Figure 4.
Intact uninfected erythrocytes, but not erythrocyte lysates, inhibit IFN-γ responses to malaria antigens. IFN-γ (pg/mL) was assayed in supernatants of PBMCs cultured for 6 days with 5 × 105/mL iRBCs in the presence or absence of intact or lysed uninfected erythrocytes (at decreasing concentrations equivalent to 1:3, 1:10, and 1:30 diluted whole blood, respectively). An identical pattern of responses was obtained for PBMCs stimulated with PfSL (data not shown). No IFN-γ was detected in control cultures containing only lysed or intact erythrocytes (ie, without PBMCs) (not shown). Data from 7 donors are shown. The dotted line indicates the LLD for the IFN-γ ELISA (125 pg/mL).
