Aspergillus cyclooxygenase-like enzymes are associated with prostaglandin production and virulence.
Oxylipins comprise a family of oxygenated fatty acid-derived signaling molecules that initiate critical biological activities in animals, plants, and fungi. Mammalian oxylipins, including the prostaglandins (PGs), mediate many immune and inflammation responses in animals. PG production by pathogenic microbes is theorized to play a role in pathogenesis. We have genetically characterized three Aspergillus genes, ppoA, ppoB, and ppoC, encoding fatty acid oxygenases similar in sequence to specific mammalian prostaglandin synthases, the cyclooxygenases. Enzyme-linked immunosorbent assay analysis showed that production of PG species is decreased in both Aspergillus nidulans and A. fumigatus ppo mutants, implicating Ppo activity in generating PGs. The A. fumigatus triple-ppo-silenced mutant was hypervirulent in the invasive pulmonary aspergillosis murine model system and showed increased tolerance to H(2)O(2) stress relative to that of the wild type. We propose that Ppo products, PG, and/or other oxylipins may serve as activators of mammalian immune responses contributing to enhanced resistance to opportunistic fungi and as factors that modulate fungal development contributing to resistance to host defenses.
Tsitsigiannis
Dimitrios I
DI
Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, USA.
Bok
Jin-Woo
JW
Andes
David
D
Nielsen
Kristian Fog
KF
Frisvad
Jens C
JC
Keller
Nancy P
NP
D000595:Amino Acid Sequence; D000818:Animals; D001228:Aspergillosis / Q000201:enzymology; D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000472:pathogenicity; D001233:Aspergillus nidulans / Q000201:enzymology* / Q000472:pathogenicity; D008172:Lung Diseases, Fungal / Q000201:enzymology; D051379:Mice; D008969:Molecular Sequence Data; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D011453:Prostaglandins / Q000096:biosynthesis*; D034622:RNA Interference / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D014774:Virulence / Q000502:physiology
D011453:Prostaglandins; D011451:Prostaglandin-Endoperoxide Synthases