Dissociation of opsonized particle phagocytosis and respiratory burst activity in an Epstein-Barr virus-infected myeloid cell line.

Abstract

A continuous tissue culture cell line (Karpas line 120) derived from a patient with acute myeloblastic leukemia demonstrates myeloblastic morphology and in vitro expression of several myeloid-specific biochemical markers and contains Epstein-Barr virus (EBV) nuclear antigen. EBV-genome-specific DNA was demonstrated within the total cellular DNA by molecular hybridization, establishing the presence of stable viral genome integration. The cells demonstrate complex coordinated myeloid functions including ingestion, degranulation and respiratory burst activity. Line 120 cells show a respiratory burst (superoxide and H2O2 generation and hexosemonophosphate shunt activity) in response to soluble (phorbol myristate acetate) and particulate (latex beads) stimuli, as do normal granulocytes. They ingest complement[C]-opsonized particles (lipopolysaccharide[Escherichia coli]-oil droplets, zymosan and bacteria [Staphylococcus aureus]) and degranulate in response to them. Unlike normal granulocytes, the line 120 cells do not demonstrate respiratory burst activity in response to these C-opsonized particles. Dissociation between ingestion of C-opsonized particles and activation of O2-dependent bactericidal activity severely impairs bacteria killing as compared with normal polymorphonuclear phagocytes.