Lympho-proliferative responses to various Fasciola hepatica worm's antigens: an in vitro study

Fascioliasis is an important zoonotic disease with approximately 2-4 million people infected worldwide and a further 180 million at risk of infection. F. hepatica can survive within the bile ducts for many years through its ability to suppress the host immunity with Fasciola cathepsin L1 cysteine protease and Glutathione S transferase playing an important role. The aim of the present study is to investigate the in vitro lympho-proliferative responses of hepatic hilar lymphocytes [HLN] of infected sheep in response to different F. hepatica antigens. The suppressive effects of Fasciola excretory/secretory [ES] and tegument [TEG] and their fractions were also investigated. Our results showed that both ES and TEG had significant suppressive effects on lymphoproliferation, up to 74% and 92%, respectively. When these antigens were fractionated, fraction 3 [MW of >10000-30000] of both ES [64%] and TEG [59%] in addition to fraction 4 [MW of

A microcalorimetric assay to measure the reactivity of antigen-stimulated mononuclear cells from Schistosoma mansoni infected patients

The reactivity of mononuclear cells (2 x 10**6/ml minimum Eagle's medium, MEM) from normal subjects and from Schistosoma mansoni-infected patients was evaluated by microcalorimetry. The results which are reported as heat production (mcal for 2 x 10**6 cells in 3600s), were 2,087 ñ 21.2 and 2,497.0 ñ 21.3 for mononuclear cells from infected patients (N = 8) under stimulation with S. mansoni soluble egg antigen (SEA) and soluble adult worm antigenic preparation (SWAP), respectively. The values for cells from normal subjects (N = 8) were 13.7 ñ 1.1 and 29.3 ñ 3.2 in the presence of the same antigens. Pre-treatment of mononuclear cells from patients with 1 mM aminophylline (a cAMP phospphodiesterase inhibitor) totally abolished heat production. Cell viability (> 95%) was not changed after the measurement. The microcalorimetric assay described here measures the cellular metabolic activity and we feed justified in suggesting this techinique as an auxiliary diagnosis of schistosomiasis. Given the sensitivity, precision and accuracy of this microcalorimetric assay, we feel it can be used for the diagnosis of disease conditions for which a reliable diagnostic method is required