Drug Abuse Research Today is a free monthly online journal that collates and summarizes the latest research about Drug Abuse, including details on psychology, rehabilitation, consequences, treatment. | ||||||||
|
HCV-specific T-cell responses in injecting drug users: evidence for previous exposure to HCV and a role for CD4+ T cells focussing on nonstructural proteins in viral clearance.Ruys TA, Nanlohy NM, van den Berg CH, Hassink E, Beld M, van de Laar T, Bruisten S, Wit F, Krol A, Prins M, Lange J, van Baarle D Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine and AIDS, International Antiviral Therapy and Evaluation Center (IATEC) and Academic Medical Center, Amsterdam, The Netherlands. In order to understand the parameters associated with resolved hepatitis C virus (HCV)-infection, we analysed the HCV-specific T-cell responses longitudinally in 13 injecting drug-users (IDUs) with a prospectively identified acute HCV infection. Seven IDUs cleared HCV and six IDUs remained chronically infected. T-cell responses were followed in the period needed to resolve and a comparable time span in chronic carriers. Ex vivo T-cell responses were measured using interferon-gamma Elispot assays after stimulation with overlapping peptide pools spanning the complete HCV genome. CD4+ memory-T-cell responses were determined after 12-day stimulation with HCV proteins. The maximum response was compared between individuals. The T-cell responses measured directly ex vivo were weak but significantly higher in resolvers compared to chronic carriers, whereas the CD4+ memory-T-cell response was not different between resolvers and chronic carriers. However, HCV Core protein was targeted more often in chronic carriers compared to individuals resolving HCV infection. CD4+ T-cell responses predominantly targeting nonstructural proteins were associated with resolved HCV infection. Interestingly, observation of memory-T-cell responses present before the documented HCV-seroconversion suggests that reinfections in IDUs occur often. The presence of these responses however, were not predictive for the outcome of infection. However, a transition of the HCV-specific CD4+ memory-T-cell response from targeting Core to targeting nonstructural proteins during onset of infection was associated with a favourable outcome. Therefore, the specificity of the CD4+ memory-T-cell responses measured after 12-day expansion seems most predictive of resolved infection. Published 14 May 2008 in J Viral Hepat, 15(6): 409-20.
© 2005-2008 Drug Abuse Research Today. All Rights Reserved. |
| ||||||
