No abstract

To locate T cell determinants of glycoprotein D (gD) of herpes simplex virus type 1 (HSV-1), proliferation assays of lymphocytes obtained from 10 healthy HSV-seropositive individuals were performed using 34 overlapping gD peptides as antigens. Despite large differences between individual responses to the peptides both in number of stimulating peptides and gD regions, three regions (1-54, 110-214, and 290-314) induced a response in 50% or more of the HSV-seropositives. T cells were less frequently stimulated by peptides of region 210-294. No correlation was found between serological data and proliferative responses to the peptides. The diversity in T cell response to the peptides suggests a lack of immunodominance, implying that a single peptide/region of gD, or a combination of peptides, will not be sufficient to serve as a basis for a future HSV-1 vaccine.

The interaction between mAb A16 and glycoprotein D (gD) of herpes simplex virus type 1 was analyzed by studying the kinetics of binding with a surface-plasmon-resonance biosensor. mAb A1 6 belongs to group VII antibodies, which recognize residues 11 -19 of gD. In a previous study, three critical residues, Aspl3, Argl6 and Phel7, of this epitope were identified by screening a phage display library that contained a random 15-amino-acid insert with the antibody. The contribution to binding of these residues in the motif DXXRF was further analyzed by an amino-acid-replacement study of the epitope gD-(9-19)-peptide and of a gD-(9-19)-peptide mimotope, previously obtained by screening the phage display library. Amino acid residues of the motif were replaced by a neutral amino acid residue, an amino acid residue with opposite charge and a corresponding D-amino acid residue. Kinetic parameters of peptide analogues were determined with a surface plasmon-resonance biosensor. The kinetic parameters of the peptide analogues were compared with the kinetic parameters of the interaction between mAb A16 and the epitope gD-(9-19)-peptide. The minimal size of the gD epitope for mAb A16 was also determined in this study. The kinetic constants of the resulting gD-(ll-l7)-peptide were found to be similar to those of entire gD. The kinetic analysis precisely defined the epitope on gD for mAb A16 to residues 11 -17, identified Argl6 as an essential residue and suggested that Asp13 and Phel7 are mainly involved in stabilization of the secondary structure of the peptide.Keywords: herpes simplex virus 1 ; glycoprotein D; linear epitope ; kinetics ; surface plasmon resonance.Glycoprotein D (gD) of herpes simplex virus (HSV) type 1 is an essential component of the virion envelope for the entry of HSV into mammalian cells [I] and is one of the HSV proteins on which immunological and vaccine studies have focused. Immunization of mice with gD of HSV-1 results in high neutralizing-antibody titers against HSV-1, and these mice are protected against a lethal HSV challenge [ 2 ] . mAbs directed against different regions of gD of HSV-1 have been divided into groups according to their antigenic sites [3], mAbs which recognize amino acid residues 11 -19 in the N-terminus are designated as group VII mAbs [4, 51. mAb A16 is a group VII mAb that binds a synthetic peptide consisting of amino acid residues 9-19 of gD [6, 71. Immunization with synthetic peptides comprising this region of HSV gD protected mice against a lethal challenge with HSV [8, 91. Substitution studies showed that Pro14 and Argl6 are important for binding of mAb A16 [7]. Additional information on residues that interact with mAb A16 was obtained by screening a random peptide library displayed on a filamentous bacteriophage [lo] with the antibody.Peptide sequences obtained by screening such a library resemble or mimic the epitope and are designated as mimotopes. We identified one mimotope. Its smallest synthetic version able to inhibit binding of the gD-(9-19)-peptide to mAb A16 was a ...

No abstract

No abstract