2.4 Peripheral blood mononuclear cells (PBMCs) functional assay; in vitro stimulation and cytokine measurement
Out of 99 healthy individuals, blood samples from 61 individuals were available for the in vitro functional assay. Whole blood samples were prepared for PBMCs extraction facilitated by Ficoll-Paque PLUS density gradient centrifugation. Cleaned PBMCs were suspended in PBS with EDTA, and cells were counted using Bio-Rad TC20 Automated Cell Counter (Bio-Rad, CA, US). 3 × 106 cells were used for stimulation. PBMCs were challenged with or without 8.33 ng/ml of lipopolysaccharide (LPS, List Biological Laboratories Inc.) for 4 h at 37°C, centrifuged at 400 g and supernatants stored at −80°C until further analysis. All incubations were performed in triplicates and thereafter pooled. The pooled samples were analysed in singlicates using the Bio-Plex Pro Human Cytokine Grp 1 Panel 17-plex assay (Cat. #M5000031YV, Bio Rad Laboratories, Inc. Hercules, USA, including G-CSF, GM-CSF, IFNγ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12(p70), IL-13, IL-17A, MCP-1, MIP-1β, TNFα) according to the manufacturer’s protocol.
Author did not specify which List Labs LPS product was utilized in their research.
List Labs provides the following LPS products: https://listlabs.com/product-information/lipopolysaccharides/