Abstract 17277: Natural Killer T Cells Mediate Myocardial Infarction in Mice
Introduction: Invariant Natural Killer T (NKT) cells express a T cell receptor encoded by the Jα18 gene segment, which recognizes antigens presented by CD1d. NKT cells have recently been implicated in hepatic ischemia/reperfusion injury. Thus, we hypothesized that both CD1d KO mice and Jα18 KO mice, which lack NKT cells, would be protected against injury in the mouse model of reperfused myocardial infarction (MI).
Methods: Reperfused MI was performed on wild-type B6 mice (n=10), congenic CD1d KO mice (n=8), and congenic Jα18 KO mice (n=8). MI consisted of 30 min coronary occlusion followed by 2 h reperfusion. Infarct size as percent area at risk (IF%) was determined by planimetry after TTC and Phthalo blue staining.
Results: IF% was reduced in CD1d KO mice by 16% compared to WT mice (29±5% vs. 45±5%, p=0.04), and was reduced in Jα18 KO mice by 19% compared to WT mice (24±4% vs. 45±5%, p=0.009). There was no significant difference in IF% between CD1d KO mice and Jα18 KO mice (p=NS). The area at risk as percent of the left ventricle (LV) are similar for all groups (p=NS).
Conclusion: This is the first direct evidence that NKT cells play an important role in mediating cardiac ischemia/reperfusion injury during MI. Better understanding of this mechanism could lead to new immunomodulatory therapies for MI. .
- © 2012 by American Heart Association, Inc.