Dissociation of TNF-alpha cytotoxic and proinflammatory activities by p55 receptor- and p75 receptor-selective TNF-alpha mutants.

Abstract

Human tumour necrosis factor alpha (TNF‐alpha) is a pleiotropic cytokine capable of killing mammalian tumour cells in vitro and in vivo, and of enhancing the proinflammatory activity of leucocytes and endothelium, the latter effects limiting its usage as an antitumour agent in humans. Using TNF‐alpha mutants with a selective capacity to bind to the TNF p55 receptor (TNFR55) or to the p75 receptor (TNFR75) we show here that these two major activities of TNF‐alpha can be dissociated. The TNFR55‐selective mutants (R32W, E146K and R32W‐S86T) which bind poorly to TNFR75 displayed similar potency to wild‐type TNF in causing cytotoxicity of a human laryngeal carcinoma‐derived cell line (HEp‐2) and cytostasis in a human leukaemic cell line (U937). However, these TNFR55‐selective mutants exhibited lower proinflammatory activity than wild‐type TNF. Specifically, TNF‐alpha's priming of human neutrophils for superoxide production and antibody‐dependent cell‐mediated cytotoxicity, platelet‐activating factor synthesis and adhesion to endothelium were reduced by up to 170‐fold. Activation of human endothelial cell functions represented by human umbilical venular endothelial cell (HUVEC) adhesiveness for neutrophils, E‐selectin expression, neutrophil transmigration and IL‐8 secretion were also reduced by up to 280‐fold. On the other hand, D143F, a TNFR75‐selective mutant tested either alone or in combination with TNFR55‐selective mutants, did not stimulate these activities despite being able to cause cytokine production in TNFR75‐transfected PC60 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

A p75 tumor necrosis factor receptor-specific mutant of murine tumor necrosis factor α expressed from an adenovirus vector induces an antitumor response with reduced toxicity

“…The p55 TNFR is a powerful inducer of a variety of immunologic/antitumor activities, including the induction of cytokine secretion, neutrophil activation, endothelial cell activation, 6,27,37,38 and cytotoxicity. 2,5 The induction of i.t.…”

Adenoviral TNF-α gene therapy and radiation damage tumor vasculature in a human malignant glioma xenograft

“…[15][16][17] Tumor vascular destruction has been reported in multiple xenograft models in mice treated with human TNF-␣. [18][19][20] Low concentrations of TNF-␣ have been shown to promote proliferation of endothelial cells 21,22 while higher concentrations are cytotoxic to, and result in apoptosis of, endothelial cells both in vitro and in vivo.…”

Synthesis and characterization of a thermally-responsive tumor necrosis factor antagonist

“…TNFα acts through two transmembrane receptors, TNFRI and TNFRII, that dissociate the cytotoxic and proinflammatory effects in target cells. [12] Soluble TNF receptors (sTNFRI and sTNFRII) are the extracellular domains of these membrane receptors that are liberated from the transmembrane domain by proteolytic cleavage. Upon removal, these truncated receptors become soluble proteins and retain the appropriate tertiary structure to act as decoy receptors sequestering TNFα away from the cell surface receptors.…”