Studies on a murine ascites-producing agent and its effect on tumor development.

Abstract

Summary A microsporidian infection of low pathogenicity in mice has been found to retard the growth of a variety of transplantable tumors and significantly prolong survival of hosts, including those bearing carcinogen-induced tumors. Resistance to tumor development remained after the hosts had recovered from the infection, but gradually waned with time. The infection did not induce resistance to Salmonella. The possible mechanisms by which the protozoan infection affects tumor development are discussed.