Abstract
Since the vast majority of species solely rely on innate immunity for host defense, it stands to reason that a critical evolutionary trait like immunological memory evolved in this primitive branch of our immune system. There is ample evidence that vaccines such as bacillus Calmette-Guérin (BCG) induce protective innate immune memory responses (trained immunity) against heterologous pathogens. Here we show that while BCG vaccination significantly reduces morbidity and mortality against influenza A virus (IAV), it fails to provide protection against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In contrast to IAV, SARS-CoV-2 infection leads to unique pulmonary vasculature damage facilitating viral dissemination to other organs, including the bone marrow (BM), a central site for BCG-mediated trained immunity. Finally, monocytes from BCG-vaccinated individuals mount an efficient cytokine response to IAV infection, while this response is minimal following SARS-CoV-2. Collectively, our data suggest that the protective capacity of BCG vaccination is contingent on viral pathogenesis and tissue tropism.
Original language | American English |
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Article number | 110502 |
Journal | Cell Reports |
Volume | 38 |
Issue number | 10 |
DOIs | |
State | Published - 8 Mar 2022 |
Externally published | Yes |
Keywords
- BCG vaccination
- SARS-CoV-2
- animal models
- hematopoietic stem cells
- influenza virus
- lung pathology
- monocytes
- trained immunity
All Science Journal Classification (ASJC) codes
- General Biochemistry,Genetics and Molecular Biology