Thursday, 20 September 2018

Drink your milk! Aiding gut immune homeostasis

Scientists from Wageningen University and Friesland Campina have investigated the immuno-modulatory properties of bovine lactoferrin (LF), an abundant glycoprotein of bovine milk.

Overall, they conclude that LF can play a role in immune homeostasis in the human GI tract, based on the findings that LF modifies dendritic cell (DC) differentiation and reduces the response by DC to TLR ligands.

In one experiment to study whether LF modulates the dendritic cell (DC) differentiation monocytes were differentiated into monocyte-derived DC by culturing them with IL-4 and GM-CSF and with high, low or no LF.

Following the three cell culture regimes, cells were analysed with the following fully-compensated antibody panel and associated chromophores: CD86, V450; anti-CD14, FITC; CD1a, PerCP-Cy5.5; PD-L1, PE-Cy7; HLA-DR, APC-efluor780.  After antibody staining, DRAQ7 was added and incubated for 10 minutes to label the leaky i.e. non-viable cells, for exclusion in the subsequent flow cytometric analysis by BD Biosciences FACSCanto II.

Given the presence of three red/far-red chromophores in the panel DRAQ7-positive events would have been excluded using DRAQ7's unique capacity to be detected in a distinct population in a bivariate plot of the available pairs of red/far-red channels including the unused FL5, without resort to compensation.  Otherwise, the panel would not readily permit the use of conventional viability dyes such as PI, 7-AAD and DAPI.

This is then a representative example of the "virtual" channel exclusion of dead cells.  This is described in detail in a recent white paper:
Channel Free Dead Cell Exclusion with DRAQ7™ - White Paper (PDF)
and a poster presentation at CYTO 2018:

Perdijk, O., van Neerven, R., van den Brink, E., Savelkoul, H., & Brugman, S. (2018). Bovine Lactoferrin Modulates Dendritic Cell Differentiation and Function. Nutrients, 10(7), 848.