Serum antibody response and germinal centre reaction in the upper respiratory tract after antigen challenge in mice

In order to establish an experimental model for the study of immunological reactions to exogenic immunogens in the upper and lower respiratory system NMRI mice were subjected to inhalation of the mitogenic and inflammatory response inducing lectin concanavalin A (Con A) and bovine serum albumin (BSA). Immunological reactions were induced in the upper respiratory tract and in the lungs. Serologically, the course of the antibody titre was measured by radio-immunoassay over several weeks. Germinal centre reactions in the nose and paranasal sinus equivalents were the morphological correlate. The lungs showed an increase in the number of macrophages and a thickening of the alveolocapillary membrane, but no germinal centre reactions were observed. These morphological and serological results may indicate a priming of the immune response in the upper respiratory tract leading to a subsequent production of antibodies in the lung.