An established CD4+ T lymphoma cell line derived from a patient with so-called Lennert's lymphoma: Possible roles of cytokines in histopathogenesis

Abstract

A T lymphoma cell line, KT-3, was established from the peripheral blood of a patient with so-called Lennert's lymphoma when the patient developed leukemic lymphoma. The KT-3 cells stain positively for α-naphthyl acetate esterase, PAS, and acid phosphatase. The surface phenotype is E rosette-positive, CD1-, CD2+, CD3-, CD4+, CD5+, CD8-, CD11-, CD20-, CD25 (anti-Tac)+, OKla-1+, HNK-1-, J-5-, and My9-, and the surface membrane immunoglobulin is negative, which is almost the same phenotype as the leukemic cells studied when the culture was started. Southern blot analysis showed rearrangement in both β and γ T cell receptor genes. Although KT-3 cells proliferate spontaneously and form clusters, they cease proliferating when they are cultured at low cell densities. They proliferate vigorously in response to macrophages, macrophage-derived factor, or recombinant interleukin 2 (rIL-2) added to the culture. Furthermore, they secrete interferon-γ (IFN-γ) spontaneously, and the secretion is augmented when they are stimulated with macrophage-derived factor. The macrophage-derived factor enhancing KT-3 cell growth is different from IL-1α, IL-1β, IL-2, or IFN-γ. To our knowledge, this is the first tumor cell line established from a patient with Lennert's lymphoma. The results conclusively confirmed that, at the least, Lennert's lymphoma included CD4+ T lymphoma and also suggested that cytokines or factors secreted by T lymphoma cells and epitheloid histiocytes play an important role in the histopathogenesis of Lennert's lymphoma.