Figure 3. CD8⁺ T cell recovery does not require expression of MHC class I or CD80/86 on B cells.

Lethally irradiated B cell–deficient μMT mice received bone marrow (BM) composed of a 1:1 mixture of μMT plus WT (control), μMT plus TAP1^−/−, or μMT plus β2M^−/− (in both, B cells lack MHC class I) (A); or μMT plus CD86^−/− CD80^−/− (B cells lack CD80 and CD86) (B). Resulting BM chimeras were transplanted with BALB/c heart allografts and treated with mATG (1 mg i.p. on days 0 and 4). Percentages of CD4⁺ and CD8⁺ among peripheral blood live cells were determined by flow cytometry. Results are cumulative of 2 experiments with n = 4–7 animals/group; error bars represent SD. *P < 0.05, **P < 0.01, ***P < 0.001; ns, P ≥ 0.05 compared with reconstitution in μMT plus WT chimeras by multiple t tests.