Figure 2. Mitochondrial FAO is not required for memory T cell formation.

(A) CD8⁺ OT-I T cells were activated with OVA peptide in the presence of IL-2 for 3 days, followed by culture with either IL-2 or IL-15 for 4 days to generate IL-2 T_eff and IL-15 T_mem cells. Expression of CD62L and CD44 on T cells of the indicated genotypes is shown. One of two experiments is shown.

(B) OCR of WT and TCpt1a IL-15 T_mem and IL-2 T_eff cells. Oligomycin (Oligo), FCCP, and rotenone and antimycin A (Rote/AA) were injected as indicated. Graphs show mean ± SEM.

(C) OCR of in vitro generated IL-15 OT-I T_mem cells assayed with 200 μM BSA-conjugated palmitate under basal conditions (left panel) and in response to FCCP (right panel). Results for maximal OCR are expressed as a percent increase in OCR relative to BSA-treated cells. Graphs show mean ± SEM, one experiment is shown.

(D) Mass isotopomer distribution (MID) of U-[¹³C]-palmitate-derived TCA cycle intermediates in WT and TCpt1a IL-15 T_mem cells. T_mem cells were cultured for 24hr in medium containing U-[¹³C]-palmitate (200 μM), and ¹³C-isotopomer distribution in citrate, α-ketoglutatrate, fumarate and malate was determined by GC-MS. The percent distribution of each isotopomer for their respective metabolite pool is shown. The overall metabolite pool size is represented by the size of the pie chart. Data are normalized to cell number (n = 3), one of two experiments is shown.

(E) WT and TCpt1a mice were immunized with a sublethal dose of attLmOVA and re-challenged 34 days later. Antigen-specific CD8⁺ cells (left panels) and cytokine production in antigen specific CD4⁺ (center panels) and CD8⁺ (right panels) cells were quantified. Data of one experiment, n=5 per group, female.

(F) WT and ACC2^ko mice were infected with 5×10³ CFU of LmOVA and re-challenged after 10 weeks. Splenocytes were analyzed as in (E). Data of one experiment, n=5 per group, male

(G) Mice deficient in long-chain acyl-CoA dehydrogenase (LCAD) and very long-chain acyl-CoA dehydrogenase (VLCAD) were infected with influenza virus (X31) and one month later re-infected with adapted human influenza virus (PR8, n=5 per group, male). Expression of viral nucleoprotein (NP) mRNA in the lungs of infected mice was measured.

(H) CD4⁺ and CD8⁺ memory T cells in patients with inherited deficiencies in long-chain (N=5) and medium-chain fatty (N=3) acid oxidation and healty controls (N=7) were evaluated by clinical flow cytometry and their age-adjusted Z score calculated.

ns depicts not significant (p>0.05) or numeric values represent p values for that comparison.