Kentaro Nakamura, Matthew Baum, David Lazer
et al.
Winter 2023-24 has seen an unusual confluence of a variety of respiratory illnesses, ranging from flu to RSV (Respiratory Syncytial Virus) and COVID-19. Between December 21, 2023 and January 29, 2024, we surveyed 30,460 individuals aged 18 and older across all 50 states plus the District of Columbia. We asked them if they had experienced an Influenza-like Illness (ILI) defined as experiencing a fever and cough, or a fever and sore throat, and/or if they had been diagnosed with COVID-19, over the previous month. Amongst those who responded yes to such questions, we asked them whether or not they had sought medical attention. In this report, we summarize our findings across a variety of demographic subgroups, including age, race, education, income, gender, and geography.
The engulfment and subsequent degradation of apoptotic cells by phagocytes is an evolutionarily conserved process that efficiently removes dying cells from animal bodies during development. Here, we report that clathrin heavy chain (CHC-1), a membrane coat protein well known for its role in receptor-mediated endocytosis, and its adaptor epsin (EPN-1) play crucial roles in removing apoptotic cells in Caenorhabditis elegans. Inactivating epn-1 or chc-1 disrupts engulfment by impairing actin polymerization. This defect is partially suppressed by inactivating UNC-60, a cofilin ortholog and actin server/depolymerization protein, further indicating that EPN-1 and CHC-1 regulate actin assembly during pseudopod extension. CHC-1 is enriched on extending pseudopods together with EPN-1, in an EPN-1-dependent manner. Epistasis analysis places epn-1 and chc-1 in the same cell-corpse engulfment pathway as ced-1, ced-6 and dyn-1. CED-1 signaling is necessary for the pseudopod enrichment of EPN-1 and CHC-1. CED-1, CED-6 and DYN-1, like EPN-1 and CHC-1, are essential for the assembly and stability of F-actin underneath pseudopods. We propose that in response to CED-1 signaling, CHC-1 is recruited to the phagocytic cup through EPN-1 and acts as a scaffold protein to organize actin remodeling. Our work reveals novel roles of clathrin and epsin in apoptotic-cell internalization, suggests a Hip1/R-independent mechanism linking clathrin to actin assembly, and ties the CED-1 pathway to cytoskeleton remodeling.