Investigating the Immune Basis of Green Tea Extract Induced Liver Injury in Healthy Donors Expressing HLA-B*35:01.

Epigallocatechin-3-O-gallate (EGCG) is the major component of green tea extract, commonly found in dietary supplements, and has been associated with immune-mediated liver injury. The purpose of this study was to investigate the immunogenicity of EGCG in healthy donors expressing HLA-B*35:01, and characterize EGCG responsive T-cell clones. We have shown that EGCG can prime peripheral blood mononuclear cells and T-cells from donors with and without the HLA-B*35:01 allele. T-cell clones were CD4+ve and capable of secreting Th1, Th2, and cytolytic molecules. These data demonstrate that EGCG can activate T-cells in vitro, suggesting a significant role in the pathogenesis of green tea extract induced liver injury.

Exposure of human immune cells, to the antiretrovirals efavirenz and lopinavir, leads to lower glucose uptake and altered bioenergetic cell profiles through interactions with SLC2A1.

SLC2A1 mediates glucose cellular uptake; key to appropriate immune function. Our previous work has shown efavirenz and lopinavir exposure inhibits T cell and macrophage responses, to known agonists, likely via interactions with glucose transporters. Using human cell lines as a model, we assessed glucose uptake and subsequent bioenergetic profiles, linked to immunological responses. Glucose uptake was measured using 2-deoxyglucose as a surrogate for endogenous glucose, using commercially available reagents. mRNA expression of SLC transporters was investigated using qPCR TaqMan™ gene expression assay. Bioenergetic assessment, on THP-1 cells, utilised the Agilent Seahorse XF Mito Stress test. In silico analysis of potential interactions between SLC2A1 and antiretrovirals was investigated using bioinformatic techniques. Efavirenz and lopinavir exposure was associated with significantly lower glucose accumulation, most notably in THP-1 cells (up to 90% lower and 70% lower with efavirenz and lopinavir, respectively). Bioenergetic assessment showed differences in the rate of ATP production (JATP); efavirenz (4 µg/mL), was shown to reduce JATP by 87% whereas lopinavir (10 µg/mL), was shown to increase the overall JATP by 77%. Putative in silico analysis indicated the antiretrovirals, apart from efavirenz, associated with the binding site of highest binding affinity to SLC2A1, similar to that of glucose. Our data suggest a role for efavirenz and lopinavir in the alteration of glucose accumulation with subsequent alteration of bioenergetic profiles, supporting our hypothesis for their inhibitory effect on immune cell activation. Clarification of the implications of this data, for in vivo immunological responses, is now warranted to define possible consequences for these, and similar, therapeutics.