Nuclear factor-κ B inducing kinase is required for graft-versus-host disease

Background Donor T lymphocytes are directly responsible for graft- versus -host disease. Molecules important in T-cell function may, therefore, be appropriate targets for graft- versus -host disease therapy and/or prophylaxis. Here we analyzed whether nuclear factor-κ B inducing kinase might have a role in graft- versus -host disease. Design and Methods We studied the expression of nuclear factor-κ B inducing kinase in human samples from patients with graft- versus -host disease. We also explored the effect of nuclear factor-κ B inducing kinase in a murine model of graft- versus -host disease using donor cells from aly/aly mice (deficient in nuclear factor-κ B inducing kinase) and C57BL/6 mice (control). Results We detected expression of nuclear factor-κ B inducing kinase in T-lymphocytes in the pathological lesions of patients with acute graft- versus -host disease. Mice transplanted with aly/aly T lymphocytes did not develop graft- versus -host disease at all, while mice receiving C57BL/6 cells died of a lethal form of the disease. Deficiency of nuclear factor-κ B inducing kinase did not affect the engrafting ability of donor T cells, but severely impaired their expansion capacity early after transplantation, and aly/aly T cells showed a higher proportion of apoptosis than did C57BL/6 T cells. Effector T lymphocytes were the T-cell subset most affected by nuclear factor-κ B inducing kinase deficiency. We also detected lower amounts of inflammatory cytokines in the serum of mice receiving aly/aly T cells than in the serum of mice receiving C57BL/6 T cells. Conclusions Our results show that nuclear factor-κ B inducing kinase has a role in graft- versus -host disease by maintaining the viability of activated alloreactive T lymphocytes.