ALI	Acute lung injury
AMs	Alveolar macrophages
AP-1	Activator protein-1
ARDS	Acute respiratory distress syndrome
ATII	Alveolar cell type II
BAL	Bronchoalveolar lavage
cAMP	Cyclic adenosine monophosphate
CAP	Community-acquired pneumonia
cGMP	Cyclic guanosine monophosphate
CREB	cAMP response element-binding protein
CRP	C-reactive protein
DAMPs	Damage-associated molecular pattern molecules
ERK	Extracellular signal-regulated kinases
FQs	Fluoroquinolones
GM-CSF	Granulocyte–macrophage colony-stimulating factor
hPBL	Human peripheral blood lymphocytes
IFN	Interferon
IL	Interleukin
iNOS	Inducible NO synthase
IκB	Inhibitory κappa B
JNK	c-Jun N-terminal kinases
KC	Keratinocytes-derived chemokine
LPS	Lipopolysaccharide
MAMPs	Microbe-associated molecular patterns
MAPK	Mitogen-activated protein kinase
MCP-1	Monocyte chemotactic protein
MIP-1α	Macrophage inflammatory protein 1α
Mpro	Main protease
NET	Neutrophil extracellular trap
NF-κB	Nuclear factor κappa-B
NO	Nitric oxide
PAMPs	Pathogen-associated molecular patterns
PBMCs	Peripheral blood mononuclear cells
PDEs	Phosphodiesterases
PKA	Protein kinase A
PRRs	Pattern recognition receptors
RBCs	Red blood cells
RCT	Randomised controlled trial
ROS	Reactive oxygen species
SARS-CoV-2	Severe acute respiratory syndrome coronavirus 2
TAK1	Transforming growth factor-activated kinase 1
TLR	Toll-like receptor
TNF	Tumour necrosis factor