Disruption of CCL21-induced chemotaxis in vitro and in vivo by M3, a chemokine-binding protein encoded by murine gammaherpesvirus 68.
Chemokine-binding proteins represent a novel class of antichemokine agents encoded by poxviruses and herpesviruses. One such protein is encoded by the M3 gene present in the murine gammaherpesvirus 68 (MHV-68) genome. The M3 gene encodes a secreted 44-kDa protein that binds with high affinity to certain murine and human chemokines and has been shown to block chemokine signaling in vitro. However, there has been no direct evidence that M3 blocks chemokine activity in vivo, nor has the nature of M3-chemokine interaction been defined. To better understand the ability of M3 to block chemokine activity in vivo, we examined its interaction with a specific subset of chemokines expressed in lymphoid tissues, areas where gammaherpesviruses characteristically establish latency. Here we show that M3 blocks in vitro chemotaxis induced by CCL19 and CCL21, chemokines expressed constitutively in secondary lymphoid tissues. Moreover, we provide evidence that chemokine M3 binding exhibits positive cooperativity. In vivo, the expression of M3 in the pancreas of transgenic mice inhibits recruitment of lymphocytes induced by transgenic expression of CCL21 in this organ. The ability of M3 to block the biological activity of chemokines may represent an important strategy used by MHV-68 to evade immune detection and favor viral replication in the infected host.
Jensen
Kristian K
KK
Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA.
Chen
Shu-Cheng
SC
Hipkin
R William
RW
Wiekowski
Maria T
MT
Schwarz
Martin A
MA
Chou
Chuan-Chu
CC
Simas
J Pedro
JP
Alcami
Antonio
A
Lira
Sergio A
SA
D000818:Animals; D002465:Cell Movement; D054415:Chemokine CCL19; D054421:Chemokine CCL21; D019742:Chemokines, CC / Q000037:antagonists & inhibitors*; D002633:Chemotaxis / Q000187:drug effects*; D018142:Gammaherpesvirinae / Q000502:physiology; D007515:Islets of Langerhans / Q000473:pathology; D008214:Lymphocytes / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D014764:Viral Proteins / Q000494:pharmacology* / Q000502:physiology*
C515460:CCL19 protein, human; C515478:CCL21 protein, human; C515461:Ccl19 protein, mouse; C515479:Ccl21c protein, mouse; D054415:Chemokine CCL19; D054421:Chemokine CCL21; D019742:Chemokines, CC; C118862:M3 protein, Murine gammaherpesvirus; D014764:Viral Proteins