Figure 3.

Invariant natural killer T (iNKT) cell lines become activated and secrete cytokines in response to α-galactosylceramide (αGalCer) in an APC-free system. iNKT cell lines (AC6, AC8 and AC10) stimulated with αGalCer more than 2 weeks earlier were washed and re-suspended with complete RPMI medium without cytokines. 1 × 10⁵ iNKT cells were incubated in the presence of plate-bound, recombinant CD1d-Fc fusion protein loaded with αGalCer or mock loaded with dimethyl sulphoxide (DMSO). Supernatants were collected and cytokine production was measured by enzyme-linked immunosorbent assay (ELISA). Results are representative of two separate experiments.