IMMUNOLOGICAL SUPPRESSION AFTER ORAL-ADMINISTRATION OF ANTIGEN .1. SPECIFIC SUPPRESSOR CELLS FORMED IN RAT PEYERS PATCHES AFTER ORAL-ADMINISTRATION OF SHEEP ERYTHROCYTES AND THEIR SYSTEMIC MIGRATION

Abstract

Rats given 1010 sheep erythrocytes (SRBC) orally contained specific suppressor cells to SRBC in their Peyer''s patches (PP) and mesenteric lymph nodes (MLN) after 2 days of feeding. After 4 days of feeding, similar suppressor cells were found in the thymus and spleen, but they were missing in the PP or MLN. These suppressor cells effectively blocked Ig[immunoglobulin]M and IgG plaque-forming cell responses to SRBC in Mishell-Dutton cultures and delayed-type-hypersensitivity responses to SRBC when transferred to syngeneic recipients, but they did not affect responses to horse erythrocytes. The orally induced specific suppressor cells appeared to be T2 cells since their activity was eliminated by in vivo treatment of SRBC-fed rats with anti-rat lymphocyte serum but not by adult thymectomy. Because carrageenan partially relieved the suppression observed in culture, the actual suppressive mechanism may involve a macrophage.