Antigen-specific suppression of cultured lymphocytes from patients with neurocysticercosis

Abstract

The biological parasite-host interactions involved in neurocysticercosis (NC) are of a complex nature. A lymphoproliferation assay was performed using mononuclear cells from 11 patients with NC, who were classified according to the alterations obtained by imaging examinations. Antigen extracts from the membrane and/or scolex of Taenia solium and from the vesicular fluid of Taenia crassiceps were used. Mononuclear cells from patients with NC showed antigen-specific suppression when compared with a control group. The patients presenting calcified cysts showed higher suppression when compared with patients in the active phase of disease. The antigen in the vesicular fluid of T. crassiceps seems to play a suppressor role in vitro, completely inhibiting cell proliferation induced by the mitogens phytohaemagglutinin, concanavalin A and pokeweed mitogen.

Fig. 1

Mean results (cpm) of the proliferation of mononuclear cells from four control individuals incubated for different periods of time and with different concentrations of antigen extract from the scolex of Taenia solium (S-Tso). Negative control: DMEM; positive control: phytohaemagglutinin (PHA, 10 µg/ml). (□) DMEM; (◊) PHA; (×) S-Tso 0·1 µg/ml; (▵) S-Tso 1 µg/ml; (○) S-Tso 10 µg/ml.

Fig. 2

Stimulation index (SI) of the lymphoproliferation assay of 11 patients with NC (▪) and eight control individuals (□). Cells were incubated for 7 days with a nitrocellulose particle suspension containing antigen extract from the vesicular fluid of Taenia crassiceps (nt-Ag) diluted 1:1, or antigen extracts from the vesicular fluid of T. crassiceps (VF-Tcra) and from the scolex (S), membrane (M) and membrane and scolex (M + S) of T. solium (Tso) at a concentration of 30 µg/ml. (—) Mean.

Fig. 3

Stimulation index (SI) of the lymphoproliferation assay of eight control individuals and 11 patients with NC classified according to the evolutive phase of the disease (type III, IV, Mixed). Cells were incubated for 7 days with antigen extracts from the vesicular fluid of Taenia crassiceps (a) and from the scolex (b), membrane (c) and membrane and scolex (d) of T. solium at a concentration of 30 µg/ml. (—) Mean.

Fig. 4

Stimulation index (SI) of the lymphoproliferation assay obtained for cells incubated with (▪) phytohaemagglutinin (PHA, 10 µg/ml) and (░) concanavalin A (ConA, 50 µg/ml) for 3 days (10 individuals) or with (▪) pokeweed mitogen (PWM, 5 µg/ml) for 7 days (four individuals) in the presence or absence of antigen from the vesicular fluid of Taenia crassiceps (VF-Tcra) and from the membrane + scolex (M + S) of T. solium (M + S-Tso).