IFN-γ and TNF-α secretion by CD4+ and CD8+ TCRαβ+ T-cell clones derived early after allogeneic bone marrow transplantation

Abstract: Secretion of the potentially antileukaemic cytokines IFN-γ and TNF-α was investigated for CD4 ⁺ and CD8 ⁺ TCRαβ⁺ T-cell clones derived from 4 leukaemia patients 3–6 weeks after allogeneic BMT. We investigated cytokine secretion in response to the activation signal accessory cells + phytohaemagglutinin + Interleukin 2. All clones derived after BMT were capable of IFN-γ and TNF-α secretion, and both for CD4⁺ (n = 96) and CD8⁺ (n = 8) T cells quantities of IFN-γ and TNF-α were significantly correlated with one another. When comparing the overall results for posttransplant and normal T-cell clones derived from 2 bone marrow donors (n = 65), both CD4⁺ and CD8⁺ TCRαβ⁺ T-cell clones showed increased IFN-γ production, and CD4⁺ but not CD8⁺ clones showed a decreased TNF-α secretion. The results suggest that noncytotoxic T cells derived after allogeneic BMT can produce IFN-γ and TNF-α and may thus be capable of mediating antileukaemic effects.