Fig. 4.

Oral γδT cells comprise both radioresistant tissue-resident cells and radiosensitive circulating cells. (A) Lethally irradiated CD45.2⁺ B6 mice were transplanted with bone marrow purified from congenic CD45.1⁺ B6 mice. Representative FACS plots demonstrate the contribution of donor (CD45.1⁺ cells) to γδT cells in the gingiva and skin epithelium 12 mo after the transplantation. Bar graphs depict the frequencies of γδT cells in the gingival epithelium at various times after the bone marrow transplantation (n = 4–6 mice per group for each time point). FACS plots represent the results of one of two independent experiments with similar results, and graphs present the mean values + SEM. (B) CD45.1⁺ B6 and CD45.2⁺ B6 mice were joined surgically for the generation of parabiotic pairs, and homeostasis of γδT cells was analyzed 2 and 6 wk after parabiosis in each parabiont. Representative flow cytometry plots from four independent experiments (n = 3–4 pairs per time point).