The cellular basis of salivary immunity in the mouse: incidence and distribution of B cells, T cells and macrophages in single-cell suspensions of the major salivary glands.

A multiparametric analysis of the resident immune populations in the parotid, submandibular and sublingual salivary glands was done in single-cell suspensions. The incidence of T and B cells and of macrophages was assessed using phenotypic markers in immunofluorescent staining and a functional assay was used to enumerate immunoglobulin (Ig)-secreting cells. Characteristic frequencies and isotype distributions of cytoplasmic Ig+ B cells and surface Ig+ B lymphocytes were found in the three types of glands. Even though IgA was always found to be the predominant isotype in individual salivary secretions (90-93%) this was not directly correlated by an absolute predominance of IgA-secreting cells in the glands (45-65%). Significant percentages of T cells (Thy-1+ and Lyt-1+ cells: 3-4%) and macrophages (Mac 1+ and esterase-positive cells: 3-10%) were also recovered in our suspensions. It is therefore concluded that the murine salivary glands contain both effector and regulatory cells required for the development and expression of salivary immunity.