Abstract: Objective Plasmodium derived macrophage migration inhibitory factor (MIF) ortholog was considered to have potential to regulate host immune cell. Plasmodium yoelii derived MIF (PyMIF) has highly conserved crystal structure and similar bioactivity with host mouse MIF. However, the regulatory mechanism, including the function of PyMIF on host macrophage, is not clear so far. Here, we report the regulation of PyMIF on host inflammatory cytokines transcription in macrophage, and the compared analysis of regulation activity between PyMIF and host mouse MIF (MmMIF). Methods Both PyMIF and MmMIF were expressed and purified as recombinant proteins and were removed the endotoxin by C8 reversed-phase column. Then the endotoxin-free protein was added to cultured mouse monocyte / macrophage cell line RAW264.7. After incubation, the total RNA was extracted and applied to "RT2 Profiler? PCR Array Mouse Inflammatory Cytokines & Receptors" analysis. Results PyMIF significantly up-regulated 17 inflammatory cytokine genes transcription level and down-regulated 3 genes (CCR6、CCR8 and IL1F6) transcription. The regulated gene quantity by PyMIF was more than MmMIF. Most genes regulated by PyMIF were involved in a Th2 response bias or in expanding inflammatory response. Conclusions There is much difference between PyMIF and MmMIF in regulating host macrophage activity. These results provided more information about Plasmodium MIF function on host immune cell, and will be meaning for deep understanding the role of Plasmodium MIF during infection.

Key words: macrophage migration inhibitory factor, Plasmodium, bio-chip, inflammatory cytokine