animal, organoid and tissue models
Recorded terms: intranasal and intravenous infection of mice; intranasal delivery; intranasal infection of hamsters; intranasal interferon administration; intranasal mouse infection; intravenous infection
In golden hamsters, productive SARS-CoV-2 replication in the airways generates circulating type I and III interferon that primes every organ against infection, and blunting or bypassing that airway response permits viremia and productive infection of liver, kidney, spleen and brain.
Comparison of young and older golden hamsters infected with SARS-CoV-2 shows that age reduces the magnitude and duration of the innate response and of tissue repair, expands suppressor T cells and IL-17-driven neutrophil recruitment, and lowers germinal centre B cell frequency and neutralizing antibody potency without raising lung virus titres.
In golden hamsters, influenza A virus infection reduces SARS-CoV-2 replication during coinfection, after preinfection, and even one to two weeks after influenza has been cleared, while SARS-CoV-2 leaves influenza replication in vivo unchanged.
Longitudinal transcriptional and histological profiling of SARS-CoV-2 infected golden hamsters maps a wave of inflammation that reaches tissues with little or no productive replication, and shows that intranasal type I interferon given before or after challenge lowers viral load and disease burden.
SARS-CoV generates three discrete small viral RNAs during infection of mouse lung, and blocking the one derived from the nucleocapsid gene with a locked nucleic acid antagomir reduces pulmonary inflammation, tissue damage and proinflammatory cytokine expression without measurably lowering lung virus titres.
Replication-incompetent influenza-based vectors carrying no DNA intermediate deliver coding messages and functional small RNAs together to primary human and mouse cells and to mouse lung, with output and cytotoxicity tuned by microRNA target sites in the nucleoprotein segment.
The inefficient 5 prime splice site of influenza A virus segment 8 functions as a timing device, causing the nuclear export protein to accumulate slowly as a minor product of abundant NS1 transcription, with both raising and lowering that rate attenuating the virus through mistimed ribonucleoprotein export.
A negative-sense cytoplasmic RNA virus, vesicular stomatitis virus, can be engineered to produce mature Dicer-dependent miR-124 that loads into Argonaute 2, silences targets, reaches many tissues in mice, and persists after the vector itself is cleared.