Fig. 2

Assays to look at Natural Killer cell function. a Model of the subset of adaptive NK cells that lack Fc receptor γ chain. These cells are particularly skilled at degranulating and producing IFNγ that can help activate the immune response to Plasmodium. b Growth inhibition antibody dependent cellular cytotoxicity assay (Alternative GI-ADCC assay). Synchronized late stage parasite culture is incubated with or without natural killer cells and with or without immune plasma or antibodies. In this assay, the NK cells can kill the infected RBCs but the antibody is still there to allow for growth inhibition via neutralizing activity against merozoites. The resulting inhibition can then be quantified in all groups and compared by looking at parasitaemia. c Growth inhibition antibody dependent cellular cytotoxicity assay (GI-ADCC assay). In this assay late stage purified (> 95% pure) infected RBCs are mixed with NK cells with or without immune plasma or antibodies. After 5 h the antibodies are washed out, then uninfected RBCs are added at 100 fold excess. The infected RBCs then rupture and the resulting parasitaemia the next day is used to assess growth inhibition. d Functional analysis of NK cells in mixed PBMCs. PBMCs are incubated at a 1:1 ratio with late stage purified infected RBCs then immune or naive plasma is added. The phenotype and ADCC function is then assessed via surface markers, CD107a as a marker for degranulation and IFNγ by intracellular cytokine staining