Chemical and Pharmacological Prospection of the Ascidian Cystodytes dellechiajei.

Marine invertebrates are a traditional source of natural products with relevant biological properties. Tunicates are soft-bodied, solitary or colonial, sessile organisms that provide compounds unique in their structure and activity. The aim of this work was to investigate the chemical composition of the ascidian Cystodytes dellechiajei, selected on the basis of a positive result in biological screening for ligands of relevant receptors of the innate immune system, including TLR2, TLR4, dectin-1b, and TREM2. Bioassay-guided screening of this tunicate extract yielded two known pyridoacridine alkaloids, shermilamine B (1) and N-deacetylshermilamine B (2), and a family of methyl-branched cerebrosides (3). Compounds 2 and 3 showed selective binding to TREM2 in a dose-dependent manner. N-deacetylshermilamine B (2), together with its acetylated analogue, shermilamine B (1), was also strongly cytotoxic against multiple myeloma cell lines. TREM2 is involved in immunomodulatory processes and neurodegenerative diseases. N-deacetylshermilamine B (2) is the first example of a polycyclic alkaloid to show an affinity for this receptor.

Marine natural product lepadin A as a novel inducer of immunogenic cell death via CD91-dependent pathway.

Immunogenic Cell Death (ICD) represents a mechanism of enhancing T cell-driven response against tumor cells. The process is enabled by release of damage-associated molecular patterns (DAMPs) and cytokines by dying cells. Based on molecular studies and clinical marker assessment, ICD can be a new target for cancer chemotherapy hitherto restricted to a few conventional anticancer drugs. In view of the development of small molecules in targeted cancer therapy, we reported the preliminary evidence on the role of the natural product lepadin A (1) as a novel ICD inducer. Here we describe the ICD mechanism of lepadin A (1) by proving the translocation of the protein calreticulin (CRT) to the plasma membrane of human A2058 melanoma cells. CRT exposure is an ICD marker in clinical studies and was associated with the activation of the intrinsic apoptotic pathway in A2058 cells with lepadin A (1). After the treatment, the tumour cells acquired the ability to activate dendritic cells (DCs) with cytokine release and costimulatory molecule expression that is consistent with a phenotypic profile committed to priming T lymphocytes via a CD91-dependent mechanism. The effect of lepadin A (1) was dose-dependent and comparable to the response of the chemotherapy drug doxorubicin (2), a well-established ICD inducer.

The immunoregulatory effect of the TREM2-agonist Sulfavant A in human allogeneic mixed lymphocyte reaction.

Introduction: Sulfavant A (SULF A) is a synthetic derivative of naturally occurring sulfolipids. The molecule triggers TREM2-related maturation of dendritic cells (DCs) and has shown promising adjuvant activity in a cancer vaccine model. Methods: the immunomodulatory activity of SULF A is tested in an allogeneic mixed lymphocyte reaction (MLR) assay based on monocyte-derived dendritic cells and naïve T lymphocytes from human donors. Flow cytometry multiparametric analyses and ELISA assays were performed to characterize the immune populations, T cell proliferation, and to quantify key cytokines. Results: Supplementation of 10 µg/mL SULF A to the co-cultures induced DCs to expose the costimulatory molecules ICOSL and OX40L and to reduce release of the pro-inflammatory cytokine IL-12. After 7 days of SULF A treatment, T lymphocytes proliferated more and showed increased IL-4 synthesis along with downregulation of Th1 signals such as IFNγ, T-bet and CXCR3. Consistent with these findings, naïve T cells polarized toward a regulatory phenotype with up-regulation of FOXP3 expression and IL-10 synthesis. Flow cytometry analysis also supported the priming of a CD127-/CD4+/CD25+ subpopulation positive for ICOS, the inhibitory molecule CTLA-4, and the activation marker CD69. Discussion: These results prove that SULF A can modulate DC-T cell synapse and stimulate lymphocyte proliferation and activation. In the hyperresponsive and uncontrolled context of the allogeneic MLR, the effect is associated to differentiation of regulatory T cell subsets and dampening of inflammatory signals.

Identification of the Marine Alkaloid Lepadin A as Potential Inducer of Immunogenic Cell Death.

Natural products and their synthetic analogs and derivatives are a traditional source of bioactive molecules with potential development as drug candidates. In this context, Marine Natural Products (MNPs) represent a rich reservoir of diverse molecular skeletons with potential pharmacological activity that, so far, has been mostly explored in cancer and infectious diseases. Starting from the development of a novel bioassay-guided screening platform for immunomodulatory compounds from an in-house MNPs library, we report the identification of the alkaloid lepadin A as a new model compound for immune-based anticancer activity with characteristics that suggest a possible mechanism as Immunogenic Cell Death inducer. The work describes the molecular-based bioprospecting in the Gulf of Naples together with the bioassay-guided fractionation, the chemical characterization of the alkaloid, and the biological activity in mouse dendritic cells (D1).

Homocysteine and education but not lipoprotein (a) predict estimated 10-year risk of cardiovascular disease in blood donors: a community based cross-sectional study.

BACKGROUND: With aging of the population, screening and prevention health programs for blood donors will increasingly be a priority. We aimed at: assessing the 10 year-cardiovascular disease (CVD) risk in blood donors, according to Italian CUORE risk score (CRS); determining the association of homocysteine (Hcy), lipoprotein (Lp)(a) and socio-demographic or lifestyle variables with estimated 10-year CVD risk. METHODS: Between June 2015 and July 2017, 1,447 (61.2% men) unselected blood donors (aged 18-69 years) were enrolled at the Blood Transfusion Service of the Pescara General Hospital, Italy. The project entailed evaluation of unalterable (age and gender) and modifiable CV risk factors (total cholesterol, HDL, LDL, triglycerides, fasting glucose, smoking, hypertension). The educational attainment, socio-demographic and lifestyle behavior information were obtained through a structured self-report questionnaire, and Health-related quality of life (HRQoL) through the Short Form Survey (SF-12). Plasma Hcy and Lp(a) were determined in the fasting state. RESULTS: A CRS within the moderate-high risk range was reported in 21.7% donors. Multivariate logistic regression, after adjustment for clinical and demographic variables, showed that Hcy [OR (95% CI): 1.09 (1.04-1.13); p < 0.001) and low educational attainment [1.71 (1.09-2.73); p = 0.019] are independent risk factors for moderate-to-high CVD risk. Instead, Lp(a), evaluated in 774 donors, was > 30 mg/dL in 22.4% of the examined population, but without any significant correlation with CRS. CONCLUSIONS: Our study highlights a previously unappreciated need for CV risk assessment in blood donors, which may include evaluation of educational attainment as a non-traditional risk marker.

Successful mobilization of peripheral blood stem cells with bortezomib + high-dose cyclophosphamide + G-CSF in a light chain myeloma patient after failure with Total Therapy 2.

Autologous stem cell transplantation is considered the best post-induction therapy for multiple myeloma (MM). Therefore, therapy for myeloma should be chosen not only on the basis of efficacy, but also taking into account their impact on the hematopoietic stem cell compartment. We describe the case of a MM patient in which a successful mobilization of peripheral stem cells was obtained with bortezomib, cyclophosphamide and G-CSF, after two failed attempts in the framework of Total Therapy 2. The patient underwent an autologous transplantation, showing a rapid and complete post-transplant hematological recovery. Our experience suggests that bortezomib is an effective anti-myeloma agent without negative impact on stem cell mobilization, even in patients with a previous history of failed harvest.