Characterization of immune response to infection of Plasmodium berghei NK65 in mice of different age

ObjectiveTo investigate the characteristics of immune response to infection of Plasmodium berghei NK65(P.b NK65)in young and middle aged C57BL/6 mice.MethodsThree weeks and 8 months aged C57BL/6 mice were infected by P.b NK65 parasitized erythrocytes.Flow cytometry was applied to quantitatively analyze myeloid dendritic cells(DCs)and DCs expressing major histocompatibility complex classⅡ (MHCⅡ)or CD86.The levels of interferon gamma(IFN-γ)and interleukin-4(IL-4)in spleen cell supermatants were dynamically detected by enzyme-linked immunosorbent assay(ELISA).ResultsThe number of myeloid DCs(40.08×10⁵)in young aged mice significantly increased 5 days after the infection.The number of myeloid DCs 5 and 8 days after the infection was 103.47×10⁵ and 104.04×10⁵ in the middle aged mice.The numbers of DCs expressing MHCⅡ or CD86 were 50.16×10⁵ and 45.39×10⁵ in young aged mice,and in middle aged mice the numbers were 239.40×10⁵ and 148.48×10⁵,which was markedly more than young aged mice.The level of IFN-γ significantly increased both in young aged(251.01 pg/ml)and middle aged mice(584.17 pg/ml).ConclusionThe cellular and humoral immune responses to infection of P.b NK65 are different between the young and middle aged C57BL/6 mice.