In vitro stimulation of immunoglobulin production from human peripheral blood lymphocytes by a soluble preparation of Actinomyces viscosus.

In this paper, we report the ability of a soluble, ultrasonicate preparation of Actinomyces viscosus to stimulate in vitro immunoglobulin production by human peripheral blood lymphocytes. Immunoglobulin A (IgA), IgG, and IgM concentrations were determined with a highly sensitive and specific micro-enzyme-linked immunosorbent assay (micro-ELISA). A viscosus-induced immunoglobulin production was T lymphocyte dependent and was inhibited by monocytes. The immunoglobulin response was optimal when A. viscosus (1,000 microgram/ml) was removed from the cultures on day 2 of incubation. Antibodies specific for A. viscosus were not detected, indicating that A. viscosus was activating a polycolonal B-lymphocyte response. Since periodontal lesions in humans are characterized by the accumulation of a large number of B lymphocytes, the polyclonal activation of these cells by A. viscosus may affect the severity and resolution of the disease.