A new marine-derived sulfoglycolipid triggers dendritic cell activation and immune adjuvant response

Abstract

Dendritic Cells (DCs) recognize infectious non-self molecules and engage the adaptive immune system thereby initiating long lasting, antigen-specific responses. As such, the ability to activate DCs is considered a key tool to enhance the efficacy and quality of vaccination. Here we report a novel immunomodulatory sulfolipid named β-SQDG18 that prototypes a class of natural-derived glycolipids able to prime human DCs by a TLR2/TLR4-independent mechanism and trigger an efficient immune response in vivo. β-SQDG18 induces maturation of DC with the upregulation of MHC II molecules and co-stimulatory proteins (CD83, CD86), as well as pro-inflammatory cytokines (IL-12 and INF-γ). Mice immunized with OVA associated to β-SQDG18 (1:500) produced a titer of anti-OVA Ig comparable to traditional adjuvants. In an experimental model of melanoma, vaccination of C57BL/6 mice with β-SQDG18-adjuvanted hgp10 peptide elicited a protective response with a reduction in tumour growth and increase in survival.

Microalgae with Immunomodulatory Activities

“…Most of these compounds act as vaccine adjuvants improving the immune response by activating APCs [7,49,58]. In Table 1, we have summarized the algae which have shown immunostimulatory activity.…”

“…For instance, it was demonstrated that they are potent glutaminyl cyclase inhibitors, with possible applications against Alzheimer's disease [76]. In addition, sulfolipids have been shown to be able to activate the immune system, with application as vaccine adjuvants [7]. In particular, Manzo et al [7] used microalgae-derived sulfolipids as lead compounds to generate a synthetic sulfoglycolipid (called β-SQDG18) as vaccine adjuvant to trigger a more effective dendritic cell (DC) activation and improve immune response against cancer cell (i.e., B16 mouse melanoma cells).…”

“…Microalgae are a source of several bioactive compounds such as vitamins, lipids, carbohydrates, and pigments. Several studies showed that microalgal raw extracts, fractions, and pure compounds had biological activities [1], such as anticancer [2], anti-microbial [3], anti-epilepsy [4], anti-inflammatory [5,6], and immunomodulatory activities [7].…”

“…Recently, various compounds from microalgae have been found to stimulate the immune system in human and murine models (e.g., modifying macrophage activations and the release of pro-and anti-inflammatory mediators [20][21][22]) and they are promising drugs with potential applications to treat human pathologies [2,7,23].…”

Recent Advances in Microalgal Bioactives for Food, Feed, and Healthcare Products: Commercial Potential, Market Space, and Sustainability

“…In the recent years, microalgal lipid extracts have gained attention as they can act as immunogenic compounds. β‐Sulfoquinovosyl diacylglycerols (β‐SQDG18), a synthetic analog of α‐SQDG from microalgae Thalassiosira weissflogii , effectively stimulates the immune response by inducing the maturation of dendritic cells resulting in cytokine production (Manzo et al., ). Apart from antioxidant and anti‐inflammatory activities, microalgae also possess antimicrobial properties.…”