[Immunoregulatory activity of the lungs in relation to corpuscular and soluble antigens]

The immunoregulatory activity of the lungs in normal Wistar rats has been evaluated by difference between primary and secondary immune response to the same dose of the antigen introduced into the respiratory tract or intravenously. As shown in this investigation, intratracheal immunization with corpuscular antigens is accompanied by faintly pronounced antibody formation and a high degree of delayed hypersensitivity, while the introduction of soluble antigens into the respiratory tract leads to the active production of antibodies. The immunoregulatory activity of the lungs is T-dependent. The preliminary introduction of corpuscular or soluble antigen into the respiratory tract is accompanied by the formation of the local mechanism in the lungs for suppressing immune response to the subsequent intratracheal immunization.