Variation of Mice Immune Responses after Infection with Lethal Strain Plasmodium yoelii: Role of Inflammatory and Anti-inflammatory Cytokines

Objective: Variability in resistance to infections is a well-known phenomenon that has been ascribed to genetic and immunologic factors. The present study was conducted to identify the mRNA expression pattern for some cytokines in two groups of mice from different genotypes.

Methods: Two groups of mice were used (C57BL/6 (B6) and DBA/2 mice). The mice were infected with lethal strain of Plasmodium yoelii 17XL (P. yoelii 17XL). Analysis of mRNA for Th1-type cytokines [Interferon-γ (IFNγ), Interleukins (IL)-12, IL-6, and tumor necrosis factor-α (TNFα)] and Th2-type cytokines [IL-4 and IL-10], was conducted using Reverse Transcription (RT)-PCR.

Results: The main difference was the significant rise in IL-12 and IL-6 in DBA/2 mice compared to their baseline value in B6 mice. The production of TNFα increased in the severe phase in B6 mice, in sharp contrast to its dominant production in the recovery phase of DBA/2 mice. The expression of anti-inflammatory cytokines, particularly IL-10, increased in DBA/2 mice. The production of immunoglobulin M (IgM) and IgG-type anti-DNA autoantibody was evaluated.

Conclusion: This study aimed to clarify the complexities of cytokines responses and give valuable evidence about the characteristic pattern of cellular cytokines mRNA expression and their role in controlling malaria in two different strains of mice. Hence presenting necessary data for the development of effective malaria vaccine and new anti-malaria drugs.