Nitric Oxide is Involved in the Upregulation of IFN-γ and IL-10 mRNA Expression by CD8(+) T Cells During the Blood Stages of P. chabaudi AS Infection in CBA/Ca Mice

Nitric oxide (NO) is involved in the clearance of several types of bacteria, viruses and parasites. Although the roles of NO and CD8(+) T cells in the immune response to malaria have been extensively studied, their actual contributions during the blood stages of malaria infection remain unclear. In this work, we corroborate that serum NO levels are not associated with the in vivo elimination of the blood stages of Plasmodium chabaudi AS. In addition, we show that CD8(+) T cells exhibit increased apoptosis and up regulate the expression of TNF-α mRNA on day 4 post-infection and IFN-γ and IL-10 mRNA on day 11 post-infection. Interestingly, only the levels of IFN-γ and IL-10 expression are affected when iNOS is inhibited with aminoguanidine (AG), suggesting that NO could be involved in the activation of CD8(+) T cells during the blood stages of plasmodium infection.