Figure 1.

GPR41 and GPR43 promote MPEC differentiation and CD8⁺ T cell function following HSV-1 infection. Ffar2^–/–;Ffar3^–/– and C57BL/6 wildtype (WT) mice were infected with 1 × 10⁶ plaque-forming units (PFU) HSV-1 epicutaneously. (A–D) 9 days after infection, endogenous gB_498-505-specific CD8⁺ T cells were analysed for absolute numbers and frequencies of total CD8⁺ T cells in the spleen (A) and skin (B) and proportions of memory precursor effector cells (MPECs) and short-lived effector cells (SLECs) in the spleen (C) and skin (D). (E–I) Expression of IFN-γ and TNF-α by total CD8⁺ T cells was measured upon a 5-hour ex vivo re-stimulation of splenocytes (E–H) or cells isolated from the skin (I) using gB_498-505 (E), RR1_822-829 (F) or RR1_982-989 peptide (G) in the presence of brefeldin A. Granzyme B (GzmB) and perforin were analysed without re-stimulation (H, I). (J) Absolute numbers of endogenous gB_498-505-specific CD69⁺CD103⁺ skin T_RM were measured 32 days after infection. Data are presented as representative contour plots or bar plots with mean + SEM of n = 8 – 19 mice per group from at least 2 independent experiments. Asterisks indicate statistically significant differences as analysed by Student’s t-tests (non-significant (ns) p ≥ 0.05, *p < 0.05, **p < 0.01, ***p < 0.001).