Research Briefing in 2022

Pandemic viruses cause major global disease burden and economic disruption. We investigated pandemic HIV-1(M) to understand its unique characteristics by comparing it with HIV strains that did not achieve pandemic human-to-human spread. We observed structural adaptations in the HIV-1(M) capsid that reduce detection by innate immune sensors.

Most prokaryotes cannot easily be grown in the laboratory and distributed as pure cultures. Thus, these organisms could not be officially named. A code of nomenclature — the SeqCode — provides paths to name such organisms on the basis of genomic data, aiming to unify field and laboratory studies in microbiology.

This work used DNA and RNA sequencing to investigate how wildfire burn severity affects forest soil microbiomes. The results revealed the mechanisms that allow specific bacteria, fungi and viruses to colonize and thrive in burned soils. These changes can influence nutrient cycling and carbon storage in soil.

Now, a study using multi-omics to investigate the mechanistic role of the airway microbiome in chronic obstructive pulmonary disease (COPD) reveals that the airway microbiome-derived metabolite indole-3-acetic acid (IAA) can alleviate COPD-associated airway inflammation and epithelial apoptosis. These results implicate IAA as a potential therapeutic candidate for further investigation in COPD.

Marine protists abound, but are challenging to study, and their interactions with other microbes in nature remain largely unknown. We captured wild predatory protists (choanoflagellates) and discovered a divergent, obligately co-associated bacterial group that lives by extracting resources from these predators.

The conserved nucleotide diadenosine tetraphosphate (Ap4A) is induced under various stresses, including heat. In a non-biased screen, we identified a critical role of Ap4A in inhibiting a central step in purine metabolism and heat resistance. We clarify the molecular mechanism of Ap4A action on the inosine-5′-monophosphate dehydrogenase (IMPDH) enzyme, showing Ap4A as a bona fide nucleotide second messenger.

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a phenotype that has changed fundamentally compared with preceding variants. Substantial antigenic change within the spike protein and a new endocytic entry mechanism underlie the immune evasion characteristics and a coincident decrease in the virulence of this variant.

Well-replicated, ecologically realistic, long-term field experiments were conducted to test the effects of warming on soil microbial diversity. Warming significantly reduced the biodiversity of soil bacteria, fungi and protists by altering environmental selections and biotic interactions, potentially disrupting the functional processes of the soil ecosystem.