Background: In 2014 PCR screen of the genes expressed by myeloid cells – identified as C/EBP-e positive cells and including monocytes/macrophages and granulocytes (neutrophils and eosinophils) –identified approximately 10% of the generated clones as belonging to novel gene called resistin-like gamma (mRetnlg). Soon after this the functional human homologue of this gene was identified as being resistin (hRetn). Both the murine and human proteins have been shown in preliminary studies to exhibit anti-bacterial activity in vitro and to be highly expressed by monocytes and neutrophils. One study also indicated a potential chemotactic activity of mRetnlg for myeloid cells and other members of the murine resistin family have been shown to have hormone-like activity. Preliminary data and tools: We have recently observed that mRetnIg is not only expressed by monocytes and neutrophils but is also one of the most abundant genes present in eosinophils. However to date no studies have investigating the in vivo role of mRetnlg in these monocytes, neutrohipls or eosinophils, or in the generation of protective immunity against pathogens, as no tools have been available to do this. We have recently developed a conditional knockout mouse model of Retnlg by flanking exon 2 with loxP sites via gene targeting in mouse ES cells. These mice are now available and are being breed to animals in which Cre-mediated deletion of floxed allele will occur selectively within the monocyte/neutrophil lineage (LysMCre), the eosinophil lineage (EPXCre) or in all cells (ROSA.DTACre). Hypothesis: We propose that mRetnlg likkley plays a crucial role in immune responses involving myeloid cells, either as an effector protein (able to target and kill bacterial or parasitic pathogens), or as an immunomodulator (able to recruit cells and/or impact on T cell differentiation). To assess these hypotheses the student would complete the following aims: 1) Develop a novel mAb against mRetnlg in collaboration with Monash Antibody Technologies Facility (for use in protein expression assays). 2) Determine the gene and protein expression of mRetnlg within various tissues and hematopoietic cells derived from naïve wildtype C57BL/6 mice. This will be compared to the expression pattern of hRetn in human myeloid cells purified from whole blood for this purpose. 3) Use the novel conditiontal Retnlg knockout mice to examine the impact of Retnlg deficiency on : a. The development of all hematopoietic cell lineages b. Macrophage, neutrophil or eosinophil mediated killing of bacterial, fungal or parasitic pathogens using in vitro using assays. c. Regulation of the overall immune response and the clearance of bacterial, fungal or parasitic pathogens using in vivo using in vivo models of infection.
immune defense, myeloid cells, pathogens, bacterial, viruses, parasites, resitin-like family member proteins
Central Clinical School » Immunology and Pathology
Alfred Centre, The Alfred Hospital