TY - JOUR T1 - Mannosylated Mucin-Type Immunoglobulin Fusion Proteins Enhance Antigen-Specific Antibody and T Lymphocyte Responses A1 - Ahlén, Gustaf A1 - Strindelius, Lena A1 - Johansson, Tomas A1 - Nilsson, Anki A1 - Chatzissavidou, Nathalie A1 - Sjöblom, Magnus A1 - Rova, Ulrika A1 - Holgersson, Jan Y1 - 2012/10/12 N2 - Targeting antigens to antigen-presenting cells (APC) improve their immunogenicity and capacity to induce Th1 responses and cytotoxic T lymphocytes (CTL). We have generated a mucin-type immunoglobulin fusion protein (PSGL-1/mIgG2b), which upon expression in the yeast Pichia pastoris became multivalently substituted with O-linked oligomannose structures and bound the macrophage mannose receptor (MMR) and dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) with high affinity in vitro. Here, its effects on the humoral and cellular anti-ovalbumin (OVA) responses in C57BL/6 mice are presented. OVA antibody class and subclass responses were determined by ELISA, the generation of anti-OVA CTLs was assessed in 51Cr release assays using in vitro-stimulated immune spleen cells from the different groups of mice as effector cells and OVA peptide-fed RMA-S cells as targets, and evaluation of the type of Th cell response was done by IFN-γ, IL-2, IL-4 and IL-5 ELISpot assays. Immunizations with the OVA − mannosylated PSGL-1/mIgG2b conjugate, especially when combined with the AbISCO®-100 adjuvant, lead to faster, stronger and broader (with regard to IgG subclass) OVA IgG responses, a stronger OVA-specific CTL response and stronger Th1 and Th2 responses than if OVA was used alone or together with AbISCO®-100. Also non-covalent mixing of mannosylated PSGL-1/mIgG2b, OVA and AbISCO®-100 lead to relatively stronger humoral and cellular responses. The O-glycan oligomannoses were necessary because PSGL-1/mIgG2b with mono- and disialyl core 1 structures did not have this effect. Mannosylated mucin-type fusion proteins can be used as versatile APC-targeting molecules for vaccines and as such enhance both humoral and cellular immune responses. JF - PLOS ONE JA - PLOS ONE VL - 7 IS - 10 UR - https://doi.org/10.1371/journal.pone.0046959 SP - e46959 EP - PB - Public Library of Science M3 - doi:10.1371/journal.pone.0046959 ER -