The CXCL16 A181V Mutation Selectively Inhibits Monocyte Adhesion to CXCR6 but Is Not Associated With Human Coronary Heart Disease
Objective—The chemokine CXCL16 serves as a scavenger receptor for oxidized low-density lipoprotein and as an adhesion molecule and chemoattractant for cells expressing the receptor CXCR6. A commonly occurring CXCL16 allele has been described containing 2 nonsynonymous single-nucleotide polymorphisms in complete linkage disequilibrium, although the effects on CXCL16 function are unknown. Here, we examined the effect of the single-nucleotide polymorphisms on CXCL16 function and assessed the association of the mutant allele with coronary heart disease (CHD).
Methods and Results—Both wild-type and mutant T123V181-CXCL16 were readily expressed in vitro and were similarly functional in assays of oxidized low-density lipoprotein scavenging and chemotaxis. However, unlike wild-type CXCL16, T123V181-CXCL16 was unable to promote adhesion of CXCR6+ cells. Findings were confirmed ex vivo, with monocytes from donors homozygous for the T123V181 allele unable to facilitate adhesion of CXCR6 transfectants. In the London Life Sciences Prospective Population cohort (n=2797), we found that the T123V181 allele was not associated with protection or susceptibility to CHD (adjusted odds ratio, 1.01; 95% CI, 0.95 to 1.10; P=0.74).
Conclusion—CXCL16-mediated cell adhesion plays at best a modest role in CHD, and the scavenging and chemotactic properties of the chemokine are more likely to be more important in disease pathogenesis.
- Received June 14, 2010.
- Accepted December 27, 2010.
- © 2011 American Heart Association, Inc.