Table 1.

Phagocytic activity of monocytes and IL-12Rβ2 expression by T cells responding to Cryptococcus-laden monocytes

Stimulus	MIA	% Phagocytic cells†	% IL-12Rβ2- positive cells‡
C. neoformans	−	32·3±5·8	9·4±1·2
(6995)	+	11·0±0·8*	4·2±0·6*
C. neoformans	−	72·8±3·2	20·0±3·1
(6995) + 18B7	+	29·1±2·6*	9·1±2·0*
IL-2 (100 U/ml)	−	−	35·2±3·1
+ IL-12 (5 U/ml)	+	−	32·4±2·2

Monocytes (1×10⁴) were untreated or treated with monoiodoacetic acid (MIA; 500 nm) and incubated for 3 hr. Then the cells were washed and incubated with encapsulated C. neoformans (6995) in the presence or absence of mAb to GXM (10μg/ml).

^†Phagocytic activity was evaluated as a percentage of phagocytosis at an E : T ratio of 1 : 10 after 2 hr of incubation at 37° in 5% CO₂.The results represent the mean±SEM of four separate experiments from four different donors.

^‡Monocytes treated as above were washed and autologous T cells (1×10⁵) were added. After 5 days of incubation T cells were harvested and IL-12Rβ2 subunit expression was analysed. The percentage of cells positive for IL-12R 2 expression is reported. The results represent the mean± SEM of three separate experiments from three different donors.

^*P<0·05 (MIA-treated vs. respective MIA untreated cells).