This work was partially funded by a R21 grant from the National Heart, Lung, and Blood Institute (NHLBI) to GS (1R21HL109761). The findings and conclusions in this paper are those of the authors and do not necessarily represent the views of their sponsoring institutions.
Development and application of a high-throughput microneutralization assay: lack of xenotropic murine leukemia virus–related virus and/or murine leukemia virus detection in blood donors
Version of Record online: 12 JAN 2012
© 2012 American Association of Blood Banks
Volume 52, Issue 2, pages 332–342, February 2012
How to Cite
Zhou, Y., Steffen, I., Montalvo, L., Lee, T.-H., Zemel, R., Switzer, W. M., Tang, S., Jia, H., Heneine, W., Winkelman, V., Tailor, C. S., Ikeda, Y. and Simmons, G. (2012), Development and application of a high-throughput microneutralization assay: lack of xenotropic murine leukemia virus–related virus and/or murine leukemia virus detection in blood donors. Transfusion, 52: 332–342. doi: 10.1111/j.1537-2995.2011.03519.x
- Issue online: 12 JAN 2012
- Version of Record online: 12 JAN 2012
- Received for publication October 20, 2011; revision received November 21, 2011, and accepted November 22, 2011.
BACKGROUND: Xenotropic murine leukemia virus (MLV)-related virus (XMRV) and other related MLVs have been described with chronic fatigue syndrome and certain types of prostate cancer. In addition, prevalence rates as high as 7% have been reported in blood donors, raising the risk of transfusion-related transmission. Several laboratories have utilized microneutralization assays as a surrogate marker for detection of anti-MLV serologic responses—with up to 25% of prostate cancer patients reported to harbor neutralizing antibody responses.
STUDY DESIGN AND METHODS: We developed a high-throughput microneutralization assay for research studies on blood donors using retroviral vectors pseudotyped with XMRV-specific envelopes. Infection with these pseudotypes was neutralized by sera from both macaques and mice challenged with XMRV, but not preimmune serum. A total of 354 plasma samples from blood donors in the Reno/Tahoe area were screened for neutralization.
RESULTS: A total of 6.5% of donor samples gave moderate neutralization of XMRV, but not control pseudotypes. However, further testing by Western blot revealed no evidence of antibodies against MLVs in any of these samples. Furthermore, no evidence of infectious virus or viral nucleic acid was observed.
CONCLUSION: A microneutralization assay was developed for detection of XMRV and can be applied in a high-throughput format for large-scale studies. Although a proportion of blood donors demonstrated the ability to block XMRV envelope-mediated infection, we found no evidence that this inhibition was mediated by specific antibodies elicited by exposure to XMRV or MLV. It is likely that this moderate neutralization is mediated through another, nonspecific mechanism.