TH1 PATTERN OF CYTOKINE SECRETION BY SPLENIC CELLS FROM PYELONEPHRITIC MICE AFTER IN-VITRO STIMULATION WITH HSP-65 OF ESCHERICHIA-COLI

Splenic lymphocytes and peritoneal macrophages from BALB/c mice with E scherichia coli pyelonephritis were obtained at various intervals afte r infection. These cells were stimulated in vitro with different antig ens and cytokine release was assayed in the supernate of the cultured cells. It was observed that both specific antigens such as outer-membr ane proteins (OMPs), porins and heat-shock protein-65 (hsp-65), as wel l as nonspecific mitogens such as phytohaemagglutinin (PHA), were able to induce cytokine production by splenic cells from infected mice. Of all these antigens, hsp-65 was found to be the best inducer of cytoki ne release. In the acute stage of pyelonephritis, the release of inter leukin-2 (IL-2) and interferon-gamma (IFN-gamma) was found to increase with time; both reached their peak values on the seventh day after in fection. The TH1 pattern of cytokine secretion by splenic cells was ob served, i.e., IL-2 and IFN-gamma, whereas there was complete absence o f IL-4 secretion. In the chronic stage of pyelonephritis, i.e., 150 da ys after infection, a decrease in the level of IL-2 and IFN-gamma was observed. Peritoneal macrophages released IL-1 on stimulation with hsp -65, which increased with the progression of disease. The possible imp lications of this study for the disease process are discussed.