Previous studies of cellular immunity in asymptomatic HBV carriers have been limited to evaluation of responses to plasma-derived HBsAg preparations. We have explored the specificity of cellular immune responses to HBV antigens in these subjects using an indirect T-lymphocyte migration inhibitory factor assay and three antigen preparations (recombinant nucleocapsid antigen (HBcAg), plasma-derived HBsAg with or without pre-S2, and Saccharomyces cerevisiae-synthesized HBsAg without pre-S2 region. T cells from 10 asymptomatic chronic HBV carriers with normal liver function tests were responsive to nucleocapsid determinants (mean migration index = 0.55 ± SD 0.07) and to pre-S2-positive plasma-derived HBsAg (MI = 0.62 ± 0.05). However, none responded to HBsAg devoid of pre-S2 sequences (MI = 0.98 ± 0.04). In further experiments, T cells from three HBV carriers, cultured with six different HBsAg preparations, exhibited responsiveness only to those preparations containing significant pre-S2 activities. Our results show that T-cell immunity to nucleocapsid determinants of the virus and HBsAg is present in asymptomatic HBV carriers; the latter is restricted to antigenic preparations containing significant pre-S2 activities. Hence, T-cell immunity to pre-S determinants may not always be associated with HBV clearance.
|Number of pages||6|
|Publication status||Published - 1987|
ASJC Scopus subject areas
- Immunology and Allergy