Escape from thymic deletion and anti-leukemic effects of T cells specific for hematopoietic cell-restricted antigen

Ji-Min Ju1,2, Min Ho Jung1, Giri Nam1

  • 1Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.

Nature Communications
|January 17, 2018
PubMed

Whether hematopoietic cell-restricted distribution of antigens affects the degree of thymic negative selection has not been investigated in detail. Here, we show that T cells specific for hematopoietic cell-restricted antigens (HRA) are not completely deleted in the thymus, using the mouse minor histocompatibility antigen H60, the expression of which is restricted to hematopoietic cells. As a result, low avidity T cells escape from thymic deletion. This incomplete thymic deletion occurs to the T cells developing de novo in the thymus of H60-positive recipients in H60-mismatched bone marrow transplantation (BMT). H60-specific thymic deletion escapee CD8+ T cells exhibit effector differentiation potentials in the periphery and contribute to graft-versus-leukemia effects in the recipients of H60-mismatched BMT, regressing H60+ hematological tumors. These results provide information essential for understanding thymic negative selection and developing a strategy to treat hematological tumors.

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