Lipo-Based Vaccines as an Approach to Target Dendritic Cells for Induction of T- and iNKT Cell Responses

Abstract

In this study we developed a liposome-based vaccine containing palmitoylated synthetic long peptides (SLP) and alpha galactosylceramide (αGC) to specifically target dendritic cells (DC) for activation of both innate (invariant natural killer T-cells [iNKT]) and adaptive (CD8 + T-cells) players of the immune system. Combination of model tumor specific antigens (gp100/MART-1) formulated as a SLP and αGC in one liposome results in strong activation of CD8 + and iNKT, as measured by IFNγ secretion. Moreover, addition of lipo-Lewis Y (Le Y) to the liposomes for C-type lectin targeting increased not only uptake by monocyte-derived dendritic cells (moDC), dermal dendritic cells and Langerhans cells but also enhanced gp100-specific CD8 + T-and iNKT cell activation by human skin-emigrated antigen presenting cells in an ex vivo explant model. Loading of moDC with liposomes containing Le Y also showed priming of MART-1 26−35L specific CD8 + T-cells. In conclusion, chemically linking a lipid tail to a glycan-based targeting moiety and SLP combined with αGC in one liposome allows for easy generation of vaccine formulations that target multiple skin DC subsets and induce tumor antigen specific CD8 + T-and iNKT cells. These liposomes present a new vaccination strategy against tumors.

Liposomal Nanovaccine Containing α-Galactosylceramide and Ganglioside GM3 Stimulates Robust CD8+ T Cell Responses via CD169+ Macrophages and cDC1

“…OVA-containing GM3, αGC and GM3-αGC liposomes were prepared using the dry film extrusion technique at the Department of Pharmaceutics, Faculty of Science, Utrecht University (Utrecht, The Netherlands), as previously described [ 39 ]. In brief, a lipid mixture containing egg phosphatidylcholine (EPC)-35 (Lipoid), egg phosphatidylglycerol (EPG)-Na (Lipoid) and Cholesterol (Sigma-Aldrich, Darmstadt, Germany) (molar ratio 3.8:1:2.5) dissolved in chloroform/methanol (2:1) was combined with 3 mol% GM3 ganglioside and/or α-galactosylceramide, KRN7000 (Funakoshi, Tokyo, Japan) (30 μg) and 0.1 mol% of the lipophilic fluorescent tracer DiD (1′-dioctadecyl-3,3,3′,3′-tetramethyl indodicarbocyanine, Life Technologies, Frederick, MD, USA).…”

“…Antigen encapsulation efficiency was around 2% (15–20 µg/mL) as determined by sandwich ELISA. The amount of αGC in the liposomes was determined as described previously (+/−20 ug/mL) [ 39 ]. The liposome dose used in the experiments was based on the molar concentration of phospholipids determined as described previously [ 40 ].…”

Optimization of Liposomes for Antigen Targeting to Splenic CD169+ Macrophages

“…Alternatively, liposomes drain to the lymph nodes, or the spleen when the liposomes are administered intravenously (IV), after which the liposomes are taken up by tissue-resident APCs [19,20]. While the uptake of non-modified liposomes relies on the intrinsic capacity of APCs to take up particulate antigens, liposomes that contain targeting moieties enable more specific targeting to particular types of APCs and thereby augment liposomal payload delivery and T-cell priming [21][22][23][24].…”

“…Multiple cell types within the myeloid compartment are considered as potential targets for cancer vaccines, such as different types of DCs and Langerhans cells (LCs), that can be targeted via their DEC205, Clec9a, DC-SIGN or langerin surface receptors [21][22][23][24]. In addition, recent interest in vaccine targeting was drawn to CD169, also known as Siglec-1 or sialoadhesin, which is the first discovered member of the Siglec family (sialic-acid-binding immunoglobulin-like lectins) [25].…”

The role of donor‐unrestricted T‐cells, innate lymphoid cells, and NK cells in anti‐mycobacterial immunity

“…181 Additional efforts are underway to design lipid-based vaccine strategies able to induce NKT-cell responses. 182…”