The CXC chemokine murine monokine induced by IFN-gamma (CXC chemokine ligand 9) is made by APCs, targets lymphocytes including activated B cells, and supports antibody responses to a bacterial pathogen in vivo.
Monokine induced by IFN-gamma (Mig; CXC chemokine ligand 9) is an IFN-gamma-inducible CXC chemokine that signals through the receptor CXCR3 and is known to function as a chemotactic factor for human T cells, particularly following T cell activation. The mig gene can be induced in multiple cell types and organs, and Mig has been shown to contribute to T cell infiltration into immune/inflammatory reactions in peripheral tissues in mice. We have investigated the expression and activities of Mig and CXCR3 in mouse cells and the role of Mig in models of host defense in mice. Murine (Mu)Mig functioned as a chemotactic factor for resting memory and activated T cells, both CD4(+) and CD8(+), and responsiveness to MuMig correlated with surface expression of MuCXCR3. Using mig(-/-) mice, we found that MuMig was not necessary for survival after infections with a number of intracellular pathogens. Surprisingly, however, we found that mig(-/-) mice showed reductions of 50-75% in Abs produced against the intracellular bacterium Francisella tularensis live vaccine strain. Furthermore, we found that MuMig induced both calcium signals and chemotaxis in activated B cells, and that B cell activation induced expression of MuCXCR3. In addition, IFN-gamma induced the expression of mumig in APCs, including CD8 alpha(+) and CD8 alpha(-) dendritic cells. Together, our data suggest that Mig and CXCR3 may be important not only to recruit T cells to peripheral inflammatory sites, but also in some cases to maximize interactions among activated T cells, B cells, and dendritic cells within lymphoid organs to provide optimal humoral responses to pathogens.
Inflammation Biology Section, Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Matthew K
MK
Park
Doron
D
Amichay
Paul
P
Love
Elizabeth
E
Wick
Fang
F
Liao
Alex
A
Grinberg
Ronald L
RL
Rabin
Hongwei H
HH
Zhang
Senkuta
S
Gebeyehu
Timothy M
TM
Wright
Akiko
A
Iwasaki
Youmin
Y
Weng
Julie A
JA
DeMartino
Karen L
KL
Elkins
Joshua M
JM
Farber
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000938:Antigen-Presenting Cells / Q000378:metabolism*; D001402:B-Lymphocytes / Q000276:immunology*; D002465:Cell Movement; D054370:Chemokine CXCL9; D019743:Chemokines, CXC / Q000502:physiology*; D002634:Chemotaxis, Leukocyte; D036341:Intercellular Signaling Peptides and Proteins; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000032:analysis; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*
D000907:Antibodies, Bacterial; C080810:CXCL9 protein, human; C515187:CXCR3 protein, human; D054370:Chemokine CXCL9; D019743:Chemokines, CXC; C515188:Cxcr3 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine