Biological Trojan horse: Antigen 43 provides specific bacterial uptake and survival in human neutrophils.
Escherichia coli is a versatile pathogen causing millions of infections in humans every year. This bacterium can form multicellular aggregates when it expresses a self-associating protein, antigen 43 (Ag43), on its surface. We have discovered that Ag43-expressing E. coli cells are efficiently taken up by human defense cells, polymorphonuclear neutrophils (PMNs), in an opsonin-independent manner. Surprisingly, the phagocytosed bacteria were not immediately killed but resided as tight aggregates within the PMNs. Our observations indicate that Ag43-mediated uptake and survival in PMNs constitute a mechanism to subvert one of the primary defense mechanisms of the human body.
Fexby
Sara
S
Center for Biomedical Microbiology, BioCentrum-DTU, Building 301, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Bjarnsholt
Thomas
T
Jensen
Peter Østrup
PØ
Roos
Viktoria
V
Høiby
Niels
N
Givskov
Michael
M
Klemm
Per
P
D018829:Adhesins, Bacterial / Q000276:immunology / Q000378:metabolism*; D018830:Adhesins, Escherichia coli; D000942:Antigens, Bacterial / Q000276:immunology / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology; D029968:Escherichia coli Proteins / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D009504:Neutrophils / Q000276:immunology / Q000382:microbiology*; D010587:Phagocytosis / Q000502:physiology
D018829:Adhesins, Bacterial; D018830:Adhesins, Escherichia coli; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; C118376:antigen 43, E coli