Enhanced Fatty Acid Synthesis Leads to Subset Imbalance and IFN-γ Overproduction in T Helper 1 Cells.

Recent reports have shown the importance of IFN-γ and T-bet B cells in the pathology of SLE, suggesting the involvement of IFN-γ-producing T-bet CD4 cells, i.e., Th1 cells. This study determined the changes in Th1 subsets with metabolic shift and their potential as therapeutic targets in SLE. Compared with healthy donors, patients with SLE had higher numbers of T-betCXCR3 effector cells and T-betFoxp3 non-suppressive cells, which excessively produce IFN-γ, and lower number of non-IFN-γ-producing T-betFoxp3 activated-T cells. These changes were considered to be involved in treatment resistance. The differentiation mechanism of Th1 subsets was investigated using memory CD4 cells obtained from healthy donors and patients with SLE. In memory CD4 cells of healthy donors, both rapamycin and 2-deoxy-D-glucose (2DG) suppressed T-betFoxp3 cells, and induced T-betFoxp3 cells. Rapamycin induced IFN-γ-producing T-betFoxp3 cells accompanied with enhanced lipid metabolism, whereas 2DG induced IFN-γ-non-producing T-betFoxp3 cells. In memory CD4 cells of SLE patients, inhibition of fatty acid synthesis, but not β-oxidation, suppressed IFN-γ production, and up-regulated of Foxp3 expression in T-betFoxp3 cells. Metabolic regulators such as fatty acid synthesis inhibitors may improve the pathological status by correcting Th1 subset imbalance and overproduction of IFN-γ in SLE.