Inhibition of Early Mouse Plasmacytoma Development in Case of Plasmodium Infection

Abstract

Background: Inhibition of early cancer development, through enhancement of cancer immunosurveillance by innate cells has been reported after infection with different microorganisms. Since Plasmodium infection modulates the innate immune system, we examined the effect of Plasmodium infection on cancer immunosurveillance.  Methods: As a model, we used Plasmodium yoelii 265 BY infection of BALB/c mice and administration of TEPC.1033.C2 plasmacytoma cells. Results: Plasmodium infection effectively inhibited the early development of plasmacytoma. The protective effect of infection was not due to a direct cytopathic destruction of cancer cells by the parasite. Plasmodium infection induced the production of proinflammatory cytokines such as interleukin-12 and interferon-gamma, known to be involved in cancer immunosurveillance. Depletion of ASGM1+ cells in vivo largely suppressed the protective effect of the parasite. Conclusions: Plasmodium infection could influence on the inhibition of early mouse plasmacytoma. This observation suggest Plasmodium infections in humans might participate to the low incidence of multiple myeloma in countries where malaria is frequent and should be taken into account in public health policy of these countries.