Hematopoietic stem cells promote the expansion and function of adoptively transferred antitumor CD8⁺ T cells
J. Clin. Invest. 117:2 doi:10.1172/JCI30414 [Go to this article.]

Figure 3
HSCs drive effector, but not naive, pmel-1 CD8⁺ T cell expansion and tumor treatment in the absence of host β₂m.

(A) HSC-driven effector pmel-1 CD8⁺ T cell expansion and tumor treatment is MHC class I independent. Effector pmel-1 CD8⁺ T cells (1 × 10⁶) were transferred together with rhIL-2 into 9-Gy irradiated β₂m^–/– or WT mice that had received the matched HSC transplant and had 10-day established B16 tumors. T cell expansion (left panels) and tumor treatment (right panels) were evaluated at the indicated days. Control groups were left untreated. Effector pmel-1 CD8⁺ T cells showed similar proliferation and tumor treatment in β₂m^–/– and WT mice (9 Gy effector PI: P = 0.9, WT versus β₂m^–/–; 9 Gy in β₂m^–/–: P = 0.001, NT versus effector PI). (B) In β₂m^–/– mice, only effector, but not naive, pmel-1 CD8⁺ showed HSC-driven T cell expansion and tumor treatment. Effector or naive pmel-1 CD8⁺ T cells were transferred into myeloablated tumor-bearing β₂m^–/– mice receiving a β₂m^–/– HCS transplant. Naive pmel-1 CD8⁺ T cells showed neither proliferation nor significant tumor treatment (P = 0.96, NT versus naive PI). Proliferation curves represent the numbers of gene-marked pmel-1 CD8⁺ T cells found in the spleens of 3 mice pooled per group per time point. Results for tumor area are the mean of measurements from 5 mice per group (±SEM). The data shown are representative of 3 independently performed experiments.