Abstract
Fluids from Listeria monocytogenes cultures contain products that possess a number of biologic activities. The fluids contain a mitogenic substance for B lymphocytes. Thus, their injection into mice produces striking hyperplasia of the B cell zones of the spleen. Also, lymphocytes in vitro are stimulated to proliferate, regardless of whether they are first depleted of T lymphocytes by exposure to anti-θ serum plus complement. These fluids injected intraperitoneally activate macrophages as judged by morphologic criteria. Mice that receive the products develop a transitory state of nonspecific resistance to infection by live Listeria. The relationships between B cell mitogenicity and macrophage activation—and protection—were not established. This kind of reaction of lymphoid cells to Listeria products may represent an early nonspecific line of defense against bacterial invasion.
Footnotes
This study was supported by National Institutes of Health Grants AI-10091 and 1-P01-CA-14723. Dr. Petit is supported by a grant from the Phillipe Foundation of France, and Dr. Unanue is the recipient of a Research Career Award from the National Institutes of Health.
