Genome analysis of three Pneumocystis species reveals adaptation mechanisms to life exclusively in mammalian hosts.
Pneumocystis jirovecii is a major cause of life-threatening pneumonia in immunosuppressed patients including transplant recipients and those with HIV/AIDS, yet surprisingly little is known about the biology of this fungal pathogen. Here we report near complete genome assemblies for three Pneumocystis species that infect humans, rats and mice. Pneumocystis genomes are highly compact relative to other fungi, with substantial reductions of ribosomal RNA genes, transporters, transcription factors and many metabolic pathways, but contain expansions of surface proteins, especially a unique and complex surface glycoprotein superfamily, as well as proteases and RNA processing proteins. Unexpectedly, the key fungal cell wall components chitin and outer chain N-mannans are absent, based on genome content and experimental validation. Our findings suggest that Pneumocystis has developed unique mechanisms of adaptation to life exclusively in mammalian hosts, including dependence on the lungs for gas and nutrients and highly efficient strategies to escape both host innate and acquired immune defenses.
|Year of Publication||
2016 Feb 22
|PubMed Central ID||
U54 HG003067 / HG / NHGRI NIH HHS / United States
U54HG003067 / HG / NHGRI NIH HHS / United States
P41 RR018502 / RR / NCRR NIH HHS / United States
P41 GM103490 / GM / NIGMS NIH HHS / United States
Intramural NIH HHS / United States
1 P41 RR018502-01 / RR / NCRR NIH HHS / United States
HHSN261200800001E / PHS HHS / United States
HHSN261200800001C / RC / CCR NIH HHS / United States
HHSN261200800001E / CA / NCI NIH HHS / United States