Immune cell activation after stimulation with <i>M</i>. <i>luminyensis</i>.

<p>Cytokine release after stimulation of 1×10⁵ PBMCs <b>(A)</b> as well as 1×10⁵ moDCs <b>(B)</b> with 1×10⁶ and 1×10⁷ <i>M</i>. <i>luminyensis</i> or <i>M</i>. <i>stadtmanae</i> cells for 20 h was quantified using commercial ELISA-Kits. Unstimulated cells (Med. ctrl.) were used as negative controls. Depicted data are means of at least 3 independent biological replicates with their respective standard errors of the mean (SEM). Values are compared to medium control. ns: not significant, * <i>P</i>≤0.05, ** <i>P</i>≤0.01, *** <i>P</i>≤0.001 (one-way ANOVA with Bonferroni post hoc test). <b>C)</b> 1×10⁵ moDCs were stimulated with 1×10⁷ FITC-labeled methanoarchaeal cells in VI channel μ-slides for a period of 16 h. After incubation, moDCs were washed, fixed with 3% paraformaldehyde and DNA was labeled with Hoechst 33342. Images were captured using Leica SP5 confocal microscope with Leica confocal software and are representative of the respective samples (three independent biological replicates). <b>D)</b> Phagocytosis rate of <i>M</i>. <i>stadtmanae</i> and <i>M</i>. <i>luminysensis</i> by moDCs was determined by counting phagocytosed archaeal cells in image sections of three biological replicates (mean of counted moDCs: Medium ctrl = 34, moDCs stimulated with <i>M</i>. <i>stadtmane</i> = 56, moDCs stimulated with <i>M</i>. <i>luminyensis</i> = 45). Values are compared to each-other. *** <i>P</i>≤0.001 (two-tailed unpaired t-test).