Differential effects of teleocidin on TNF alpha receptor regulation in human B cell lines: relationship to coexpression of IL-2 and IL-1 receptors and to lymphokine secretion.
We have studied 23 human B cell lines for TNF alpha receptor reactivities and TNF secretion. High affinity TNF alpha receptors with a wide range of 200 to 7200 receptor sites/cell and an average kD of approximately 10(-10) M were detected in 22 of 23 cell lines. Following activation with the tumor promoter teleocidin, changes in TNF alpha receptor binding were classified into three categories: (I) Downregulation of TNF alpha receptors (n = 15); (II) Upregulation of TNF alpha receptors (n = 5); and (III). No change of TNF alpha receptor binding (n = 3). Constitutive secretion of TNF was detected in 2 cell lines only, and teleocidin triggered TNF secretion in an additional 10 cell lines in category I. Although this suggests possible association between TNF alpha receptor downregulation and secreted TNF, 48-hr kinetic studies demonstrated that TNF alpha receptors were downregulated at approximately 1 hr after activation with teleocidin, whereas TNF secretion was detected only at 24 hr. TNF alpha receptor regulation did not seem to be influenced by secreted IL-1 and/or B cell IL-2-like molecule as well, but correlates with coexpression of IL-1 and IL-2 receptors. Dissecting the complexity between these three types of lymphokine receptors and their corresponding lymphokines suggest that TNF alpha receptor regulation is influenced by IL-2 receptors and/or IL-1 receptors coexpressed on the same cell, and that cross-talk between B cell lymphokine receptors exists.