Cytocidal effects of Escherichia coli hemolysin on human T lymphocytes.
Escherichia coli hemolysin is the prototype of a large family of pore-forming toxins produced by gram-negative organisms. Besides its known cytotoxic activities against granulocytes, monocytes, endothelial cells, and renal epithelial cells, we now demonstrate that the toxin potently kills human T lymphocytes. Evidence based on different and independent approaches indicates that lymphocidal activity is due to formation of transmembrane pores. Additionally, cells prestimulated with phytohemagglutinin respond to low doses of E. coli hemolysin with DNA fragmentation similar to that observed in cells undergoing programmed cell death. Kinetic considerations lead us to conclude that DNA degradation may, however, represent an epiphenomenon. Killing of T cells is another means through which E. coli hemolysin could directly impair host defense.
Jonas
D
D
Institute of Medical Microbiology, University of Mainz, Germany.
Schultheis
B
B
Klas
C
C
Krammer
P H
PH
Bhakdi
S
S
D000255:Adenosine Triphosphate / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004247:DNA / Q000187:drug effects; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000472:pathogenicity*; D006460:Hemolysin Proteins / Q000633:toxicity*; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects*; D013997:Time Factors
D006460:Hemolysin Proteins; D000255:Adenosine Triphosphate; D004247:DNA