1. Sialic acid blockade in dendritic cells enhances CD8 + T cell responses by facilitating high-avidity interactions.
- Author
-
Balneger N, Cornelissen LAM, Wassink M, Moons SJ, Boltje TJ, Bar-Ephraim YE, Das KK, Søndergaard JN, Büll C, and Adema GJ
- Subjects
- Animals, Bone Marrow Cells metabolism, CD8-Positive T-Lymphocytes cytology, CD8-Positive T-Lymphocytes metabolism, Cell Adhesion genetics, Cell Adhesion immunology, Cell Communication genetics, Cell Differentiation genetics, Cell Differentiation immunology, Cell Proliferation genetics, Cell Survival genetics, Cell Survival immunology, Cells, Cultured, Dendritic Cells metabolism, Female, Gene Expression Profiling methods, Lymphocyte Activation genetics, Lymphocyte Activation immunology, Mice, Inbred C57BL, N-Acetylneuraminic Acid antagonists & inhibitors, N-Acetylneuraminic Acid metabolism, Receptors, Antigen, T-Cell genetics, Receptors, Antigen, T-Cell immunology, Receptors, Antigen, T-Cell metabolism, Toll-Like Receptors genetics, Toll-Like Receptors immunology, Toll-Like Receptors metabolism, Mice, Bone Marrow Cells immunology, CD8-Positive T-Lymphocytes immunology, Cell Communication immunology, Dendritic Cells immunology, N-Acetylneuraminic Acid immunology
- Abstract
Sialic acids are negatively charged carbohydrates that cap the glycans of glycoproteins and glycolipids. Sialic acids are involved in various biological processes including cell-cell adhesion and immune recognition. In dendritic cells (DCs), the major antigen-presenting cells of the immune system, sialic acids emerge as important regulators of maturation and interaction with other lymphocytes including T cells. Many aspects of how sialic acids regulate DC functions are not well understood and tools and model systems to address these are limited. Here, we have established cultures of murine bone marrow-derived DCs (BMDCs) that lack sialic acid expression using a sialic acid-blocking mimetic Ac
5 3Fax Neu5Ac. Ac5 3Fax Neu5Ac treatment potentiated BMDC activation via toll-like receptor (TLR) stimulation without affecting differentiation and viability. Sialic acid blockade further increased the capacity of BMDCs to induce antigen-specific CD8+ T cell proliferation. Transcriptome-wide gene expression analysis revealed that sialic acid mimetic treatment of BMDCs induces differential expression of genes involved in T cell activation, cell-adhesion, and cell-cell interactions. Subsequent cell clustering assays and single cell avidity measurements demonstrated that BMDCs with reduced sialylation form higher avidity interactions with CD8+ T cells. This increased avidity was detectable in the absence of antigens, but was especially pronounced in antigen-dependent interactions. Together, our data show that sialic acid blockade in BMDCs ameliorates maturation and enhances both cognate T cell receptor-MHC-dependent and independent T cell interactions that allow for more robust CD8+ T cell responses., (© 2022. The Author(s).)- Published
- 2022
- Full Text
- View/download PDF