Immunostimulating cell surface substance from Staphylococcus epidermidis strain ATCC-31432 prevents metastatic lung colonization in Balb/c-mice.

The antineoplastic activity of cell surface substance from Staphylococcus epidermidis ATCC-31432 (CSS-subfraction 2) in mice and its influence on the activation of human leucocytes was studied. After in vitro incubation with CSS-subfraction 2, human polymorphonuclear leucocytes were evidently stimulated. In vivo (Balb/c-mice) intraperitoneal application of subfraction 2 of CSS induced a considerable splenomegaly and greatly increased IgM levels indicating a strong immuno-stimulating activity. In order to evaluate antineoplastic effects of CSS-subfraction 2, we used sarcoma L-1 cells (Balb/c-mouse origin) which cause heavy tumor colonization of the lung. After single systemic injection of subfraction 2 of CSS, the number of lung tumor-cell colonies drastically decreased. The combination of this immunomodulating therapy with a temporary anticoagulation resulted in a further reduction of tumor colonies in the lungs of Balb/c-mice.