Synthesis of Mannosylated Lipopeptides with Receptor Targeting Properties

Abstract

Present on the surface of antigen presenting cells (APCs), the mannose receptor (MR) has long been recognized as a front-line receptor in pathogen recognition. During the past decade many attempts have been made to target this receptor for applications including vaccine and drug development. In the present study, a library of vaccine constructs comprising fluorescently labeled mannosylated lipid-dendrimers that contained the ovalbumin CD4(+) epitope, OVA(323-339), as the model peptide antigen were synthesized using fluorenylmethyloxycarbonyl (Fmoc) solid phase peptide synthesis (SPPS). The vaccine constructs were designed with an alanine spacer between the O-linked mannose moieties to investigate the impact of distance between the mannose units on receptor-mediated uptake and/or binding in APCs. Uptake studies performed on F4/80(+) and CD11c(+) cells showed significant uptake and/or binding for lipopeptides containing mannose, and also the lipopeptide without mannose when compared to the control peptides (peptide with no lipid and peptide with no mannose and no lipid). Furthermore, mannan inhibition assays demonstrated that uptake of the mannosylated and lipidated peptides was receptor mediated. To address the specificity of receptor uptake, surface plasmon resonance studies were performed using biacore technology and confirmed high affinity of the mannosylated and lipidated vaccine constructs toward the MR. These studies confirm that both mannose and lipid moieties play significant roles in receptor-mediated uptake on APCs, potentially facilitating vaccine development.

Mannosylation of budesonide palmitate nanoprodrugs for improved macrophage targeting

“…The results suggest that the pre-incubation of cells with mannan probably leads to the saturation of mannose receptors on the cell surface, confirming mannose receptor-mediated uptake of mannosylated nanoprodrugs. Our results are in agreement with mannose receptor-mediated mechanisms as shown by others [33].…”

“…After 24h, the medium was replaced with a fresh medium DMEM containing 1% bovine serum albumin (BSA), 25 mM HEPES, 3 mM CaCl 2, and mannan 1%, and the cells were incubated for 2h. PEGylated and mannosylated nanoprodrugs were added at the final BP concentration of 25μg/mL and incubated for 24 and 48 hours at 37 o C. DMEM medium was used for negative control [30][31][32][33]. Flow cytometry experiments were performed as described above.…”

Systematic Dual Targeting of Dendritic Cell C-Type Lectin Receptor DC-SIGN and TLR7 Using a Trifunctional Mannosylated Antigen

“…Another approach for the development of well-defined anti-cancer vaccines entails the covalent attachment of other adjuvants to the antigens of choice, targeting other Pattern Recognition Receptors (PRR), such as members of the Toll-Like Receptor (TLR) family (Deres et al, 1989; Cho et al, 2000; Blander and Medzhitov, 2006; Fujita and Taguchi, 2012; Willems et al, 2014), the NOD-like receptor (NLR) family (Willems et al, 2016), or combinations thereof (Buskas et al, 2005; Moyle et al, 2007; Sedaghat et al, 2016; Zom et al, 2019). PAMP recognition by TLRs induces DC maturation, stimulating antigen processing, and presentation for the induction of pathogen-specific T cells (Ackerman and Cresswell, 2003).…”

Liposomal Formulations of a Polyleucine–Antigen Conjugate as Therapeutic Vaccines against Cervical Cancer

“…We designed our ligands ( M1 – M3 ) to have different spacer lengths between the mannose and lipidic moieties, where the importance of these spacers has been previously reported [ 3 , 43 , 44 , 45 ]. We have also demonstrated the mechanism of mannose-receptor-mediated uptake [ 46 ]. Importantly, the ability of M2 anchored into liposomes to greatly enhance humoral immune responses against a bacterial antigen has also been proven (unpublished data).…”