Recombinant human interleukin 5 is an eosinophil differentiation factor but has no activity in standard human B cell growth factor assays

作者：Elaine J. Clutterbuck, John G. Shields, John Gordon, Susan Harless Smith, Andy Boyd, Robin E. Callard, Hugh Douglas Campbell, Ian G. Young, Colin J. Sanderson · 发表于：European Journal of Immunology · 年份：1987 · DOI：10.1002/eji.1830171210 · 被引用次数：179 · 研究领域：Immunodeficiency and Autoimmune Disorders、Immune Cell Function and Interaction、Lymphoma Diagnosis and Treatment

Following the observation that mouse interleukin 5 (IL5) is active as a B cell growth factor (BCGF) as well as an eosinophil differentiation factor, this work was carried out to test recombinant human IL5 for BCGF activity. A highly active, partially purified batch of recombinant human IL5 was prepared and tested for BCGF activity in four laboratories. This batch gave a 50% endpoint of 1:77,450 in the human eosinophil differentiation assay, 1:983 in the mouse eosinophil differentiation assay and 1:42 in the mouse BCL1 assay, thus demonstrating that, like mouse IL5, human IL5 has cross-species activity. By comparison with the assays in the mouse this batch would be expected to have 50% maximal human BCGF activity of about 1:4000. In each assay a known positive factor was used as a positive control, and there was no inhibitory activity in the preparation. However, despite the activity towards the mouse B cell lymphoma, the results showed no detectable activity in a panel of assays used to identify human BCGF and B cell differentiation factors. These assays included (a) proliferation assays with tonsillar or splenic B cells in the presence of the co-stimulators anti-mu or phorbol myristate acetate; (b) a restimulation assay in which tonsillar B cells are first activated with either Staphylococcus aureus Cowan 1 or a mixture of phorbol dibutyrate and ionomycin, or splenic B cells are first activated with anti-mu; (c) production of immunoglobulin by B cells in a restimulation assa...