Fig. 5: B cells from elderly individuals induce pro-inflammatory CD4+ T cells through metabolic and inflammatory pathways.
From: Immunometabolic effects of lactate on humoral immunity in healthy individuals of different ages
B cells from young (white symbols) and elderly (blue symbols) individuals were cultured at the bottom of transwells together with CD4+ T cells, sorted from young individuals, placed at the top of transwells. After 24 hrs, CD4+ T cells were harvested, mRNA extracted and qPCR performed. a Fold-change in RNA expression of metabolic markers (Glut1/LDHA/PDHX). Fold-change is the ratio of RNA expression in CD4+ T cells co-cultured with B cells (from either young or elderly individuals)/RNA expression in CD4+ T cells co-cultured without B cells. Results show mean ± SE. b Fold-change in cytokine secretion (IL-17A/IFN-γ) measured by CBA. Fold-change is the ratio of IL-17A and IFN-γ in co-cultures with B cells (from either young or elderly individuals)/IL-17A and IFN-γ in co-cultures without B cells (only CD4+ T cells). Results show mean ± SE. c, d CD4+ T cells from co-cultures with B cells from young or elderly individuals were run at the concentration of 2 × 105/well in triplicate in a mitostress test. OCR and ECAR results are representative of two independent experiments. e Lactate measured in co-cultures of B cells from young or elderly individuals after 48 hrs by ELISA, mean ± SE. f Cytoplasmic (CE) and nuclear (NE) protein extracts (5 μg/lane) from CD4+ T cells from young individuals, co-cultured with B cells from young or elderly individuals, were blotted with the indicated antibodies. Results are representative of 3 independent experiments. Densitometric analyses of p65 normalized to UBC9 are shown for these samples below the images, mean ± SE. g Top, representative flow cytometry histograms of p-STAT3 in CD4+ T cells after co-culture with B cells from either young (black) or elderly (blue) individuals, as compared to CD4+ T cells alone (gray), same individuals in f. Bottom, MFI results from all 3 individuals, mean ± SE (MFI from CD4+ T cells alone = 349 ± 33). Source data are provided as a Source Data file. Mean comparisons between groups were performed by unpaired Student’s t test (two-tailed). **p < 0.01, ***p < 0.001, ****p < 0.0001.
