With the help of single-cell transcriptome sequencing and other approaches, a team from the US and the UK takes a look at mesenchymal cell populations and heterogeneity in the adult mouse lung. The researchers characterized the adult mesenchymal cells using a combination of marker-based genetic lineage tracing, organoid cultures, and single-cell RNA sequencing. Their results suggest that the same markers found in epithelial stem cells — known as Lgr5 and Lgr6 — also appear in adult lung mesenchymal cells. Based on the distribution and interactions of the Lgr5-positive and Lgr6-positive mesenchymal cells, the authors argue that "region-specific crosstalk between airway stem cells and adjacent mesenchymal cells is required to maintain proper tissue integrity."
University of Texas MD Anderson Cancer Center researcher James Allison and colleagues consider and compare immune checkpoint blockade response mechanisms in human melanoma and mouse models of melanoma treated with anti-CTLA-4 or anti-PD-1 drugs. Using mass cytometry, the team tracked the immune T cell populations infiltrating solid tumors after immune checkpoint blockade treatment, uncovering differences in the precise immune cells that expand after CTLA-4- and PD-1-focused treatments. "[T]hese pre-clinical and clinical analyses indicate that anti-tumor immune responses induced by CTLA-4 and PD-1 blockade are driven by distinct cellular mechanisms," the authors write.
Based on patterns in almost 5,600 human papillomavirus genomes, an international team argues that enhanced genetic diversity in HPV16 may offer some protection against cervical cancer or precancerous conditions. The researchers sequenced cervical HPV16 isolates from women in the US and Costa Rica, comparing HPV16 profiles from individuals with or without cancer or precancerous lesions. In the benign cases, they saw more marked genetic diversity, while conservation across the E7 oncogene and other parts of the HPV16 genome tended to coincide with increased cancer risk. GenomeWeb has more on the study, here.