Fig. 2.

Effects of gradual heat-inactivation on IA-induced cytokine production. The same normal human serum as in Fig. 1 was heat-inactivated and mixed with native serum to obtain variation in percentage of native serum, and added (10% v/v of human serum altogether) to separate cell cultures. PBMC (10⁶/ml) from a healthy donor were stimulated with HAGG or mIgG (100 µg/ml) and SN were collected after 20 h incubation and levels of (a) IL-6, (b) IL-10 and (c) IL-12p40 analysed by ELISA. In (d) functional activity of the classical and alternative complement pathways (12) of the corresponding serum mixtures in RPMI are shown. Data from one of four PBMC donors with similar results is shown.