Therefore, to examine whether exogenous ligand LPS-mediated TLR4 engagement in iNKT cells modulates immune responses in SR-induced HP and BIPF, sorted WT or TLR4-deficient iNKT cells were pre-incubated with LPS in vitro and adoptively transferred into CD1d−/− mice. Here, TLR4 is linked to hypersensitivity pneumonitis.