P2Z-Independent and P2Z Receptor-Mediated Macrophage Killing byPseudomonas aeruginosaIsolated from Cystic Fibrosis Patients

作者：Olga E. Zaborina, Namita Misra, Jan Košťál, Shilpa Kamath, Vinayak Kapatral, M. El-Azami El-Idrissi, Bellur S. Prabhakar, A. M. Chakrabarty · 发表于：Infection and Immunity · 年份：1999 · DOI：10.1128/iai.67.10.5231-5242.1999 · 被引用次数：50 · 研究领域：Adenosine and Purinergic Signaling、Cystic Fibrosis Research Advances、Neonatal Respiratory Health Research

We demonstrate that a mucoid, alginate-producing strain of Pseudomonas aeruginosa isolated from the lungs of a cystic fibrosis (CF) patient secretes multiple enzymes with nucleoside diphosphate kinase (Ndk), ATPase, adenylate kinase, 5'-nucleotidase, and ATP-modifying enzymatic activities. The secretion is triggered at high cell density and in complex media but is greatly reduced when the mucoid cells are grown in mineral salts media or in presence of 5.0 mM Ca2+ or Mg2+. Interestingly, the secretion is triggered primarily in the mucoid CF isolate of strain 8821M (or in strain FRD1) but not in a nonmucoid laboratory strain, PAO1. The purified secreted Ndk shows 100% match in its N-terminal amino acid sequence with that of purified intracellular Ndk and demonstrates similar enzymatic properties. The N-terminal sequence of the purified ATPase isolated from an ndk knockout mutant shows its identity with that of the heat shock chaperonin Hsp60. During fractionation, the flowthrough fraction from a Mono Q column demonstrates the presence of 5'-nucleotidase, adenylate kinase, and a putative ATP reductase activity. These fractions demonstrate high cytotoxic activities for murine peritoneal primary macrophages which can be further stimulated in the presence of ATP or inhibited by pretreatment of macrophages with oxidized ATP (oATP). The cytotoxicity associated with ATP-induced stimulation is believed to be due to activation of macrophage surface-associated P2Z (P2X7) receptors, which...