Cellular Haemostasis Group

Principal Investigator: János Kappelmayer, MD, PhD, DSc

Members of the group:
Adrienne Kerényi, MD, PhD; Béla Nagy Jr, MD, PhD; Judit Tóth Budai, MD, PhD; Zsolt Fejes, MSc, PhD; Gábor Szabó, MD; Bernadett Szilágyi, MSc; Marianna Pócsi, MSc.

Technician: Ildikó Beke Debreceni, MSc

Thrombosis is a multicellular process that implicates the involvement of platelets, leukocytes and endothelial cells. These events are governed by cell-cell interactions as well as released soluble markers. Our group investigates the effect of different agonists in vitro on the level of various cell surface-associated and soluble platelet activation markers like P-selectin and CD40L, platelet-leukocyte interactions, coated-platelet generation and platelet-derived microparticle formation. Special attention is paid to thrombotic (thrombin, collagen) and immunological/inflammatory (LPS, PAF, MASP-1) stimuli. We also investigate the effect of phosphatase inhibitors on these activation events. These studies are carried out in collaboration with the Department of Medical Chemistry at our University with the group of Prof. Ferenc Erdődi.

Platelet activation is also investigated in ex vivo clinical samples from patients with enhanced thrombotic tendency like diabetes, stroke and coronary disease. We also study the association of platelet polymorphisms on these events, and analyze platelet activation markers in relation to disease severity and clinical status. These studies are done in collaboration with the Departments of Internal Medicine and Cardiology. Our group has collaborations with the group of Prof. László Muszbek in Clinical Research Center in Debrecen, where several Glanzmann-patients have been extensively characterized in the past years.

Another aspect of the hemostatic multicellular process is the direct interaction of platelets with leukocytes, primarily the myeloid cells. We investigate the effect of the major ligand of P-selectin on thrombus formation in a mouse model. This protein entitled P-selectin Glycoprotein Ligand-1 (PSGL-1), and is a dimeric mucin that is crucial in the formation of such heterotypic complexes. We possess a mouse strain, where PSGL-1 is knocked out and we study the effect of the lack of PSGL-1 on thrombus formation and cellular release from the bone marrow. These studies are carried out in collaboration with the group of Prof. Rodger McEver at the Oklahoma Medical Research Foundation.

In addition, we maintain regular scientific discussions with Prof. Kenneth Clemetson (University of Berne, Switzerland), and Prof. Satya P. Kunapuli (Temple University, Philadelphia, PA).

The Cellular Hemostasis Group utilizes mostly flow cytometry, Western-blot and ELISA techniques, but we have access to PCR-RFLP and gene sequencing capabilities as well.

Representative publications