A profound and long-lasting state of specific immune unresponsiveness may be induced in adult inbred mice given a single dose of protein immunogens – such as ovalbumin or hemocyanin – by the digestive route. The degree of unresponsiveness induced by intragastric exposure to ovalbumin could not be achieved by intravenous injection of deaggregated ovalbumin solutions across a wide range of doses. Unresponsiveness induced by intragastric exposure to hapten-protein conjugates is specific to the carrier protein.

No abstract

Adult normal inbred mice rendered tolerant to OVA by previous oral exposure do not respond to intraperitonela immunization with DNP-OVA in adjuvant. These tolerant mice also form less DNP-specific antibodies to DNP-KLH when immunized with mixtures of DNP-KLH and DNP-OVA, or less HGG-specific antibodies when immunized with cross-linked conjugates of OVA and HGG. These same procedures increased DNP-specific or HGG-specific responses in non-tolerant control mice. The cross-supperssion was ineffective, however, to inhibit already ongoing antibody responses.
Camundongos adultos normais tornados imunologicamente tolerantes a ovoalbumina (OVA) por exposição oral não formam anticorpos antidinitrofenil (anti-DNP) quando imunizados com DNP-OVA, mas respondem normalmente à DNP-hemocianina (DNO-KLH). Entretanto, a adição de DNP-OVA à injeção de DNP-KLH reduz a formação de anticorpos anti-DNP em animais tolerantes a OVA, mas não em animais normais. Similarmente animais tolerantes à OVA formam menos anticorpos antiglobulina humana (HGG) quando imunizados com agregados (por glutaraldeído) de OVA e HGG. A tolerância oral e, portanto, capaz de inibir a indução de respostas imunes por um esquema de supressão-cruzada. Esse esquema, no entanto, não foi capaz de inibir respostas imunes já iniciadas

No abstract

Three injections of 100 μgof soluble ovalbumin (Ova) significantly reduced IgE responses of DBA/1J mice to immunization with 0.1 μgOva in Al(OH)₃ gel, whereas IgG1 responses were not similarly affected.