STUDY OF THE EFFECT OF SCHISTOSOME SOLUBLE EGG ANTIGEN ON THE DYNAMICS OF THE HOST IMMUNE RESPONSE

Abstract

This work aimed at studying the dynamics of immunoregulatory factors implicated in the murine model of SEA-induced granulomatous hyporesponsiveness. To achieve this objective, the following experimental design was carried out. Naive C57BL/6 mice were classified into three groups. One group (SEA group) was treated by intravenous injection with four doses of 10 Jlg SEA, given two days apart, starting seven days prior to infection. The second group (infected control group) was untreated but infected. All animals were infected by tail immersion with 25 cercariae of an Egyptian strain of S. mansoni. Mice (6-8/group) were sacrificed 6, 8 and 16 weeks post­ infection. A third group, untreated and not infected served as uninfected control group in some e;x:periments. Several parameters were studied: hepatic histopathological criteria and function, immunolocalization of cell surface markers in frozen sections of hepatic tissue including the adhesion molecules ICAM-1, LFA-1, Mac-1; costimulatory molecules B7-2, CD28 and the chemokine MIP-1a. The cellular immune responses were assessed by studying the lymphoproliferative response and cytokine measurement. The humoral immune response was evaluated by measuring serum SEA specific immunoglobulin isotypes.