Experimental amebiasis: Immunohistochemical study of immune cell populations

Distribution of immune cell populations was studied in a C3H/HeJ mouse mode l of intestinal amebiasis from 5 to 60 days post-inoculation with Entamoeba histolytica, using immunoperoxidase techniques. At various time intervals, the ceca from mice were fixed in 10% formalin, dehydrated, embedded and se ctioned at 5 mu m. Sections were incubated with conjugated peroxidase-label led antibodies to mouse IgA, IgM, and IgG. Color was developed with 3, 3'-d iaminobenzidine tetrahydrochloride (DAB)/H2O solution. CD3, CD4, and CD8 ce lls, as well as neutrophils were detected by reacting with biotin-conjugate d anti-mouse CD3, CD4, CD8, and CD11 monoclonal antibodies, followed by the ir incubation with avidin-peroxidase and color development with DAB/H2O2 so lution. Erythrocin B and toluidine blue were used to stain eosinophils and Mast cells, respectively. It was observed that the IgA(+) plasma cell was t he dominating immune cell present in the mucosa, although eosinophils, neut rophils, CD3(+), CD4(+), CD8(-), IgM(+), IgG(+) cells and Mast cells were a lso seen. Results of this study suggest that infiltration of immune cells a t the mucosal surface during intestinal amebiasis might be important in the defense against this parasite.