Table 1.

Response of different ILC groups in various intracellular and extracellular bacterial infections.

ILC Group	Bacterial Infections	Role/Response
NK cells	Shigella flexneri Mycobacterium lepraemurium Mycobacterium avium Listeria monocytogenes Salmonella typhimurium Bacillus anthracis Escherichia coli Staphylococcus aureus Mycobacterium tuberculosis Lactobacillus johnsonii Propioni-bacterium acnes Yersinia pestis Citrobacter rodentium Yersinia enterocolitica Mycobacterium bovis Legionella pneumophila Francisella tularensis Bordetella pertussis Pseudomonas aeruginosa Streptococcus pneumoniae	Cytotoxicity/Lysis via perforin and granzymes Cytotoxicity/Lysis via granulysin IFN-γ and TNF-α production Activation by dendritic cell released cytokines including IL-12, IL-18, and type-1 interferons Secretion of IL-10 to inhibit dendritic cell Activation of adaptive immune cells Secrete antibacterial mediators: cathelicidin, IDO, nitric oxide and α-defensins
ILC1s	Clostridium difficile Salmonella typhimurium Klebsiella pneumoniae	Production of IFN-γ, TNF-α, IL-23, IL-17 and nitric oxide synthase 2
ILC2s	Helicobacter pylori Clostridium difficile Streptococcus pneumoniae	Production of IL-4, IL-5, IL-9 and IL-13 cytokines
ILC3s	Salmonella typhimurium Salmonella enterica Citrobacter rodentium Listeria monocytogenes Clostridium difficile Helicobacter apodemus Helicobacter typhlonius Streptococcus pneumoniae Klebsiella pneumoniae Pseudomonas aeruginosa Mycobacterium tuberculosis	Secretion of cytokines including IL-17, GM-CSF, IL-22 Production of anti-microbial peptides such as RegIIIβ and RegIIIγ, calprotectin and lipocalin-2