Allogeneic acute rejection on fetal small-bowel graft: role of gangliosides.
In previous work, it was shown that gangliosides (Gang) have an inhibitory effect on lymphocyte proliferation as well as on delayed-type hypersensitivity response and mixed lymphocyte reaction. Therefore, we decided to examine the effect of gangliosides in acute allorejection after fetal intestinal transplantation. We used two female C57BL/6 mice on pregnancy day 19 as a source of fetal intestine. All animals were anesthetized with ketamine (70 mg/kg) and xylazine (10 mg/kg), intramuscularly. We harvested intestinal segments of 1 cm to transplant into BALB/c and C57BL/6 mice (male, weighing around 20 g) used as recipients. They were divided into groups of six animals each: isogeneic and allogeneic without treatment, or treated with tacrolimus 1 mg/kg/day, or gangliosides 3 and 9 mg/kg/day, during 7 days posttransplantation, intramuscularly. On postoperative day 7, intestinal grafts were collected and fixed in 10% formalin solution. Using an anesthetic overdose as euthanasia, we removed the intestinal grafts. Tissue samples were stained with hematoxylin-eosin for histological analysis regarding grafts development (D) and rejection (R) aspects. Data were analyzed by the Kruskal-Wallis test, considering P < or = 0.05 as significant. In the isogeneic and tacrolimus groups, we observed a very good degree of development (D = 9 +/- 0.5; D = 9 +/- 0.4, respectively), but a severe degree of rejection (R = 15 +/- 1.3) and a low degree of development (D = 1 +/- 0.8) in animals without treatment. The ganglioside groups showed D = 5 +/- 1.6 and R = 13 +/- 3.3, and D = 7 +/- 2.9 and R = 9 +/- 1.9, for the 3-mg and 9-mg groups, respectively. There was a statistically significant difference between the ganglioside groups and allogeneic groups without treatment. Based on the above data, we conclude that avascular fetal intestine transplantation is a good experimental model for studying immunological events, and that gangliosides only partially modulate the allorejection response, allowing intestinal development, mainly at the highest ganglioside dose. Maybe immunomodulation would be better observed by using isolated types of gangliosides or association with other immunosuppressive drugs.
Montero
Edna Frasson de Souza
EF
Department of Surgery, Federal University of São Paulo, São Paulo, Brazil.
Steffens
Vânia Antunes
VA
Manna
Mônica Cecília Bochetti
MC
Koike
Márcia Kiyomi
MK
de Almeida
Carlos Eduardo Saldanha
CE
de Oliveira
Kátia Ferreira
KF
Simões
Manuel de Jesus
Mde J
D000818:Animals; D005260:Female; D016332:Fetal Tissue Transplantation / Q000276:immunology*; D005732:Gangliosides / Q000502:physiology*; D006084:Graft Rejection / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007421:Intestine, Small / Q000276:immunology / Q000473:pathology / Q000637:transplantation*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016559:Tacrolimus / Q000627:therapeutic use; D014184:Transplantation, Homologous
D005732:Gangliosides; D007166:Immunosuppressive Agents; D016559:Tacrolimus