Intestinal microbial translocation: immunologic consequences and effects of interleukin-4.
BACKGROUND
Administration of a chemically defined, liquid, elemental diet (CDD) results in intestinal microbial translocation, but the immunologic consequences of this process are unclear. This study evaluated the effects of CDD feeding and interleukin-4 (IL-4) administration on mesenteric lymphocyte, peritoneal macrophage (PMO), and hepatic Kupffer cell (KC) functions.


METHODS
BALB/C mice (n = 60) were randomized to receive a paired feeding of regular diet (RD) or a CDD for 14 days. Mesenteric lymph nodes (MLN) and cecum were cultured for bacteria. Mixed lymphocyte response and cytotoxic T-lymphocyte function of MLN lymphocytes were assayed. PMO and KC were harvested to measure tumor necrosis factor production, macrophage binding of fluorescent-labeled lipopolysaccharide, and Candida albicans phagocytosis (CAP) and killing (CAK); KC-hepatocyte interaction was assessed by hepatocyte protein synthesis. In a second study 75 BALB/c mice received RD, CDD, and CDD+IL-4 (30,000 units/mouse intraperitoneally). MLN lymphocyte and PMO functions were measured and intestinal immunoglobulin A levels were determined.


RESULTS
Oral feeding of a CDD resulted in significant impairment of mesenteric lymphocyte mixed lymphocyte response and cytotoxic T-lymphocyte functions and decreased PMO tumor necrosis factor production, fluorescent-labeled lipopolysaccharide binding, CAP, and CAK. KC function was preserved in CDD-fed mice. Administration of IL-4 significantly reduced the incidence of bacteria positive MLN and increased PMO superoxide production, CAP, CAK, and MLN lymphocyte mitogenesis.


CONCLUSIONS
Use of IL-4 may be beneficial in situations where intestinal microbial translocation contributes to sepsis.
Shou
J
J
Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia.
Motyka
L E
LE
Daly
J M
JM
D000818:Animals; D018407:Bacterial Physiological Phenomena; D002478:Cells, Cultured; D005526:Food, Formulated; D015847:Interleukin-4 / Q000276:immunology* / Q000494:pharmacology; D007422:Intestines / Q000382:microbiology*; D007728:Kupffer Cells / Q000187:drug effects / Q000502:physiology; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes / Q000187:drug effects / Q000502:physiology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000502:physiology; D008643:Mesentery / Q000166:cytology; D051379:Mice; D008807:Mice, Inbred BALB C; D011897:Random Allocation; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology
D015847:Interleukin-4