By analyzing the genomes of different strains of Bordetella pertussis, the bacteria responsible for whooping cough, a team led by scientists from the Institut Pasteur gains insights into how changes in vaccine use drives genotype changes in this significant human pathogen. Population immunity is thought to drive pathogen evolutionary dynamics, but this can be hard to measure. Looking at the shift from whole-cell vaccines to acellular vaccines (ACV) for B. pertussis as a natural experiment, the researchers analyzed 3,344 sequences from 23 countries to infer local changes in strain fitness after ACV introduction. As reported in Science Translational Medicine this week, they find that ACVs have led to the increased fitness of strains lacking the virulence factor pertactin. The findings, the study's authors write, "provides a quantitative description of strain fitness and highlights the key role of vaccine policy decision-making in driving ecological change."
A Science Advances study published this week examines the transcriptomes of long-lived individuals and some of their relatives, identifying decreased ribosomal activity as a potential contributor to healthy aging and life span extension. While it is known that adaptation to reduced energy production is fundamental for a long life, the underlying mechanism in long-lived people is unknown. In the study, a group led by Chinese Academy of Sciences investigators analyzed the transcriptomes of peripheral white blood cells from 193 long-lived females and 83 gender-matched spouses of their children from two independent Chinese longevity cohorts. They find that the ribosome pathway was significantly downregulated in long-lived individuals. This process, they write, is likely controlled by ETS1, a transcription factor downregulated in the aged people and positively coexpressed with most ribosomal protein genes. In vitro experiments, meanwhile, showed that ETS1 knockdown reduces ribosomal protein gene expression and alleviates cellular senescence. "Our study provides evidence that reducing ribosomal activity is an alternative approach to achieve healthy aging and longevity," at least in certain long-lived females, the researchers write. "However, since our RNA-seq results are obtained from the peripheral white blood cells, the relevance of this observation to the other cell types or the other organs awaits further investigation."