Biomedicines (Jul 2022)

Vitamin D-Dimer: A Possible Biomolecule Modulator in Cytotoxic and Phagocytosis Processes?

  • Ralf Herwig,
  • Katharina Erlbacher,
  • Amela Ibrahimagic,
  • Mehtap Kacar,
  • Naime Brajshori,
  • Petrit Beqiri,
  • Joachim Greilberger

DOI
https://doi.org/10.3390/biomedicines10081785
Journal volume & issue
Vol. 10, no. 8
p. 1785

Abstract

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Background: Vitamin D3 complexed to deglycosylated vitamin D binding protein (VitD-dgVDBP) is a water-soluble vitamin D dimeric compound (VitD-dgVDBP). It is not clear how VitD-dgVDBP affects circulating monocytes, macrophages, other immune cell systems, including phagocytosis and apoptosis, and the generation of reactive oxygen species (ROS) compared to dgVDBP. Methods: Flow cytometry was used to measure superoxide anion radical (O2*−) levels and macrophage activity in the presence of VitD-dgVDBP or dgVDBP. VitD-dgVDBP was incubated with normal human lymphocytes (nPBMCs), and several clusters of determination (CDs) were estimated. dgVDBP and VitD-dgVDBP apoptosis was estimated on malignant prostatic cells. Results: The macrophage activity was 2.8-fold higher using VitD-dgVDBP (19.8·106 counts) compared to dgVDBP (7.0·106 counts), but O2*− production was 1.8-fold lower in favor of VitD-dgVDBP (355·103 counts) compared to dgVDBP (630·106 counts). The calculated ratio of the radical/macrophage activity was 5-fold lower compared to that of dgVDBP. Only VitD-dgVDBP activated caspase-3 (8%), caspase-9 (13%), and cytochrome-C (11%) on prostatic cancer cells. PE-Cy7-labeled VitD-dgVDBP was found to bind to cytotoxic suppressor cells, monocytes/macrophages, dendritic and natural killer cells (CD8+), and helper cells (CD4+). After 12 h of co-incubation of nPBMCs with VitD-dgVDBP, significant activation and expression were measured for CD16++/CD16 (0.6 ± 0.1% vs. 0.4 ± 0.1%, p + (96.0 ± 6.0% vs. 84.7 ± 9.5%, p + (24.3 ± 13.2% vs. 3.8 ± 3.2%, p +/CD123+ (46.8 ± 8.1% vs. 3.5 ± 3.7%, p p 3 form VitD-dgVDBP affected cytotoxic suppressor cells by activating the low radical-dependent CD16 pathway and seemed to induce apoptosis in malignant prostatic cells.

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