RT info:eu-repo/semantics/article T1 Desialylation of T lymphocytes overcomes the monocyte dependency of pokeweed mitogen-induced T-cell activation. A1 Gallart, T. A1 Fuente García, Miguel Ángel de la A1 Barceló, Josep A1 Alberola-Ila, J. A1 Lozano, F. K1 Células hematopoyéticas K1 Hematología AB Activation of T lymphocytes by pokeweed mitogen (PWM) is strictly monocyte (Mo)-dependent and results in T-cell mitogenesis and interleukin-2 (IL-2) secretion, coupled with an inability to utilize IL-2 due to an impaired expression of functional IL-2 receptor (IL-2R). Such IL-2R impairment could arise in PWM-activated T cells themselves or, alternatively, be the result of Mo-derived influences, as it is known that PWM binds Mo strongly and does not or poorly binds lymphocytes, and Mo becomes rapidly destroyed in PWM-stimulated cultures of blood mononuclear cells or T cells plus Mo. The present study investigated these possibilities. The results show for the first time that desialylation of T lymphocytes strongly increases their PWM-binding capacity and, in addition, overcomes the Mo requirement for PWM to induce T-cell mitogenesis and IL-2 secretion. Such secreted IL-2 levels were even higher that those found in cultures of Mo-dependent PWM-activated T lymphocytes but similarly to the latter, PWM-activated desialylated purified T lymphocytes exhibited negligible high-affinity IL-2 binding capacity and an inability to utilize the IL-2 they produced. These effects were not due to desialylation itself, as indicated by data obtained with peanut agglutinin, a lectin that becomes strongly reactive with desialylated T lymphocytes. The data clearly indicate the existence of PWM-related events capable of impairing the expression of functional IL-2R without affecting IL-2 secretion, and indicate that such events are due to mechanisms arising at the level of PWM-activated T cells themselves. PB Wiley SN 0019-2805 YR 1997 FD 1997 LK http://uvadoc.uva.es/handle/10324/10384 UL http://uvadoc.uva.es/handle/10324/10384 LA eng NO Immunology, 1997, 90(1):57-65 NO Producción Científica DS UVaDOC RD 22-nov-2024