Expression profiling by high throughput sequencing
Summary
Purpose: We aim to identify transciptional changes of human CD4+/CD8+ T cells due to high fat low carbohydrate ketogenic diet (KD) in vivo. Method: Healthy volunteers conducted a 21 days ketogenic diet, limiting carbohydrate intake to <30g/day. Before the start (T0) and at the end (T1) of the diet, blood samples were taken and PBMC were isolated. PBMCs were obtained by density centrifugation (Histopaque 1077, Sigma-Aldrich, St. Louis, MO, USA). A ViCell analyzer (Beckman Coulter, Fullerton, CA, USA) was used to evaluate the cell count and viability. Only samples exceeding a cell viability of 90% were processed further. PBMCs were subjected to cell cultivation in RPMI 1640 (Invitrogen, Carlsbad, CA, USA) containing 10% heat-inactivated fetal calf serum (Biochrom, Berlin, Germany), 1% HEPES (Sigma-Aldrich, St. Louis, MO) and 1% L-glutamine (Life Technologies, Carlsbad, CA, USA). T cells were stimulated via the addition of CD3/CD28 Dynabeads (Thermo Fisher Scientific, Waltham, MA, USA) with a bead-to-cell ratio of 1:8 for a duration 24 hours. After stimulation, CD3/CD28 Dynabeads were magnetically removed. Pan T cell-, CD4+- and CD8+-cell-isolation was performed by magnetic cell separation (Pan T Cell Isolation Kit, # 130-096-535 | human CD4 MicroBeads, # 130-045-101 | human CD8 MicroBeads, # 130-045-201, Miltenyi Biotec, Bergisch Gladbach, Germany) using an AutoMACS Pro Separator ( # 130-092-545, Miltenyi Biotec, Bergisch-Gladbach, Germany) according to the manufacturer’s instructions. Results: 11.545 expressed genes were identified, for CD4/CD8 T cells, we detected 5.667/ 5.799 up-regulated genes and 5.878/5.746 down-regulated genes. 294/346 genes and 325/252 genes were significantly up/down-regulated for CD4+/CD8+ T cells (p-val. <0.05). Gene set enrichment analysis revealed 117/17 and 22/6 significantly up/down-regulated pathways for CD4+/CD8+ T cells (p-val. <0.05). Genes and Gene sets differentially regulated were relevant for T cell immune response and metabolic function. Conclusion: KD resulted in immunometabolic reprogramming of human CD4+/CD8+ T cells.
Overall design
RNAseq analysis of human CD4+/CD8+ T cells prior and post 21 days of ketogenic diet