Cellular immunity to nucleocapsid and pre-S determinants in asymptomatic carriers of hepatitis B virus.
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 nucleocapside 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 in 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.
D000293:Adolescent; D000328:Adult; D002213:Capsid / Q000276:immunology*; D002353:Carrier State / Q000276:immunology*; D002648:Child; D000939:Epitopes / Q000276:immunology; D005260:Female; D006509:Hepatitis B / Q000276:immunology*; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007961:Leukocyte Migration-Inhibitory Factors / Q000276:immunology; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology; D014758:Viral Core Proteins / Q000276:immunology*
D000939:Epitopes; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D007961:Leukocyte Migration-Inhibitory Factors; D014758:Viral Core Proteins