Data/hora: 12/06/2024 17:40:09

Provedor de dados: | 56
País: | Brazil
Título: | Indirect effects of oral tolerance to ovalbumin interfere with the immune responses triggered by Schistosoma mansoni eggs
Autores: | Carvalho,C.R.; Lenzi,H.L.; Correa-Oliveira,R.; Vaz,N.M.
Data: | 2002-10-01
Ano: | 2002
Palavras-chave: | Oral tolerance; Ovalbumin; Granuloma; Schistosoma mansoni.
Resumo: | The objective of the present study was to investigate whether the injection of a tolerated protein (indirect effects) affects the formation of granulomas around Schistosoma mansoni eggs trapped in the lungs after intravenous (iv) injection into normal (noninfected) C57BL/6 mice (6 animals per group). To induce oral tolerance to chicken egg ovalbumin a 1/5 dilution of egg white in water was offered ad libitum in a drinking bottle for 3 days. Control mice received water. After 7 days, control and experimental animals were injected iv with 2,000 S. mansoni eggs through a tail vein. In some mice of both groups the iv injection of eggs was immediately followed by intraperitoneal (ip) immunization with 10 µg of dinitrophenylated conjugates of ovalbumin (DNP-Ova) emulsified in complete Freund's adjuvant (CFA) or only CFA; 18 days later, mice were bled and killed by ether inhalation. The lungs were fixed in formalin and embedded in paraffin. Serial sections of 5 µm were stained with Giemsa, Gomori's silver reticulin and Sirius red (pH 10.2). Granuloma diameters were measured in histological sections previously stained with Gomori's reticulin. Anti-DNP and anti-soluble egg antigen (SEA) antibodies were analyzed by ELISA. In mice orally tolerant to ovalbumin the concomitant ip injection of DNP-Ova resulted in significantly lower anti-SEA antibodies (ELISA*: 1395 ± 352 in non-tolerant and 462 ± 146 in tolerant mice) and affected granuloma formation around eggs, significantly decreasing granuloma size (area: 22,260 ± 2478 to 12,993 ± 3242 µm²). Active mechanisms triggered by injection of tolerated antigen (ovalbumin) reduce granuloma formation.
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002001000012
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2002001000012
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.35 n.10 2002
Fonte: | info:eu-repo/semantics/openAccess