This week’s articles describe molecular changes in tumors that affect the efficacy of immunotherapies; signaling mechanisms that mediate the CRISPR system in prokaryotes and regulatory T cell function in mammals; and a mechanism that maintains healthy tissue turnover in the gut.
CANCER
Screening for immunotherapy success
Patel et al. report that loss of the apelin receptor, which interacts with the kinase JAK1 and modulates interferon-γ responses in tumors, reduces the efficacy of adoptive cell transfer and checkpoint blockade immunotherapies in mouse models.
IMMUNOLOGY
CRISPR second messenger
Niewoehner et al. report that in prokaryotes CRISPR-associated protein Csm6 is activated by a cyclic oligoadenylate second messenger generated by Cas10 activity upon RNA binding by the CRISPR interference complex (see also Johnson and Bailey).
Regulatory fitness
Yang et al. discover that liver kinase B1 (LKB1) regulates the metabolic and functional fitness of regulatory T cells in the control of immune tolerance and homeostasis.
PHYSIOLOGY
A life-death relay in the gut
Liang et al. show that normal turnover of the midgut in Drosophila is mediated by an intercellular, E-cadherin–EGFR mechanism that couples the death of individual enterocytes to the divisions of nearby stem cells.
