Manifestation of Novel Social Challenges of the European Union in the Teaching Material of Medical Biotechnology Master’s Programmes at the University of Pécs and at the University of Debrecen Identification number: TÁMOP /1/A

FCG RECEPTOR SIGNALING Tímea Berki and Ferenc Boldizsár Signal transduction Manifestation of Novel Social Challenges of the European Union in the Teaching Material of Medical Biotechnology Master’s Programmes at the University of Pécs and at the University of Debrecen Identification number: TÁMOP /1/A

TÁMOP /1/A Fc  RI Types of human Fc  receptors Activating Fc Receptors Inhibitory Fc Receptor Fc  RIIA Fc  RIIC Fc  RIIIA Fc  RIIIB Fc  RIIB HighLow-medium Fc  RIIA 131H Fc  RIIA 131R Fc  RIIIA 158V Fc  RIIIA 158F Fc  RIIB 232I Fc  RIIB 232T Human Affinity Alleles 22 NN CC  C N N  C N  C 22 NN CC  C N  C N N  C GPI ITIM ITAM

TÁMOP /1/A Mouse Fcgamma receptorsITAM 22 NN CC  C N Low-medium 22 NN CC  C N N  C Fc  RII Fc  RIV Fc  RIIB Fc  RI 22 NN CC  C N High ITIM Mouse Affinity Activating Fc Receptors Inhibitory Fc Receptor

TÁMOP /1/A Role of ITAMs ITAM is a specific sequence of amino acids (YXXL) occurring twice in close succession in the intracellular tail of a receptor. After ligand binding, the tyrosine (Y) residue of the ITAM is phosphorylated by tyrosine kinases, and a signaling cascade is generated within the cell. An ITAM is present in the intracellular tail of Fc  RIIA and C, and in the  chains of Fc  RI and Fc  RIIIA.

TÁMOP /1/A Activatory Fc  receptor signaling 22  22  Fc  RIII Immune complex Plasma membrane Cytoplasm Ca 2+ LYN SYK ITAMs P P RAS SOS PlP 3 PLC  BTK PlP 2 Ca 2+ Downstream signalling pathways (ERK, p38, JNK) Downstream signalling pathways (ERK, p38, JNK) Cell activation ADCC Phagocytosis Cytokine release Oxidative burst PI3K RHO PKC RAC DAG IP 3 Ca 2+ ER

TÁMOP /1/A Steps of Fc  signaling 1 1Src kinase-mediated tyrosine phosphorylation of the ITAMs 2 2Following by SH2 domain-mediated recruitment of Syk family kinases to ITAMs 3 3Activation of PI-3 kinase 4 4Recruitment of adapter molecules like SLP-76 and BLNK 5 5Recruitment of enzymes like phospholipase C  and Tec family kinases 6 6Generation of IP3 and DAG 7 7Intracellular free Ca 2+ mobilization

TÁMOP /1/A Inhibitory Fcγ receptor signaling SHIP Fc  RIIB P  BCR Ig  Ig β ITIM LYN PLC  BTK No membrane recruitment RAS SHC DOK Simultaneous cross-linking Inhibition of calcium flux and proliferation PlP 3 PlP 2

TÁMOP /1/A Inhibitory Fcγ receptor signaling  ITIM P BTK cABL JNK Apoptosis Fc  RIIB Immune complex

TÁMOP /1/A ITIM The presence of only one YXXL motif is not sufficient to activate cells, and represents a motif (I/VXXYXXL) known as an Immunoreceptor tyrosine-based inhibitory motif (ITIM) FcγRIIB1 and FcγRIIB2 have an ITIM sequence and are inhibitory Fc receptors: they do not induce phagocytosis but counteract the antigen-induced BcR signal on B cells and shut off B cell activation The inhibitory signal is controlled by SHP-1 and SHIP-phosphatases

TÁMOP /1/A Overview of Fcγ receptor signaling SYK SHIP SYK P P P P P P P P P P P P 22   22   Fc  RIFc  RIIAFc  RIIIAFc  RIIB Ca 2+ ITAM ITIM RAS PLC  BTK RAC DAG IP 3 ER Ca 2+ Actin polymerization Phagocytosis Cell proliferation Actin polymerization and remodelling Actin polymerization and remodelling Cytokine release ADCC Degranulation Proinflammatory responses Proinflammatory responses Co-ligation to Activation partner Phagocytosis VAV PYK2 PI3K PIP 3 SYK JNK BLNK PKC  p38 Src Family PTKs Src Family PTKs Src Family PTKs Src Family PTKs Rho family GTPases Rho family GTPases MAPK pathway IgG Ag Calcium signali ng CaCn IP 3 R

TÁMOP /1/A Mediators produced by cells Triggering agents and regulatory cytokines IL-5IL-3GM-CSF IL-5RIL-3R IL-4 Eosinophil SCFIgE Fc  RI Basophil IL-5 and IL-13 IgGIL-4 KIT Mast cell IL-4R Histamine TLR Bacteria and other TLR ligands Monocyte/ macrophage IL-1, IL-6 and TNF Fc  R Triggering agents and regulatory cytokines

TÁMOP /1/A Role of Fc  Rs: enhanced phagocytosis SYK P P P P 22  Fc  RIIIA P P  Fc  RIIA P P P P 22  Fc  RI ITAM IgG Ag IgG opsonized particle Src Family PTKs Src Family PTKs PLC2 DAG IP 3 PI3K Ca 2+ PKC Actin polymerization and particle internalization Src Family PTKs Src Family PTKs Src Family PTKs Src Family PTKs Phosphorylation of ITAMs

TÁMOP /1/A I Role of Fc  Rs: enhanced phagocytosis I 22  Fc  R IgG Pathogen Effector cell Ag D1 D2

TÁMOP /1/A II Role of Fc  Rs: enhanced phagocytosis IIAntibody Microbe Fc receptor

TÁMOP /1/A ADCC Lytic enzymes Perforin TNF Granzymes Neutrophil NK cell Eosinophil Macrophage Ab bound to Ag and Fc receptor Fc receptor Target cell Surface Ag