MIF promotes B cell chemotaxis through the receptors CXCR4 and CD74 and ZAP-70 signaling.
Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with chemokine-like functions that plays a pivotal role in the pathogenesis of inflammatory diseases by promoting leukocyte recruitment. We showed that MIF promotes the atherogenic recruitment of monocytes and T cells through its receptors CXCR2 and CXCR4. Effects of MIF on B cell recruitment have not been addressed. In this study, we tested the involvement of MIF in B cell chemotaxis and studied the underlying mechanism. We show that MIF promotes primary murine B cell chemotaxis in a dose-dependent manner, comparable to the B cell chemokines CXCL13 and CXCL12. Splenic B cells express CXCR4 and the receptor CD74 but not CXCR2. Inhibition of CXCR4 or CD74 or a genetic deficiency of Cd74 in primary B cells fully abrogated MIF-mediated B cell migration, implying cooperative involvement of both receptors. MIF stimulation of B cells resulted in a rapid increase in intracellular Ca(2+) mobilization and F-actin polymerization. Intriguingly, the tyrosine kinase ZAP-70 was activated upon MIF and CXCL12 treatment in a CXCR4- and CD74-dependent manner. Pharmacological inhibition of ZAP-70 resulted in abrogation of primary B cell migration. Functional involvement of ZAP-70 was confirmed by small interfering RNA-mediated knockdown in Ramos B cell migration. Finally, primary B cells from ZAP-70 gene-deficient mice exhibited ablated transmigration in response to MIF or CXCL12. We conclude that MIF promotes the migration of B cells through a ZAP-70-dependent pathway mediated by cooperative engagement of CXCR4 and CD74. The data also suggest that MIF may contribute to B cell recruitment in vivo (e.g., in B cell-related immune disorders).
Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälisch Technical University (RWTH) Aachen, D-52074 Aachen, Germany;
Christina
C
Klasen
Department of Pediatrics, Rheinisch-Westfälisch Technical University (RWTH) Aachen, D-52074 Aachen, Germany;
Kim
K
Ohl
Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälisch Technical University (RWTH) Aachen, D-52074 Aachen, Germany;
Marieke
M
Sternkopf
Weizmann Institute, Rehovot 76100, Israel;
Idit
I
Shachar
Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälisch Technical University (RWTH) Aachen, D-52074 Aachen, Germany;
Corinna
C
Schmitz
Institute of Medical Statistics, Rheinisch-Westfälisch Technical University (RWTH) Aachen, D-52074 Aachen, Germany;
Nicole
N
Heussen
Department of Molecular Immunology, Biology III, University of Freiburg, 79108 Freiburg, Germany; and Max Planck Institute for Immunobiology and Epigenetics, 79108 Freiburg, Germany.
Elias
E
Hobeika
Department of Molecular Immunology, Biology III, University of Freiburg, 79108 Freiburg, Germany; and Max Planck Institute for Immunobiology and Epigenetics, 79108 Freiburg, Germany.
Ella
E
Levit-Zerdoun
Department of Pediatrics, Rheinisch-Westfälisch Technical University (RWTH) Aachen, D-52074 Aachen, Germany;
Klaus
K
Tenbrock
Department of Molecular Immunology, Biology III, University of Freiburg, 79108 Freiburg, Germany; and Max Planck Institute for Immunobiology and Epigenetics, 79108 Freiburg, Germany.
Michael
M
Reth
Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälisch Technical University (RWTH) Aachen, D-52074 Aachen, Germany; jbernhagen@ukaachen.de oelbounkari@ukaachen.de.
Jürgen
J
Bernhagen
Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälisch Technical University (RWTH) Aachen, D-52074 Aachen, Germany; jbernhagen@ukaachen.de oelbounkari@ukaachen.de.
Omar
O
El Bounkari
D000818:Animals; D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002118:Calcium / Q000276:immunology; D054377:Chemokine CXCL12 / Q000235:genetics / Q000276:immunology; D002633:Chemotaxis / Q000235:genetics / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000276:immunology*; D008263:Macrophage Migration-Inhibitory Factors / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D019718:Receptors, CXCR4 / Q000235:genetics / Q000276:immunology*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000235:genetics / Q000276:immunology*
D000944:Antigens, Differentiation, B-Lymphocyte; C514936:CXCR4 protein, mouse; D054377:Chemokine CXCL12; C515256:Cxcl12 protein, mouse; D000949:Histocompatibility Antigens Class II; D008263:Macrophage Migration-Inhibitory Factors; D019718:Receptors, CXCR4; C045084:invariant chain; D051746:ZAP-70 Protein-Tyrosine Kinase; C497262:Zap70 protein, mouse; D019746:Intramolecular Oxidoreductases; C076231:Mif protein, mouse; D002118:Calcium