Data/hora: 06/06/2024 05:29:06

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Stabilization of serum antibody responses triggered by initial mucosal contact with the antigen independently of oral tolerance induction	
Autores: 	Verdolin,B.A.; Ficker,S.M.; Faria,A.M.C.; Vaz,N.M.; Carvalho,C.R.	
Data: 	2001-02-01	
Ano: 	2001	
Palavras-chave: 	Oral tolerance; Mucosal immunity; Stability; Memory.	
Resumo: 	Initial contacts with a T-dependent antigen by mucosal routes may result in oral tolerance, defined as the inhibition of specific antibody formation after subsequent parenteral immunizations with the same antigen. We describe here an additional and permanent consequence of these initial contacts, namely, the blockade of secondary-type responsiveness to subsequent parenteral contacts with the antigen. When repeatedly boosted ip with small doses (3 µg) of ovalbumin (OVA) (or lysozyme), primed B6D2F1 mice showed progressively higher antibody responses. In contrast, mice primed after a single oral exposure to the antigen, although repeatedly boosted, maintained their secondary antibody titers on a level which was inversely proportional to the dose of antigen in the oral pretreatment. This phenomenon also occurred in situations in which oral tolerance was not induced. For example, senile 70-week-old B6D2F1 mice pretreated with a single gavage of 20 mg OVA did not become tolerant, i.e., they formed the same secondary levels of anti-OVA antibodies as non-pretreated mice. However, after 4 weekly challenges with 3 µg OVA ip, orally pretreated mice maintained the same anti-OVA serum levels, whereas the levels of control mice increased sequentially. This "stabilizing" effect of mucosal exposure was dose dependent, occurred with different proteins and was triggered by single or multiple oral or nasal exposures to the antigen.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000200008	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2001000200008	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.34 n.2 2001	
Fonte: 	info:eu-repo/semantics/openAccess