Analysis of T- and B-cell epitopes of capsid protein of rubella virus by using synthetic peptides

Abstract

A nested set of 11 overlapping synthetic peptides covering the entire sequence of rubella virus capsid protein was synthesized, purified, and tested against human rubella virus-specific T-cell lines and rubella virusseropositive sera. T-cell lines derived from four donors responded strongly to four synthetic peptides containing residues 96 to 123, 119 to 152, 205 to 233, and 255 to 280. Only one peptide (residues 255 to 280) was recognized by all four T-cell lines. Two human immunodominant linear B-cell epitopes were mapped to residues 1 to 30 and 96 to 123 by using peptide-specific enzyme-linked immunosorbent assay. All 11 synthetic peptides were highly immunogenic and induced strong antibody responses in rabbits against the respective immunized peptides. Seven of the 11 rabbit antipeptide antisera (anti-1-30,-74-100,-96-123,-119-152,-205-233,-231-257, and-255-280) specifically recognized the capsid protein on immunoblots. Identification of these Tand B-cell epitopes represents the first step toward rational design of synthetic vaccines against rubella.

Characterization of the specificity and genetic restriction of human CD4+ cytotoxic T cell clones reactive to capsid antigen of rubella virus

“…We have synthesized 49 synthetic peptides comprising approximately 95% of the amino acid sequences of the structural proteins El (23 peptides), E2 (15 peptides), and C (1 1 peptides) of RV strain M33 (Clarke et a/., 1987) and initiated a series of experiments to search for peptide-specific T cell responses in individuals naturally infected with RV. We have showed that C peptides such as C5 (residues 96-l 23), C6 (residues 119-152), C9 (residues 205-233) or Cl 1 (residues 255-280) can induce significant proliferation of T cells in short-term cultured T cell lines from some RV-seropositive donors (Ou et a/., 1992). The T cell clones used in this study were initially established from the T cell lines of two RV seropositive donors (Ou et a/., 1992).…”

“…We have showed that C peptides such as C5 (residues 96-l 23), C6 (residues 119-152), C9 (residues 205-233) or Cl 1 (residues 255-280) can induce significant proliferation of T cells in short-term cultured T cell lines from some RV-seropositive donors (Ou et a/., 1992). The T cell clones used in this study were initially established from the T cell lines of two RV seropositive donors (Ou et a/., 1992). A total of 36 clones were isolated by the method a A total of 2 X 1 O4 T cells from each clone was tested for their proliferative response to each synthetrc peptide at a final concentration of 5 pg/ml in the presence of y-irradiated (3000 rad) autologous PBMC 5 X 1 O4 as APC.…”

“…' Underlined numbers represent significant cell proliferation values of limiting dilution (Celis et al, 1988a,b) and their RV specificity was tested in proliferation assays (Ou et al, 1992). To further identify the capacity of these T cell clones to recognize the T cell epitopes of the structural proteins of RV, their responses to 49 synthetic peptides were tested in proliferation assays.…”

“…On the other hand, C9, or Cl l-reactive T cell clones, are located at the B Cell lines used as targets were incubated with or without peptide C9 at 5 &ml overnight before addition of T cells. b Cytotoxicity was determined using the T cell clone Al 1 at an effectorkarget ratio of 5. peak region of the a-helix index within the C6, C9, or Cl 1 peptide sequences according to the profiles of a-helix, P-turn and hydrophilicity of the C protein of RV (Ou et a/., 1992). We have analyzed the T cell motif (second model) structures within C6, C9, and Cl 1 sequences (Ou et a/., 1992).…”

“…b Cytotoxicity was determined using the T cell clone Al 1 at an effectorkarget ratio of 5. peak region of the a-helix index within the C6, C9, or Cl 1 peptide sequences according to the profiles of a-helix, P-turn and hydrophilicity of the C protein of RV (Ou et a/., 1992). We have analyzed the T cell motif (second model) structures within C6, C9, and Cl 1 sequences (Ou et a/., 1992). C6E is located in the region between two T cell motif structures.…”