Project: Inhibitory plasma membrane receptor LAIR-1 in mast cell physiology and mastocytosis
Mast cells are immune cells with multifaceted functions in homeostasis and diseases. They have traditionally been associated with type I allergies, such as rhinitis, asthma, and urticaria, causing a global health burden of approximately 20% of the human population worldwide. They play essential roles in both innate and adaptive immunity. Accumulating evidence suggests that a complex network of inhibitory and activating receptors controls mast cell responsiveness to various stimuli. Recently, we found that mast cells from mice with defects in the ORMDL family proteins, inhibitors of serine palmitoyltransferase, exhibit increased antigen-induced degranulation and cytokine response. Mass spectrometry analysis revealed that ORMDL-deficient cells express increased leukocyte-associated immunoglobulin-like receptor 1 (Lair-1). This was an unexpected finding, given that LAIR-1 is a negative regulator of immunoreceptor signaling in several immune cell types. In this project, we will test the hypothesis that increased expressions of LAIR-1 counterbalance the enhanced response of mast cells from ORMDL-deficient mice. We will also test the hypothesis using human mast cell lines ROSA that LAIR-1 regulates the progress of mastocytosis. In the frame of the project, we will also prepare and test bispecific constructs, aggregating LAIR-1 with IgE receptor or cKIT, for the treatment of mast cell-mediated allergies and other inflammatory diseases and mastocytosis. Various techniques will be used to address the research questions of the project, including cell culture of different cell types, analysis of mast cell activation by antigen, immunoprecipitation of selected molecules followed by mass spectrometry, gene expression studies by whole genome transcriptome analysis, immunoblotting and other immunochemical procedure. Part of the project will also be the production of bispecific recombinant constructs for enhanced crosstalk of LAIR-1 with the high-affinity IgE receptor or c-kit and testing the constructs under in vitro and in vivo conditions. In vivo experiments will require working with laboratory mice.
Techniques of molecular immunology
Harvima IT, Levi-Schaffer F, Dráber P, Friedman S, Polakovičová I, Gibbs BF, Blank U, Nilsson G, Maurer M: Molecular targets on mast cells and basophils for novel therapies. J Allergy Clin Immunol 2014 134(3): 530-544. [pubmed] [doi]
Bugajev V, Paulenda T, Utekal P, Mrkacek M, Halova I, Kuchar L, Kuda O, Vavrova P, Schuster B, Fuentes-Liso S, Potuckova L, Smrz D, Cernohouzova S, Draberova L, Bambouskova M, Draber P: Crosstalk between ORMDL3, serine palmitoyltransferase, and 5-lipoxygenase in the sphingolipid and eicosanoid metabolic pathways. J Lipid Res 2021, 100121. [pubmed] [doi]
Bugajev V, Halova I, Demkova L, Cernohouzova S, Vavrova P, Mrkacek M, Utekal P, Draberova L, Kuchar L, Schuster B, Draber P: ORMDL2 Deficiency Potentiates the ORMDL3-Dependent Changes in Mast Cell Signaling. Front Immunol 202111: 591975. [pubmed] [doi]