Figure 5. Transferred IL-2^−/− CD8⁺ cells dramatically exacerbate bone marrow failure independent of antibody response.

TCRα^−/− recipient mice were injected with 5×10⁶ FACS sorted IL-2^−/− CD4⁺ cells, CD8⁺ cells, or a 1:1 mixture of both. Hematocrit from peripheral blood samples was calculated as percentage relative to hematocrit from uninjected littermate controls (A). Significance is indicated relative to uninjected littermate control mice at indicated time points. At 7 weeks post-transfer mice were euthanized and total cell numbers from RBC-lysed BM determined by flow cytometry (B-C). (D) TCRα^−/− and RAG^−/− recipient mice were injected with 5×10⁶ FACS sorted IL-2^−/− CD4⁺ cells and an equal number of IL-2^−/− CD8⁺ cells and analyzed 7 weeks post-transfer. Relative hematocrit was calculated as in (A). (E) Total LSK HSCs and CMPs were determined from RBC-lysed BM. Data are from 4 independent experiments with 6-16 mice per group (A) and 2 independent experiments with 3-6 mice per group (B-E). n.s. - not significant; * p < 0.05; ** p < 0.01 based on students t test.