Characteristics of IL-3 Derived and IL-3 Dependent Lymphocyte Cell Lines

Abstract

Interleukin-3 (IL-3) is a recently described lymphokine which induces expression of the enzyme 20 alpha hydroxysteroid dehydrogenase (20αSDH) in spleen cells of nu/nu mice (1). In normal mice 20αSDH is associated with cortisone-resistant Thy 1⁺ cells (1–3) whereas cortisone sensitive Thy 1⁺ cells in the thymus are terminal deoxynucleotidyl transferase (TdT) positive and 20αSDH negative (4–6). IL-3 induces proliferation of Thy l^Lyt 1^- 2 spleen cells, but has no effect on thymocytes (1). The factor is found in conditioned media (CM) from: a) mixed leucocyte reactions; b) antigen stimulated immune lymphocytes; c) PHA or Con A stimulated lymphocytes; and d) the WEHI-3 cell line. In the first three cases IL-3 is produced by a Thy 1⁺ Lyt 1⁺ 2^- cell. Conditioned media from in vitro stimulated lymphocytes have been used to support the growth of cytotoxic Thy 1⁺ Lyt 1^- 2⁺ T cell lines due to the presence of IL-2 (7, 8). Recently, Nabel et al. (9) have demonstrated that CM from Con A stimulated lymphocytes will support the growth of several distinct phenotypes of “T” lymphocytes. One interpretation of this finding is that IL-2 supports the growth of many phenotypically different subsets of T cells.