Conditioned immunosuppression in orally immunized mice

Mice were given oral immunization after pretreatment with a regimen (cyclophosphamide and a novel taste in the drinking water, chocolate milk (CHM)) which leads to suppression of the antibody response to intravenously administered antigens given concurrently with CHM. Following this treatment mice were reexposed to CHM and IgM and IgA antibody forming cells (AFC) were measured in spleen and Peyer's patch cells. Conditioned immunosuppression of AFC production was most marked (>fivefold) for IgA-AFC in Peyer's patch, with effects of lesser magnitude for IgM-AFC in Peyer's patch (twofold) and both IgM- and IgA-AFC in spleen. Analysis of cytokine production from stimulated Peyer's patch and splenic T cells in vitro showed significant decreased production of both IL-2 and IL-4, with the latter being the predominant cytokine produced in Pryer's patch cells of control animals. (C) 1996 Academic Press, Inc.Universidade Federal de São Paulo,ESCOLA PAULISTA MED,DEPT PEDIAT,São Paulo,BRAZILUNIV TORONTO,DEPT SURG & IMMUNOL,TORONTO,ON M5G 2C4,CANADAUniversidade Federal de São Paulo,ESCOLA PAULISTA MED,DEPT PEDIAT,São Paulo,BRAZILWeb of Scienc