HEPATITIS-B VIRUS SMALL SURFACE-ANTIGEN PARTICLES ARE PROCESSED IN A NOVEL ENDOSOMAL PATHWAY FOR MAJOR HISTOCOMPATIBILITY COMPLEX CLASS I-RESTRICTED EPITOPE PRESENTATION
R. Schirmbeck et al., HEPATITIS-B VIRUS SMALL SURFACE-ANTIGEN PARTICLES ARE PROCESSED IN A NOVEL ENDOSOMAL PATHWAY FOR MAJOR HISTOCOMPATIBILITY COMPLEX CLASS I-RESTRICTED EPITOPE PRESENTATION, European Journal of Immunology, 25(4), 1995, pp. 1063-1070
We investigated the major histocompatibility complex (MHC) class I-res
tricted presentation of an epitope of the hepatitis B virus small surf
ace (S) antigen particle to cloned murine cytotoxic T lymphocytes (CTL
). Efficient L(d)-restricted presentation of the S-28-39 epitope to CT
L is observed in cells of different tissue origin pulsed in vitro, eit
her with the antigenic S-28-39 12-mer S-peptide, or with particulate S
-antigen. The kinetics of epitope presentation differ in S-peptide-pul
sed and in S-particle-pulsed cells: while a 15-min pulse with the anti
genic peptide sensitizes targets for class I-restricted CTL lysis, pre
sentation of S-particles requires 30-60 min to sensitize cells for CTL
lysis. Uptake of antigenic material and active metabolism of the pres
enting cell are required for processing of S-particles, but not for se
nsitizing targets with S-peptides. Intracellular processing and presen
tation of S-particles is blocked in cells treated with chloroquine, NH
4Cl, primaquine, or leupeptin, but not by treatment with cycloheximide
or brefeldin A. This processing pathway operates efficiently in pepti
de-transporter-deficient, L(d)-transfected T2 cells, revealing a novel
endosomal/lysosomal processing pathway for class I-restricted present
ation of peptides derived from exogenous S-particles.