The organelle proteome of p14-/- macrophage cells

The endocytic pathway is involved in a large variety of cellular processes such as the uptake of nutrients, the biological response to extracellular stimuli through regulation of receptor recycling or degradation and the antigen presentation in the immune response. In the context of the innate immunity, the phagocytic activity of macrophages is fundamental for the defence against pathogenic microbe and requires the close cooperation between the endocytic pathway and the maturing phagosomes. The central role of the endocytic pathway in the immune response is emphasized by the recent identification of a novel human primary immunonodeficiency syndrome that was traced back to a homozygous single point mutation in the human endosomal adaptor protein p14 gene. The project proposed here combines mouse genetics, cell biology and proteomic approaches to elucidate the molecular basis of the p14-related human immunodeficiency syndrome. Phagosomal and endosomal organelles derived from p14 deficient macrophages obtained from LMCp14-/- mice will be subjected to proteomic analysis aimed at the complete disclosure of the p14 interaction partners and downstream targets involved in phagolysosomal maturation underlying an efficient antimicrobial response. The proteomic analysis will provide detailed information on proteins modulated by p14 during immune response, shed light on the p14 mediated ERK and mTOR pathways and their respective spatial and temporal control over adaptive immunity and highlight targets for therapeutic intervention for the recently described human primary immunonodeficiency syndrome.

The endocytic pathway is the process by which cells absorb molecules by engulfing them. Endocytosis is involved in a large variety of cellular processes such as the uptake of nutrients, the biological response to extracellular stimuli and immune response. In the context of the immune response, macrophages are able to engulf and digest microbes in a process called phagocytosis. The phagocytic activity of macrophages is fundamental for the defence against pathogenic microbes and requires the close cooperation with the endocytic pathway. The central role of the endocytic pathway in the immune response is emphasized by the identification of a novel human primary immunodeficiency syndrome caused by the abnormal function of the endosomal protein p14/LAMTOR2. Here we present a combination of mouse genetics, cell biology and proteomic approaches to elucidate the molecular basis of the p14/LAMTOR2-related human immunodeficiency syndrome. Our analyses aimed at the complete disclosure of the p14/LAMTOR2 interaction partners and downstream targets involved in endosomal maturation. The results obtained provide information on proteins modulated by p14/LAMTOR2 and therefore highlight targets for therapeutic intervention for the described human primary immunodeficiency syndrome.