Presence of effector CD8+ T cells in hepatitis C virus-exposed healthy seronegative donors

摘要: CTL responses against multiple hepatitis C virus (HCV) epitopes were detected in 7 of 29 (24.1%) healthy family members (HFM) persistently exposed to chronically HCV-infected patients (HCV-HFM). These precursor at very low or undetectable frequencies, as determined by limiting dilution analysis. However, when HCV-specific effector CD8 + T cells, freshly isolated from PBMC HCV-HFM, assessed a sensitive enzyme-linked immunospot assay, their frequencies severalfold higher than those CTL. results indicate that the two assays detect functionally distinct cell populations and cells are not assayed 51 Cr-release assay. Furthermore, combination depletion analyses showed confined into CD45RO CD28 − population. The persistence specific for both structural nonstructural viral proteins uninfected suggest that: 1) an immunological memory is established upon subclinical infection without any evidence hepatitis, large cohort HCV-exposed individuals; 2) because these required neither restimulation nor addition particular cytokines vitro differentiating effectors, they should be capable prompt function vivo, possibly providing antiviral protection; 3) maintenance may sustained persisting low-level stimulation induced inapparent infections.