Indirect effects of oral tolerance inhibit pulmonary granulomas to Schistosoma mansoni eggs.
Parenteral injection of tolerated proteins into orally tolerant mice inhibits the initiation of immunological responses to unrelated proteins and blocks severe chronic inflammatory reactions of immunological origin, such as autoimmune reactions. This inhibitory effect which we have called "indirect effects of oral tolerance" is also known as "bystander suppression." Herein, we show that i.p. injection of OVA + Al(OH)(3) minutes before i.v. injection of Schistosoma mansoni eggs into OVA tolerant mice blocked the increase of pulmonary granulomas. In addition, the expression of ICAM-1 in lung parenchyma in areas outside the granulomas of OVA-orally tolerant mice was significantly reduced. However, at day 18 after granuloma induction there was no difference in immunofluorescency intensity to CD3, CD4, F4/80, andα-SMA per granuloma area of tolerant and control groups. Reduction of granulomas by reexposure to orally tolerated proteins was not correlated with a shift in Th-1/Th-2 cytokines in serum or lung tissue extract.
Departamento de Morfologia, ICB-UFMG, Avenue Antônio Carlos 6627, Pampulha, Belo Horizonte, MG, CEP 31270-901, Brazil.
Geraldo Magela
GM
Azevedo
Raquel Alves
RA
Costa
Mariana Araujo
MA
Resende
Claudiney Melquiades
CM
Rodrigues
Nelson Monteiro
NM
Vaz
Cláudia Rocha
CR
Carvalho
D000284:Administration, Oral; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D024201:Bystander Effect; D002478:Cells, Cultured; D004531:Eggs / Q000469:parasitology; D006099:Granuloma / Q000209:etiology / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D007108:Immune Tolerance; D016130:Immunophenotyping; D007249:Inflammation; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D008168:Lung / Q000276:immunology / Q000378:metabolism* / Q000469:parasitology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000008:administration & dosage; D012550:Schistosoma mansoni / Q000276:immunology* / Q000472:pathogenicity; D012555:Schistosomiasis mansoni / Q000150:complications / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology
D015703:Antigens, CD; D018799:Intercellular Adhesion Molecule-1; D010047:Ovalbumin