FIG 2.

Adoptive transfer of innate lymphoid cells from the intestinal lamina propria for restoring IL-7R-deficient mice to gain colon resistance to colonization by the IFN-γ-susceptible mutant Chlamydia strain. (a and b) Live lin⁻ (negative for CD3, Ly6G/Ly6C, CD11b, CD45R/B220, and TER-119) CD45⁺ CD90⁺ cells sorted from the intestinal intraepithelial cellular extract (defined as intraepithelial innate lymphoid cells [IE-ILCs]) (a) or the lamina propria cellular extract (defined as lamina propria innate lymphoid cells [LP-ILCs]) (b) of Rag1^−/− mice were used as donor cells in the adoptive transfer experiment. The transfer was carried out twice with 1 × 10⁶ cells each and 1 day before and 1 day after infection, respectively, as indicated at the bottom. (c to j) The IFN-γ-susceptible mutant Chlamydia strain (clone G28.51.1) was used to infect groups of C57BL/6J mice (c and d) (n = 3) and IL-7R^−/− mice (e to j) (n = 3 to 5) via intracolonic inoculation at a dose of 1 × 107 IFU (inclusion-forming units). IL-7R^−/− mice were transferred without (e and f) or with IE-ILCs (g and h) or LP-ILCs (i and j). On days 3 and 7 and weekly thereafter after inoculation, rectal swabs were taken (c, e, g, and i), or on day 28, mouse tissues were harvested (d, f, h, and j), as indicated along the x axis, for monitoring live chlamydial organisms (see the Fig. 1 legend for tissue name abbreviations). The yields of chlamydial organisms from swabs or tissues are expressed as log₁₀ IFU per swab or tissue, as shown along the y axis. Note that adoptive transfer of LP-ILCs but not IE-ILCs conferred large intestinal resistance to mutant Chlamydia colonization in IL-7R^−/− mice. *, P < 0.05; **, P < 0.01 (by a Wilcoxon rank sum test [areas under the curve between IL-7R^−/− mice transferred with IE-ILCs and those transferred with LP-ILCs]). Data were acquired from two independent experiments.