Laboratory of Molecular Membrane Biology
Head: Katarzyna Kwiatkowska
Staff: Kinga Borzęcka (PhD student), Justyna Dębińska (PhD student), Anna Grzelczyk, Aneta Hromada-Judycka, Agnieszka Płóciennikowska (PhD student), Paula Roszczenko, Anna Świątkowska, Gabriela Traczyk
The laboratory conducts studies on molecular mechanisms of activation of plasma membrane receptors of immune cells with special attention paid to signal transduction by receptors of Toll-like family. Among them, we focus on TLR4 which serves as signaling receptor for bacterial lipopolysaccharide (LPS); activated TLR4 triggers downstream pathways leading to production of pro-inflammatory mediators which can evoke septic shock. Our aim is to elucidate how signaling complexes of immune receptors are assembled in the plasma membrane and how microdomain organization of the plasma membrane affects formation of those complexes. We are especially interested in the role of lipids in controlling the dynamics of immune receptors in the membrane, their interaction with the actin cytoskeleton and internalization of the receptors. These studies are dedicated to unravel factors shaping the mode and magnitude of activation of macrophages by microbial components.
• molecular biology, gene silencing, protein overexpression and purification
• ELISA, cellular ELISA, flow cytometry
• immunoelectron microscopy and 3D tomography, confocal microscopy
• combination of biochemical approaches aiming to affect structure and function of plasma membrane rafts
Current research activities:
• elucidating the role of plasma membrane lipids in TLR4 signaling which leads to production of pro-inflammatory mediators and cell migration
• examining the participation of proteins and lipids enriched in rafts of the plasma membrane, like tyrosine and phosphatidylinositol kinases in activation of cells with microbial components, such as LPS
• studies on the engagement of TLR4, CD14 and scavenger receptors in internalization of LPS which induces pro- and anti-inflammatory responses of macrophages
• microscopic and biochemical analysis of an assembly of TLR4 signaling complex and its trafficking in macrophages
• exploring a possibility to apply lipid-binding probes to reveal and affect lipid distribution in cells
Płóciennikowska A., Hromada-Judycka A., Borzecka K., Kwiatkowska K. (2015) Co-operation of TLR4 and raft proteins in LPS-induced pro-inflammatory signaling. Cellular and Molecular Life Sciences 72:557-581
Borzęcka K., Płociennikowska A., Bjorkelund H., Sobota A., Kwiatkowska K. (2013) CD14 mediates binding of high doses of LPS but is dispensable for TNF-α production. Mediator of Inflammation 2013:824919.
Czerkies M., Borzęcka K., Mykola I. Zdioruk, Płóciennikowska A., Sobota A., Kwiatkowska K. (2013) An interplay between scavenger receptor A and CD14 during activation of J774 cells by high concentrations of LPS. Immunobiology. 218:1217-1226.
Kleveta G., Borzęcka K., Zdioruk M.I., Czerkies M., Kuberczyk H., Sybirna N., Sobota A., Kwiatkowska K. (2012) LPS induces phosphorylation of actin-regulatory proteins leading to actin reassembly and macrophage motility. Journal of Cellular Biochemistry 113:80-92.
Kulma M., Kwiatkowska K., Sobota A. (2012) Raft coalescence and FcγRIIA activation upon sphingomyelin clustering induced by lysenin. Cellular Signalling 24:1641-1647.
Józefowski S., Czerkies M., Sobota A., Kwiatkowska K. (2011) Determination of cell surface expression of Toll-like receptor 4 by cellular enzyme-linked immunosorbent assay and radiolabeling. Analytical Biochemistry 413:185-191.
Kwiatkowska K. (2010) One lipid, multiple functions: how various pools of PIP2 are created in the plasma membrane. Cellular and Molecular Life Science 67:3927-3946.
Józefowski S., Czerkies M., Łukasik A., Bielawska A., Bielawski J., Kwiatkowska K., Sobota A. (2010) Ceramide and ceramide 1-phosphate are negative regulator of TNF-a production induced by lipopolysaccharide. Journal of Immunology 185:6960-6973.