Head of laboratory

Staff

Research profile

Our studies concern the molecular mechanisms of activation of receptors localized in the plasma membrane of immune cells with a focus on signal transduction by TLR4 which serves as a signaling receptor for bacterial lipopolysaccharide (LPS). Activated TLR4 triggers downstream pathways leading to production of pro-inflammatory mediators which can evoke a septic shock. TLR4 is assisted by CD14 protein anchored in the plasma membrane nanodomains (rafts) enriched in distinct lipids and contribution of those lipids to LPS-inducing signaling is in the center of our studies. We are especially interested in the role of the turnover of PI(4,5)P2, ceramide and acylated proteins in LPS-stimulated macrophages. Our aim is to elucidate how signaling complexes of TLR4 are assembled in the plasma membrane, how they interact with the actin cytoskeleton, and how microdomain organization of the plasma membrane affects formation of those complexes and subsequent endocytosis of the receptor. We conduct the studies on cell culture lines, CD14 knockout mice and primary macrophages transiently or stably depleted/overexpressing distinct proteins of LPS-induced signaling pathways. For analyses we utilize an array of molecular biology and immunobiology techniques, and also immunoelectron and confocal microscopy, various biochemical techniques including “click chemistry” and mass spectrometry. These complementary approaches are dedicated to unravel factors shaping the mode and magnitude of activation of macrophages by LPS and can in the future help to invent new therapeutic tools for the treatment of sepsis.

Current research activities

  • elucidating the role of plasma membrane lipid, PI(4,5)P2, in LPS-induced production of pro-inflammatory mediators and cell migration. We aim to dissect the contribution of CD14 and TLR4 to signaling pathways which controls phosphatidylinositol turnover in LPS-stimulated cells, identify enzymes involved in PI(4,5)P2 generation and depletion in these conditions and reveal effectors of the lipid shaping the response of macrophages to LPS.
  • exploring the role of S-acylation (palmitoylation) of proteins in signaling activity of TLR4. These studies include proteomics analysis of changes of S-acylation of proteins based on metabolic labeling of macrophages with palmitic acid analogue, “click chemistry” and application of mass spectrometry to identify labeled proteins. The goal of these studies is to establish whether modification of proteins with palmitic acid, a typical component of the westernized diet, can affect pro-inflammatory signaling triggered by LPS.
  • examining  how  activation  of  macrophages  by  LPS depends on the participation of raft lipids, sphingomyelin and ceramide, and raft proteins, including CD14 and tyrosine kinase Lyn, and how this activation is modulated by naturally occurring exogenous lipids, like bis(monoacylglycerol)phosphate. Studies include microscopic and biochemical analysis of an assembly of TLR4 signaling complex and immune responses of macrophages depleted or enriched in distinct raft proteins and lipids.
  • Exploring the role of retromer in recirculation of CD14 and TLR4 in LPS-stimulated cells.

Selected publications

Sobocińska J., Roszczenko-Jasińska P., Ciesielska A., Kwiatkowska K. (2018) Protein palmitoylation and its role in bacterial and viral infections. Frontiers in Immunology, 8:2003.

Sobocińska J., Roszczenko-Jasińska P., Zaręba-Kozioł M., Hromada-Judycka A., Matveichuk O.V., Traczyk G., Łukasiuk K., Kwiatkowska K. (2018) Lipopolysaccharide upregulates palmitoylated enzymes of the phosphatidylinositol cycle: An insight from proteomic studies. Molecular & Cellular Proteomics, 17:233-254

Borzęcka-Solarz K., Dembińska J., Hromada-Judycka A., Traczyk G., Ciesielska A., Ziemlińska E., Świątkowska A., Kwiatkowska K. (2017) Association of Lyn kinase with membrane rafts determines its negative influence on LPS-induced signaling. Molecular Biology of the Cell, 28:1147-1159.

Ciesielska A., Sas-Nowosielska H., Kwiatkowska K. (2016) Bis(monoacylglycero)phosphate inhibits TLR4-dependent RANTES production in macrophages. The International Journal of Biochemistry & Cell Biology, 83:15-26.

Płóciennikowska A., Hromada-Judycka A., Dembinńska J., Roszczenko P., Ciesielska A., Kwiatkowska K. (2016)  Contribution of CD14 and TLR4 to changes of the PI(4,5)P2 level in LPS-stimulated cells. Journal of Leukocyte Biology, 100:1363-1373.

Ciesielska A., Kwiatkowska K. (2015) Modification of pro-inflammatory signaling by dietary components: The plasma membrane as a target. BioEssays, 37:789-801.

Płóciennikowska A., Hromada-Judycka A.,  Borzęcka 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.

Abdel Shakor A. B., Atia M., Ismail I. A., Alshehri A., El-Refaey H., Kwiatkowska K., Sobota A. (2014) Curcumin induces apoptosis of multidrug-resistant human leukemia HL60 cells by complex pathways leading to ceramide accumulation. Biochimica et Biophysica Acta – Molecular and Cell Biology of Lipids, 1841:1672-1682.

Recent research grants

1. The role of diacylglycerol kinase epsilon, an enzyme of the phosphatidylinositol cycle, in the regulation of LPS-induced pro-inflammatory signaling of macrophages. 2019 – 2022, NCN, Krakow, [DEC-2018/29/B/NZ3/00407, OPUS] PI: prof. dr hab. Katarzyna Kwiatkowska

2. New plasma membrane lipid-dependent mechanisms of regulation of inflammatory responses induced by LPS. 2013 – 2019, NCN, Krakow, [DEC-2013/08/A/NZ3/00850, MAESTRO] PI: prof. dr hab. Katarzyna Kwiatkowska

3. Role of retromer in a regulation of inflammatory responses of macrophages to lipopolysaccharide. 2017 – 2020, NCN, Krakow, [UMO-2016/23/D/NZ3/02212, SONATA] PI: dr Anna Ciesielska

4. Lysobisphosphatidic acid – new signaling mediator and factor modulating pro-inflammatory activity of lysophosphatidic acid and lipopolysaccharide. 2013 – 2016, NCN, Krakow,  UMO-2013/08/S/NZ1/00844, FUGA ] PI: dr Anna Ciesielska

5. Palmitoylated proteins of plasma membrane microdomains as regulators of TLR4 signaling. 2016-2020, EU Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant No. 665735. PI: prof. dr hab. Katarzyna Kwiatkowska