FIGURE 1.

Attenuated BM destruction and reduced BM T cell activation in CVB-housed CByB6F1 mice following infusion of allogeneic LN cells from SPF-housed B6-CD45.1 donors. A, LN cells from SPF-housed B6-CD45.1 donors were injected into CByB6F1 recipients in both CVB and SPF facilities at 28 × 10⁶ LN cells/mouse. B, Recipient mice measured 17 days after LN cell infusion (BMF) showed drastic declines in WBCs, RBCs and platelets indicative of BM failure relative to control mice (CON) without LN cell infusion. C, Sterna from BMF and CON mice were collected at day 17, fixed in 10% formalin, decalcified, cut, hematoxylin & eosin stained. Representative 20× photomicrographs (and 40× insets) of sternal BM from mice representing each group: CVB-CON and CVB-BMF or SPF-CON and SPF-BMF. D, Overall percent cellularity of each BM slide was estimated, under blinded-review, by a comparative veterinary pathologist and confirmed by general consensus among authors. E, BM and spleen cells were stained with CD62L and CD44 antibodies to divide T cells into naïve (NV, CD44⁻CD62L⁺), center memory (CM, CD44⁺CD62L⁺), effector (EF, CD44⁻CD62L⁻), and effector memory (EM, CD44⁺CD62L⁻) subsets for both CD4 and CD8 cells, shown as representative dot plots. F, Proportions of EM-CD4 and EM-CD8 T cells were calculated and shown as means with standard errors. *, P<.05; **, P<.01; ***, P<.001; ****, P<.0001.