Establishment of a T cell hybridoma continuously producing Interleukin 2 (IL2) and functional analysis of secreted IL2

The AKR-derived T lymphoma cell line BW5147 was fused with a Mycobacterium tuberculosis-primed and boosted BALB/c T cell to produce a T cell hybridoma (A55-24) which continuously produces Interleukin 2 (IL2). A55-24 cells produce IL2 without stimulation by lectin or antigen. The hybridoma culture supernatant did not contain other lymphokine-activities, T cell-replacing factor (TRF), B cell growth factor (BCGF), or macrophage activating factor (MAF). The secreted IL2 possessed the following characteristics: 1) IL2 activity was precipitated at an ammonium sulphate saturation of 50-85% . 2) a molecular weight of 30 Kd 3) an isoelectric point of pH 5.3±0.2 4) IL2 activity was destroyed only partially by pH 2 treatment and heating (56℃, 30min), but eliminated by boiling (100℃, 10min). 5) IL2 activity was absorbed by an IL2-dependent cytotoxic T cell line. 6) Addition of IL1 and this IL2 could not generate any significant CTL responses from PNA(+)-thymocytes, whereas further addition of PPD-CFS obtained from PPD-stimulated Mycobacterium-primed T cells induced noticiable responses.