Neutralizing antibodies against SARS-CoV-2 require intact Fc effector functions and monocytes for optimal therapeutic activity
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ABSTRACT:
PROVIDER: PRJNA678953 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR13073055_1.fastq.gz | Fastqsanger.gz | |||
| SRR13073055_2.fastq.gz | Fastqsanger.gz | |||
| SRR13073056_1.fastq.gz | Fastqsanger.gz | |||
| SRR13073056_2.fastq.gz | Fastqsanger.gz | |||
| SRR13073057_1.fastq.gz | Fastqsanger.gz |
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Project description:SARS-CoV-2 has spread globally and caused the COVID-19 pandemic. Although passively delivered neutralizing antibodies against SARS-CoV-2 are in clinical trials, their mechanism of action in vivo is incompletely understood. Here, we define correlates of protection of neutralizing human monoclonal antibodies (mAbs) in SARS-CoV-2-infected mice. Whereas Fc effector functions are fully dispensable when mAbs are administered as prophylaxis, they are required for optimal protection as therapy. When given after infection, intact but not LALA-PG loss of Fc effector function variant mAbs reduce SARS-CoV-2 burden and lung disease in mice and hamsters. Fc engagement of neutralizing antibodies mitigates inflammation and improves respiratory mechanics, and transcriptional profiling suggests these phenotypes are associated with diminished innate immune signaling and enhanced tissue repair. Immune cell depletions establish that neutralizing mAbs require monocytes for therapeutic efficacy. Our study demonstrates that therapeutic neutralizing mAbs require Fc effector functions to reduce SARS-CoV-2 infection and modulate protective immune responses.
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Project description:SARS-CoV-2 has caused the global COVID-19 pandemic. Although passively delivered neutralizing antibodies against SARS-CoV-2 show promise in clinical trials, their mechanism of action in vivo is incompletely understood. Here, we define correlates of protection of neutralizing human monoclonal antibodies (mAbs) in SARS-CoV-2-infected animals. Whereas Fc effector functions are dispensable when representative neutralizing mAbs are administered as prophylaxis, they are required for optimal protection as therapy. When given after infection, intact mAbs reduce SARS-CoV-2 burden and lung disease in mice and hamsters better than loss-of-function Fc variant mAbs. Fc engagement of neutralizing antibodies mitigates inflammation and improves respiratory mechanics, and transcriptional profiling suggests these phenotypes are associated with diminished innate immune signaling and preserved tissue repair. Immune cell depletions establish that neutralizing mAbs require monocytes and CD8+ T cells for optimal clinical and virological benefit. Thus, potently neutralizing mAbs utilize Fc effector functions during therapy to mitigate lung infection and disease.
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Project description:Treatment of HIV infection with either anti-retroviral therapy (ART) or neutralizing monoclonal antibodies (NAbs) leads to a reduction in HIV plasma virus. Both ART and NAbs prevent new rounds of viral infection but NAbs may have the additional capacity to accelerate the loss of virus-infected cells through Fc gamma receptor (FcgR) mediated effector functions, which should affect the kinetics of plasma virus decline. Here we formally test this premise in vivo by comparing the plasma virus response to a single dose treatment with either unmodified NAb or those with either reduced or augmented Fc function. When infused into viremic SHIV-infected rhesus macaques, there was a 21% difference in slope of plasma virus decline between wt NAb and NAb with reduced Fc function. NAb engineered to increase FcgRIII binding and improve ADCC in vitro resulted in arming of effector cells in vivo yet led to viral decay kinetics similar to NAbs with reduced Fc function. These studies show that the predominant mechanism of antiviral activity of HIV NAbs is through inhibition of viral entry, but that Fc function does contribute to the overall antiviral activity, making them unique from standard ART. However, these data also show that increased FcgRIII engagement is insufficient to improve in vivo virus clearance.
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