Figure 5.

The secretion of cytokines by T cells developed from spleen and Peyer’s patch (PP) cells in response to various bacteria. Spleen and PP cells prepared from ovalbumin-specific T-cell receptor transgenic (OVA-TCR-Tg) mice were primarily cultured with or without various bacteria (10 μg/ml) in the presence of OVA for 6 days in order to induce the development of effector T helper (Th) cells. CD4⁺ T cells were enriched from the cultured cells and re-stimulated with OVA plus irradiated BALB/c mouse spleen cells as antigen-presenting cells for 2 days. The levels of interferon (IFN)-γ and interleukin (IL)-17 in culture supernatants were determined by enzyme-linked immunosorbent assay (ELISA). The data are the mean ± standard deviation of triplicate cultures. All experiments were repeated twice with similar results. *P < 0·05; **P < 0·01, compared with the OVA-only groups. White bars, OVA only; black bars, Lactobacillus casei; bars with oblique lines, Bifidobacterium bifidum; grey bars, Staphylococcus aureus; hatched bars, Escherichia coli.