Cellular and growth factor requirements for activation of human T lymphocytes by neuraminidase and galactose oxidase-treated lymphoid cells.

Proliferation of peripheral blood mononuclear leukocytes (PBL) can be stimulated by irradiated autologous PBL that have been treated with neuraminidase and galactose oxidase (NAGO). We determined the types of cells that stimulate and respond by isolating populations of cells enriched for macrophages, B lymphocytes, and T lymphocytes. With PBL as responding cells, proliferation was stimulated by irradiated, NAGO-treated cells with the following hierarchy: macrophage greater than PBL greater than B cells greater than T cells. Irradiated NAGO-treated macrophages and PBL induced proliferation of isolated T cells greater than or equal to the proliferation they stimulated in PBL, indicating that T cells are the predominant responding cell type. Irradiated, NAGO-treated B cells or T cells were weak stimulators of isolated T cell proliferation when compared to their ability to stimulate PBL. The ability of irradiated NAGO-treated B cells or T cells to stimulate isolated T cell proliferation was greatly enhanced by the addition of untreated macrophages or by the addition of conditioned media from mitogen-activated PBL. Biologic, biochemical, and biophysical characterization of the conditioned media revealed it contained both lymphocyte polypeptide growth factors, interleukin 1 and interleukin 2. Semipurified preparations of either of these growth factors were capable of enhancing T cell proliferation stimulated by irradiated NAGO-treated B or T cells. These data indicate T cell proliferation induced by irradiated, NAGO-treated cells requires the aldehyde-bearing cells for the induction of soluble growth factor production and for the induction of putative membrane receptors for these growth factors.