Table 1

Overview of pattern recognition receptors (PRRs), antimicrobial peptides (AMPs) and proteins and cytokines and chemokines produced by lung epithelial cells and their modulation by mycobacterial exposure

Airway epitheliumAlveolar epithelium
PrimaryCell linePrimaryCell line
PRRsTLRsTLR121 48 90TLR148 90TLR291TLR291
TLR221 48 90TLR248 90TLR392TLR392
TLR321 48 90TLR348 90TLR491TLR491
TLR421 48 90TLR448 90 93
TLR521 48 90TLR548 90 93
TLR621 48 90TLR648 90
TLR790TLR748
TLR890TLR990
TLR948 90TLR1090
TLR1090
TLR coreceptorsCD1490CD1491
MD291
NLRsNOD148NOD193NOD194NOD194
NLRP195NOD293
NLRP396
LectinsDectin-197Dectin-197
MINCLE98L-SIGN99
MINCLE98
Nucleic acid sensorsRIG1100RIG1101RIG192RIG192
MDA5101MDA5102
LGP2101
OtherSDC440
AMPs and proteinsDefensinshBD180hBD2103
hBD280
CathelicidinsLL-3780LL-3725
OtherLactoferrin80Hepcidin104
Hepcidin80
CytokinesPro-inflammatoryIL-621 44 48IL-848 90 93 105IL-18106IL-6107
IL-821 48 80IL-32108IL-891 105 107
IL-32108IL-17107
IL-32108
IFN-γ107
TNF-α107
Anti-inflammatoryIL-1044IL-10105IL-1RA107
IL-2244IL-4107
IL-9107
IL-10105
IL-13107
ChemotacticCCL2021CCL291 107
CXCL1021CCL3107
GM-CSF21 80CCL4107
CCL5107
CXCL1092 107
GM-CSF107
G-CSF107
  • PRRs expressed by human lung epithelial cells (blue). AMPs and cytokines expressed or produced by human lung epithelium on mycobacterial stimulation (green).

  • GM-CSF, Granulocyte-Macrophage Colony Stimulating Factor; IFN-γ, interferon gamma; IL, interleukin; NK, Natural Killer; NLRs, NOD-like receptors; SDC4, syndecan 4; TLR, Toll-like receptor; TNF-α, Tumor Necrosis Factor - Alpha.