Characterization of antibodies elicited by XMRV infection, development of immunoassay

urbantravels

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http://www.retrovirology.com/content/7/1/68

Characterization of antibodies elicited by XMRV infection and development of immunoassays useful for epidemiologic studies

etrovirology 2010, 7:68doi:10.1186/1742-4690-7-68
Published: 17 August 2010
Abstract (provisional)

Background

Xenotropic Murine Leukemia Virus-related Virus (XMRV) is a human gammaretrovirus recently identified in prostate cancer tissue and in lymphocytes of patients with chronic fatigue syndrome. To establish the etiologic role of XMRV infection in human disease requires large scale epidemiologic studies. Development of assays to detect XMRV-specific antibodies would greatly facilitate such studies. However, the nature and kinetics of the antibody response to XMRV infection have yet to be determined.
Results

Three rhesus macaques were infected with XMRV to determine the dynamics of the antibody responses elicited by infection with XMRV. All macaques developed antibodies to XMRV during the second week of infection, and the predominant responses were to the envelope protein gp70, transmembrane protein p15E and capsid protein p30. In general, antibody responses to gp70 and p15E appeared early with higher titers than to p30, especially in the early period of seroconversion. Antibodies to gp70, p15E and p30 persisted to 158 days and were substantially boosted by re-infection, thus, were identified as useful serologic markers. Three high-throughput prototype assays were developed using recombinant proteins to detect antibodies to these viral proteins. Both gp70 and p15E prototype assays demonstrated 100% sensitivity by detecting all Western Blot (WB) positive serial bleeds from the XMRV-infected macaques and good specificity (99.5-99.9%) with blood donors. Seroconversion sensitivity and specificity of the p30 prototype assay was 92% and 99.4% respectively.
Conclusions

This study provides the first demonstration of seroconversion patterns elicited by XMRV infection. The nature and kinetics of antibody responses to XMRV in primates were fully characterized. Moreover, key serologic markers useful for detection of XMRV infection were identified. Three prototype immunoassays were developed to detect XMRV-specific antibodies. These assays demonstrated good sensitivity and specificity; thus will facilitate large scale epidemiologic studies of XMRV infection in humans.
 

shannah

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Note the authors:

Xiaoxing Qiu , Priscilla Swanson , Ka-Cheung Luk , Bailin Tu , Francois Villinger , Jaydip Das Gupta , Robert H Silverman , Eric A Klein , Sushil Devare , Gerald Schochetman and John Hackett Jr

Retrovirology 2010, 7:68doi:10.1186/1742-4690-7-68
 

Sunshine

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These assays demonstrated good sensitivity and specificity; thus will facilitate large scale epidemiologic studies of XMRV infection in humans.
I wonder if any of these assays will be made available through the upcoming WPI/UneVX lab in Nevada USA? (UneVX was VIPDX) to the general public as a 'test'?
The XMRV antibody test is not available to us yet, although it's apparently going to be so this year or at least was....
 
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From Alter's Zagreb presentation: "XMRV and related MLVs are in the donor supply with an early prevalence estimate of 3%‐7%."

Qiu et al in Retrovirology: "Due to the high sequence homology, the assays described herein detect antibody responses not only to XMRV but also to other known MuLVs."

Qie et al CROI presentation: "Preliminary results showed evidence of detectable reactivity to all 3 antigens in a low proportion (~0.1%) of US blood donors."

This shows that either the Silverman / Klein / Abbott test is under-reporting the background level of infection or Alter is over-reporting; the results differ by an order of magnitude.
 

illsince1977

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Characterization of antibodies elicited by XMRV infection and development of immunoas

Characterization of antibodies elicited by XMRV infection and development of immunoassays useful for epidemiologic studies

Xiaoxing Qiu , Priscilla Swanson , Ka-Cheung Luk , Bailin Tu , Francois Villinger , Jaydip Das Gupta , Robert H Silverman , Eric A Klein , Sushil Devare , Gerald Schochetman and John Hackett Jr

Retrovirology 2010, 7:68doi:10.1186/1742-4690-7-68


Published: 17 August 2010

Abstract (provisional)

Background
Xenotropic Murine Leukemia Virus-related Virus (XMRV) is a human gammaretrovirus recently identified in prostate cancer tissue and in lymphocytes of patients with chronic fatigue syndrome. To establish the etiologic role of XMRV infection in human disease requires large scale epidemiologic studies. Development of assays to detect XMRV-specific antibodies would greatly facilitate such studies. However, the nature and kinetics of the antibody response to XMRV infection have yet to be determined.

Results
Three rhesus macaques were infected with XMRV to determine the dynamics of the antibody responses elicited by infection with XMRV. All macaques developed antibodies to XMRV during the second week of infection, and the predominant responses were to the envelope protein gp70, transmembrane protein p15E and capsid protein p30. In general, antibody responses to gp70 and p15E appeared early with higher titers than to p30, especially in the early period of seroconversion. Antibodies to gp70, p15E and p30 persisted to 158 days and were substantially boosted by re-infection, thus, were identified as useful serologic markers. Three high-throughput prototype assays were developed using recombinant proteins to detect antibodies to these viral proteins. Both gp70 and p15E prototype assays demonstrated 100% sensitivity by detecting all Western Blot (WB) positive serial bleeds from the XMRV-infected macaques and good specificity (99.5-99.9%) with blood donors. Seroconversion sensitivity and specificity of the p30 prototype assay was 92% and 99.4% respectively.

Conclusions
This study provides the first demonstration of seroconversion patterns elicited by XMRV infection. The nature and kinetics of antibody responses to XMRV in primates were fully characterized. Moreover, key serologic markers useful for detection of XMRV infection were identified. Three prototype immunoassays were developed to detect XMRV-specific antibodies. These assays demonstrated good sensitivity and specificity; thus will facilitate large scale epidemiologic studies of XMRV infection in humans.​

Dare I hope that the ball is finally rolling and our time has come at last?
:victory::D:tear: (tears of joy!!!) :D:victory:
 

Otis

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That looks great. The team of Silverman & Klein are back together which adds instant credibility.
 
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I wonder if any of these assays will be made available through the upcoming WPI/UneVX lab in Nevada USA? (UneVX was VIPDX) to the general public as a 'test'?
The XMRV antibody test is not available to us yet, although it's apparently going to be so this year or at least was....
I heard that VIPdx will announce that its serology tests will be available before next week. Their tests will be more specific than Abbott's because they look for more than just VP62; you get all the variants with the WPI licensed tests.