Coupling of palmitate to ovalbumin inhibits the induction of oral tolerance

Autor: C.M. Gontijo, C.A. Silva, A.F. Silva-Neto, F.M. Oliveira
Rok vydání: 1998
Předmět:
Zdroj: Brazilian Journal of Medical and Biological Research, Vol 31, Iss 11, Pp 1421-1424 (1998)
Brazilian Journal of Medical and Biological Research, Volume: 31, Issue: 11, Pages: 1421-1424, Published: NOV 1998
ISSN: 0100-879X
DOI: 10.1590/s0100-879x1998001100009
Popis: Oral tolerance is a phenomenon that may occur in animals exposed to protein antigens for the first time by the oral route. They become unable to produce immune responses at the levels normally observed when they are immunized parenterally with antigen in the presence of adjuvants. Lipids have been used as adjuvants for both parenteral and oral immunization. In the present study we coupled ovalbumin with palmitate residues by incubating the protein with the N-hydroxysuccinimide palmitate ester and tested the preparation for its ability to induce oral tolerance. This was performed by giving 20 mg of antigen to mice by the oral route 7 days prior to parenteral immunization in the presence of Al(OH)3. Mice were bled one week after receiving a booster that was given 2 weeks after primary immunization. Specific antibodies were detected by ELISA. Despite the fact that the conjugates are as immunogenic as the unmodified protein when parenterally injected in mice, they failed to induce oral tolerance. This discrepancy could be explained by differences in the intestinal absorption of the two forms of the antigen. In fact, when compared to the non-conjugated ovalbumin, a fast and high absorption of the lipid-conjugated form of ovalbumin was observed by "sandwich" ELISA.
Databáze: OpenAIRE