Aflatoxins of type B and G affect porcine dendritic cell maturationin vitro

Abstract

The toxic effects of highly carcinogenic mycotoxins, especially aflatoxins (AF), on key antigenpresenting cells, such as dendritic cells (DC), are largely unknown. To elucidate the effect of AF on DC function, porcine monocyte-derived DC (MoDC) were treated with a mixture of several AF (i.e., AFB 1 , AFB 2 , AFG 1 , and AFG 2 ) and the phagocytic capacity, the membrane expression level of several DC activation markers, the T-cell proliferation-inducing capacity, and the cytokine secretion pattern were assessed. As compared to untreated MoDC, AF significantly up-regulated the expression of the co-stimulatory molecules CD25 and CD80/86. However, the phagocytic activity of MoDC was not affected by AF treatment. While the cytokine secretion pattern of AF-treated MoDC was similar to control MoDC, the T-cell proliferation-inducing capacity of MoDC was increased upon aflatoxin treatment. The results indicate that a mixture of naturally occurring AF enhances the antigen-presenting capacity of DC, which could explain the observed immunotoxicity of AF by breaking down tolerance and further emphasizes the need to reduce the admissible level of AF in agricultural commodities.

Effects of arsenic on porcine dendritic cells in vitro

“…Indeed, the increased expression of CD25, CD40 and CD80/86 indicated an activation of the As-treated DC. Interestingly, As did not affect MHC-II surface levels, which might explain the reduced T-cell proliferation-inducing capacity of As-treated MoDC (Mehrzad et al 2015). Immunotoxicologically though incomparable, nonetheless, this diminished T-cell proliferationinducing activity is in line with a diminished cell-mediated immunity in piglets fed with other environmental toxicants (Meissonnier et al 2008;Hong et al 2015).…”

“…Monocytes were further enriched to >97% purity (Supplementary material) by use of positive immunomagnetic bead selection (MACS; Miltenyi Biotec, Bergisch Gladbach, Germany) using kit-provided anti-CD172a monoclonal antibody (mAb, clone 74-12-15a) and goat anti-mouse microbeads together with LS separation columns (Miltenyi Biotec) (Devriendt et al 2010;Mehrzad et al 2015). Final isolates of CD172a þ monocytes were re-suspended in phenol-red-free Dulbecco's modified Eagle's Medium (DMEM; Gibco, Merelbeke), supplemented with 10% (v/v) fetal calf serum (FCS, Greiner Bio One, Wemmel, Belgium), 100 U penicillin/ml and 100 lg streptomycin/ml (Gibco, Grand Island, NY), $800 U recombinant porcine (rp) granulocyte-macrophage colony-stimulating factor (GM-CSF)/ml and 5 ng rpIL-4/ml (R&D systems, Abingdon, UK) and counted.…”

“…Final isolates of CD172a þ monocytes were re-suspended in phenol-red-free Dulbecco's modified Eagle's Medium (DMEM; Gibco, Merelbeke), supplemented with 10% (v/v) fetal calf serum (FCS, Greiner Bio One, Wemmel, Belgium), 100 U penicillin/ml and 100 lg streptomycin/ml (Gibco, Grand Island, NY), $800 U recombinant porcine (rp) granulocyte-macrophage colony-stimulating factor (GM-CSF)/ml and 5 ng rpIL-4/ml (R&D systems, Abingdon, UK) and counted. Thereafter, the cells were plated into wells of 24-well plates (Nunc, Thermo Fisher Scientific, Langenselbold, Germany) at 5.0 Â 10 5 cells/ml and incubated at 37 C in a humidified atmosphere at 5% CO 2 to generate MoDC as previously described (Devriendt et al 2010;Mehrzad et al 2015). On Day 3 of culture, fresh medium supplemented with the same levels of rpGM-CSF and rpIL-4 was added.…”

“…The T-cell stimulatory capacity of MoDC was analyzed in an allogeneic T-cell polarization assay as previously described (Devriendt et al 2013;Mehrzad et al 2015). Tcells were isolated from the original PBMC fractions by enriching CD6 þ cells to a >95% purity by positive immunomagnetic selection with anti-CD6 mAb (IgG 1 , clone a38b2) and goat anti-mouse micro-beads, together with an LS column (Miltenyi Biotec).…”

Stressed (acute) mice display neuroimmunodysregulation and defective innate immune response against coliform infection

“…Splenic immune cells and brain (sagittal sections of frontal part of whole brain) were separated accordingly [10,16]. The harvested RBC-free splenic cell suspensions were then washed (400 × g, 10 min, 4°C) twice with RPMI-1640, counted (in nigrosin solution) in a Neubauer chamber, and after cell viability assessment using nigrosin solution and the Neubauer chamber, in which necrotic cells appeared bright and dark-blue in the mixture [10][11][12][13][14][15][16], respectively, the cells and brain were eventually used for further cellular and molecular analyses.…”