T-cell inhibition does not aggravate bacterial translocation from rat small bowel.
BACKGROUND
T-cell mediated immunity has been proposed to have an important function in the defence against translocating microbes from the gastrointestinal tract. After small bowel transplantation massive T-cell immunosuppression is necessary to avoid rejection. As a consequence, infections with intestinal bacteria are the main contributors to mortality in this setting. This could further imply that T cells are important in limiting bacterial translocation. In a model for bacterial translocation from small bowel in the rat we examined the outcome of T-cell inactivation.


METHODS
The studies were performed in a model of bacterial translocation from a Thiry-Vella loop of small bowel in the rat. The animals were treated with an anti-alpha/beta T-cell receptor monoclonal antibody (R73). Inhibition of T-cell activation was also made using the immunosuppressive drug cyclosporin A. All animals were sacrificed on day 3 postoperatively and translocation to the mesenteric lymph nodes, liver, spleen, lung and blood was evaluated.


RESULTS
Treatment with R73 resulted in an almost complete labelling of T cells but did not result in any increased bacterial translocation compared to animals treated with saline. Neither did immunosuppression with cyclosporin A.


CONCLUSIONS
In the model of bacterial translocation from a defunctionalised loop of small bowel the inhibition of T cells does not increase bacterial translocation to mesenteric lymph nodes or promote the systemic spread of the translocating bacteria. This indicates that T cells do not have any important protective function against translocating microbes from defunctionalised small bowel.
Stenbäck
Anders
A
Department of Pediatric Surgery, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
Lorant
Tomas
T
Meurling
Staffan
S
Johnsson
Cecilia
C
D000818:Animals; D018988:Bacterial Translocation / Q000502:physiology*; D005434:Flow Cytometry; D018928:Immunity, Mucosal / Q000502:physiology; D007150:Immunohistochemistry; D007421:Intestine, Small / Q000276:immunology / Q000382:microbiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013601:T-Lymphocytes / Q000276:immunology*