Interleukin-2 enhances the translocation of Escherichia coli from the intestines to other organs.
To determine if interleukin-2 (IL-2) would inhibit gastrointestinal bacterial translocation, mice were gut-decontaminated and recolonized with Escherichia coli C25; some groups were pretreated with 200 mg/kg cyclophosphamide. IL-2 (1.68 mg/kg) or sterile diluent was injected twice daily for 3 or 5 days, and mice were sacrificed the next day. High cecal levels of E. coli C25 were present in all mice. The overall incidence of E. coli C25 translocation to mesenteric lymph nodes was not reduced by IL-2. The median numbers of translocated E. coli C25/g of mesenteric lymph node were significantly (P less than .005) higher after both 3 days (659 vs. 117) and 5 days (550 vs. 50) of treatment with IL-2 with cyclophosphamide and after 5 days (1784 vs. 225) of IL-2 without cyclophosphamide. IL-2 prevented neutropenia and exacerbated lymphopenia caused by cyclophosphamide. The in vitro growth of E. coli C25 was not affected by up to 10(5) units/ml IL-2. Ileal and cecal structures assessed by light and electron microscopy were not altered by IL-2. Thus, IL-2 unexpectedly enhanced the translocation of E. coli C25 from the gastrointestinal tracts of both cyclophosphamide-pretreated and normal mice.
Penn
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RL
Department of Medicine, Louisiana State University, Shreveport Medical School.
Nguyen
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VQ
Specian
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Stevens
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Berg
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RD
D000818:Animals; D002432:Cecum / Q000382:microbiology / Q000473:pathology / Q000648:ultrastructure; D003520:Cyclophosphamide / Q000494:pharmacology; D004926:Escherichia coli / Q000254:growth & development / Q000276:immunology / Q000502:physiology*; D005260:Female; D007165:Immunosuppression Therapy; D007376:Interleukin-2 / Q000276:immunology*; D007413:Intestinal Mucosa / Q000648:ultrastructure; D007422:Intestines / Q000382:microbiology* / Q000473:pathology; D007958:Leukocyte Count / Q000187:drug effects; D008198:Lymph Nodes / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron; D013047:Specific Pathogen-Free Organisms
D007376:Interleukin-2; D003520:Cyclophosphamide