Estudo da temporalidade dos efeitos da injeção parenteral de proteínas imunologicamente toleradas no reparo de feridas na pele

Abstract

Oral tolerance results from a systemic modification of immunological responsiveness to previously ingested proteins that inhibit specific antibody responses. Different proteins such as ovalbumin (OVA) and the maize protein zein are widely used in oral tolerance studies. Administration of OVA either by continuously feeding or by gavage can turn mice orally tolerant to this protein; due to the ingestion of regular mouse chow, mice are tolerant to zein. In addition of decreasing specific immune responses, parenteral injection of orally-tolerated proteins in adjuvant also inhibits immune responses to unrelated antigens injected simultaneously. Our previous studies show that intraperitoneal injections of OVA or Zein in Al(OH)3 adjuvant, concomitantly with skin lesions in animals tolerant to these proteins, reduce inflammation and result in the formation of smaller and better looking scars. Herein, we tested if subcutaneous (s.c.) injection of orally-tolerated proteins up to 7 days before skin lesions also reduced inflammation and improved the repair. Our results show that subcutaneous injection of zein either 3 or 5 days before skin lesions results in lower number of leukocytes, of mast cells and neutrophils, and in higher numbers of T lymphocytes in the wound bed. Injection of zein 7 days before skin lesions does not reduce the total number of leukocytes nor increases the number of T lymphocytes, but still reduce the number of mast cells. At 40 days after injury, the reorganization of collagen in the scar area was similar to that of intact skin in the animals that received the tolerated protein up to 5 days before the lesions. These results indicate that parenteral injection of orally-tolerated proteins up to 5 days before skin lesions can be used to improve healing. These results may become important in situations of programmed surgical interventions.