Communications

Abstract

Antibodies to influenza virus have been shown to be present not only in serum, but also in secretions of the respiratory tract (1–4). Gamma A is the predominant immunoglobulin class in the secretions, whereas this immunoglobulin is a minor component in the serum. The γ A of the secretions differs chemically and antigenically from serum γ A. These observations suggest that antibodies associated with secretory γ A are produced locally, and are not simply the result of transudation from the serum. There is considerable indirect evidence for the synthesis of local antibodies in the respiratory tract. The problem remains to elucidate the mechanism of local antibody formation. The lymphocytosis-promoting factor (LPF) obtained from Bordetella pertussis has been shown partially to suppress the formation of circulating antibody when given intravenously in mice (5). Therefore, the possibility of demonstrating a dissociation between the levels of antibody activity in the serum and in the secretions of mice infected with influenza virus was investigated.