Read on for our selection of miscellaneous Covid-related studies from the scientific press for August 2022:
Tropism of SARS-CoV-2 for human cortical astrocytes
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) readily infects a variety of cell types impacting the function of vital organ systems, with particularly severe impact on respiratory function. Neurological symptoms, which range in severity, accompany as many as one-third of COVID-19 cases, indicating a potential vulnerability of neural cell types. To assess whether human cortical cells can be directly infected by SARS-CoV-2, this study utilized stem-cell-derived cortical organoids as well as primary human cortical tissue, both from developmental and adult stages. Significant and predominant infection was found in cortical astrocytes in both primary tissue and organoid cultures, with minimal infection of other cortical populations. Infected and bystander astrocytes have a corresponding increase in inflammatory gene expression, reactivity characteristics, increased cytokine and growth factor signaling, and cellular stress. Although human cortical cells, particularly astrocytes, have no observable ACE2 expression, high levels of coronavirus coreceptors were found in infected astrocytes, including CD147 and DPP4. Decreasing coreceptor abundance and activity reduces overall infection rate, and increasing expression is sufficient to promote infection. Thus, the study’s authors found tropism of SARS-CoV-2 for human astrocytes resulting in inflammatory gliosis-type injury that is dependent on coronavirus coreceptors.
Andrews MG, Mukhtar T, Eze UC, Simoneau CR, Ross J, Parikshak N, Wang S, Zhou L, Koontz M, Velmeshev D, Siebert CV, Gemenes KM, Tabata T, Perez Y, Wang L, Mostajo-Radji MA, de Majo M, Donohue KC, Shin D, Salma J, Pollen AA, Nowakowski TJ, Ullian E, Kumar GR, Winkler EA, Crouch EE, Ott M, Kriegstein AR. Tropism of SARS-CoV-2 for human cortical astrocytes. Proc Natl Acad Sci U S A. 2022 Jul 26;119(30):e2122236119. doi: 10.1073/pnas.2122236119. Epub 2022 Jul 12.