asialo-gm1-ganglioside and Klebsiella-Infections

The effects of recombinant human interleukin-2 (rIL-2) administered prophylactically on the death of CBA/J mice challenged with Klebsiella pneumoniae 27 intraperitoneally were examined. rIL-2 administered subcutaneously at 20 micrograms per mouse for 7 days enhanced survival after a lethal challenge. The injection of anti-asialo GM1 antibody did not influence the effect of rIL-2. In mice given rIL-2, the number of peritoneal macrophages increased, and the infiltration of polymorphonuclear leukocytes (PMN) into the peritoneal cavity after the bacterial challenge was enhanced. In addition, adoptive transfer of sera and peritoneal exudate cells (PEC), consisting of an approximately equal number of macrophages and PMN, obtained from mice given rIL-2 enhanced resistance to a K. pneumoniae infection, compared with adoptive transfer of sera and PEC obtained from mice not given rIL-2. These results indicate that rIL-2 protects mice from a lethal challenge with K. pneumoniae, and suggest that the protective effect is due to an increase in the number of phagocytic cells and in the cooperative activity of the sera and the phagocytic cells.

Topics: Animals; Antibodies, Bacterial; Colony Count, Microbial; Female; G(M1) Ganglioside; Glycosphingolipids; Humans; Interleukin-2; Klebsiella Infections; Klebsiella pneumoniae; Mice; Mice, Inbred CBA; Neutrophils; Peritoneal Cavity; Phagocytosis; Recombinant Proteins; Survival Rate

The effect of recombinant human interleukin-2 (rIL-2) on the course of experimental chronic respiratory tract infection caused by Klebsiella pneumoniae in mice was examined. rIL-2 was administered subcutaneously once a day for 7 or 14 days, starting 2 weeks after the mice were infected. Administration of 2 or 20 micrograms of rIL-2 per mouse daily for 7 days reduced bacterial counts in the lungs dose dependently. At a dose of 0.2 microgram per day, proliferation of bacteria in the lungs was suppressed after 14 days of administration. Agglutinin titers in serum were not affected by rIL-2 treatment. Monocyte and lymphocyte counts in peripheral blood were increased by administration of 20 micrograms of rIL-2 daily for 14 days but not by treatment for 7 days. In addition, clearance of bacteria from the lungs after aerosol exposure was enhanced by treatment for 7 days before infection. Thus, rIL-2 acted therapeutically or prophylactically in the presence or absence, respectively, of a specific antigen. These effects were not abolished by anti-asialo GM1 antibody. This suggests that activation of natural killer cells does not play a critical role in the therapeutic and prophylactic effects of rIL-2.

Topics: Aerosols; Agglutination Tests; Animals; Antibodies; Chronic Disease; Female; G(M1) Ganglioside; Glycosphingolipids; Interleukin-2; Kinetics; Klebsiella Infections; Klebsiella pneumoniae; Leukocyte Count; Lung Diseases; Mice; Mice, Inbred CBA; Recombinant Proteins; Respiratory Tract Infections