Fig. 5. Skin CD4⁺ T cells display antigen-specific responses to H. polygyrus.

Mice were infected with H. polygyrus (Hp) or not (−). a–c Soluble worm antigen (SWAg) from H. polygyrus (and PBS (P) in contralateral side as control) was injected in the back skin four weeks post infection. Fold change of mRNA expression of indicated cytokines analysed by qPCR. d Footpad swelling after SWAg injection in anti-MHC-II antibody or isotype treated mice and in e FYT720 or PBS treated mice as indicated. f Footpad swelling after injection of antigen from adult N. brasiliensis (Nb) or g stage L3 N. brasiliensis larvae (L3 Nb), 4 weeks post Hp infection. PBS was injected in the contralateral side as control. h Representative FACS plots of Ki-67⁺ cells gated on skin CD4⁺ , CD44⁺ T cells. i Frequency of Ki-67⁺ cells out of skin CD4⁺ , CD44⁺ T cells. j Fold change of Ki67 mRNA expression analysed by qPCR. k–m Mice were injected daily with FTY720 or PBS ip 1 day prior to and 3 days after a 10 days infection with Hp. k, l Frequencies of T_H2 (ST2⁺ , Foxp3⁻) and T_H1 (Tbet⁺ , CXCR3⁺ ) cells out of CD4⁺ , CD44⁺ T cells (the dashed line show average levels in uninfected mice from previous experiments), 2 weeks after end of treatment. m Footpad swelling after SWAg injection in FYT720-treated and untreated mice as indicated. One out of at least two independent experiments with similar results are shown. Each dot represents the mean ± SEM of a group of mice (n = 5) in line graphs and an individual mouse in bar graphs where bars indicate the mean ± SEM. Statistical differences were analysed by Mann–Whitney U test (a–c) or unpaired t-tests (d, k–m) and depicted as *p < 0.05, **p < 0.01, ***p < 0.001. In d and m statistical comparisons are made to the Hp-infected, SWAg footpad injected but PBS ip injected group.