Je. Gairin et al., OPTIMAL LYMPHOCYTIC CHORIOMENINGITIS VIRUS SEQUENCES RESTRICTED BY H-2D(B) MAJOR HISTOCOMPATIBILITY COMPLEX CLASS-I MOLECULES AND PRESENTEDTO CYTOTOXIC T-LYMPHOCYTES, Journal of virology, 69(4), 1995, pp. 2297-2305
Infection with lymphocytic choriomeningitis virus induces the generati
on of CD8(+) cytotoxic T lymphocytes (CTL). In the H-2(b) mouse, this
cellular immune response is directed against three viral structural ep
itopes (GP1, GP2, and NP) presented by the major histocompatibility co
mplex (MHC) class I H-2D(b) molecules. This study was undertaken to de
lineate which sequence of each of these three epitopes is optimal for
MHC binding and CTL recognition. The first step was to synthesize the
relevant peptides truncated at the N or C terminus and flanking the cr
ucial H-2D(b)-anchoring Asn residue in position 5. These peptides were
then tested (i) for their binding properties in two H-2D(b)-specific
assays with viable cells (upregulation of H-2D(b) expression on the su
rface of RMA-S cells and competition against the D-b-restricted peptid
e I-125-gp276-286 on T2-D-b cells) and (ii) for their abilities to sen
sitize H-2(b) target cells for CTL lysis in vitro. For optimal antigen
ic presentation, all three epitopes required the MHC-anchoring Asn res
idue at position 5 of their sequences. The results clearly and unambig
uously delineated optimal lengths for two of the epitopes and two opti
ons for the third. NP appeared as a conventional 9-amino-acid (aa)-lon
g peptide, np396-404 (FQPQNGQFI). GP2 was defined as a longer peptide
(11 aa), gp276-286 (SGVENPGGYCL). Characterization of the GPI epitope
was more complex: the 9-aa-long peptide gp33-41 (KAVYNFATC) and the ca
rboxyl-extended 11-aa-long peptide gp33-43 (KAVYNFATCGI) were both est
ablished as possible optimal sequences depending on the cell line used
to test binding and lysis.