PMID- 33968084 OWN - NLM STAT- MEDLINE DCOM- 20211018 LR - 20211018 IS - 1664-3224 (Electronic) IS - 1664-3224 (Linking) VI - 12 DP - 2021 TI - Quantitative Phosphoproteomic Analysis Reveals Dendritic Cell- Specific STAT Signaling After alpha2-3-Linked Sialic Acid Ligand Binding. PG - 673454 LID - 10.3389/fimmu.2021.673454 [doi] LID - 673454 AB - Dendritic cells (DCs) are key initiators of the adaptive immunity, and upon recognition of pathogens are able to skew T cell differentiation to elicit appropriate responses. DCs possess this extraordinary capacity to discern external signals using receptors that recognize pathogen-associated molecular patterns. These can be glycan-binding receptors that recognize carbohydrate structures on pathogens or pathogen-associated patterns that additionally bind receptors, such as Toll-like receptors (TLRs). This study explores the early signaling events in DCs upon binding of alpha2-3 sialic acid (alpha2-3sia) that are recognized by Immune inhibitory Sialic acid binding immunoglobulin type lectins. alpha2-3sias are commonly found on bacteria, e.g. Group B Streptococcus, but can also be expressed by tumor cells. We investigated whether alpha2-3sia conjugated to a dendrimeric core alters DC signaling properties. Through phosphoproteomic analysis, we found differential signaling profiles in DCs after alpha2-3sia binding alone or in combination with LPS/TLR4 co-stimulation. alpha2-3sia was able to modulate the TLR4 signaling cascade, resulting in 109 altered phosphoproteins. These phosphoproteins were annotated to seven biological processes, including the regulation of the IL-12 cytokine pathway. Secretion of IL-10, the inhibitory regulator of IL-12 production, by DCs was found upregulated after overnight stimulation with the alpha2-3sia dendrimer. Analysis of kinase activity revealed altered signatures in the JAK-STAT signaling pathway. PhosphoSTAT3 (Ser727) and phosphoSTAT5A (Ser780), involved in the regulation of the IL-12 pathway, were both downregulated. Flow cytometric quantification indeed revealed de- phosphorylation over time upon stimulation with alpha2-3sia, but no alpha2-6sia. Inhibition of both STAT3 and -5A in moDCs resulted in a similar cytokine secretion profile as alpha-3sia triggered DCs. Conclusively, this study revealed a specific alteration of the JAK-STAT pathway in DCs upon simultaneous alpha2-3sia and LPS stimulation, altering the IL10:IL-12 cytokine secretion profile associated with reduction of inflammation. Targeted control of the STAT phosphorylation status is therefore an interesting lead for the abrogation of immune escape that bacteria or tumors impose on the host. CI - Copyright (c) 2021 Li, de Haas, Rodriguez, Kalay, Zaal, Jimenez, Piersma, Pham, Henneman, de Goeij-de Haas, van Vliet and van Kooyk. FAU - Li, Rui-Jun Eveline AU - Li RE AD - Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - de Haas, Aram AU - de Haas A AD - Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - Rodriguez, Ernesto AU - Rodriguez E AD - Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - Kalay, Hakan AU - Kalay H AD - Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - Zaal, Anouk AU - Zaal A AD - Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - Jimenez, Connie R AU - Jimenez CR AD - Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - Piersma, Sander R AU - Piersma SR AD - Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - Pham, Thang V AU - Pham TV AD - Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - Henneman, Alex A AU - Henneman AA AD - Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - de Goeij-de Haas, Richard R AU - de Goeij-de Haas RR AD - Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - van Vliet, Sandra J AU - van Vliet SJ AD - Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. FAU - van Kooyk, Yvette AU - van Kooyk Y AD - Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20210422 PL - Switzerland TA - Front Immunol JT - Frontiers in immunology JID - 101560960 RN - 0 (Ligands) RN - 0 (STAT Transcription Factors) RN - GZP2782OP0 (N-Acetylneuraminic Acid) SB - IM MH - Antigen Presentation/*immunology MH - Cells, Cultured MH - Dendritic Cells/*immunology/metabolism MH - Humans MH - Ligands MH - N-Acetylneuraminic Acid/*immunology MH - STAT Transcription Factors/*immunology/metabolism MH - Signal Transduction/*immunology PMC - PMC8100677 OTO - NOTNLM OT - Phosphoproteomics OT - STAT3 OT - STAT5 OT - Siglec OT - dendritic cell OT - sialic acid OT - tolerance OT - alpha2-3sia COIS- The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. EDAT- 2021/05/11 06:00 MHDA- 2021/10/21 06:00 PMCR- 2021/01/01 CRDT- 2021/05/10 06:21 PHST- 2021/02/27 00:00 [received] PHST- 2021/04/06 00:00 [accepted] PHST- 2021/05/10 06:21 [entrez] PHST- 2021/05/11 06:00 [pubmed] PHST- 2021/10/21 06:00 [medline] PHST- 2021/01/01 00:00 [pmc-release] AID - 10.3389/fimmu.2021.673454 [doi] PST - epublish SO - Front Immunol. 2021 Apr 22;12:673454. doi: 10.3389/fimmu.2021.673454. eCollection 2021.