Anti-spike IgG causes severe acute lung injury by skewing macrophage responses during acute SARS-CoV infection

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Thanks Dr J Couey. Dr.Tenpenny also reported this in 2020.

Background

"By simplified classification, macrophage phenotype has been divided into 2 groups: M1 (classically activated macrophages) and M2 (alternatively activated macrophages). ... M2 macrophages were described to have quite the opposite function: regulation of the resolution phase of inflammation and the repair of damaged tissues."

https://en.m.wikipedia.org/wiki/Macrophage_polarization

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Anti-spike IgG causes severe acute lung injury by skewing macrophage responses during acute SARS-CoV infection (2019)

Consistently, preexisting serum antibodies against influenza antigens were found to associate with worse clinical severity and poor outcomes in patients during the 2009 influenza pandemic (15, 16). Moreover, multiple vaccine platforms and viral infection appeared to induce SARS-CoV–specific immune memory that enhanced lung inflammation following homologous challenge in mice and African green monkeys (17–19). The mechanism responsible for the immunopathologic reaction remains elusive. Recent studies suggested that T cells play a crucial role in protection of mice against lethal SARS-CoV infection (20–22). Enhanced pulmonary immunopathology in vaccinated and challenged animals reflects an inadequate Th1 response (22, 23). The role of virus-specific antibody response in SARS-CoV–induced lung injury has yet to be clearly defined. Therefore, we used vaccination and anti–S-IgG passive immunization strategies to evaluate the effects of anti-S antibodies on SARS-CoV–induced ALI in Chinese rhesus monkeys (Macaca mulatta). Our results now show that, in productively infected lungs, anti–S–IgG causes severe ALI by skewing inflammatory resolving responses during acute infection.

Full paper:

https://insight.jci.org/articles/view/123158