis (RA), but the precise mechanisms underlying their activation remain elusive. Here, we hypothesized that extracellular microRNAs released in RA synovial fluids may represent a novel, physiological stimulus triggering unwanted immune response via TLR8-expressing DC stimulation. METHODS: Human monocyte-derived DCs were stimulated with a mixture of GU-rich miRNAs upregulated in RA tissues and released in synovial fluids (Ex-miRNAs). Activation of DCs was assessed in terms of NF-κB activation by Western blot, cytokine production by ELISA, T cell proliferation and polarization by allogeneic mixed lymphocyte reaction. DC differentiation into osteoclasts was evaluated in terms of tartrate-resistant acid phosphatase production and formation of resorption pits in dentine slices. Induction of joint inflammation in vivo was evaluated using a murine model of DC-induced arthritis. TLR7/8 involvement was assessed by specific inhibitors. RESULTS: Ex-miRNAs activate DCs to secrete TNFα, induce joint inflammation, start an early autoimmune response and potentiate the differentiation of DCs into aggressive osteoclasts. CONCLUSIONS: This work represents a proof of concept that the pool of extracellular miRNAs overexpressed in RA joints can act as a physiological activator of inflammation via the stimulation of TLR8 expressed by human DCs, which in turn exert arthritogenic functions. In this scenario, pharmacological inhibition of TLR8 might offer a new therapeutic option to reduce inflammation and osteoclast-mediated bone destruction in RA.

Inhibitory receptors of plasmacytoid dendritic cells as possible targets for checkpoint blockade in cancer.

Plasmacytoid dendritic cells (pDCs) are the major producers of type I interferons (IFNs), which are essential to mount antiviral and antitumoral immune responses. To avoid exaggerated levels of type I IFNs, which pave the way to immune dysregulation and autoimmunity, pDC activation is strictly regulated by a variety of inhibitory receptors (IRs). In tumors, pDCs display an exhausted phenotype and correlate with an unfavorable prognosis, which largely depends on the accumulation of immunosuppressive cytokines and oncometabolites. This review explores the hypothesis that tumor microenvironment may reduce the release of type I IFNs also by a more pDC-specific mechanism, namely the engagement of IRs. Literature shows that many cancer types express de novo, or overexpress, IR ligands (such as BST2, PCNA, CAECAM-1 and modified surface carbohydrates) which often represent a strong predictor of poor outcome and metastasis. In line with this, tumor cells expressing ligands engaging IRs such as BDCA-2, ILT7, TIM3 and CD44 block pDC activation, while this blocking is prevented when IR engagement or signaling is inhibited. Based on this evidence, we propose that the regulation of IFN secretion by IRs may be regarded as an "innate checkpoint", reminiscent of the function of "classical" adaptive immune checkpoints, like PD1 expressed in CD8+ T cells, which restrain autoimmunity and immunopathology but favor chronic infections and tumors. However, we also point out that further work is needed to fully unravel the biology of tumor-associated pDCs, the neat contribution of pDC exhaustion in tumor growth following the engagement of IRs, especially those expressed also by other leukocytes, and their therapeutic potential as targets of combined immune checkpoint blockade in cancer immunotherapy.