Clostridium difficile toxin A stimulates macrophage-inflammatory protein-2 production in rat intestinal epithelial cells.
Neutrophil infiltration of the colonic mucosa is a hallmark of Clostridium difficile toxin A-mediated enterocolitis. Macrophage-inflammatory protein-2 (MIP-2) is a potent neutrophil chemoattractant secreted by rat macrophages and epithelial cells in response to inflammatory stimuli. In this work, we report that administration of toxin A into rat ileal loops increased mucosal levels of MIP-2 before the onset of fluid secretion and mucosal neutrophil infiltration. Administration of rabbit anti-MIP-2 IgG, but not control IgG, reduced toxin A-mediated secretion (by 58%), mucosal permeability (by 80%), and myeloperoxidase activity (by 85%). Immunohistochemical analysis demonstrated increased MIP-2 expression in intestinal epithelial and lamina propria cells 1 h after toxin A administration. Intestinal epithelial cells purified from toxin A-exposed ileal loops also showed increased MIP-2 mRNA expression and MIP-2 protein release that was inhibited by pretreatment of rats with the transcriptional inhibitor actinomycin D. These results indicate that C. difficile toxin A induces MIP-2 release from intestinal epithelial cells and that MIP-2 contributes to neutrophil mucosal influx during toxin A enteritis.
Castagliuolo
I
I
Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
Keates
A C
AC
Wang
C C
CC
Pasha
A
A
Valenick
L
L
Kelly
C P
CP
Nikulasson
S T
ST
LaMont
J T
JT
Pothoulakis
C
C
D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D054426:Chemokine CXCL2; D002630:Chemotactic Factors / Q000096:biosynthesis*; D016360:Clostridioides difficile; D004751:Enteritis / Q000139:chemically induced / Q000276:immunology; D004768:Enterotoxins / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D015846:Monokines / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D051381:Rats
D001427:Bacterial Toxins; D054426:Chemokine CXCL2; D002630:Chemotactic Factors; D004768:Enterotoxins; D015846:Monokines; D012333:RNA, Messenger; C041348:tcdA protein, Clostridium difficile